Fatores sócio-culturais e éticos relacionados com os processos de diagnóstico da esquistossomíase mansônica em área de baixa endemicidade

Abstract

Five annual parasitological surveys and one serological survey, respectively based on the Kato-Katz and free sedimentation methods and the Western blot technique, were conducted in Sumidouro, Rio de Janeiro, Brazil, an endemic county for schistosomiasis. Possible influences of the use of these methodologies on social, cultural, and ethical aspects of the study population were also evaluated. Having the opportunity to choose the different techniques was a conclusive issue influencing participation by the population. Prevalence rates of positive results for stool tests were: 11.6% (1995); 8.8% (1996); 12.2% (1998); 5.9% (1999); and 3.2% (2000). In the period during which the serological survey was performed, the use of laboratory testing in association with analysis of clinical data and available data on transmission and treatment generated a diagnostic procedure termed "coproseroepidemiology". This methodology contributed to significant improvements in the accuracy of measurement of local schistosomiasis prevalence, indicating that epidemiological surveillance could help prevent the recurrence of high prevalence rates. The fact that Biomphalaria glabrata was replaced by Melanoides tuberculata in the main transmission focus contributed to a significant decrease in infection rates.

Case Report: Diagnosis and Assessment of Cure Approaches for Acute Schistosomiasis in Pre-School Children

“…Acute asymptomatic infection was also detected in two children, one being a pre-school child. Although direct measurement of Schistosoma infection of the intermediate hosts failed to demonstrate active infection (personal communication), the area has been well-known for its low endemicity since 2000 with presumably low transmission rates ( 35 ). Despite that, most children exposed to low parasite burdens develop a broad range of manifestations, including severe disease.…”

The Role of Wild Rodents in the Transmission of Schistosoma mansoni in Brazil

“…The socio-economic conditions contributed to the complexity of schistosomiasis control by exposing the population to psycho-social and chemical risks, given that irregularities and excesses in pesticide use were common in local agricultural production, with strong consequences for human and environmental health. The historical approach of schistosomiasis in Sumidouro showed the following: a) since the 1960s, there were cases of severe collateral effects from medicine, failures of sanitation, as well as environmental and material injuries after the use of moluscicides for snail control; b) in addition to these low quality of life, poverty, lack of good life quality perspectives, alcoholism and other factors that stimulate pessimism and inaction turned part of the communities against the diagnosis and treatment of schistosomiasis, as well as against the methodologies of sanitation and snail control suggested by the public powers and by the researchers; c) these refusals increased the limitations of coprological diagnosis that contributed to uncertainty in the real number of infected people; d) these facts demand the adoption of a wide range of measures, such as methodologies to understand the needs of the population and to make people understand schistosomiasis transmission and the serological techniques used for diagnosis (Gonçalves et al, 2005;Soares et al 2002). In this complex context, schistosomiasis transmission to the human population occurred in home backyards and for other reasons (occupational, recreational and occasional), with high ratios of non-treatment due to migration, refusal or medical precaution and with a high prevalence in specific groups (men and farm workers).…”