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Strongyloidiasis is a neglected tropical disease caused mainly by Strongyloides stercoralis, a nematode that can persist for decades in the human host with a very low parasitic burden and without specific symptoms. Hence, it is difficult to diagnose and control. Larval concentration and culture methods with fecal samples show higher sensitivity for the diagnosis of Strongyloides-infected individuals; however, these techniques are not routinely used, primarily due to the challenges associated with processing a substantial volume of fecal samples. In the current study, we comparatively evaluated the sensitivity and applicability of modifications made to the Rugai parasitological method for the diagnosis of strongyloidiasis in fecal samples of experimentally infected rats and in 68 individuals from an urban community close to Maceió, Brazil. The presence and quantity of parasite larvae in the feces were comparatively evaluated using different parasitological techniques. In the experimental model, we demonstrated that the modified Rugai technique (RMOD) allowed for significantly higher recovery of larvae than the original Rugai technique (RO). Moreover, the sediment was cleaner and easier to evaluate using optical microscopy. Compared to other parasitological techniques, such as agar-plate culture (A-PC) and spontaneous sedimentation (SS), the RMOD technique showed higher sensitivity in the detection of larvae in all infected groups and presented comparatively better performance, especially in rats with a low parasite burden. In the human population, among the 68 stool samples evaluated, Strongyloides larvae were detected in the feces of six individuals with an estimated prevalence of 8.82%. However, the performance of each parasitological method was remarkably different. SS identified Strongyloides larvae in only two individuals and A-PC in three, whereas RMOD was able to identify six infected individuals, resulting in sensitivities of 33.3%, 50%, and 100%, respectively. In conclusion, the modifications introduced to the Rugai technique resulted in improved sensitivity for the detection of Strongyloides spp. infections, especially in stool samples with a low parasite burden, in comparison with other routinely used parasitological techniques.

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Cryptococcosis is a systemic mycosis that causes pneumonia and meningoencephalitis. Strongyloidiasis is a chronic gastrointestinal infection caused by parasites of the genus Strongyloides. Cryptococcosis and strongyloidiasis affect the lungs and are more prevalent in the same world regions, i.e., Africa and tropical countries such as Brazil. It is undeniable that those coincidences may lead to the occurrence of coinfections. However, there are no studies focused on the interaction between Cryptococcus spp. and Strongyloides spp. In this work, we aimed to investigate the interaction between Strongyloides venezuelensis (Sv) and Cryptococcus gattii (Cg) in a murine coinfection model. Murine macrophage exposure to Sv antigens reduced their ability to engulf Cg and produce reactive oxygen species, increasing the ability of fungal growth intracellularly. We then infected mice with both pathogens. Sv infection skewed the host's response to fungal infection, increasing lethality in a murine coinfection model. In addition to increased NO levels and arginase activity, coinfected mice presented a classic Th2 anti-Sv response: eosinophilia, higher levels of alternate activated macrophages (M2), increased concentrations of CCL24 and IL-4, and lower levels of IL-1ß. This milieu favored fungal growth in the lungs with prominent translocation to the brain, increasing the host's tissue damage. In conclusion, our data shows that primary Sv infection promotes Th2 bias of the pulmonary response to Cg-infection and worsens its pathological outcomes.

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Human schistosomiasis is caused by helminths of the genus Schistosoma. Macrophages play a crucial role in the immune regulation of this disease. These cells acquire different phenotypes depending on the type of stimulus they receive. M1 macrophages can be 'classically activated' and can display a proinflammatory phenotype. M2 or 'alternatively activated' macrophages are considered anti-inflammatory cells. Despite the relevance of macrophages in controlling infections, the role of the functional types of these cells in schistosomiasis is unclear. This review highlights different molecules and/or macrophage activation and polarization pathways during Schistosoma mansoni and Schistosoma japonicum infection. This review is based on original and review articles obtained through searches in major databases, including Scopus, Google Scholar, ACS, PubMed, Wiley, Scielo, Web of Science, LILACS and ScienceDirect. Our findings emphasize the importance of S. mansoni and S. japonicum antigens in macrophage polarization, as they exert immunomodulatory effects in different stages of the disease and are therefore important as therapeutic targets for schistosomiasis and in vaccine development. A combination of different antigens can provide greater protection, as it possibly stimulates an adequate immune response for an M1 or M2 profile and leads to host resistance; however, this warrants in vitro and in vivo studies.

