HUMAN TRICHOSTRONGYLIASIS IN QUEENSLAND

Trichostrongylus infection, an uncommonly reported zoonosis in Austral ia, is common in parts of the world where there is close human contact with herbivorous animals. We report 5 cases diagnosed in our laborato ry since 1992. Over this period the laboratory has conducted over 46,0 00 parasitological examinations on feces. All 5 cases were investigate d for fecal parasites following detection of a,blood eosinophilia. Two of the 5 cases complained of mild abdominal discomfort and diarrhea. It is likely that all obtained their infection following ingestion of contaminated unwashed vegetables which had been fertilized with animal manure. Four of the cases acquired their infection in Queensland and the fifth may have become infected in rural Victoria. All were treated with pyrantel embonate with resolution of the eosinophilia. Follow up fecal specimens showed no parasites. Patients were instructed on the mode of transmission and advised to thoroughly wash any uncooked veget ables prior to ingestion. In our cases, goats and horses were possibly implicated. No published reports of Trichostrongylus spp. in humans i n Australia have occurred since the 1930s and it may be more common in Australia than is recognized. The infection may be missed because pat ients are asymptomatic or have mild gastrointestinal symptoms or only a blood eosinophilia. Trichostrongylus eggs may also be mistaken for h ookworm eggs. It is important therefore to distinguish these infection s from hookworm infection as the modes of transmission, management and advice regarding prevention differ.