Erlei Cassiano Keppeler

Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier

Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county) to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003–2013) was divided into two phases (epidemic and post-epidemic). Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011–2012) and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39). These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region.

Contribution of fish farming ponds to the production of immature Anopheles spp. in a malaria-endemic Amazonian town

BackgroundIn the past decade fish farming has become an important economic activity in the Occidental Brazilian Amazon, where the number of new fish farms is rapidly increasing. One of the primary concerns with this phenomenon is the contribution of fishponds to the maintenance and increase of the anopheline mosquito population, and the subsequent increase in human malaria burden. This study reports the results of a 2-year anopheline abundance survey in fishponds and natural water bodies in a malaria-endemic area in northwest Brazil. The objective of this study was to investigate the contribution of natural water bodies (rivers, streams, creeks, ponds, and puddles) and artificial fishponds as breeding sites for Anopheles spp. in Mâncio Lima, Acre and to investigate the effect of limnological and environmental variables on Anopheles spp. larval abundance.MethodsNatural water bodies and fishponds were sampled at eight different times over 2 years (early, mid and late rainy season, dry season) in the Amazonian town of Mâncio Lima, Acre. Anopheline larvae were collected with an entomological dipper, and physical, chemical and ecological characteristics of each water body were measured. Management practices of fishpond owners were ascertained with a systematic questionnaire.ResultsFishponds were four times more infested with anopheline larvae than natural water bodies. Electrical conductivity and the distance to the nearest house were both significant inverse predictors of larval abundance in natural water bodies. The density of larvae in fishponds raised with increasing border vegetation. Fishponds owned by different farmers varied in the extent of anopheline larval infestation but ponds owned by the same individual had similar infestation patterns over time. Commercial fishponds were 1.7-times more infested with anopheline larvae compared to fishponds for family use.ConclusionsThese results suggest that fishponds are important breeding sites for anopheline larvae, and that adequate management activities, such as removal of border vegetation could reduce the abundance of mosquito larvae, most importantly Anopheles darlingi.

Spatial distribution of the rotifers community in fishponds in Cruzeiro do Sul - Acre State

Os rotiferos sao organismos microscopicos e representam um dos mais importantes grupos da comunidade zooplanctonica, nao apenas pela riqueza de especies, mas tambem pela abundância dos organismos. A situacao hipotetica para a realizacao desta pesquisa consiste em verificar se a distribuicao espacial da comunidade de rotiferos e heterogenea e se ha diversidade de organismos em tanques de piscicultura em Cruzeiro do Sul. Os tanques selecionados foram agrupados, considerando o zooplâncton, atraves da analise de cluster utilizando dissimilaridade, e ainda sobre a comunidade foram aplicados tambem os indices de diversidade e riqueza. Os resultados nao revelaram agrupamento significativo para os tanques; cada sistema apresentou sua peculiaridade. Abstract Rotifers are microscopic organisms that present themselves as one of most significant groups of the zooplankton community, not only by species richness, but also by the numerical abundance. A hypothetical situation for this research is whether the spatial distribution of the rotifer community in fishponds is heterogeneous and has organism’s diversity in Cruzeiro do Sul is heterogeneous. The selected tanks were grouped, considering the zooplankton by cluster analysis using dissimilarity multivariate analysis, as well as on the community has been applied also the diversity and richness indexes. The results revealed no significant clustering for tanks, with each system its peculiarity.