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Wild rodent species are naturally infected by Schistosoma mansoni; however, the genetic characterization of the parasite, its parasitological features, and its role in human schistosomiasis are poorly understood. In this study, we isolated and characterized Schistosoma from naturally infected Holochilus sciureus, called HS strain, collected from a schistosomiasis endemic region in Maranhão State, Brazil. To isolate the parasite, miracidia obtained from the livers of H. sciureus were used to infect Biomphalaria glabrata of sympatric (called SB) and allopatric (called BH) strains, and the produced cercariae were subcutaneously inoculated into hamsters and/or BALB/c mice. Parasitological kinetics in experimentally infected hosts were evaluated, and the tRNACys-12S (referred to as 16S herein) and cox 1 regions of mtDNA from isolated worms were amplified and sequenced. Only miracidia obtained from infected mice, but not from hamsters, were capable of infecting B. glabrata, allowing maintenance of the isolated parasite. Cox1 and 16S mtDNA sequences showed 100% similarity with S. mansoni, and phylogenetic analysis showed that the HS strain of S. mansoni forms an assemblage with isolates from America and Kenya, confirming the conspecificity. Experimental infection of B. glabrata SB with S. mansoni HS resulted in two peaks of cercariae shedding at 45 and 70 days post-infection (dpi) and caused higher mortality than in B. glabrata BH. The worm recovery rate in mice was approximately 13%, and the peak of egg elimination occurred at the 10th week post-infection. Therefore, S. mansoni obtained from H. sciureus was successfully isolated, genetically characterized, and maintained in mice, allowing further study of this schistosome strain.

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Praziquantel (PZQ) is the drug of choice for the treatment of all forms of schistosomiasis, although its mechanisms of action are not completely understood. PZQ acts largely on adult worms. This narrative literature review describes what is known about the mechanisms of action of PZQ against schistosomes from in vitro and in vivo studies and highlights the molecular targets in parasites and immune responses induced in definitive hosts by this drug. Moreover, new therapeutic uses of PZQ are discussed. Studies have demonstrated that in addition to impacting voltage-operated Ca2 + channels, PZQ may interact with other schistosome molecules, such as myosin regulatory light chain, glutathione S-transferase, and transient receptor potential channels. Following PZQ administration, increased T regulatory type 1 (Tr1) cell differentiation and decreased inflammation were observed, indicating that PZQ promotes immunoregulatory pathways. Although PZQ is widely used in mass drug administration schemes, the existence of resistant parasites has not been proven; however, it is a concern that should be constantly investigated in human populations. In addition, we discuss studies that evaluate health applications of PZQ (other than helminth infection), such as its effect in cancer therapy and its adjuvant action in vaccines against viruses.

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Wild mammals, especially rodents, can participate in the life cycle of Schistosoma mansoni; however, the impact of these parasite strains on the severity of schistosomiasis remains unclear. The aim of this study was to comparatively evaluate the parasitological and immunopathological alterations induced by an S. mansoni strain isolated from the wild rodent Holochilus sciureus (HS strain) and a parasite strain isolated from a human (LE strain) in experimentally infected mice. Male BALB/c mice were subcutaneously infected with 50 cercariae/mouse of either the HS or the LE strain and were evaluated for 12 weeks. In the experimental groups, the parasite burden was estimated by worm and egg (feces and tissues) count, and immunopathological alterations were evaluated in the liver and intestines. Compared to experimental infection with the LE parasite strain, HS-infected mice showed reduced number of parasite worms but higher fecundity rate, significant reduction in IL-5, IL-10 and IL-13 concentrations, lower EPO-activity in liver homogenate and higher concentrations of TNF-α, IFN-γ, IL-12 and IL-17 in the small intestine homogenate. Moreover, HS infection resulted in higher concentrations of NO end-products in both the liver and intestine, suggesting a predominance of the Th1/Th17 immune response. HS-infected mice also showed higher plasma transaminase levels, formed larger granulomas, and had a higher mortality rate in comparison with LE-infected mice. Data indicate that BALB/c mice infected with the HS strain of S. mansoni showed reduced susceptibility to the parasite but stronger tissue inflammation and high disease severity.

