Laboratory Test Reference Guide

Laboratory diagnosis is made by finding typical eggs in stool or urine.

S. haematobium eggs can be found in urine and occasionally in faeces, the eggs of the other species are normally found in stool, although S. mansoni eggs are in rare cases present in urine. S. mansoni eggs are discharged at irregular intervals and may not be found in every stool specimen. Several samples may be necessary for the diagnosis.

A urinary sediment is suitable for the diagnosis of S. haematobium. A full void urine sample is ideally collected between 10 a.m. and 2 p.m. to coincide with the maximal excretion of eggs.

S. haematobium - Urine (Faeces)

S. intercalatum - Faeces

S. japonicum - Faeces

S. mansoni - Faeces (Urine)

S. mekongi - Faeces

The laboratory diagnosis of schistosomiasis and Katayama syndrome in returning travelers is difficult because the number of excreted eggs is often very limited. In early infections and in patients with only a few contacts with contaminated water, the total number of parasites, migrating larvae or schistosomulae, and adult worms, is very low. Eggs can only be found in faeces or urine when there is at least one pair of adult worms at the final location. The number of parasites increases as a function of the number of contacts with infected water. The exact latency between contamination and egg production is unknown. It is estimated that excretion of eggs starts after 40-50 days.