Esquistossomose mansoni em area de baixa endemicidade : soroepidemiologia e controle

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

In 1980, schistosomiasis mansoni control measures were introduced in the municipality of Pedro de Toledo, a low endemic region in the State of Sao Paulo and this study was conducted, in 1998, to evaluate the program. Flaws were detected in the sensitivity of the parasitological methods used in this area of low infection indices due to the reduced number of eggs in the feces, which resulted in underestimated prevalence indices. Highly sensitive-specific serological methods provide prevalence indices that are closer to reality. A random sample of 12% of the residents in the municipality provided clinical samples that consisted of 749 stool samples and 591 blood samples from the finger on filter paper. The Kato-Katz parasitological technique for stool examinations and the serological techniques of indirect immunofluorescence for the detection of IgG (RIF-IgG) and IgM (RIF-IgM) antibodies were used in the diagnostics of mansoni schistosomiasis. The prevalence index obtained by the parasitological method was 1.6% with an infection intensity of 40.9 eggs per gram of feces (epg). Good concordance was shown by the serological reactions (Kappa = 0.84) with a prevalence of 33.2% for the RIF-IgG and 33.5% for RIF-IgM. The serological test RIF-IgM proved to be safe, practical and an important tool for assessing the epidemiological profile of a population in a low endemic area. A clear discrepancy was observed between the prevalence indices obtained by the parasitological and immunological methods, as the serological prevalence was 20 times greater than the parasitological prevalence. These results demonstrated the importance of incorporating serological techniques in epidemiological surveillance, for complementing parasitological findings and in the diagnosis and treatment of parasitoses. These techniques help in diagnosis and treatment of individuals who are false negative for stool examinations, which in turn reduces potential infection foci. When the prevalence distribution curve according to age group for 1980 was compared with that of this study (1998), a transference was observed of the highest prevalence, which was in the 10 -19 year old age group (190) to the 25 - 29 year old age group (1998). In 1980, the indices obtained by the Kato- Katz and RIF-IgM methods were 22.8% (58.5 epg of feces) and 55.5%, respectively. When compared with the results obtained by this study, a significant fall was observed in prevalence indices that indicated the effectiveness of the control measures. Nevertheless, the occurrence of residue transmission demonstrates the need for a joint effort in extending control and surveillance measures related to schistosomiasis mansoni

ASSUNTO(S)

sorodiagnostico schistosoma mansoni epidemiologia

ACESSO AO ARTIGO

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