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Schistosomiasis is a neglected tropical disease that affects millions of people around the world. Currently, the only drug available for the treatment of this disease is praziquantel, which has low efficacy against immature helminth stages and there are reports of drug resistance. In this study, the chemical composition and the in vitro effect of essential oils (EOs) and major compounds from Lippia gracilis and Lippia alba against schistosomula and adult Schistosoma mansoni worms were evaluated. Adult S. mansoni worms cultured for 8h in the presence of L. gracilis EO (50 and 100 µg/mL) or for 2h with its major compound, carvacrol (100 µg/mL), had a 100% reduction in viability. After interaction with L. alba EO (100µg/mL), there was a reduction of approximately 60% in the viability of adult worms after 24 hours of exposure; citral (50 and 100 µg/mL), its major compound, reduced the viability after 24 hours by more than 75%. Treatment of schistosomula with 100 µg/mL of L. gracilis or L. alba EOs for 6h led to a reduction in parasite viability of 80% and 16% respectively. Both EOs and their major compounds significantly reduced the oviposition of adult worms exposed to a non-lethal concentration (5 µg/mL). In addition, morphological changes such as the destruction of the tegument and disorganization of the reproductive system of male and female worms were visualized. Both EOs showed low cytotoxicity at a concentration of 50 µg/mL. The results encourage further investigation of these plants as a potential source of bioactive compounds against S. mansoni.

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The present study aimed to evaluate the changes in peripheral blood glucose concentrations induced by Schistosoma mansoni infection in Holochilus sciureus rodents, a wild reservoir of the parasite. Glucose concentration was measured in the plasma of blood samples using a colorimetric enzymatic test. Biological parameters and S. mansoni burden in each rodent were also verified and correlated with glucose concentrations. A total of 76 H. sciureus were captured, out of which 20 (26%) were infected with S. mansoni (n=13 males and n=7 females). Although the parasite burden was comparable between the sexes, blood glucose concentration was lower in infected males and almost unchanged in females. Furthermore, histopathological data revealed that male rodents had a greater hepatic granulomatous inflammatory reaction than females. In addition, we also confirmed that the weight and total length of the analyzed animals had no effect on glucose levels. Therefore, natural infection with S. mansoni in H. sciureus may have a lower impact on glycemic homeostasis in females, which will help us understand the role of these rodents as reservoirs of S. mansoni.

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The present study aimed to evaluate the changes in peripheral blood glucose concentrations induced by Schistosoma mansoni infection in Holochilus sciureus rodents, a wild reservoir of the parasite. Glucose concentration was measured in the plasma of blood samples using a colorimetric enzymatic test. Biological parameters and S. mansoni burden in each rodent were also verified and correlated with glucose concentrations. A total of 76 H. sciureus were captured, out of which 20 (26%) were infected with S. mansoni (n=13 males and n=7 females). Although the parasite burden was comparable between the sexes, blood glucose concentration was lower in infected males and almost unchanged in females. Furthermore, histopathological data revealed that male rodents had a greater hepatic granulomatous inflammatory reaction than females. In addition, we also confirmed that the weight and total length of the analyzed animals had no effect on glucose levels. Therefore, natural infection with S. mansoni in H. sciureus may have a lower impact on glycemic homeostasis in females, which will help us understand the role of these rodents as reservoirs of S. mansoni.(AU)

Neste presente estudo, objetivou-se avaliar as alterações induzidas pela infecção natural de Schistosoma mansoni nas concentrações de glicose do sangue periférico de roedores Holochilus sciureus, reservatório silvestre do parasito. A dosagem da concentração de glicose foi realizada no plasma de amostras de sangue por meio de teste enzimático colorimétrico. Parâmetros biológicos e carga parasitária de S. mansoni também foram verificados em cada roedor e correlacionados com as concentrações de glicose. Um total de 76 H. sciureus foram capturados, dentre os quais 20 (26%) estavam infectados por S. mansoni (n=13 machos e n=7 fêmeas). Apesar da carga parasitária ter sido semelhante entre os sexos, as concentrações de glicose no sangue foram menores em machos naturalmente infectados e quase inalteradas em fêmeas. Além disso, os dados histopatológicos mostraram uma maior reação inflamatória granulomatosa hepática em roedores machos, quando comparados com as fêmeas. Adicionalmente, também foi confirmado que o peso e o comprimento total dos animas analisados não interferiram nos valores de glicose. Portanto, a infecção natural por S. mansoni em H. sciureus pode induzir menos impacto na homeostase glicêmica em fêmeas, o que pode ajudar a melhor entender o papel desses roedores como reservatórios de S. mansoni.(AU)

