Assessment of schistosomiasis, through school surveys, in the Forest Zone of Pernambuco, Brazil

Abstract

This work had the objective of assessing the present epidemiological situation regarding schistosomiasis through performing Kato-Katz coproscopic tests on representative samples of schoolchildren from each of the 43 municipality of endemic area of the state of Pernambuco, Brazil. The methodology is recommended by the World Health Organization to conduct sampled surveys among children at elementary school levels, ideal target group for baseline surveys: (i) schools are accessible; (ii) the greatest prevalence of schistosomiasis is found within this group; (iii) the data gathered from this age group can be used for intervention within the community as a whole. The following infection indicators were utilized: positivity (percentage of individuals examined with eggs of Schistosoma mansoni in the feces) and severity (geometric mean number of eggs per gram of feces, epg). These indicators allowed the area in general and the municipalities in particular toSince the last decade, the coastal and forest zones of the state of Pernambuco have been the target of various field investigations on schistosomiasis. The emphasis has been on the ecology and control of the mollusks that are the intermediate hosts (Barbosa 1992a,b, 1996, Barbosa & Barbosa 1994, 1996, Barbosa et al. 1992, 1993, Bogéa et al. 1996, Dannemann & Pieri 1989, 1991, 1993a, b, Favre et al. 1995, 1997, Gazin et al. 2000, Pieri 1995, Pieri & Dannemann 1996, Pieri & Thomas 1986, 1987, Randall et al. 2001, Sarquis et al. 1997, the ecological and epidemiological determinants of the disease (Barbosa 1992b, 1997, 1998a, b, Barbosa & Coimbra 2000, Barbosa & Gouveia 2000, Coutinho et al. 1997, Gazin et al. 2002, Gonçalves et al. 1992, Simões-Barbosa et al. 2001, and also the impact of chemotherapy treatment for infected individuals, in relation to the transmission dynamics of the disease , Favre et al. 2002, Zani et al. 2004). The knowledge resulting from these studies has made it possible to adapt the schistosomiasis evaluation and control strategies recommended by central health bodies -WHO at the worldwide level and the Health Surveillance Department of the Ministry of Health at the national level -to the regional characteristics and demands.A critical assessment of the schistosomiasis control actions implemented in Pernambuco by the national bodies prior to the introduction of the Unified Health System (Sistema Único de Saúde -SUS) showed that the situation in the endemic area continued to be of concern, despite the occurrence of an apparent reduction in preva- In view of the fact that the estimated population at risk of contracting schistosomiasis in the 43 municipalities in the Forest Zone of Pernambuco is 1.2 million (http:/ /www.ibge.gov.br/cidadesat/), it is unlikely that the covenanted targets will allow the real situation regarding schistosomiasis to be known over the short to medium term. One alternative recommended by WHO (2002) is to conduct sampled surveys among children at elementary school levels (i.e. between 7 and 14 years of age). These childre...

Reliability of current estimates of schistosomiasis prevalence in the Rainforest Zone of the state of Pernambuco, Northeastern Brazil

“…Such techniques minimize the problems of precision and validity, and can be easily executed by the PCE-SUS. A recent study involving school surveys among 9-12 yrs old children in all 43 municipalities of the ZMP (Barbosa et al 2006b) identified 25 (58%) of them in the moderate prevalence class and the remaining, in the low prevalence one. Surveys based on representative samples enable not only to know the real situation of schistosomiasis but also to suggest adequate control strategies.…”

Análise da positividade da esquistossomose mansoni em Regionais de Saúde endêmicas em Pernambuco, 2005 a 2010

“…12,13 Inquéritos realizados em escolares na faixa etária de 9 a 12 anos, residentes em municípios situados na Zona da Mata do estado, região de localização dos municípios das RS II e III, demonstraram a ocorrência de transmissão recente da parasitose nessa área. 14,15 No inquérito realizado por Barbosa 14,15 em 2005, quase metade (45,5%) dos municípios localizados na área que compõe a RS II apresentou positividade considerada moderada (10 a 50%) para esquistossomose e a grande maioria (73%) dos municípios localizados na área correspondente à RS III apresentou a mesma positividade. Os resultados apresentados neste trabalho mostram concordância com os resultados dos estudos supracitados e reforçam a permanência da Zona da Mata de Pernambuco como a área de maior transmissão da doença, apresentando a RS III como a de maior positividade nos anos analisados, seguida pela RS II.…”

Spatial distribution of schistosomiasis and geohelminthiasis cases in the rural areas of Pernambuco, Brazil

“…Even though various surveys and studies over the last 30 years have shown occurrences of schistosomiasis and geohelminthiasis in the ZMP 7,8,14,15 no preventive measures are known to have been effective in the endemic area for decreasing the numbers of cases and morbidity due to these health hazards among schoolchildren in the ZMP. …”

“…In a survey conducted by Barbosa et al 8 in the ZMP, it was shown that there was an accumulated prevalence of schistosomiasis of 14.4%, and that for geohelminthiasis the prevalence was over 50% in some municipalities, thus proving that these parasites are a relevant public health issue in this state. Hence, the present study aimed to spatially assess occurrences of schistosomiasis and geohelminthiasis in the ZMP, using GIS as an auxiliary tool, with the intention of showing the epidemiological landscape of occurrences of these parasitoses, as a support for planning and applying effective prevention and control measures.…”