Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 3. Techniques for assessment and surveillance.
Severe morbidity due to schistosomiasis mansoni is now quite rare in Brazil; thus it is proposed that surveillance plus selective and multidisciplinary intervention limited to areas at high risk be the next step. Such a policy has to be carried out periodically and on a state-wide scale, and therefore will have to rely upon cheap and time-saving sampling procedures. Clinical features cannot at present be used as indicators, with the exception of grossly enlarged livers, which are more frequent in areas at high risk. Overall prevalence rates for a county or even city may also be misleading, even if broken down into units of smaller size. Thus, egg counts in the young age groups remain the best indicators for the detection of areas at high risk (i.e., the main foci of transmission). Egg counts performed on pooled specimens adequately reflect the risk rating of a particular neighbourhood, and have a favourable cost-benefit ratio. In addition, it is suggested that field personnel be trained in the empirical recognition of potential foci; such 'screening by suspicion' has been tested and found to be reliable.
Kloetzel
K
K
Departamento de Medicina Social, Faculdade de Medicina da Universidade Federal de Pelotas, Pelotas, Brazil.
Chieffi
P P
PP
de Siqueira
J G
JG
D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008099:Liver / Q000469:parasitology; D008297:Male; D010270:Parasite Egg Count; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D012307:Risk Factors; D012555:Schistosomiasis mansoni / Q000453:epidemiology* / Q000469:parasitology; D013163:Splenomegaly / Q000469:parasitology