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INTRODUCTION: Curtailing the development of the aquatic immature stages of Aedes aegypti is one of the main measures to limit their spread and the diseases transmitted by them. The use of plant extracts is a promising approach in the development of natural insecticides. Thus, this research aimed to characterize the inhibitory effect of the hydroalcoholic extract of Caryocar brasiliense leaves on the emergence of adult A. aegypti and the main substances that constitute this extract. METHODS: C. brasiliense leaf extract was prepared by ethanol (70%) extraction. Bioassays using L3 larvae were performed at concentrations of 200, 300, 400, and 500 ppm. We identified the major secondary metabolites present in this extract, and performed toxicity tests on an off-target organism, Danio rerio. RESULTS: We observed a significant delay in the development of A. aegypti larvae mainly at a concentration of 500 ppm, and estimated an emergence inhibition for 50% of the population of 150 ppm. Moreover, the C. brasiliense leaf extracts exhibited low toxicity in D. rerio. The main compounds found in the extract were quercetin, violaxanthin, myricetin3-O-hexoside, methyl-elagic-3-arabinose acid, and isoquercitrin. CONCLUSIONS: Herein, we demonstrate the inhibition of mosquito development by the hydroalcoholic extract of C. brasiliense and suggest substances that may act as active principles.

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Efficient snail production is essential for the proper maintenance of the Schistosoma mansoni life cycle in the laboratory. In order to improve the breeding of Biomphalaria glabrata under laboratory conditions, this study aimed to demonstrate the effectiveness of a handmade shell-based substrate on the physiological performance of B. glabrata. The shells used to make the substrate were cleaned, sterilized and macerated until a powder was obtained (yield of 92.3%). B. glabrata specimens were randomly assigned to three treatment groups: negative control group (NCG) exposed to a clay-only substrate; a positive control group (PCG) containing clay, oyster flour and calcium carbonate; and the test group (TG) with the shell-based substrate and clay. B. glabrata bred in the test group showed improved growth, sexual maturity, fertility, mortality rate, and shell morphology when compared to the NCG, and similar to the PCG. Therefore, the shell-based substrate proved to be efficient and has a low cost for the breeding of B. glabrata.

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Abstract INTRODUCTION: Curtailing the development of the aquatic immature stages of Aedes aegypti is one of the main measures to limit their spread and the diseases transmitted by them. The use of plant extracts is a promising approach in the development of natural insecticides. Thus, this research aimed to characterize the inhibitory effect of the hydroalcoholic extract of Caryocar brasiliense leaves on the emergence of adult A. aegypti and the main substances that constitute this extract. METHODS: C. brasiliense leaf extract was prepared by ethanol (70%) extraction. Bioassays using L3 larvae were performed at concentrations of 200, 300, 400, and 500 ppm. We identified the major secondary metabolites present in this extract, and performed toxicity tests on an off-target organism, Danio rerio. RESULTS: We observed a significant delay in the development of A. aegypti larvae mainly at a concentration of 500 ppm, and estimated an emergence inhibition for 50% of the population of 150 ppm. Moreover, the C. brasiliense leaf extracts exhibited low toxicity in D. rerio. The main compounds found in the extract were quercetin, violaxanthin, myricetin3-O-hexoside, methyl-elagic-3-arabinose acid, and isoquercitrin. CONCLUSIONS: Herein, we demonstrate the inhibition of mosquito development by the hydroalcoholic extract of C. brasiliense and suggest substances that may act as active principles.

