Abstract. Soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) negatively impact the health and wellbeing of hundreds of millions of people, particularly in tropical and subtropical countries, including Brazil. Reliable maps of the spatial distribution and estimates of the number of infected people are required for the control and eventual elimination of soil-transmitted helminthiasis. We used advanced Bayesian geostatistical modelling, coupled with geographical information systems and remote sensing to visualize the distribution of the three soil-transmitted helminth species in Brazil. Remotely sensed climatic and environmental data, along with socioeconomic variables from readily available databases were employed as predictors. Our models provided mean prevalence estimates for A. lumbricoides, T. trichiura and hookworm of 15.6%, 10.1% and 2.5%, respectively. By considering infection risk and population numbers at the unit of the municipality, we estimate that 29.7 million Brazilians are infected with A. lumbricoides, 19.2 million with T. trichiura and 4.7 million with hookworm. Our model-based maps identified important risk factors related to the transmission of soiltransmitted helminths and confirm that environmental variables are closely associated with indices of poverty. Our smoothed risk maps, including uncertainty, highlight areas where soil-transmitted helminthiasis control interventions are most urgently required, namely in the North and along most of the coastal areas of Brazil. We believe that our predictive risk maps are useful for disease control managers for prioritising control interventions and for providing a tool for more efficient surveillance-response mechanisms.

A geographic information system (GIS) was constructed using maps of regional agroclimatic features, vegetation indices and earth surface temperature data from environmental satellites, together with Schistosoma mansoni prevalence records from 270 municipalities including snail host distributions in Bahia, Brazil to study the spatial and temporal dynamics of infection and to identify environmental factors that influence the distribution of schistosomiasis. In an initial analysis, population density and duration (months) of the annual dry period were shown to be important determinants of disease. In cooperation with the National Institute of Spatial Research in Brazil (INPE), day and night imagery data covering the state of Bahia were selected at approximately bimonthly intervals in 1994 (six day-night pairs) from the data archives of the advanced very high resolution radiometer (AVHRR) sensor of the National Oceanic and Atmospheric Administration (NOAA)-11 satellite. A composite mosaic of these images was created to produce maps of: (1) average values between 0 and +1 of the normalized difference vegetation index (NDVI); and (2) average diurnal temperature differences (dT) on a scale of values between 0 and 15 degrees C. For each municipality, NDVI and dT were calculated for a 3x3 pixel (9 km(2) area) grid and analyzed for relationships to prevalence of schistosomiasis. Results showed a statistically significant relationship of prevalence to dT (rho=-0.218) and NDVI (rho=0.384) at the 95% level of confidence by the Spearman rank correlation coefficient. Results support use of NDVI, dT, dry period climatic stress factors and human population density for development of a GIS environmental risk assessment model for schistosomiasis in Brazil.

Abstract. A geographic information system was constructed using maps of regional environmental features, Schistosoma mansoni prevalence in 30 representative municipalities, and snail distribution in Bahia, Brazil to study the spatial and temporal dynamics of infection and to identify environmental factors that influence the distribution of schistosomiasis. Results indicate that population density and the duration of annual dry period are the most important determinants of prevalence of schistosomiasis in the areas selected for study. Maximum rainfall, total precipitation during three consecutive months, annual maximum or minimum temperatures, and diurnal temperature difference were not shown to be significant factors influencing S. mansoni prevalence in local populations or distribution of snail hosts. Prevalence of the disease was highest in the coastal areas of the state. Higher prevalence tended to occur in areas with latossolo soil type and transitional vegetation.Schistosomiasis, which is caused by Schistosoma mansoni, was introduced into Brazil in the mid 1550s 1 and became established as a significant health problem in the endemic states of the northeast region of the country. Ecologic factors favorable to the intermediate snail hosts and the concentration of susceptible humans hosts living under substandard conditions have contributed to maintenance of the disease and expansion of the endemic area. 2 While spatial distribution and prevalence have remained constant in some regions since surveys done in the 1950s, outbreaks have been reported in regions previously considered free of schistosomiasis. Spread of the disease to newly settled areas is a major concern of the National Schistosomiasis Control Program.Studies done on rural communities in Bahia 3-5 have shown that the number, distribution, and rate of infection of the intermediate host Biomphalaria glabrata and contact with domestic water were key determinants of human infection prevalence and that snail populations responded to seasonal rainfall patterns, with an increase in reproduction during the period October through January and proportional decreases during months of drought. A study contrasting communities with high and low prevalence rates of S. mansoni in Sao Paulo State revealed that high altitude, low population density, high standards of sanitation, and limited numbers of breeding sites for B. tenagophila, the principal intermediate host in the Sao Paulo area, contributed to low rates of infection. 5 A knowledge of the factors contributing to the size and location of snail populations is pivotal to planning and implementing effective programs of suppression using molluscicides. Since the number of intermediate hosts, their concentration, and rate of infection may be functions of rainfall, vegetation, topography, soil type, and characteristics of water bodies, geographic information system (GIS) methods may be suitable for analysis of the spatial relationships of the environment, mollusk intermediate hosts, and schistosomiasis in specific...

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RESUMONo intuito de classificar a distribuição geográfica da procedência dos animais infectados e mensurar as áreas quanto ao risco de se contrair a cisticercose bovina, foi utilizada a análise espacial de varredura para identificação de O complexo teníase/cisticercose envolvendo a larva infectante da Taenia saginata e os bovinos têm caráter zooantroponótico, com consideráveis reflexos negativos para o agronegócio e para a saúde pública (Marques et al., 2008). O regime de criação dos bovinos, somado ao baixo nível socioeconômico-cultural da população e à Recebido em 13 de março de 2011 Aceito em 22 de maio de 2012 *Autor para correspondência (corresponding author) E-mail: lucianacardim@yahoo.com.br precariedade das condições sanitárias, contribui para a contaminação das pastagens e mantém uma relação direta com a ocorrência da cisticercose entre os bovinos. A inter-relação desses animais com os seres humanos no campo passa a ser o principal responsável pela manutenção da endemia.Apesar de o valor oficial da produção agropecuária brasileira ser da ordem de R$ 239,8

This study evaluated the effects of homeopathic treatment on control of Haemonchus contortus infection in sheep. Twenty lambs were randomized to three treatments: treated with the homeopathic medicines, Ferrum phosphoricum, Arsenicum album and Calcarea carbonica; treated with a conventional antihelminthic, doramectin, and an untreated control group. Fecal and blood samples were taken from each animal on days 18, 38 and 68 after start of treatment. A significant reduction in number of H. contortus larvae (p<0.01) was observed for animals in the homeopathic treatment group compared to the control group. Fecal egg counts showed negative correlation between haematocrit and haemoglobin concentrations in the homeopathic treatment group (p<0.01); however, the biochemical and immunological parameters showed better correlation, indicating that the homeopathic medicine improved vital functions. Daily weight gain in the homeopathic treatment group was superior to the control and to the antihelminthic groups, 31 and 6.5%, respectively. The cost benefit analysis confirmed that homeopathy group increases economic trend when compared with the other groups.

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