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INTRODUCTION: Leishmaniasis is a complex vector-borne infectious diseases caused by protozoan parasites in the genus Leishmania and spread by hematophagous phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae). The aim of this study was to investigate the phlebotomine fauna, endophily and exophily of the species found, and possible influence of climatic factors on their populations. METHODS: The study was conducted in the Xakriabá Indigenous Reserve (XIR) in the municipality of São João das Missões in northern Minas Gerais state, Brazil. Insects were collected over three consecutive nights in the last week of each month for 12 months from July 2015 to May 2016 from four houses in four different villages. Two traps were set up in each house: one in the intra-domicile and another in the peri-domicile. RESULTS: A total of 2,012 phlebotomine sand fly specimens representing 23 species and belonging to 10 different genera were captured and identified. Among the studied villages, Riacho do Brejo showed the highest density and diversity of phlebotomine sand flies. The species Lutzomyia longipalpis (80.3%) and Nyssomyia intermedia (7.3%), which are major vectors of visceral and cutaneous leishmaniasis, respectively, had the highest population densities, both in the intra- and peri-domicile. No correlation was observed between climatic factors and the density of phlebotomine sand flies. CONCLUSIONS: The results of the present study may contribute to a better understanding and targeting of the measures for preventing and controlling leishmaniasis by the authorities responsible for indigenous health.

Leishmaniasis is a zoonotic disease of worldwide relevance. Visceral leishmaniasis is endemic in Brazil, where it is caused by Leishmania infantum with Lutzomyia longipalpis being the most important invertebrate vector. Non-human primates are susceptible to L. infantum infection. However, little is known about the role of these species as reservoirs. The aim of this study was to evaluate the transmissibility potential of visceral leishmaniasis by non-human primates through xenodiagnosis using the phlebotomine Lu. longipalpis as well as to identify phlebotomine species prevalent in the area where the primates were kept in captivity, and assess infection by Leishmania in captured phlebotomine specimens. Fifty two non-human primates kept in captivity in an endemic area for leishmaniasis were subjected to xenodiagnosis. All primates were serologically tested for detection of anti-Leishmania antibodies. Additionally, an anti-Lu. longipalpis saliva ELISA was performed. Sand flies fed on all animals were tested by qPCR to identify and quantify L. infantum promastigotes. Eight of the 52 non-human primates were positive by xenodiagnosis, including three Pan troglodytes, three Leontopithecus rosalia, one Sapajus apella, and one Miopithecus talapoin, with estimated numbers of promastigotes ranging from 5.67 to 1,181.93 per μg of DNA. Positive animals had higher levels of IgG anti-Lu. longipalpis saliva when compared to negative animals, prior to xenodiagnosis. Captive non-human primates are capable of infecting Lu. longipalpis with L. infantum. Our findings also demonstrate the relevance of non-human primates as sentinels to zoonotic diseases. Several phlebotomine species, including Lu. longipalpis, have been identified in the area where the primates were maintained, but only one pool of Lutzomyia lenti was infected with L. infantum. This study has implications for public health strategies and conservation medicine., Author summary Visceral leishmaniasis is a zoonotic disease with worldwide distribution. The disease is endemic in several Brazilian regions, including the city of Belo Horizonte, where visceral leishmaniasis is caused by Leishmania infantum and transmitted by Lutzomyia longipalpis. This study evaluated the competence of non-human primates to infect Lutzomyia longipalpis with Leishmania infantum. Eight of 52 non-human primates were positive to leishmaniasis by xenodiagnosis, i.e. capable of infecting sand flies, with averages of 5.67 to 1,181.93 promastigotes/μg of DNA. Positive animals had higher levels of IgG anti-Lu. longipalpis saliva when compared to negative animals, prior to xenodiagnosis. This study highlights the importance of non-human primates in the leishmaniasis cycle, providing information that is relevant for development of better public health strategies, and to conservation medicine.