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INTRODUCTION: The occurrence of wild rodents in the Schistosoma mansoni life cycle may increase the transmission of schistosomiasis and understanding the spatial and seasonal distribution of the natural infection of these reservoirs is essential for the development of more effective control strategies. MATERIAL AND METHODS: In this study, Holochilus sciureus rodents were captured from the flooded fields of São Bento city (an endemic area for schistosomiasis in Northeast Brazil), during the dry and rainy seasons. All these sites were georeferenced and the prevalence of S. mansoni was verified by the presence of adult worms in the mesenteric branches and livers of each animal. RESULTS: It was demonstrated that almost half of the animals collected were naturally infected with S. mansoni (45.45%) and this infection was not related to the distance from urban areas. Furthermore, the temperature, precipitation, sex, and weight did not interfere with the H. sciureus infection rates. Interestingly, we found, for the first time, the natural infection of H. sciureus in another endemic city of S. mansoni in Northeast Brazil. CONCLUSIONS: Therefore, the H. sciureus rodent shows a high natural infection rate for S. mansoni in the flooded fields of São Bento, regardless of the weather station, capture distance, and biological aspects. Additionally, we have demonstrated that H. sciureus naturally parasitized with S. mansoni may inhabit a much more extensive area that is currently described in the literature.

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Neste estudo, objetivou-se mapear os criadouros de Biomphalaria spp., transmissoras da esquistossomose mansoni, presentes no município de São Bento, localizado na região da Baixada Maranhense, área na qual esta doença é endêmica. Foram visitados 16 dos 22 bairros existentes na cidade durante o período de agosto de 2012 a julho de 2013. Os caramujos foram coletados com auxílio de conchas de captura e pinças, armazenados e transportados para o Laboratório de Parasitologia Humana da Universidade Estadual do Maranhão, em São Luís, onde foram acondicionados em aquários de vidro e alimentados com folhas de alface. Os moluscos foram submetidos à análise parasitológica à procura de estágios larvais de Schistosoma mansoni e identificados pela conquiliologia e por meio de dissecções. Em 18 criadouros mapeados foram obtidos 1.195 exemplares de Biomphalaria glabrata e de B. straminea. Nenhum molusco eliminou cercárias de S. mansoni. Considerando os resultados obtidos e os aspectos epidemiológicos relacionados à transmissão da esquistossomose, o mapeamento das espécies vetoras no município permitirá a localização e identificação dos criadouros, o que poderá auxiliar substancialmente os serviços de saúde locais nas atividades de vigilância e controle da esquistossomose, além de nortear futuros estudos epidemiológicos sobre a esquistossomose mansoni na região da Baixada Maranhense

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Abstract In the present study, we aimed to analyze the reproductive aspects (seasonal period and number of embryos) and positivity for S. mansoni in rodent of Holochilus gender, in São Bento - MA. For this, monthly captures of up to 10 Holochilus sp. rodents were conducted, randomly for sex, taking notes of the seasonal period of São Bento in each month of capture. At the laboratory, rodents had feces analyzed for S. mansoni infection by Kato-Katz method. After the analysis, they were adequately anesthetized for obtaining full length, weight and sex determination. In females, an incision of the ventral portion of the body was carried out to verify the presence of embryos and to count them. Among the captured rodents, there was male dominance in almost all months and they tended to be heavier and had larger bodies than the females. The animals showed high reproductive potential. The positivity for S. mansoni and the reproduction of Holochilus sp. were greater in the rainy season of São Bento. As for the number of embryos, we observed that, in the rainy season, more males were found than female. In short, the intense reproductive activity, along the susceptibility to S. mansoni presented by rodents are factors that help to maintain and aggravate schistosomiasis in Baixada Maranhense.

