Characterisation of an area of coexistent visceral and cutaneous leishmaniasis transmission in the State of Piauí, Brazil.

BACKGROUND: In Brazil, transmission of visceral and cutaneous leishmaniasis has expanded geographically over the last decades, with both clinical forms occurring simultaneously in the same area. OBJECTIVES: This study characterised the clinical, spatial, and temporal distribution, and performed entomological surveillance and natural infection analysis of a leishmaniasis-endemic area. METHODS: In order to characterise the risk of leishmaniasis transmission in Altos, Piauí, we described the clinical and socio-demographic variables and the spatial and temporal distribution of cases of American visceral leishmaniasis (AVL) and American cutaneous leishmaniasis (ACL) cases and identified potential phlebotomine vectors. FINDINGS: The urban area concentrated almost 54% of ACL and 86.8% of AVL cases. The temporal and spatial distribution of AVL and ACL cases in Altos show a reduction in the number of risk areas, but the presence of permanent disease transmission foci is observed especially in the urban area. 3,808 phlebotomine specimens were captured, with Lutzomyia longipalpis as the most frequent species (98.45%). Of the 35 females assessed for natural infection, one specimen of Lu. longipalpis tested positive for the presence of Leishmania infantum and Leishmania braziliensis DNA. MAIN CONCLUSION: Our results indicate the presence of risk areas for ACL and AVL in the municipality of Altos and highlight the importance of entomological surveillance to further understand a possible role of Lu. longipalpis in ACL transmission.

The phlebotomine fauna (Diptera: Psychodidae) of Guaraí, state of Tocantins, with an emphasis on the putative vectors of American cutaneous leishmaniasis in rural settlement and periurban areas.

Phlebotomine sandflies were captured in rural settlement and periurban areas of the municipality of Guaraí in the state of Tocantins (TO), an endemic area of American cutaneous leishmaniasis (ACL). Forty-three phlebotomine species were identified, nine of which have already been recognised as ACL vectors. Eleven species were recorded for the first time in TO. Nyssomyia whitmani was the most abundant species, followed by Evandromyia bourrouli, Nyssomyia antunesi and Psychodopygus complexus. The Shannon-Wiener diversity index and the evenness index were higher in the rural settlement area than in the periurban area. The evaluation of different ecotopes within the rural area showed the highest frequencies of Ev. bourrouli and Ny. antunesi in chicken coops, whereas Ny. whitmani predominated in this ecotope in the periurban area. In the rural settlement area, Ev. bourrouli was the most frequently captured species in automatic light traps and Ps. complexus was the most prevalent in Shannon trap captures. The rural settlement environment exhibited greater phlebotomine biodiversity than the periurban area. Ps. complexus and Psychodopygus ayrozai naturally infected with Leishmania (Viannia) braziliensis were identified. The data identified Ny. whitmani as a potential ACL vector in the periurban area, whereas Ps. complexus was more prevalent in the rural environment associated with settlements.

Association between the potential distribution of Lutzomyia longipalpis and Nyssomyia whitmani and leishmaniasis incidence in Piauí State, Brazil.

BACKGROUND: Leishmaniases are vector borne diseases caused by Leishmania spp. parasites transmitted by female sandflies (Diptera: Psychodidae) whose geographic distribution is influenced by environmental factors. Among the main tools for studying the distribution of vector species, modeling techniques are used to analyze the influence of climatic and environmental factors on the distribution of these insects and their association with human cases of the disease. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used a multiscale ecological niche modeling approach to assess the environmental suitability of sandfly vectors of the etiological agents of Visceral (VL) and American Cutaneous Leishmaniasis (ACL) in Piauí state, northeastern Brazil, and then evaluated their relationship with human disease incidence. For this, we obtained the geographic coordinates of the vector species Lutzomyia longipalpis and Nyssomyia whitmani through literature review, online databases and unpublished records. These data were used for the development of predictive models of the distribution of both sandflies species based on climatic and environmental variables. Finally, the environmental suitability for the presence of these vectors was compared with the incidence of both the diseases at the municipality level. The final models for each sandfly species showed good predictive powers with performance metric values of 0.889 for Lu. longipalpis and 0.776 for Ny. whitmani. The areas with greater environmental suitability for the presence of these species were concentrated in the central-north region of Piauí and coincide with the location of those municipalities presenting higher incidences of VL and ACL, situated in the central-north and extreme north of the state, respectively. The south and southeast regions of Piauí state have low incidence of these diseases and presented low environmental suitability for the presence of both vectors. CONCLUSIONS/SIGNIFICANCE: We discuss how predictive modeling can guide entomological and epidemiological surveillances and recommend an increased supervision and control activities in Teresina (capital of the state of Piaui), Altos and Pedro II, in addition to other municipalities with similar social and environmental characteristics.

Scanning Electron Microscopy of Sand Flies of the Chagasi Series, Psychodopygus (Diptera: Psychodidae) Genus, Focusing on the Genitalia.

