Verônica Santos Barbosa

Criadouros de Biomphalaria, temporários e permanentes, em Jaboatão dos Guararapes, PE

A malacological survey of permanent and temporary breeding sites was conducted in the Piedade neighborhood of Jaboatão dos Guararapes, Pernambuco, between November 2006 and November 2007, with the aim of determining the malacological fauna at this locality, along with the potential for Schistosomiasis mansoni transmission. In addition to Biomphalaria glabrata (Say, 1818), the molluscs Drepanotrema cimex (Moricand, 1837), Pomacea sp and Melanoides tuberculatus (Muller, 1774) were collected. Among the specimens of Biomphalaria glabrata that were collected, 1,490 were found alive, and 74 (5%) were positive for Schistosoma mansoni. The largest numbers of molluscs collected, and all of the specimens that were positive for Schistosoma mansoni, were collected during the annual rainy season. The presence of larvae of other trematodes infecting the Biomphalaria glabrata molluscs was also observed. These trematodes were from the families Strigeidae and Diplostomatidae and, at first sight, they presented morphology that could lead to confusion with Schistosoma mansoni cercariae. Thus, knowledge of these trematodes becomes essential for the differential diagnosis of the etiological agent for schistosomiasis.

Aspectos ecológicos e levantamento malacológico para identificação de áreas de risco para transmissão da esquistossomose mansoni no litoral norte de Pernambuco, Brasil

Realizou-se levantamento malacologico na praia de Carne de Vaca, municipio de Goiana, litoral norte de Pernambuco, entre novembro de 2006 e outubro de 2007, com o objetivo de conhecer a fauna malacologica dessa localidade e verificar as condicoes naturais, pouco ou bastante alteradas das areas de estudo atraves da aplicacao de um protocolo de avaliacao de diversidade de habitats. Foram coletados 5.912 moluscos, representados por sete especies e quatro familias, dos quais, 5.209 exemplares de Biomphalaria glabrata (Say, 1818), 113 de Drepanotrema lucidum (Pfeiffer, 1839), 55 de Drepanotrema cimex (Moricand, 1837), 13 de Drepanotrema anatinum (Pfeiffer, 1839), 222 de Melanoides tuberculatus (Muller, 1774), 263 de Pomacea sp. e 37 de Physa marmorata Guilding, 1828. Entre os exemplares de B. glabrata coletados, 44 mostraram-se positivos para Schistosoma mansoni Sambon, 1907 e 91 mostraram-se positivos para outras larvas de trematodeos. Um exemplar de Pomacea sp. mostrou-se positivo para larva de trematodeo. Os dados obtidos, georreferenciados espacialmente, serao utilizados para a determinacao das areas de risco para a transmissao da esquistossomose na praia de Carne de Vaca, alem de simulacoes computacionais para estudos de previsibilidade e comportamento do processo de expansao da esquistossomose no estado de Pernambuco.

Spatial distribution of schistosomiasis and geohelminthiasis cases in the rural areas of Pernambuco, Brazil

INTRODUCTION The prevalence and intensity of geohelminth infections and schistosomiasis remain high in the rural areas of Zona da Mata, Pernambuco (ZMP), Brazil, where these parasites still represent a significant public health problem. The present study aimed to spatially assess the occurrences of schistosomiasis and geohelminthiasis in the ZMP. METHODS The ZMP has a population of 1,132,544 inhabitants, formed by 43 municipalities. An ecological study was conducted, using secondary data relating to positive human cases and parasite loads of schistosomiasis and positive human cases of geohelminthiasis that were worked up in Excel 2007. We used the coordinates of the municipal headquarters to represent the cities which served as the unit of analysis of this study. The Kernel estimator was used to spatially analyze the data and identify distribution patterns and case densities, with analysis done in ArcGIS software. RESULTS Spatial analysis from the Kernel intensity estimator made it possible to construct density maps showing that the northern ZMP was the region with the greatest number of children infected with parasites and the populations most intensely infected by Schistosoma mansoni. In relation to geohelminths, there was higher spatial distribution of cases of Ascaris lumbricoides and Trichuris trichiura in the southern ZMP, and greater occurrence of hookworms in the northern/central ZMP. CONCLUSIONS Despite several surveys and studies showing occurrences of schistosomiasis and geohelminthiasis in the ZMP, no preventive measures that are known to have been effective in decreasing these health hazards have yet been implemented in the endemic area.