Resumo Neste estudo objetivou-se analisar os aspectos reprodutivos (período estacional e quantidade de embriões) e a positividade para S. mansoni em roedores do gênero Holochilus, no município de São Bento - MA. Para isso, foram realizadas capturas mensais de até 10 roedores Holochilus sp., aleatoriamente quanto ao sexo, anotando-se o período estacional do município de São Bento nos meses de captura. Em laboratório, os roedores tiveram as fezes analisadas quanto à positividade para S. mansoni pelo método Kato-Katz. Após a análise, os animais foram anestesiados para a obtenção do comprimento total, peso corporal e determinação do sexo. Nas fêmeas, foi realizada a incisão da porção ventral do corpo, para a verificação da presença de embriões e contagem dos mesmos. Dentre os roedores capturados, ocorreu dominância de machos em quase todos os meses e eles tenderam a ser mais pesados e apresentaram maior porte que as fêmeas. Os animais mostraram elevado potencial reprodutivo. A positividade para S. mansoni e a reprodução dos Holochilus sp. foram maiores no período chuvoso de São Bento. Quanto ao número de embriões, constatou-se que, no período chuvoso, foram encontrados em maior quantidade por fêmea. Em suma, a intensa atividade reprodutiva juntamente à suscetibilidade para S. mansoni apresentada pelos roedores são fatores que ajudam na manutenção e agravam a esquistossomose na Baixada Maranhense.

RESUMO

In the present study, we aimed to analyze the reproductive aspects (seasonal period and number of embryos) and positivity for S. mansoni in rodent of Holochilus gender, in São Bento - MA. For this, monthly captures of up to 10 Holochilus sp. rodents were conducted, randomly for sex, taking notes of the seasonal period of São Bento in each month of capture. At the laboratory, rodents had feces analyzed for S. mansoni infection by Kato-Katz method. After the analysis, they were adequately anesthetized for obtaining full length, weight and sex determination. In females, an incision of the ventral portion of the body was carried out to verify the presence of embryos and to count them. Among the captured rodents, there was male dominance in almost all months and they tended to be heavier and had larger bodies than the females. The animals showed high reproductive potential. The positivity for S. mansoni and the reproduction of Holochilus sp. were greater in the rainy season of São Bento. As for the number of embryos, we observed that, in the rainy season, more males were found than female. In short, the intense reproductive activity, along the susceptibility to S. mansoni presented by rodents are factors that help to maintain and aggravate schistosomiasis in Baixada Maranhense(AU)

Neste estudo objetivou-se analisar os aspectos reprodutivos (período estacional e quantidade de embriões) e a positividade para S. mansoni em roedores do gênero Holochilus, no município de São Bento MA. Para isso, foram realizadas capturas mensais de até 10 roedores Holochilus sp., aleatoriamente quanto ao sexo, anotando-se o período estacional do município de São Bento nos meses de captura. Em laboratório, os roedores tiveram as fezes analisadas quanto à positividade para S. mansoni pelo método Kato-Katz. Após a análise, os animais foram anestesiados para a obtenção do comprimento total, peso corporal e determinação do sexo. Nas fêmeas, foi realizada a incisão da porção ventral do corpo, para a verificação da presença de embriões e contagem dos mesmos. Dentre os roedores capturados, ocorreu dominância de machos em quase todos os meses e eles tenderam a ser mais pesados e apresentaram maior porte que as fêmeas. Os animais mostraram elevado potencial reprodutivo. A positividade para S. mansoni e a reprodução dos Holochilus sp. foram maiores no período chuvoso de São Bento. Quanto ao número de embriões, constatou-se que, no período chuvoso, foram encontrados em maior quantidade por fêmea. Em suma, a intensa atividade reprodutiva juntamente à suscetibilidade para S. mansoni apresentada pelos roedores são fatores que ajudam na manutenção e agravam a esquistossomose na Baixada Maranhense(AU)

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In the present study, we aimed to analyze the reproductive aspects (seasonal period and number of embryos) and positivity for S. mansoni in rodent of Holochilus gender, in São Bento - MA. For this, monthly captures of up to 10 Holochilus sp. rodents were conducted, randomly for sex, taking notes of the seasonal period of São Bento in each month of capture. At the laboratory, rodents had feces analyzed for S. mansoni infection by Kato-Katz method. After the analysis, they were adequately anesthetized for obtaining full length, weight and sex determination. In females, an incision of the ventral portion of the body was carried out to verify the presence of embryos and to count them. Among the captured rodents, there was male dominance in almost all months and they tended to be heavier and had larger bodies than the females. The animals showed high reproductive potential. The positivity for S. mansoni and the reproduction of Holochilus sp. were greater in the rainy season of São Bento. As for the number of embryos, we observed that, in the rainy season, more males were found than female. In short, the intense reproductive activity, along the susceptibility to S. mansoni presented by rodents are factors that help to maintain and aggravate schistosomiasis in Baixada Maranhense

