BackgroundPraziquantel at 40 mg/kg in a single dose is the WHO recommended treatment for all forms of schistosomiasis, but 60 mg/kg is also deployed nationally.Methodology/Principal FindingsFour trial sites in the Philippines, Mauritania, Tanzania and Brazil enrolled 856 patients using a common protocol, who were randomised to receive praziquantel 40 mg/kg (n = 428) or 60 mg/kg (n = 428). While the sites differed for transmission and infection intensities (highest in Tanzania and lowest in Mauritania), no bias or heterogeneity across sites was detected for the main efficacy outcomes. The primary efficacy analysis was the comparison of cure rates on Day 21 in the intent-to-treat population for the pooled data using a logistic model to calculate Odd Ratios allowing for baseline characteristics and study site. Both doses were highly effective: the Day 21 cure rates were 91.7% (86.6%–98% at individual sites) with 40 mg/kg and 92.8% (88%–97%) with 60 mg/kg. Secondary parameters were eggs reduction rates (ERR), change in intensity of infection and reinfection rates at 6 and 12 months. On Day 21 the pooled estimate of the ERR was 91% in both arms. The Hazard Ratio for reinfections was only significant in Brazil, and in favour of 60 mg/kg on the pooled estimate (40 mg/kg: 34.3%, 60 mg/kg: 23.9%, HR = 0.78, 95%CI = [0.63;0.96]). Analysis of safety could not distinguish between disease- and drug-related events. 666 patients (78%) reported 1327 adverse events (AE) 4 h post-dosing. The risk of having at least one AE was higher in the 60 than in the 40 mg/kg group (83% vs. 73%, p<0.001). At 24 h post-dosing, 456 patients (54%) had 918 AEs with no difference between arms. The most frequent AE was abdominal pain at both 4 h and 24 h (40% and 24%).ConclusionA higher dose of 60 mg/kg of praziquantel offers no significant efficacy advantage over standard 40 mg/kg for treating intestinal schistosomiasis caused by either S. mansoni or S. japonicum. The results of this study support WHO recommendation and should be used to inform policy decisions in the countries.Trial Registration Controlled-Trials.com ISRCTN29273316 ClinicalTrials.gov NCT00403611

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INTRODUÇÃO: Em 1988, 22 casos autóctones de esquistossomose foram registrados na Praia do Forte Orange, ilha de Itamaracá, Pernambuco. Todos os casos ocorreram em indivíduos de classe média/alta que veraneavam na ilha. Foi realizado estudo com o objetivo de identificar e caracterizar criadouros/focos de vetores da esquistossomose na localidade, correlacionando os determinantes biológicos da doença com o contexto ambiental da sua ocorrência. MÉTODOS: Foram levantados dados secundários para resgatar as características ambientais da área antes da ocupação humana. O inquérito malacológico teve a duração de um ano com mapeamento da área, coleta mensal e exame dos moluscos. RESULTADOS/CONCLUSÕES: Em 1 km de extensão da praia, foram identificados 20 criadouros e demarcadas 28 estações de coleta. Os resultados mostram a variação mensal da densidade populacional de moluscos e das taxas de infecção, correlacionados com sazonalidade e tipos de criadouros. Destaca-se a importância desse novo perfil epidemiológico da esquistossomose em Pernambuco, relacionando o modo de ocupação daquele espaço com o estabelecimento de sítios de transmissão ativa da esquistossomose.

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...

This study assesses the evolution of schistosomiasis in the endemic area of Pernambuco, using data from five campaigns of chemotherapy control carried out by national health programmes from 1977 to 1996. Analysis of the data showed that: a) the proportion of municipalities with prevalence above 25% was significantly higher in the coastal-forest zone than in the zone of transitional vegetation Agreste in the four evaluations made in the endemic area; b) the prevalence of infection decreased in both zones even when the interval between campaigns were more than five years. The last survey (1996) indicated a predominance of municipalities with prevalences below 25%. However, the majority of these municipalities had localities with prevalence above 50%. A proposal is presented for the identification of the problematic localities, where complementary measures to chemotherapy, such as systematic snail control, improved sanitation, health education and community mobilization, are still necessary.