INFECTIOUS DISEASE OF
Dr. Naila Awal
• Causative organism- Toxoplasma gondii
• Toxoplasma comes from- Toxo & Plasma
Toxo bow shaped.
• Forms of toxoplasmaIt’s a bow shaped parasite
1) Tachyzoite-Most common infected form.
2) BradyzoitePresent in tissue cyst.
Mode of Transmission
• Tissue cyst containing bradyzoite
.Ex- Ingestion of infected undercooked meat- e.g-Sushi
• Tachyzoite infection-
Ex- Meat handler / Butcher
Handling infected cat
Handling of culture media of toxoplasma
• Oocyst infection- by contaminated food & drink.
• Acute toxoplasmosis- May be asymptomatic
1) Flu like syndrome- Fever, sore throat, rhinitis
2)Lymphadenopathy- most commonly posterior cervical
Congenital toxoplasmosis- Very dangerous
Sign1) Coroido- retinitis- Parasite multiply within choroid
Inflammation of retina Mild illumination of vision to
2)Microcephaly / Hydrocephalus
3)Calcification of cerebral ventricle.
Diagnosis of Toxoplasmosis
Specimen1) Lymph node biopsy
2) Bone marrow aspiration
5) Peritoneal fluid
4)Broncho alveolar lavage
Lab procedure1) Direct microscopy- Smear is taken in a glass slide air dry
Leishman/ Giemsa stain
2) Culture- Specimen is inocculated in –
corio-allantoic membrane of embryonated cheek egg/
lab animal-mice incubate Observation.
Serology (Mother)- It is the best test for toxoplasmosis.
of transmission to
Patient is never infected with toxoplasmosis
Patient got infected
Repeat after 2 weeks
2) Amniocentesis- For detection of DNA of toxoplasma.
3) Associated test TC of WBC- Leukocytosis
DC- Lymphocytosis with atypical mononuclear cell.
Fate of fetus
Diagnosis of toxoplasmosis in HIV positive
By Ig G titer.
• Ig G titer is used for diagnosis of reactivation
of tissue cyst in HIV positive patient.
• If Ig G titer is increased 16 folds
Lymph nodePoster cervical lymph nodes commonly affected.
• Findings1) Folicular hyperplesia with intense mitotic activity.
2) Reactive follicles are surrounded by small granuloma,
composed of epithelioid cells. Rarely necrosis & Langhan’s
giant cell are present.
EyeFocal area of coagulation necrosis of retina surrounded by
granulomatous inflammation in adjacent choroid & retina.
Within necrotic retina- cyst of Toxoplasma can be found.