Infecção por Schistossoma mansoni em uma região historicamente endêmica no estado de Alagoas: o uso de diferentes técnicas diagnósticas e padronização de teste imunoenzimático - dados preliminares

Abstract

Schistosomiasis is a disease caused by the helminth of the Trematoda class, of the Schistossoma genus, Schistossoma mansoni species. In addition, it is considered a public health disease in Brazil, as there are about 43 million people living in areas at risk of infection and 7 million infected. Currently, the test considered the gold standard most used for the diagnosis of S. mansoni is the Kato katz test, but it has low sensitivity, especially in individuals with low parasite load. Therefore, it is necessary to standardize the serological tests. However, there are still no protocols and standardized antigens to be used as a diagnostic alternative by the public health system. The objective of this study was to standardize a serological test to detect Schistosoma mansoni infection in the population of a region historically endemic to schistosomiasis in the state of Alagoas. The population sample was from an endemic region, in the Vergel do Lago neighborhood, Maceió, Alagoas. The present study used coproparasitological techniques (Kato-Katz, HPJ and Helmintex), POC-CCA and Indirect Elisa for the analysis of the samples. Of the 93 samples analyzed, a frequency of S. mansoni infection of 32.2% (30/93) was observed. Furthermore, the frequency of positivity was different for each of the techniques analyzed. From 52 samples analyzed by POC-CCA, 19% (10/52) were positive; from 92 samples analyzed by Kato Katz 5% (5/92) and from 91 samples analyzed by HPJ 5% (5/91) were positive, and for the 27 samples analyzed by Helmintex 66% (18/27) were positive. Finally, the serological results obtained by Elisa are preliminary results that cannot yet be used as a diagnostic method. It is of utmost importance that further studies be carried out with a larger number of samples for its standardization. Once standardized, it will be a diagnostic alternative with greater sensitivity, and will be favorable for reducing false-negative results in individuals with low parasite load.