[Occurrence of snail vectors of schistosomiasis in a dam of the semi-arid region of Pernambuco State, Brazil]

Comportamento da diarréia infantil antes e após consumo de água pluvial em município do semi-árido Brasileiro

Objetivou-se investigar a correlação entre consumo de água das cisternas e comportamento da diarréia infantil. Estudo quantitativo, transversal, realizado em Canindé-CE, com 56 famílias. As principais fontes de água utilizadas antes da construção das cisternas foram cacimbão (21-37,5%) e açude (17-30,4%). Verificou-se correlação linear, inversamente proporcional e estatisticamente significante, entre a taxa de diarréia infantil e o número de cisternas construídas por ano (r=-0,943; p=0,001). A cloração foi o principal tipo de tratamento da água, antes (46-82,1%) e depois (37-66%) da aquisição das cisternas, porém com diluição incorreta (41-89,2%). As cisternas de captação de água pluvial refletiram na melhoria da saúde infantil na região, contudo a população ainda necessita melhorar as medidas de tratamento da água consumida.

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

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 to be categorized into prevalence and severity classes for S. mansoni. The prevalence classes were: low (<10%), medium (> 10 and < 50%), and high (> 50%); the severity classes were: low (1-99 epg), moderate (100-399 epg), and severe (> 400 epg). For the geohelminthic diseases, the following indicators were used: positivity for each geohelminth (percentage of individuals examined with eggs of geohelminths), and cumulative positivity (percentage of individuals examined with eggs of at least one geohelminth). The municipalities were categorized by means of their cumulative positivity into the following geohelminth prevalence classes (WHO 2002): low (< 50%), medium (> 50 and < 70%), and high (> 70%). The study covered 271 schools in 179 different localities, thus giving a total of 11,234 examinations performed. The overall positivity for S. mansoni was 14.4% and the egg count for this parasite in the feces gave a geometric mean of 67.9 epg which suggests a low general state of infection. These results allow this mesoregion to be categorized as presenting medium prevalence and low severity of schistosomiasis. The overall positivity rates for the geohelminths, Ascaris lumbricoides, Ancylostomidae, and Trichuris trichiura were, respectively, 30.4, 10.1, and 27.8%; the cumulative positivity was 45.4%. These results allow this mesoregion to be categorized as presenting low prevalence of geohelminthic diseases. The data show some municipalities in Pernambuco with prevalence greater than 20%, while others presented parasite loads greater than 100 epg. These indicators attest to the significant morbidity due to schistosomiasis regarding to the severity of infections established in young populations.

[Hospitalization and mortality from mansoni schistosomiasis in the state of Pernambuco, Brazil, 1992/2000]

In order to investigate the historical trends, epidemiological profile, and spatial distribution of hospital admissions and deaths from schistosomiasis in the State of Pernambuco, Brazil, an analysis was conducted of data from the Hospital Information System and Mortality Information System from 1992 to 2000. The results showed a reduction in hospital admissions and mortality, while identifying more admissions and deaths among males. There was a lower percentage of deaths and admissions from schistosomiasis in individuals under 30 years of age. However, schistosomiasis is still of relevant magnitude, as evidenced by the number of deaths from this cause and the number of patients admitted to the hospital system in Pernambuco. A spatial analysis of the endemic's distribution in the State showed that although from 1995 to 1999 there was a greater spread of admissions due to schistosomiasis in the municipalities (counties) of the Sertão (backlands) and São Francisco river valley, the number of municipalities with hospitalizations due to schistosomiasis decreased from 1995 to 1998, followed by an increase in 1999 and 2000.

Susceptibility of Biomphalaria straminea (Dunker, 1848) from Serra da Mesa Dam, Goiás, Brazil to infection with three strains of Schistosoma mansoni Sambon, 1907

Ecological changes from water resources development projects often affect the epidemiology of water-associated diseases. In order to investigate the occurrence and distribution of freshwater snails of medical and veterinary importance in the area of influence of the Serra da Mesa Hydroelectric a survey has been performed since 1997 and revealed the occurrence of well-established populations of Biomphalaria straminea (Dunker, 1848) in the 8 municipalities surrounding the lake. Areas of epidemiologic risk for schistosomiasis were selected and studies of parasite-mollusc compatibility were undertaken using specimens from 19 populations of B. straminea and 3 strains (CM, EC and PB) originally isolated from B. straminea. Among 1,135 specimens used 15 became infected (infection index of 1.3%) and 8 populations were susceptible to the schistosome strains: B. straminea from Campinorte (Castelão, susceptible to CM and EC strains, and Planeta Agua, EC strain), Colinas (Tocantinzinho river, CM and EC strains), Minaçu (Canabrava river, EC strain), Niquelândia (Codemin, CM and PB strains, and Almas river, CM strain), Uruaçu (touristic area, PB strain) and Santa Rita do Novo Destino (Maranhão river, CM and EC strains). These results, associated with marked social and ecological changes occurred, strongly suggest the possibility of B. straminea coming to act as a vector of schistosomiasis in the studied area.