Parasites Flashcards
Infective form of naegleria fowleri
Free living amoebic trophozoites
Transmission by inhalation
naegleria fowleri affects
Olfactory nerve, penetrates cribriform palate
Tissue destruction by naegleria fowleri mediated by
Ingestion of brain tissue by amoebostome
Contact dependent cytolysis
naegleria fowleri causes
Primary amoebic meningoencephalitis
Incubation period of naegleria fowleri
1-2 weeks
Early symptoms of naegleria fowleri
Taste and smell changes Headache Nausea, vomiting High fever Stiff neck, +Kernig's sign
Late symptoms of naegleria fowleri
Confusion
Hallucinations
Ataxia
Seizures
Specimen to be collected for naegleria fowleri
CSF
CSF properties in naegleria fowleri
Thick, purulent
Pus cells >20,000/microl
Inc. protein, dec. Sugar
Trophozoites detected in microscopy
Histopathology of naegleria fowleri
Brain biopsy
H&E/Giemsa
Trophozoites with sky blue cytoplasm and pink nucleus
Culture for naegleria fowleri
Non nutrient agar
Trail sign - naegleria feeds on bacteria and crawls over lawn culture of E.Coli
Special test for naegleria fowleri
Enflagellation test
When scrapping of non nutrient agar is transferred to sterile tubes, amoeboid form transforms into pear shaped flagellated form
CT/MRI for naegleria fowleri
Obliteration of cisterns
Diffuse enhancement
Toxoplasma gondii is (intra/extra)
Obligate intracellular
Morphological forms of Toxoplasma gondii
Tachyzoites Pseudocyst Tissue cyst Sporulated oocyst Sporozoites/bradyzoites
C/F of Toxoplasma gondii in immunocompetents
Flu like symptoms Cervical lymphadenopathy Headache Fever Malaise
C/F of Toxoplasma gondii in HIV
necrotising encephalitis Seizures C.N palsies Altered mental status Motor defects
C/F of Toxoplasma gondii in congenital
3rd trimester
Intracranial calcifications
Hydrocephaly
Chorioretinitis
Microcephaly
Toxoplasma gondii direct microscopy
PBS, body fluids, bone marrow aspirate, l.n aspirate
Giemsa, PAS
Comma shaped tachyzoites
Tissue cyst in muscle and brain tissue
Ab detection in Toxoplasma gondii
IgG - 4 fold rise needed. Can’t differentiate
IgM - confirms congenital
IgA - acute and congenital
Special test for Toxoplasma gondii
Sabin Feldman Dye Test
Detects IgG
Complement mediated neutralization test
Needs live tachyzoites
CT/MRI for Toxoplasma gondii
Multiple ring enhancing lesions
CSF of Toxoplasma gondii
Inc. ICP
Lymphocytosis
Normal glucose
Antenatal DX of Toxoplasma gondii
Ultrasonography
PCR/isolation using amniotic fluid
Postnatal DX of Toxoplasma gondii
Isolation from amniotic fluid, placenta, cord leukocyte
IgG > 1000 in neonates
IgM > 1:4 in neonates
African sleeping sickness caused by
Trypanosoma brucei gambiense
Trypanosoma brucei rhodesiense
Vector for African sleeping sickness
Tsetse fly
Forms of Trypanosoma
Infective - metacyclic promastigote
Long slender trypomastigote
Epimastigote
Special feature of trypanosoma
Variable Surface Glycoprotein (VSG) Ag
Stage 1 of African sleeping sickness
1 wk - trypanosomal chancre (self limiting)
Few months - asymptomatic
Systemic febrile illness