INTRODUCTION: A study on the phlebotomine sandfly fauna was carried out in an endemic area for American tegumentary leishmaniasis in the municipality of Governador Valadares, in the State of Minas Gerais, Brazil. METHODS: Captures were undertaken using HP light traps in four districts, on three nights per month, for one year (from January to December 2008). Correlations between climatic factors (temperature, relative air humidity and rainfall) and the numbers of sandflies collected was observed. RESULTS: 5,413 phlebotomine specimens were caught and were identified as belonging to 12 species. Of these specimens, 2,851 (52%) were females and 2,562 (48%) were males. CONCLUSIONS: Lutzomyia intermedia predominated (29.9% of the species caught), thus suggesting that they were responsible for transmission of American tegumentary leishmaniasis, together with L. whitmani, which was also found in the area (4.3%). The presence of L. longipalpis (11.9%), the main vector for visceral leishmaniasis in Brazil, is an important finding, which makes rigorous entomological surveillance of the area necessary. INTRODUÇÃO: Um estudo da fauna de flebotomíneos foi realizado em uma área endêmica para leishmaniose tegumentar americana no município de Governador Valadares, no Estado de Minas Gerais, Brasil. MÉTODOS: Capturas foram feitas com armadilhas luminosas HP em quatro bairros, três noites por mês, durante o período de janeiro a dezembro de 2008. A correlação entre fatores climáticos (temperatura, umidade relativa do ar e pluviosidade) e o número de flebotomíneos coletados foi avaliada. RESULTADOS: Foram capturados 5.413 espécimes de flebotomíneos, distribuídos em 12 espécies, sendo 2.851 (52%) fêmeas e 2.562 (48%) machos. CONCLUSÕES: Lutzomyia intermedia foi predominante com 29,9% das espécies capturadas, sugerindo ser a responsável pela transmissão de LTA, juntamente com L. whitmani, que também foi encontrada na região (4,3%). A presença de L. longipalpis (11,9%), principal vetor de LV no Brasil, é um dado relevante tornando-se necessário uma rigorosa vigilância entomológica na região.

This paper deals with current knowledge of the interrelationships between Schistosoma infection and malnutrition. It emphasizes the relevance of these investigations in the face of dynamic and evolving changes occurring in population diets and changes in the epidemiological patterns of schistosomiasis in endemic countries. The paper further discusses the basis for continuing the studies on this subject and the reasons why it represents a misunderstood association. This review also focuses on the cellular and humoral immune responses in the undernourished mouse model infected with Schistosoma mansoni, with updated information on the immune response in wild-type and iNOS knockout mice concerning soluble egg antigen specific antibodies and kinetics of IFN-γ, IL-4, IL-10 and IL-13 cytokines, in the chronic phase of Manson's schistosomiasis. There is indication that schistosome-infected undernourished mice are able to develop a humoral immune response, but antibody titres are much lower than in the control animals. Cytokine production (IFN-γ, IL-4, IL-10) is lower in the undernourished mice, but as infection progresses to the chronic phase its kinetics run an antagonistic course when compared to that of well-nourished animals. Marked variation in the secretion of IL-13 (a fibrogenic cytokine) could explain why undernourished mice do not develop liver "pipe-stem" fibrosis described in previous papers on well-nourished animals.

Visceral leishmaniasis has been notified in nearly all states of Brazil, and particularly in the north of Minas Gerais, where the disease is endemic. The aim of this study was to detect natural infection of Lutzomyia longipalpis and, through the PCR/RFLP technique, identify Leishmania species found in sandflies in the municipality of Janaúba.Using light traps, 1,550 females of L. longipalpis were caught and grouped into pools of 10 specimens to be subjected to DNA extraction and amplification, by means of generic PCR and cacophony.Out of the 155 pools, six were positive for Leishmania sp., and thus the infection rate in the municipality was 3.9%. Through PCR/RFLP, the digestion pattern among the positive samples was found to be similar to that of the reference strain of Leishmania chagasi (MHOM/BR/74/PP75).The detection of natural infection associated with studies on the epidemiology of visceral leishmaniasis suggests that L. longipalpis is involved in transmission of L. infantum chagasi in Janaúba, particularly in areas of intense transmission of visceral leishmaniasis.

In Brazil, visceral leishmaniasis (VL) is caused by Leishmania chagasi parasites that are transmitted to man through the bites of infected females of Lutzomyia longipalpis sand flies. In order to evaluate transmission risk and to clarify the epidemiology of this tropical disease, studies focused on the vector and favorable environmental conditions are of fundamental importance. In this work, we surveyed the phlebotomine sand fly fauna in Janaúba, a Brazilian municipality that is endemic for VL. During a two-year period, entomological captures were performed monthly in 15 districts with high, moderate and low profiles of VL transmission. A total of 14,591 phlebotomine sand flies were captured (92% L. longipalpis), with a predominance of males. Most specimens were captured in the peri-domicile setting, although the number of specimens captured in the intra-domicile setting emphasises the anthropophilic behaviour of this insect. The population density of L. longipalpis was modulated by climate variations, particularly with clear increases immediately after the rainy season. However, the pattern of distribution did not coincide with the occurrence of human or canine cases of VL. This suggests that the eco-epidemiology of VL is particular to each area of transmission and must be taken into account during the design of public health control actions.

