Zoonosis and food safety course

1. Toxoplasmosis
Course instructor: Dr. Faisal Sher
Submitted by: Tanveer Ahmad, Kamran Nosher, Ghulam
Mohy ud din, Mubashir Afzal

2. Toxoplasmosis
Definition:
Toxoplasmosis is a zoonotic infection of animals caused by the
protozoan parasite Toxoplasma gondii. It has the capacity to infect all
warm-blooded animals.
 Causative agent: Toxoplasma gondii (Tissue cyst forming coccidia)

3. Epidemiology
 In United States: 11% of the population 6 years and older have been infected
with Toxoplasma.(more than 40 Million people).60% of cats are infected with
Toxoplasmosis.
25%of human population was serologically positive.
 Worldwide distribution: More than 60% of some populations have been
infected with Toxoplasma.
 Pakistan: Toxoplasma infection was significantly more prevalent in Khyber
Pakhtunkhwa province (25.87%) than in Punjab (20.42%). This is the first
comprehensive analysis of T. gondii infection epidemiology in Pakistan. It reveals
a high frequency of infection among women
(https://mdpi-res.com/d_attachment/pathogens/pathogens-11-
00675/article_deploy/pathogens-11-00675-v2.pdf?version=1655359167)
 Toxoplasmosis prevalence was about 11.3% to 29.5% in Pakistan.

4. Continue…
Deaths in Pakistan:. A total of 5082 deaths were observed in this
kohat, a mortality rate of 35.8%.
 Mortality rate in other countries:
 Brazil, 77.5%,
 Sao Tome and Principe, 75.2%,
 Iran, 63.9%,
 Colombia, 63.5%,
 Cuba, 61.8%.
Environment: Areas having hot, humid climates and lower altitudes,
because the oocysts survive better in these environments.

5. History
 Discovered in 1908
 Named in 1909
 Remained unknown until seen in tissues of congenitally infected
infant(1939)
 Cause abortion storms in sheep in 1957.
Reservoir Host:
Rodents and some birds
Definite Host:
Felidae family (wild and domesticated cats mainly)

6. Life cycle
a. Bradyzoites
b. Tachyzoites
c. Sporozoites
d. Sporulated oocytes.
Asexual Reproduction
(intermediate host)
Sexual reproduction
(Final host)

7. Types of zoonoses
 Cyclozoonoses
 Orth zoonoses
 Transmission in human:
• Contaminated water and food, contact with cat feces, human
contamination(sub clinical signs), raw meat or half cooked meat,
blood Transfusion, vertical Transmission (from mother to offspring)
 Transmission in animals:
• Environment (soil, water, raw meat eating and eating plants grown
in contaminated water)

8.  Intermediate fever:
Human, herbivores and pigs etc.
 Site of infection in Final Host:
Intestine and blood, , vital organs (brain, heart and Lungs).
 Site of infection in Intermediate host:
Intestinal mucosa/tissue, vital organs (brain, heart and Lungs), reproductive
tract(uterus).

9. Clinical signs
usually begin 1 to 3 weeks after being exposed to the parasite.
Symptoms usually last for 2 to 4 weeks.
 In Humans:
• Mostly asymptomatic
• Anemia
• Fever
• Lymph node swelling
• Cause Abortion in pregnant females.
• Still birth
If abortion does not occur, it cause different abnormalities in the fetus:
• Encephalitis
• Retinochoroiditis
• Hydrocephalus

10. • Myocarditis
• Splenomegaly
• Lymphadenopathy may also be seen.
Ruminants:
• Anemia
• Fever
• Abortion
• Still birth
• Mummification
• Fetal lesions on placental membrane (2mm size)

11. Cats:
• Mostly Asymptomatic
• Anemia
• Degenerative changes in CNS,
• Enteritis,
• Swelling of lymph nodes(mainly cervical LN; supraclavicular, inguinal,
mediastinal, axillary, and mammary lymph nodes may also be involved)
• Encephalitis
• Diarrhea
• Seizures
• Death

12. Diagnosis
• Blood tests
• Faecal microscopy
• Serological tests (high level of IgG) also known as Tarch test.
• Blood count method

13. Treatment and Control
 Pyrimethamine
 Diamino diphenyl sulfone ,
 Atovaquone,
 Spiramycin (Humans)
 Clindamycin( cats and dogs 10–40 mg/kg and 25–50 mg/kg,
respectively, for 3–4 weeks)

14. Control
 Feed your cat commercial dry or canned food.
 Never feed cats raw meat because this can be a source of Toxoplasma
infection.
 Keep indoor cats indoors so they do not become infected by eating small
animals.
 Rinse fresh fruits and vegetables under running water.
 Wash your utensils, cutting boards, and countertops with hot, soapy water
after preparing each food item.
 Do not eat raw or undercooked oysters, mussels, or clams (these may be
contaminated with Toxoplasma that has washed into seawater).

15.  Heating tissue cysts to 67°C will kill them instantly.
 Cysts in meat can be killed by heating the meat to >60 °C or freezing it at -20
°C 18.
 Oocysts are killed if kept at a temperature of 55-60°C for 1-2 minutes .
 Avoid drinking untreated water.
 Wear gloves when gardening and during any contact with soil or sand because
it might be contaminated with cat feces that contain Toxoplasma.

16. Vaccine
 TOXOVAX for animals
 No vaccine for humans

17. Thank You