Frequência de infecção por Schistosoma mansoni em duas localidades endêmicas de Alagoas e comparação de duas técnicas parasitológicas

Abstract

Schistosomiasis mansoni is an important parasite that affects humans. It has become endemic in a large part of Brazil, and is considered a serious public health problem, as it affects millions of individuals, causing severe forms and death. In the Americas, Brazil is the country with the largest endemic area, and the state of Alagoas is endemic in more than 70% of its municipalities. The control of this parasitosis depends on several factors, one of which is the early diagnosis for adequate treatment. The diagnostic method of choice is the Kato-Katz, considered the gold standard by the World Health Organization. In regions with cases of medium or high parasite load, the gold standard has satisfactory performance, however, the same cannot be said for low loads, and in an effort to improve this situation, techniques with greater sensitivity were developed and are now being evaluated, as is the case of Helmintex. Therefore, early diagnosis and treatment of individuals infected with S. mansoni are necessary, not only to improve the health of carriers, but also to reduce the spread of an important public health problem that is schistosomiasis. With that in mind, the present study sought to determine the frequency of infections by S. mansoni in historically endemic populations in the cities of Maceió-AL and Viçosa-AL. This study was carried out between 2021 and 2022, with non-probabilistic convenience sampling, in which a total of 201 fecal samples were collected in different regions, with 89 samples from Maceió and 112 samples from Viçosa. For the parasitological diagnosis, three techniques were used to search for parasite eggs: HPJ, Kato-Katz and Helmintex. Of the total of 201 fecal samples analyzed, in 48.25% (97/201) eggs of the parasite S. mansoni were found in at least one of the coproparasitological techniques used, with a frequency of 66.96% (75/112) in Vila Nova and 24.71% (22/89) in Vergel do Lago. 111 samples were processed simultaneously by the KatoKatz and Helmintex methods; of these, only 15 samples were positive in both methods, concomitantly, while 25 were negative, generating a level of agreement of 0.0869. Based on the results found, high rates of frequency of schistosomiasis cases were observed in communities in Maceió-AL (24.71%) and Viçosa-AL (66.96%). In addition, the Helmintex technique demonstrated greater sensitivity, detecting a greater number of positive cases than the gold standard technique.