Casos autoctones de esquistossomose mansonica em criancas de Recife, PE

OBJECTIVE Investigate breeding sites with host snails and autochthonous human cases of schistosomiasis. METHODS Between July 2010 and September 2012 were performed: (1) malacological survey searching for breeding sites, collection and identification of Biomphalaria snails positive for Schistosoma mansoni in Recife, PE, Northeastern Brazil; (2) prevalence survey in 2,718 schoolchildren aged from seven to 14 years old to identify cases of schistosomiasis, clinical examination and ultrasound in positive cases of S. mansoni. The autochthony of the cases was investigated and the case were clinically evaluated. The cases and breeding sites were georeferenced and spatially described. RESULTS The results identified 30 breeding with B. straminea, four of which were potential foci of transmission, as molecular testing identified snails with S. mansoni DNA. There were 14 children diagnosed with schistosomiasis, of which five were considered to be autochthonous cases of the disease. CONCLUSIONS Urgent measures are required in order to avoid schistosomiasis becoming endemic to Recife, as has happened in other coastal areas of the state of Pernambuco.

An ecological model for quantitative risk assessment for schistosomiasis: the case of a patchy environment in the coastal tropical area of northeastern Brazil.

We developed a stochastic model for quantitative risk assessment for the Schistosoma mansoni (SM) parasite, which causes an endemic disease of public concern. The model provides answers in a useful format for public health decisions, uses data and expert opinion, and can be applied to any landscape where the snail Biomphalaria glabrata is the main intermediate host (South and Central America, the Caribbean, and Africa). It incorporates several realistic and case-specific features: stage-structured parasite populations, periodic praziquantel (PZQ) drug treatment for humans, density dependence, extreme events (prolonged rainfall), site-specific sanitation quality, environmental stochasticity, monthly rainfall variation, uncertainty in parameters, and spatial dynamics. We parameterize the model through a real-world application in the district of Porto de Galinhas (PG), one of the main touristic destinations in Brazil, where previous studies identified four parasite populations within the metapopulation. The results provide a good approximation of the dynamics of the system and are in agreement with our field observations, i.e., the lack of basic infrastructure (sanitation level and health programs) makes PG a suitable habitat for the persistence and growth of a parasite metapopulation. We quantify the risk of SM metapopulation explosion and quasi-extinction and the time to metapopulation explosion and quasi-extinction. We evaluate the sensitivity of the results under varying scenarios of future periodic PZQ treatment (based on the Brazilian Ministry of Healths plan) and sanitation quality. We conclude that the plan might be useful to slow SM metapopulation growth but not to control it. Additional investments in better sanitation are necessary.

Using mobile technology to conduct epidemiological investigations

INTRODUCTION The aim of this study was to report the experience of an epidemiological field survey for which data were collected and analyzed using tablets. METHODS The devices used Epi Info 7 (Android version), which has been modeled a database with variables of the traditional form. RESULTS Twenty-one households were randomly selected in the study area; 75 residents were registered and completed household interviews with socioeconomic and environmental risk variables. CONCLUSIONS This new technology is a valuable tool for collecting and analyzing data from the field, with advantageous benefits to epidemiological surveys.

