Page 75 - Medical Parasitology_ A Textbook ( PDFDrive )

68 7 Coccidia

Cysts with bradyzoites
2
Merozoites penetrate ingested in undercooked meat
muscle cells, and
develop into cysts
with bradyzoites.
i d

Schizonts rupture
releasing merozoites.

Sporocyst ruptures
releasing sporozoites
that enter endothelial
cells of blood vessels
and undergo schizogony.

Sporocysts 1
ingested d i
i = Infective Stage by cows Sporocysts and thin-walled
d = Diagnostic Stage and pigs. oocysts passed in faeces
Microgamete
3 6
5 7
4 Enter intestinal cells Fertilization
Bradyzoites
released from
ruptured cyst Immature oocyst Exits host
Macrogamete

Fig. 7.8 Life cycle of Sarcocystis (Reproduced from https://www.cdc.gov/dpdx/sarcocystosis/
index.html)

(b) Molecular diagnosis
PCR of stool specimen.
2. Muscular sarcocystosis
(a) Biopsy/autopsy
Histopathological examination to demonstrate sarcocysts in the striated
muscles. PCR of biopsy/autopsy specimens.
(b) Serodiagnosis
Not commercially available for human infection.