[Observation on the clinical symptoms and sporocyst excretion in human volunteers experimentally infected with Sarcocystis hominis]

Abstract

Aim: To investigate the excretion of sporocysts and clinical manifestations in humans experimentally infected of Sarcocystis hominis.

Methods: Three volunteers were infected by eating raw beef containing cysts of S. hominis. One ingested about 1,567 cysts in skeletal muscles of a naturally infected cattle; two volunteers each ingested about 14,740 cysts from an experimentally infected water buffalo meat. Fecal examination by zinc sulfate flotation method was conducted daily since d4 postinfection (pi).

Results: Free sporocysts and oocysts were found in their faeces from d11-40, d12-23, d10-30 pi, and peaked at d18, d14, d14. All of them presented clinical symptoms such as abdominal pain, distension, watery diarrhea and eosinophilia 1 wk approximately 4 wk pi and were spontaneously cured within 29 days pi without taking any medicine.

Conclusion: All the experimentally infected persons had gastrointestinal symptoms and passed sporocysts and oocysts in faeces 10-12 days after infection and persisted for 11-29 days.