The document discusses Toxoplasma gondii, the causative agent of ocular toxoplasmosis. It states that T. gondii is a protozoan parasite that exists in three forms - oocysts, tissue cysts, and tachyzoites. Oocysts are the "soil form" found in cat feces. Tissue cysts are the "latent form" that reside in host tissues. Tachyzoites are the "infectious form" found circulating in the bloodstream. The document provides some basic epidemiological data about T. gondii infection rates in humans.

1. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?

2. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii

3. Toxoplasma gondii

4. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?

5. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite

6. Toxoplasma gondii intracellular

7. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found?

8. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found?
Everywhere—it has a worldwide distribution

9. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution

10. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide

11. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?

12. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat

13. A cat

14. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?

15. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans

16. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?

17. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?
This is not answered consistently in the BCSC books. The Uveitis book gives two different answers:
22.5%, then 3%-10.8% a page later.

18. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?
This is not answered consistently in the BCSC books. The Uveitis book gives two different answers:
22.5%, then 3%-10.8% a page later. The Peds book says positivity increases with age, from 5% at
age 5 to 60% at age 80.

19. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?
This is not answered consistently in the BCSC books. The Uveitis book gives two different answers:
22.5%, then 3%-10.8% a page later. The Peds book says positivity increases with age, from 5% at
age 5 to 60% at age 80. Further, EyeWiki gives a range of 22.5 to 70%. (The Retina book doesn’t
address the issue.) Caveat emptor.

20. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?
This is not answered consistently in the BCSC books. The Uveitis book gives two different answers:
22.5%, then 3%-10.8% a page later. The Peds book says positivity increases with age, from 5% at
age 5 to 60% at age 80. Further, EyeWiki gives a range of 22.5 to 70%. (The Retina book doesn’t
address the issue.) Caveat emptor.
What percent of the IgG-positive US population have signs of ocular involvement?

21. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
What is the causative organism in ocular toxoplasmosis?
Toxoplasma gondii
What are its basic properties, ie, what sort of organism is it in a microbiology sense?
It is a protozoan—an obligate intracellular parasite
Where in the world can T gondii be found? Is it a common human pathogen?
Everywhere—it has a worldwide distribution
Yes—it’s likely that a billion people are infected worldwide
What animal is its definitive host?
The cat
A variety of animals can serve as intermediate hosts—which is of particular concern?
Us, ie, humans
What percent of people living in the US are IgG positive for toxoplasmosis?
This is not answered consistently in the BCSC books. The Uveitis book gives two different answers:
22.5%, then 3%-10.8% a page later. The Peds book says positivity increases with age, from 5% at
age 5 to 60% at age 80. Further, EyeWiki gives a range of 22.5 to 70%. (The Retina book doesn’t
address the issue.) Caveat emptor.
What percent of the IgG-positive US population have signs of ocular involvement?
About 2

22. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
T gondii has a complex life cycle, existing in three forms.

23. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
? ?
?
T gondii:
three forms

24. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms

25. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
?
T gondii:
three forms
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?

26. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?
‘Soil form’
--‘Soil form’

27. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
?
T gondii:
three forms
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?
‘Soil form’
--‘Soil form’

28. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
‘Soil form’ ‘Infectious form’
T gondii:
three forms
--‘Soil form’ --‘Infectious form’
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?

29. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
‘Soil form’ ‘Infectious form’
T gondii:
three forms
--‘Soil form’ --‘Infectious form’
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?
?

30. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
‘Soil form’ ‘Latent form’
‘Infectious form’
T gondii:
three forms
--‘Soil form’ --‘Latent form’
--‘Infectious form’
Each form has a ‘nickname’ capturing its essence.
What is the nickname for this form?

31. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
?
T gondii:
three forms
--‘Soil form’
--Found in…
--‘Latent form’
--‘Infectious form’
Where does this form reside?

32. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Latent form’
--‘Infectious form’
Where does this form reside?
Cat GI tract
--‘Soil form’
--Found in GI tract of
cat (shed in feces)

33. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
?
T gondii:
three forms
--‘Latent form’
--‘Infectious form’
--Found in…
Where does this form reside?
Cat GI tract
--‘Soil form’
--Found in GI tract of
cat (shed in feces)

34. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
Cat GI tract
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
Host circulatory system
--‘Infectious form’
--Found in circulatory
system
--‘Latent form’
Where does this form reside?

35. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
Cat GI tract
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
?
Host circulatory system
--‘Infectious form’
--Found in circulatory
system
--‘Latent form’
--Found in…
Where does this form reside?

36. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
Cat GI tract Host tissue
Host circulatory system
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
Where does this form reside?

37. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
Infectious? Yes
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
Is this form infectious?

38. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
Is this form infectious? Yes
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
Infectious? Yes

39. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
Infectious? Yes Infectious?
Is this form infectious?

40. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
--+infectious
Infectious? Yes Infectious? Yes
Is this form infectious? Yes

41. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
--‘Latent form’
--Found in host tissue
--‘Infectious form’
--Found in circulatory
system
--+infectious
Infectious? Yes Infectious?
Infectious? Yes
Is this form infectious?

42. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
--‘Latent form’
--Found in host tissue
--+infectious
--‘Infectious form’
--Found in circulatory
system
--+infectious
Infectious? Yes Infectious? Yes
Infectious? Yes
Is this form infectious? Yes

43. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
All forms are infectious under the right circumstances.
Don’t let the nickname of the tachyzoite form fool you into
thinking it’s the only one!
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious
--‘Latent form’
--Found in host tissue
--+infectious
--‘Infectious form’
--Found in circulatory
system
--+infectious
Infectious? Yes Infectious? Yes
Infectious? Yes

44. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
--‘Latent form’
--Found in host tissue
--+infectious
--‘Infectious form’
--Found in circulatory
system
--+infectious
How is infection transmitted for this form?
Infectious via…

45. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Latent form’
--Found in host tissue
--+infectious
--‘Infectious form’
--Found in circulatory
system
--+infectious
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil

46. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Latent form’
--Found in host tissue
--+infectious
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
Infectious via…

47. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Latent form’
--Found in host tissue
--+infectious
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
How is infection transmitted for this form?
Infectious via… Infectious via…

48. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
Infectious via…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Infectious via…

49. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
Infectious via…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
Infectious via…

50. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
Infectious via…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
Infectious via…
What very, very important means of dz transmission is not mentioned here?
Transplacentally, resulting in congenital toxoplasmosis (we will have much to
say about this later in the slide-set)

51. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
How is infection transmitted for this form?
Infectious via…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
Infectious via…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
Infectious via…
What very, very important means of dz transmission is not mentioned here?
Transplacentally, resulting in congenital toxoplasmosis (we will have much to
say about this later in the slide-set)

52. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--?
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
In a nutshell, how should we think of each form?
--Oocysts…

53. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
bug name

54. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)

55. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--?
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…

56. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active

57. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--?
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…

58. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…contain toxo adults that are dormant

59. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…contain toxo adults that are dormant
What is the name for the dormant adults in the tissue cysts?
Bradyzoites

60. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…contain toxo adults that are dormant
What is the name for the dormant adults in the tissue cysts?
Bradyzoites

61. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…contain toxo adults that are dormant
What is the name for the dormant adults in the tissue cysts?
Bradyzoites
It’s not a coincidence that the dormant adults are
identified as brady (‘slow’) –zoites…whereas the active
adults are tachy (‘fast’) –zoites

62. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
In a nutshell…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
In a nutshell…
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
In a nutshell…
In a nutshell, how should we think of each form?
--Oocysts…are toxo eggs or ‘spores’ (the bug is a sporozoite at this stage)
--Tachyzoites…are toxo ‘adults’ that are active
--The tissue cysts…contain toxo adults that are dormant
What is the name for the dormant adults in the tissue cysts?
Bradyzoites
It’s not a coincidence that the dormant adults are
identified as brady (‘slow’) –zoites…whereas the active
adults are tachy (‘fast’) –zoites

63. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
(No question—review slide, proceed when ready)
Toxoplasmosis Basics tl;dr
The person consumes either oocysts (wash your hands!) or tissue cysts (cook your meat!).
The consumed bugs transform into tachyzoites, enter the bloodstream, then disseminate
throughout the body. The immune system quickly clears the circulating parasites, but not
before some get encased in tissue cysts, which are impervious to the host’s immune system.

64. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
(No question—review slide, proceed when ready)
Toxoplasmosis Basics tl;dr
The person consumes either oocysts (wash your hands!) or tissue cysts (cook your meat!).
The consumed bugs transform into tachyzoites, enter the bloodstream, then disseminate
throughout the body. The immune system quickly clears the circulating parasites, but not
before some get encased in tissue cysts, which are impervious to the host’s immune system.

65. Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’
(No question—review slide, proceed when ready)
Toxoplasmosis Basics tl;dr
The person consumes either oocysts (wash your hands!) or tissue cysts (cook your meat!).
The consumed bugs transform into tachyzoites, enter the bloodstream, then disseminate
throughout the body. The immune system quickly clears the circulating parasites, but not
before some get encased in tissue cysts, which are impervious to the host’s immune system.

66. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

67. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

68. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

69. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

70. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
baa…
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

71. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

72. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

73. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

74. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals?fruits/veggies…and goat’s milk?
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

75. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
Meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals?fruits/veggies…and goat’s milk?
It gets into them when they eat meat that is undercooked
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

76. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals?fruits/veggies…and goat’s milk?
It gets into them when they eat meat that is undercooked…
Undercooked
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

77. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals? From fruits/veggies?and goat’s milk?
It gets into them when they eat meat that is undercooked…eat fruits/veggies that are unwashe
Undercooked
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

78. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals? From fruits/veggies?and goat’s milk?
It gets into them when they eat meat that is undercooked…eat fruits/veggies that are unwashed…
f
Undercooked
Unwashed
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

79. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals? From fruits/veggies? From goat’s milk?
It gets into them when they eat meat that is undercooked…eat fruits/veggies that are unwashed…
or drink goat’s milk that is unpasteurized
f
Undercooked
Unwashed
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

80. T gondii has a complex life cycle, existing in three forms.
What are they?
Uveitis: Toxoplasmosis
Toxoplasmosis: Basics
Oocyst Tissue cyst
Tachyzoite
T gondii:
three forms
What foodstuffs are commonly involved?
meat, especially pork
Fruits and veggies
Goat’s milk
How does toxo get into the animals and/or onto the fruits and veggies?
It gets into animals when they eat feed that has been pooped on by
infected cats (ie, that contains oocysts)
How is toxo able to get into humans from the animals? From fruits/veggies? From goat’s milk?
It gets into them when they eat meat that is undercooked…eat fruits/veggies that are unwashed…
or drink goat’s milk that is unpasteurized
Undercooked
Unwashed
Unpasteurized
f
g
--‘Soil form’
--Found in GI tract of
cat (shed in feces)
--+infectious via…
Ingestion of
contaminated soil
--’Spores’
--‘Infectious form’
--Found in circulatory
system
--+infectious via…
Blood-to-blood contact
--’Active adult’
--‘Latent form’
--Found in host tissue
--+infectious via…
Consumption in foodstuffs
--’Dormant adult’

81. Uveitis
?
?
?
?
What are the four basic anatomic locations for uveitis?

82. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
What are the four basic anatomic locations for uveitis?

83. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
Toxoplasmosis
Can toxoplasmosis present with anterior uveitis?

84. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
Toxoplasmosis
Can toxoplasmosis present with anterior uveitis? Yes

85. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
Toxoplasmosis
Can toxoplasmosis present with anterior uveitis? Yes
Let’s drill down on toxoplasmosis anterior uveitis

86. Uveitis: Anterior
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis

87. Uveitis: Anterior
? ?
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
What is this first, fundamental way
we divvy up anterior uveitis?
Key
distinction

88. Uveitis: Anterior
Granulomatous Nongranulomatous
Key
distinction
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
What is this first, fundamental way
we divvy up anterior uveitis?

89. Uveitis: Anterior
Granulomatous Nongranulomatous
? ?
Key
distinction
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
Now this one…

90. Acute Chronic
Uveitis: Anterior
Granulomatous Nongranulomatous
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
Key
distinction
Now this one…

91. Acute Chronic
Uveitis: Anterior
Granulomatous Nongranulomatous
Key
distinction
?
?
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
Finally…

92. Acute Chronic
Uveitis: Anterior
Unilateral Bilateral
Granulomatous Nongranulomatous
But first, let’s review the basic taxonomy of anterior uveitis
Let’s drill down on toxoplasmosis anterior uveitis
Key
distinction
Finally…

93. Acute Chronic
Uveitis: Anterior
Unilateral Bilateral
Granulomatous Nongranulomatous
Now that the taxonomy is laid out:
Where does toxoplasmosis reside?
?
?
?
?