Neste estudo objetivou-se analisar os aspectos reprodutivos (período estacional e quantidade de embriões) e a positividade para S. mansoni em roedores do gênero Holochilus, no município de São Bento MA. Para isso, foram realizadas capturas mensais de até 10 roedores Holochilus sp., aleatoriamente quanto ao sexo, anotando-se o período estacional do município de São Bento nos meses de captura. Em laboratório, os roedores tiveram as fezes analisadas quanto à positividade para S. mansoni pelo método Kato-Katz. Após a análise, os animais foram anestesiados para a obtenção do comprimento total, peso corporal e determinação do sexo. Nas fêmeas, foi realizada a incisão da porção ventral do corpo, para a verificação da presença de embriões e contagem dos mesmos. Dentre os roedores capturados, ocorreu dominância de machos em quase todos os meses e eles tenderam a ser mais pesados e apresentaram maior porte que as fêmeas. Os animais mostraram elevado potencial reprodutivo. A positividade para S. mansoni e a reprodução dos Holochilus sp. foram maiores no período chuvoso de São Bento. Quanto ao número de embriões, constatou-se que, no período chuvoso, foram encontrados em maior quantidade por fêmea. Em suma, a intensa atividade reprodutiva juntamente à suscetibilidade para S. mansoni apresentada pelos roedores são fatores que ajudam na manutenção e agravam a esquistossomose na Baixada Maranhense

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The occurrence of non-human mammals such as schistosomiasis reservoir has always been an aggravating factor to be studied. Family cricetidae rodents like Nectomys sp, seem to have an important role in the potentiation of the spread of it. However, for Holochilus sp. (Rodentia: Cricetidae), found in Maranhão, studies with this function seem scarce. Thereby, we aimmed to analyze the infection rate of these animals for S. mansoni in São Bento MA, endemic area for the parasite. These rodents were monitored during 12 months, by the Tomahawk traps for caught and triplicates of stool tests blades, made by KatoKatz kit, for parasitogical exam. A total of 101 rodents were captured, of which 28.7% were naturally infected by S. mansoni (17.3% females and 82.7% males). This analysis showed that an average of 2.4 rodents was infected for one year, being possible to find positive animals in almost all the collects. Therefore, the rodent Holochilus sp. is a potential candidate in ensuring the maintenance of the schistosomiasis cycle in the region under study.(AU)

A ocorrência de mamíferos não humanos como reservatório da esquistossomose sempre foi um fator agravante a ser estudado. Roedores da família dos cricetídeos, como o Nectomys sp, parecem  desempenhar importante papel na potencialização da disseminação da mesma. No entanto, para Holochilus sp (Rodentia: Cricetidae), encontrado no  Maranhão, estudos com essa finalidade parecem pouco elucidativos. Desse modo, objetivou-se analisar o índice de infecção desses animais por S. mansoni na cidade de São Bento MA, área endêmica para o parasito. Para tanto, foi realizado um monitoramento desses roedores durante 12 meses, através de armadilhas do tipo Tomahawk para captura e triplicatas de lâminas cropológicas, confeccionadas por meio do kit Kato-Katz, para exame parasitológico. Foram contabilizados um total de 101 roedores, sendo que 28,7% apresentaram- se naturalmente infectados para S. mansoni, (17,3% fêmeas e 82,7% machos).  Tal análise evidenciou que, por mês, uma média de 2,4 roedores estavam infectados para o período de um ano. Sendo possível encontrar animais positivos em quase todas as coletas. Portanto, o roedor Holochilus sp. é um possível candidato à manutenção do ciclo da esquistossomose na região em estudo.(AU)