The mouse model of schistosomal periportal fibrosis (Symmers’ “pipestem” fibrosis), that develops in 30–50% of the infected animals, is not reproduced in undernourished mice. Host nutritional status is likely to be a variable that may influence the outcome and progression of infection, since it interferes with the dynamics of connective tissue changes occurring in chronic hepatic schistosomiasis. Re-infections increase the occurrence of periportal liver fibrosis in well-nourished animals, but it is not known how undernourished mice would behave being repeatedly re-infected. So, 21-day-old male albino Swiss mice were individually exposed to 30 cercariae (percutaneous route) of the BH strain of Schistosoma mansoni, 4 weeks after being on a low-protein diet. Control animals were fed on a commercial balanced chow for mice. The nutritional status was evaluated by body weight gain and measurement of food intake. Mice were divided into four groups: A1 (undernourished, single infected), A2 (well-nourished, single infected), B1 (undernourished, re-infected), B2 (well-nourished, re-infected). The primary infection was performed 4 weeks after ingesting the respective diet. Re-infections started 45 days later, with exposure to 15 cercariae, at 15 day intervals. Mice were sacrificed 18 weeks after the primary exposure. The livers were submitted to morphological (gross and microscopic pathology), morphometric (percentage of fibrosis; granuloma size; volume and numerical densities) by using semi-automatic morphometry, and biochemical (quantification of collagen as hydroxyproline) studies. Worm burdens and hepatic egg counting were also recorded. Values for body weight gains were always lower in undernourished mice, the effects of re-infection being minimal on this regard. Liver and spleen weights were higher in well-nourished mice (either single infected or re-infected) and mainly related to the type of ingested diet. A greater number of re-infected well-nourished mice developed periportal fibrosis, but undernourished re-infected animals did not reproduce this lesion. The percentage of fibrosis and hepatic collagen content were higher in well-nourished mice, but differences between single infected and re-infected groups were not statistically significant.

O estudo foi realizado em Juatuba, Minas Gerais, cujos dados anteriores de casos das leishmanioses humana e canina apontam para um perfil complexo dessa doença no município. Objetivou-se estudar a fauna flebotomínica, os aspectos epidemiológicos, climáticos e ambientais relacionados à transmissão das leishmanioses no município, além de correlacionar as variáveis de estudo com a prevalência de leishmaniose visceral canina (LVC). Foi realizado um estudo epidemiológico prospectivo de coleta sistemática de flebotomíneos e inquérito sorológico canino no período de abril de 2015 a março de 2016. O estudo entomológico foi realizado em duas áreas de estudo, a saber: Área 1 Satélite, contemplou os bairros Satélite I e II e Área 2- Vila Maria Regina (VMR), contemplou os bairros VMR I e II. Foram instaladas 24 armadilhas luminosas em 12 residências distribuídas nas duas áreas de estudo. Em cada ponto de captura foram instaladas duas armadilhas, localizadas no intradomicílio e peridomicílio. As coletas se deram de maneira sistemática, na última semana de cada mês, durante 12 meses. Para análise dos aspectos climáticos, utilizou-se a correlação simples de Spearman para cada par de variáveis e para análise espacial foram utilizados a estimativa de Kernel, a função K e a lógica Fuzzy. Para determinar a taxa de prevalência de LVC, foram coletadas amostras de sangue de cães das duas áreas estudadas para realização do teste diagnóstico de triagem TR-DPP e teste diagnóstico sorológico confirmatório ELISA. Em relação ao estudo entomológico, foram capturados 431 flebotomíneos, sendo 69% machos e 74% do total provenientes do peridomicílio. A espécie Lutzomyia longipalpis foi capturada em maior número (44%). Em relação à infecção natural, das 89 fêmeas submetidas a análise por PCR, 5,6% apresentaram positividade à infecção por Leishmania spp.. Dessas, 100% das fêmeas apresentaram-se infectadas por Leishmania infantum e pertenciam ao VMR. Em relação aos fatores climáticos, a variável temperatura média apresentou correlação positiva (p