Modelling of the distribution of Biomphalaria glabrata and Biomphalaria straminea in the metropolitan region of Recife, Pernambuco, Brazil

The occurrence of schistosomiasis is directly linked to the presence of its snail intermediate host Biomphalaria spp. Knowledge of geographical distribution, habitats and behaviour of these snails in relation to the climate is essential for guiding measures for disease prevention and control. This study aims to model the distribution of B. glabrata and B. straminea in schistosomiasis non-endemic areas of the metropolitan region of Recife (MRR) based on environmental data and estimates of snail distributions in endemic and neighbouring areas. We applied Kriging with the aim of determining the spatial distribution of these two snail species and MaxEnt for modelling their ecological behaviour. Kriging showed that the North and the Centre of the MRR were generally either snail-free or contained only B. straminea, while both snail species could be found in the South. MaxEnt supported our observation that the northern and southern coastal regions were favoured by B. glabrata and diurnal mean temperature variation; July rainfall and November rainfall were the three variables favouring Biomphalaria breeding sites that contributed the most in the predictive model we developed. The study showed the location of areas suitable to Biomphalaria spp. and therefore at potential risk, first for invasion of these snails and later for the development of new schistosomiasis- endemic areas. This information should be useful, not only to estimate expansion possibilities of this disease in the MRR, but also to point out the climatic variables that would contribute to this expansion, thereby allowing timely application of prevention and control measures.

First report of schistosomiasis on Serrambi beach, Ipojuca, State of Pernambuco

INTRODUCTION The expansion of schistosomiasis to previously unaffected areas is being monitored by identifying new cases and georeferencing outbreaks of vector snails. METHODS In 2014, the Laboratório de Esquistossomose began an epidemiological survey in Serrambi and registered 2,574 people living there. RESULTS Of these subjects, 1,414 (54.9%) underwent feces examination and 63 (4.5%) were diagnosed with Schistosoma mansoni infection. At this locality, seven breeding sites each were identified for Biomphalaria straminea and Biomphalaria glabrata. At two sites, B. glabrata were shedding cercariae. CONCLUSIONS Implementing preventive measures is necessary to avoid the establishment of schistosomiasis in yet another tourist locality, Pernambuco.

Os Sistemas de Informação Geográfica em estudo sobre a esquistossomose em Pernambuco

OBJETIVO Diagnosticar ambientes de risco para esquistossomose em localidades litorâneas de Pernambuco utilizando tecnicas de geoprocessamento. METODOS Foi realizado inquerito coproscopico e malacologico nas localidades Forte Orange e Serrambi. Foram coletadas variaveis ambientais (temperatura, salinidade, pH, solidos totais dissolvidos e dosagem de coliformes fecais da agua) relacionadas aos criadouros ou focos de Biomphalaria. A analise […]

The Geographic Information System applied to study schistosomiasis in Pernambuco

ABSTRACT OBJECTIVE Diagnose risk environments for schistosomiasis in coastal localities of Pernambuco using geoprocessing techniques. METHODS A coproscopic and malacological survey were carried out in the Forte Orange and Serrambi areas. Environmental variables (temperature, salinity, pH, total dissolved solids and water fecal coliform dosage) were collected from Biomphalaria breeding sites or foci. The spatial analysis was performed using ArcGis 10.1 software, applying the kernel estimator, elevation map, and distance map. RESULTS In Forte Orange, 4.3% of the population had S. mansoni and were found two B. glabrata and 26 B. straminea breeding sites. The breeding sites had temperatures of 25ºC to 41ºC, pH of 6.9 to 11.1, total dissolved solids between 148 and 661, and salinity of 1,000 d. In Serrambi, 4.4% of the population had S. mansoni and were found seven B. straminea and seven B. glabrata breeding sites. Breeding sites had temperatures of 24ºC to 36ºC, pH of 7.1 to 9.8, total dissolved solids between 116 and 855, and salinity of 1,000 d. The kernel estimator shows the clusters of positive patients and foci of Biomphalaria, and the digital elevation map indicates areas of rainwater concentration. The distance map shows the proximity of the snail foci with schools and health facilities. CONCLUSIONS Geoprocessing techniques prove to be a competent tool for locating and scaling the risk areas for schistosomiasis, and can subsidize the health services control actions.