Although involved in biliary disease, hepatitis, pancreatitis, arthritis, and possibly respiratory tract infections also, the protozoan organism
Cryptosporidium parvum
is primarily responsible for watery diarrhoea.
1,2 A mean infective dose of 132 oocysts has been proved to be adequate in producing infection in healthy volunteers.
2 Diarrhoea is self-limited in immunocompetent individuals or in those whose CD4 cell counts are more than 200/mm
3, but may be severe, sometimes cholera-like, and unremitting or relapsing in severely immunodeficient patients (CD4 cell counts below 100/mm
3). In these cases chronic infection can lead to dehydration, malnurtrition, malabsorption, wasting and frequently, death.
3 Biliary cryptosporidiosis is more frequent in patients with CD4 cell counts below 50/mm
3 and commonly presents with right upper quadrant pain, nausea, fever, and vomiting. Diarrhea may be absent, and laboratory findings may include elevated serum alkaline phosphatase and bilirubin levels, with only scant elevation of liver transaminase levels. Coinfection with cytomegalovirus or microsporidia has frequently been found in biliary cryptosporidiosis.
2,4 Some cases of pneumatosis cystoides intestinalis in AIDS-associated cryptosporidiosis have been reported, suggesting a pathogenetic role for the parasite.
5,6
See related Brief Report - Bioline Code:
jp02062
