This specimen is from the faeces of a 23 year old woman recently returned from a holiday in South Africa, where she stayed in a resort on the shores of a large freshwater lake. Since returning home to Australia six months ago, she has complained of recurrent gastrointestinal upset and diarrhoea, although bacterial, parasitological and even virus investigations presented negative results. Doses of Flagyl (metronidazole), Combantrin (pyrantel) and Vermox (mebendazole) have not improved her condition.


1) Identify the parasite indicated (genus and species)

Schistosoma mansoni

2) Suggest how she may have contracted the infection

Infection by cercaria whilst swimming in fresh water

3) Suggest why the infection was not detected earlier

Egg counts are frequently low, eggs are not concentrated by routine methods, infection does not respond to any of the treatments listed above