94. Acute Chronic
Uveitis: Anterior
Unilateral Bilateral
Granulomatous Nongranulomatous
Toxoplasmosis
Now that the taxonomy is laid out:
Where does toxoplasmosis reside?
Among the granulomatous uveitides

95. Acute Chronic
Uveitis: Anterior
Unilateral Bilateral
Granulomatous Nongranulomatous
Toxoplasmosis
?
?
?
?
?
?
What is the rest
of the DDx for
granulomatous
uveitis?
Now that the taxonomy is laid out:
Where does toxoplasmosis reside?
Among the granulomatous uveitides

96. Acute Chronic
Uveitis: Anterior
Unilateral Bilateral
Granulomatous Nongranulomatous
HSV
Syphilis
Sarcoid
TB
Lyme
Toxoplasmosis
VKH
What is the rest
of the DDx for
granulomatous
uveitis?
Now that the taxonomy is laid out:
Where does toxoplasmosis reside?
Among the granulomatous uveitides

97. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
The BCSC Uveitis book does not list toxoplasmosis in the DDx for intermediate uveitis
Toxoplasmosis

98. Uveitis
Anterior
Posterior
Intermediate
Panuveitis
Toxoplasmosis
OTOH, toxoplasmosis is a premiere cause of posterior uveitis!

99. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
It is called: It is called:
It is called:
?
? ?
…Is divided into three subtypes based on what attribute?
Uveitis: Toxoplasmosis

100. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
It is called: It is called:
It is called:
?
? ?
…Is divided into three subtypes based on what attribute?
Inflammation location
Uveitis: Toxoplasmosis

101. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
?
? ?
?
? ?
What are the three ‘inflammation locations’?
Uveitis: Toxoplasmosis

102. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
?
? ?
What are the three ‘inflammation locations’?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Uveitis: Toxoplasmosis

103. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
?
? ?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Uveitis: Toxoplasmosis

104. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
? ?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Choroiditis
Uveitis: Toxoplasmosis

105. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
? ?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Choroiditis
Uveitis: Toxoplasmosis

106. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Choroiditis Retinitis
Uveitis: Toxoplasmosis

107. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
It is called: It is called:
It is called:
?
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Choroiditis Retinitis
Uveitis: Toxoplasmosis

108. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Chorioretinitis
Retinochoroiditis
Choroiditis Retinitis
It is called: It is called:
It is called:
Uveitis: Toxoplasmosis
or

109. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
Exclusively in
the choroid
In both the choroid
and the retina
Chorioretinitis
Retinochoroiditis
Choroiditis Retinitis
It is called: It is called:
It is called:
Uveitis: Toxoplasmosis
or
It is called:
?
and ONH
Exclusively
in the retina

110. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
Exclusively in
the choroid
In both the choroid
and the retina
Chorioretinitis
Retinochoroiditis
Choroiditis Retinitis
It is called: It is called:
It is called:
Uveitis: Toxoplasmosis
or
It is called:
Neuroretinitis
and ONH
Exclusively
in the retina

111. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Chorioretinitis
Retinochoroiditis
Choroiditis? Retinitis?
It is called: It is called:
It is called:
Uveitis: Toxoplasmosis
or
?
?
What is the classic posterior manifestation of toxoplasmosis?

112. The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
The onset, duration and
course of the uveitis
--Onset: Sudden vs insidious
--Duration: Limited vs persistent
--Course: Acute vs recurrent vs
chronic
The severity of the uveitis
--AC cell grade
--AC flare grade
--Vitreous haze score
Posterior uveitis
If inflammation is located…
Exclusively in
the choroid
In both the choroid
and the retina
Exclusively
in the retina
Chorioretinitis
Retinochoroiditis
Choroiditis Retinitis
It is called: It is called:
It is called:
Uveitis: Toxoplasmosis
or
What is the classic posterior manifestation of toxoplasmosis?
Retinochoroiditis

113. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?

114. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar

115. Toxoplasmosis: Inactive scar

116. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?

117. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell

118. Recurrent ocular toxoplasmosis. Note the active
retinal lesion associated with an old inactive scar
Uveitis: Toxoplasmosis

119. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
The fact that active lesions are usually adjacent to an old scar indicates
what about their origin?
It indicates they represent reactivation of a previously dormant infection
What is indicated if an active is not adjacent to a scar?
It indicates the dz is newly acquired
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell

120. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
The fact that active lesions are usually adjacent to an old scar indicates
what about their origin?
It indicates they represent reactivation of a previously dormant infection
What is indicated if an active is not adjacent to a scar?
It indicates the dz is newly acquired
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell

121. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
The fact that active lesions are usually adjacent to an old scar indicates
what about their origin?
It indicates they represent reactivation of a previously dormant infection
What is indicated if an active is not adjacent to a scar?
It indicates the dz is newly acquired
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
not
^

122. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
The fact that active lesions are usually adjacent to an old scar indicates
what about their origin?
It indicates they represent reactivation of a previously dormant infection
What is indicated if an active is not adjacent to a scar?
It indicates the dz is newly acquired
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
not
^

123. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?

124. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’

125. Uveitis: Toxoplasmosis
Active toxoplasmosis: Headlight in the fog

126. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
In terms of the Headlight in the fog appearance…
The headlight =
The fog =

127. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
In terms of the Headlight in the fog appearance…
The headlight = the white toxo lesion
The fog =

128. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
In terms of the Headlight in the fog appearance…
The headlight = the white toxo lesion
The fog =

129. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
In terms of the Headlight in the fog appearance…
The headlight = the white toxo lesion
The fog = the

130. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
What is the natural history of active toxo retinochoroiditis in immunocompetent pts?

131. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
What is the natural history of active toxo retinochoroiditis in immunocompetent pts?
The news in this regard is mixed. In one sense it is a self-limited condition in that active
lesions resolve spontaneously over a couple of months.

132. Uveitis: Toxoplasmosis
Toxoplasmosis: Retinochoroiditis
What is the classic appearance of an inactive toxoplasmosis lesion?
A pigmented chorioretinal scar
What is the classic appearance of an active toxoplasmosis lesion?
A white lesion adjacent to a scar, with overlying vitreous cell
What is the classic description of the appearance of an active lesion?
‘Headlight in the fog’
What is the natural history of active toxo retinochoroiditis in immunocompetent pts?
The news in this regard is mixed. In one sense it is a self-limited condition in that active
lesions resolve spontaneously over a couple of months. However, it is also a chronic and
progressive condition in that new lesions appear periodically adjacent or near to old scars.

133. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
Uveitis: Toxoplasmosis

134. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Uveitis: Toxoplasmosis

135. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
Uveitis: Toxoplasmosis

136. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection.
Uveitis: Toxoplasmosis
Ig?
Ig? Ig?

137. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection.
Uveitis: Toxoplasmosis

138. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection. Because of the
high prevalence of toxo exposure in the population at large, IgG positivity cannot be considered
confirmatory vis a vis a pt who presents with retinochoroiditis. However, if the pt’s toxo serology is IgG(-),
this result removes toxo from the DDx.
Uveitis: Toxoplasmosis

139. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection. Because of the
high prevalence of toxo exposure in the population at large, IgG positivity cannot be considered
confirmatory vis a vis a pt who presents with retinochoroiditis. However, if the pt’s toxo serology is IgG(-),
this result removes toxo from the DDx.
What about suspected congenital toxo—is serology helpful in these cases?
Uveitis: Toxoplasmosis

140. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection. Because of the
high prevalence of toxo exposure in the population at large, IgG positivity cannot be considered
confirmatory vis a vis a pt who presents with retinochoroiditis. However, if the pt’s toxo serology is IgG(-),
this result removes toxo from the DDx.
What about suspected congenital toxo—is serology helpful in these cases?
Again, it can be. Maternal IgG antibodies will cross the placenta, so their presence in a newborn is
noncontributory.
Uveitis: Toxoplasmosis
Ig?

141. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection. Because of the
high prevalence of toxo exposure in the population at large, IgG positivity cannot be considered
confirmatory vis a vis a pt who presents with retinochoroiditis. However, if the pt’s toxo serology is IgG(-),
this result removes toxo from the DDx.
What about suspected congenital toxo—is serology helpful in these cases?
Again, it can be. Maternal IgG antibodies will cross the placenta, so their presence in a newborn is
noncontributory.
Uveitis: Toxoplasmosis

142. Diagnosis
How is the diagnosis of ocular toxoplasmosis made?
In most cases, clinically
Is serology testing helpful?
It can be. As with most infectious conditions, toxo acquisition produces a transient (<1 yr) IgM response,
and a lifelong IgG response. Thus, a positive IgM result confirms a recent infection. Because of the
high prevalence of toxo exposure in the population at large, IgG positivity cannot be considered
confirmatory vis a vis a pt who presents with retinochoroiditis. However, if the pt’s toxo serology is IgG(-),
this result removes toxo from the DDx.
What about suspected congenital toxo—is serology helpful in these cases?
Again, it can be. Maternal IgG antibodies will cross the placenta, so their presence in a newborn is
noncontributory. In contrast, IgM does not cross the placenta, so if a newborn is IgM(+), it is confirmatory
of congenital infection.
Uveitis: Toxoplasmosis

143. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
Treatment
Uveitis: Toxoplasmosis

144. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--
--
--
--
--
Treatment
Uveitis: Toxoplasmosis

145. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--
--
--
--
Treatment
Uveitis: Toxoplasmosis
location location

146. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--
--
--
--
Treatment
Uveitis: Toxoplasmosis

147. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--
--
--
Treatment
Uveitis: Toxoplasmosis
exam
finding

148. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--
--
--
Treatment
Uveitis: Toxoplasmosis

149. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--
--
Treatment
Uveitis: Toxoplasmosis

150. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--
--
Treatment
Uveitis: Toxoplasmosis

151. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--
Treatment
Uveitis: Toxoplasmosis
amount of time

152. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--
Treatment
Uveitis: Toxoplasmosis

153. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
Treatment
Uveitis: Toxoplasmosis
exam finding (two words)

154. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
Treatment
Uveitis: Toxoplasmosis

155. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--
--
Treatment
Uveitis: Toxoplasmosis

156. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--
Treatment
Uveitis: Toxoplasmosis
general medical condition

157. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--
Treatment
Uveitis: Toxoplasmosis

158. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
Treatment
Uveitis: Toxoplasmosis
specific
medical
condition

159. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
Treatment
Uveitis: Toxoplasmosis

160. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Treatment
Uveitis: Toxoplasmosis

161. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis

162. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis

163. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

164. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

165. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

166. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

167. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

168. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
Pyrimethamine and sulfadiazine inhibit the metabolism of what vitamin?
Folate
What critical hematopoietic issues can arise if folate metabolism is inhibited?
Leukopenia and thrombocytopenia
In order to prevent pyrimethamine/sulfadiazine-induced leukopenia and
thrombocytopenia, what med is given along with triple therapy?
Folinic acid (aka leucovorin). In addition, pts treated with triple therapy should
have their blood count checked weekly.

169. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye

170. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye

171. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye

172. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye

173. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye

174. Diagnosis
What are the indications for treating active ocular toxoplasmosis?
This is controversial. Some physicians tx all lesions, whereas other elect to watch small peripheral ones.
That said, the following clinical scenarios are considered relative indications to tx:
--Lesions in the fovea or threatening the ONH
--Lesions associated with decreased VA
--Large or multifocal lesions
--A lesion that remains active for >1 month
--Lesions associated with significant vitreous inflammation
And most physicians consider the following clinical scenarios absolute indications to tx:
--If the pt is immunocompromised
--If the pt is pregnant , and has newly-acquired dz
How is ocular toxo treated?
Multiple regimens have been developed:
--So-called ‘triple therapy’ consists of pyrimethamine + sulfadiazine + steroids
Treatment
Uveitis: Toxoplasmosis
In terms of route, are steroids given…
--Systemically? Yes, so long as anti-microbial tx is on-board
--Topically? Sure, especially if anterior segment inflammation is present
--Periocular-depot? No! This route can lead to uncontrollable inflammation
and loss of the eye