As
Schistosoma
sp. control programs are chiefly based on treatment of infected population,
adequate case finding has a crucial role. The available diagnostic methods
are far from ideal, since the search for eggs in stools and the detection
of circulating antigens lack sensitivity in low prevalence and post-treatment
situations and antibody detection lacks specificity. In most endemic foci,
repeated treatment of infected people leaves a number of non-diagnosed and
consequently non-treated persons, enough to maintain a persistent residue
of 5 to 10% prevalence. In an attempt to surpass these diagnostic limitations
we have developed a polymerase chain reaction (PCR) for the detection of
Schistosoma sp. in feces that, in a first population study, has shown to
be more sensitive than three-repeated stool Kato-Katz examination. The PCR
may constitute a valuable tool for the diagnosis of the
Schistosoma
sp. infection in special situations, when high sensitivity and specificity
are required and infrastructure is available.