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RESUMO

title>Abstract /title> p>The occurrence of non-human mammals such as schistosomiasis reservoir has always been an aggravating factor to be studied. Family cricetidae rodents like Nectomys sp, seem to have an important role in the potentiation of the spread of it. However, for italic>Holochilus sp /italic>. (Rodentia: Cricetidae), found in Maranhão, studies with this function seem scarce. Thereby, we aimmed to analyze the infection rate of these animals for S. mansoni in São Bento - MA, endemic area for the parasite. These rodents were monitored during 12 months, by the Tomahawk traps for caught and triplicates of stool tests blades, made by Kato-Katz kit, for parasitogical exam. A total of 101 rodents were captured, of which 28.7% were naturally infected by italic>S. mansoni /italic> (17.3% females and 82.7% males). This analysis showed that an average of 2.4 rodents was infected for one year, being possible to find positive animals in almost all the collects. Therefore, the rodent Holochilus sp. is a potential candidate in ensuring the maintenance of the schistosomiasis cycle in the region under study. /p>

title>Resumo /title> p>A ocorrência de mamíferos não humanos como reservatório da esquistossomose sempre foi um fator agravante a ser estudado. Roedores da família dos cricetídeos, como o italic>Nectomys /italic> sp, parecem desempenhar importante papel na potencialização da disseminação da mesma. No entanto, para italic>Holochilus /italic> sp (Rodentia: italic>Cricetidae), /italic>encontrado no Maranhão, estudos com essa finalidade parecem pouco elucidativos. Desse modo, objetivou-se analisar o índice de infecção desses animais por italic>S. mansoni /italic> na cidade de São Bento - MA, área endêmica para o parasito. Para tanto, foi realizado um monitoramento desses roedores durante 12 meses, através de armadilhas do tipo Tomahawk para captura e triplicatas de lâminas cropológicas, confeccionadas por meio do kit Kato-Katz, para exame parasitológico. Foram contabilizados um total de 101 roedores, sendo que 28,7% apresentaram- se naturalmente infectados para italic>S. mansoni, /italic>(17,3% fêmeas e 82,7% machos). Tal análise evidenciou que, por mês, uma média de 2,4 roedores estavam infectados para o período de um ano. Sendo possível encontrar animais positivos em quase todas as coletas. Portanto, o roedor italic>Holochilus /italic> sp. é um possível candidato à manutenção do ciclo da esquistossomose na região em estudo. /p>

RESUMO

The occurrence of non-human mammals such as schistosomiasis reservoir has always been an aggravating factor to be studied. Family cricetidae rodents like Nectomys sp, seem to have an important role in the potentiation of the spread of it. However, for Holochilus sp. (Rodentia: Cricetidae), found in Maranhão, studies with this function seem scarce. Thereby, we aimmed to analyze the infection rate of these animals for S. mansoni in São Bento MA, endemic area for the parasite. These rodents were monitored during 12 months, by the Tomahawk traps for caught and triplicates of stool tests blades, made by KatoKatz kit, for parasitogical exam. A total of 101 rodents were captured, of which 28.7% were naturally infected by S. mansoni (17.3% females and 82.7% males). This analysis showed that an average of 2.4 rodents was infected for one year, being possible to find positive animals in almost all the collects. Therefore, the rodent Holochilus sp. is a potential candidate in ensuring the maintenance of the schistosomiasis cycle in the region under study.

A ocorrência de mamíferos não humanos como reservatório da esquistossomose sempre foi um fator agravante a ser estudado. Roedores da família dos cricetídeos, como o Nectomys sp, parecem  desempenhar importante papel na potencialização da disseminação da mesma. No entanto, para Holochilus sp (Rodentia: Cricetidae), encontrado no  Maranhão, estudos com essa finalidade parecem pouco elucidativos. Desse modo, objetivou-se analisar o índice de infecção desses animais por S. mansoni na cidade de São Bento MA, área endêmica para o parasito. Para tanto, foi realizado um monitoramento desses roedores durante 12 meses, através de armadilhas do tipo Tomahawk para captura e triplicatas de lâminas cropológicas, confeccionadas por meio do kit Kato-Katz, para exame parasitológico. Foram contabilizados um total de 101 roedores, sendo que 28,7% apresentaram- se naturalmente infectados para S. mansoni, (17,3% fêmeas e 82,7% machos).  Tal análise evidenciou que, por mês, uma média de 2,4 roedores estavam infectados para o período de um ano. Sendo possível encontrar animais positivos em quase todas as coletas. Portanto, o roedor Holochilus sp. é um possível candidato à manutenção do ciclo da esquistossomose na região em estudo.

Assuntos