In the Brazilian state of Pernambuco, schistosomiasis exhibits an epidemiological profile of chronic infection and persistent reinfection in the rainforest area (Zona da Mata). Heavy infections are also frequent in the coastal area (Barbosa et al. , 2001. Despite the amount of data amassed over the years and the advances in immunological and therapeutic clinical research, control of schistosomiasis transmission still represents a challenge for government institutions (Barbosa & Coimbra 2000). Although morbidity indices remain low, the prevalence of infection and the rate of reinfection have remained high in rural areas despite repeated treatment with oxamniquine , Favre 1999.Longitudinal studies of infected snails in critical areas, in parallel with application of control measures may shed light on why control measures fail. Nevertheless, few have been carried out (Dazo et al. 1976, Gundersen et al. 1990).In Pernambuco, there are two intermediate host species of Schistosoma mansoni: Biomphalaria straminea and B. glabrata. The first species is widespread over the Agreste, a zone of transitional vegetation, and the Zona da Mata, where it maintains high endemicity levels despite the low rates of natural and experimental infection (Paraense & Corrêa 1989). The second species, with infection rates reaching up to 20%, is mainly found in coastal areas, and remains responsible for several active foci of transmission .The present study aims to assess, on a monthly basis over a period of four years, the relative abundance and the natural infection of B. straminea and B. glabrata by S. mansoni in two representative localities in an endemic area in the state of Pernambuco, where infected persons were treated periodically with oxamniquine. In addition, tests were carried out to ascertain the susceptibility of snail species found in these localities to local parasite strains. MATERIALS AND METHODSTwo rural localities sharing similar sociodemographic characteristics and displaying medium levels of endemicity in relation to schistosomiasis (prevalence ranging from 30% to 40%), populated by distinct intermediate host species, were chosen after a preliminary stool survey and the application of a home questionnaire as described by Moza et al. (1998). Nine stool surveys by the Kato-Katz method (Katz et al. 1972) were undertaken every three months in both localities and individuals who tested positive for S. mansoni were treated with oxamniquine ), in March 1995, June 1995, March 1997 and March 1998 Characterization of the study area -Ecological features relevant to schistosomiasis transmission were recorded, including water-contact habits and rainfall. As recommended by Olivier (1973), sketch maps were used to display the location of houses, land use and water resources of each locality.Malacological survey -Snail breeding sites regarded as potential of transmission foci were identified in both localities. Snails were collected monthly from predetermined stations over the four years of the follow-up sur-+ Corresponding

BackgroundSince its beginning in 1999, the Schistosomiasis Control Program within the Unified Health System (PCE-SUS) has registered a cumulative coverage of just 20% of the population from the Rainforest Zone of Pernambuco (ZMP), northeast Brazil. This jeopardizes the accomplishment of the minimum goal of the Fifty-Fourth World Health Assembly, resolution WHA54.19, of providing treatment for schistosomiasis and soil-transmitted helminthiases (STH) to 75% of school-aged children at risk, which requires attending at least 166,000 residents in the 7–14 age range by year 2010 in that important endemic area. In the present study, secondary demographic and parasitological data from a representative municipality of the ZMP are analyzed to provide evidence that the current, community-based approach to control schistosomiasis and STH is unlikely to attain the WHA-54.19 minimum goal and to suggest that school-based control actions are also needed.Methodology/Principal FindingsData available on the PCE-SUS activities related to diagnosis and treatment of the population from the study municipality were obtained from the State Secretary of Health of Pernambuco (SES/PE) for 2002–2006, complemented by the Municipal Secretary of Health (SMS) for 2003–2004. Data from a school-based stool survey carried out by the Schistosomiasis Reference Service of the Oswaldo Cruz Foundation (SRE/Fiocruz) in 2004 were used to provide information on infection status variation among school-aged children (7–14 years). According to the SES, from 2004 to 2006, only 2,977 (19.5%) of the estimated 15,288 residents of all ages were examined, of which 396 (13.3%) were positive for Schistosoma mansoni. Among these, only 180 (45.5%) were treated. According to the SMS, of the 1,766 examined in the 2003–2004 population stool survey 570 (32.3%) were children aged 7–14 years. One year later, the SRE/Fiocruz school survey revealed that the infection status among those children remained unchanged at 14%–15% prevalence. By 2006, the school-aged population was estimated at 2,981, of which 2,007 (67.3%) were enrolled as pupils.ConclusionsIt is suggested that in the most troubled municipalities individual diagnosis and treatment should be concentrated in school-aged children rather than the whole population. School-based actions involving teachers and children's families may help the health teams to scale up control actions in order to attain the WHA-54.19 minimum goal. This strategy should involve health and education organs and include both enrolled and non-enrolled children.

This work aims to evaluate the impact of drug treatment on infection by Ascaris lumbricoides (Al), Trichuris trichiura (Tt) and hookworms (Hook) in a rural community from the sugar-cane zone of Pernambuco, Brazil. Four parasitological surveys were carried out from March 2001 to March 2002. Individual diagnosis was based on eight slides (four by the Kato-Katz method and four by the Hoffman method) per survey. Infected subjects were assigned to two groups for treatment with either albendazole (n = 62) or mebendazole (n = 57). Prevalence of infection fell significantly (p < 0.05) one month after treatment: Al (from 47.7% to 6.6%); Tt (from 45.7% to 31.8%) and Hook (from 47.7% to 24.5%). One year after treatment, infections by Tt and Hook remained significantly below pre-control levels. A substantial decrease in single-infection cases and multiple infections was found. Egg-negative rate was significant for Al (94.0%), Hook (68.3%) but not for Tt (45.5%), and did not differ significantly between subjects treated with mebendazole or albendazole. Egg counts fell significantly in the individuals remaining positive for Tt. It is recommended that antihelminthic treatment should be selective and given at yearly intervals preferably with albendazole, due to its cost-effectiveness.

Praziquantel chemotherapy has been the focus of the Schistosomiasis Control Program in Brazil for the past two decades. Nevertheless, information on the impact of selective chemotherapy against Schistosoma mansoni infection under the conditions confronted by the health teams in endemic municipalities remains scarce. This paper compares the spatial pattern of infection before and after treatment with either a 40 mg/kg or 60 mg/kg dose of praziquantel by determining the intensity of spatial cluster among patients at 180 and 360 days after treatment. The spatial-temporal distribution of egg-positive patients was analysed in a Geographic Information System using the kernel smoothing technique. While all patients became egg-negative after 21 days, 17.9% and 30.9% reverted to an egg-positive condition after 180 and 360 days, respectively. Both the prevalence and intensity of infection after treatment were significantly lower in the 60 mg/kg than in the 40 mg/kg treatment group. The higher intensity of the kernel in the 40 mg/kg group compared to the 60 mg/kg group, at both 180 and 360 days, reflects the higher number of reverted cases in the lower dose group. Auxiliary, preventive measures to control transmission should be integrated with chemotherapy to achieve a more enduring impact

If the patients in this sample had been previously vaccinated with PCV13 plus PPV23, theoretically, 50.8% of the cases of invasive pneumococcal disease that required hospital admission could potentially have been prevented. Invasive pneumococcal disease should be prevented by vaccination not only of children and the elderly but also of adults in their economically productive years, so as to reduce the socioeconomic costs, morbidity, and mortality still associated with the disease, especially in underdeveloped countries.