Males of cryptic or closely related species present great morphological variation in their genitalia, whereas females, such as those of the Chagasi Series of the Psychodopygus Mangabeira, 1941 genus, are more similar. Therefore, our aim was to study the fine structure of the male genitalia of five species of the Chagasi Series to better understand the variation in their morphology and its influence on the copulatory process. The sand fly species were captured in the following Brazilian states: Psychodopygus chagasi (Costa Lima, 1941) (Rondônia), Psychodopygus complexus (Mangabeira, 1941) (Tocantins), Psychodopygus squamiventris maripaensis (Floch & Abonnenc, 1946) (Amapá), Psychodopygus squamiventris squamiventris (Lutz & Neiva, 1912) (Amazonas), and Psychodopygus wellcomei Fraiha, Shaw & Lainson, 1971 (Pará and Ceará). Insects were stored in ethanol 70% (then dehydrated) and dry after they were sputtered with gold. The samples were observed under a scanning electron microscope. Microtrichiae, two types of trichoid sensilla, coeloconic and chaetic sensillae, were observed on the antenna of all species, with no difference between them. Only on the anepimeron of P. squamiventris squamiventris a modified 'racket'-like scale was observed. As for the male genitalia, the setae and structures of each species were fully described, such as the small setae on the paramere apex of the P. squamiventris subspecies, and the grooves present in this region and on the paramere lobe of P. complexus and P. wellcomei, which are impossible to observe with optic microscopy. New information is thus provided on the male genitalia, which can contribute to future bionomic studies of these species.

Characterisation of an area of coexistent visceral and cutaneous leishmaniasis transmission in the State of Piauí, Brazil

BACKGROUND In Brazil, transmission of visceral and cutaneous leishmaniasis has expanded geographically over the last decades, with both clinical forms occurring simultaneously in the same area. OBJECTIVES This study characterised the clinical, spatial, and temporal distribution, and performed entomological surveillance and natural infection analysis of a leishmaniasis-endemic area. METHODS In order to characterise the risk of leishmaniasis transmission in Altos, Piauí, we described the clinical and socio-demographic variables and the spatial and temporal distribution of cases of American visceral leishmaniasis (AVL) and American cutaneous leishmaniasis (ACL) cases and identified potential phlebotomine vectors. FINDINGS The urban area concentrated almost 54% of ACL and 86.8% of AVL cases. The temporal and spatial distribution of AVL and ACL cases in Altos show a reduction in the number of risk areas, but the presence of permanent disease transmission foci is observed especially in the urban area. 3,808 phlebotomine specimens were captured, with Lutzomyia longipalpis as the most frequent species (98.45%). Of the 35 females assessed for natural infection, one specimen of Lu. longipalpis tested positive for the presence of Leishmania infantum and Leishmania braziliensis DNA. MAIN CONCLUSION Our results indicate the presence of risk areas for ACL and AVL in the municipality of Altos and highlight the importance of entomological surveillance to further understand a possible role of Lu. longipalpis in ACL transmission.

Geometric morphometry of the head in sand flies (Diptera: Psychodidae: Phlebotominae), an alternative approach to taxonomy studies.

Almost 30% of female American sand flies are morphologically indistinguishable from one another. These females belong to species-complexes or groups with closely related species, making species-level identification difficult or even impossible. This fact has implications for public health since several of these groups include species which are vectors of human pathogens. Thus, new tools are needed to minimize species-level identification problems. In this context, our research sought to use geometric morphometry in the study of the head of females of closely related species of the genus Psychodopygus, Chagasi series, which includes the following species: P. chagasi, P. complexus, P. squamiventris maripaensis, P. squamiventris squamiventris, and P. wellcomei. We have used ten landmarks distributed on the head of these species. All species were clearly distinguished using the centroid size and shape together. These results highlight the head analysis as an effective tool for future geometric morphometry studies in sand flies.

Aspects on the Ecology of Phlebotomine Sand Flies (Diptera: Psychodidae) From Guaraí, State of Tocantins, Brazil, Endemic Area for American Cutaneous Leishmaniasis.

In Brazil, American cutaneous leishmaniasis (ACL) ecology involves a diversity of Leishmania species transmitted by different sand fly species. Workers involved in agricultural activities are those mainly affected by ACL in some regions from Tocantins State (TO), Brazil, where the disease can be established in new settlements. The objective of this study was to examine the seasonal and hourly frequency of sand fly species, focusing on the potential vectors of ACL, in a settlement in Guaraí (TO), an ACL transmission area. Sand flies were captured in forested area close to Pedra Branca Agricultural Project settlement, from March 2006 until December 2007, using Shannon trap. Monthly captures were made from 06:00 p.m. to 10:00 p.m., and 24-h captures were done twice per semester, from 06:00 a.m. to 06:00 a.m. A total of 10,089 specimens from 30 species were identified. Psychodopygus complexus Mangabeira, Psychodopygus llanosmartinsi Fraiha & Ward, and Nyssomyia antunesi Coutinho were the most abundant species. Nyssomyia antunesi was more frequent during the dry period, whereas Ps. complexus and Ps. llanosmartinsi had high frequencies during the rainy season. Precipitation was positively correlated with Ps. complexus and Ps. llanosmartinsi abundance, and negatively correlated with Ny. antunesi During 24-h captures, the majority of specimens were captured during the night followed by a decrease at dawn. The behavior and previous finding of natural infection by Leishmania (Viannia) braziliensis of Ps. complexus led us to the conclusion that this species can be a potential vector of L. (V.) braziliensis during the rainy season in Guaraí.

Phlebotomine fauna (Diptera: Psychodidae) and putative vectors of leishmaniases in impacted area by hydroelectric plant, State of Tocantins, Brazil.

BACKGROUND: Although leishmaniases are regarded as serious public health issues in the State of Tocantins, as consequence of the impact of environmental changes, small advances in taxonomic and ecological studies of Phlebotominae fauna are taking place in this state. The present study aimed to improve the knowledge about the sand flies, as well as about the aspects of the bioecology of leishmaniases vectors from Porto Nacional, a city that was directly impacted by the construction of Luís Eduardo Magalhães Hydroelectric Plant (HEP-Lajeado). METHODOLOGY/PRINCIPAL FINDINGS: Sand flies were collected monthly using CDC light traps and Shannon traps for a period of 40 consecutive months, at different monitoring stations, where 7162 specimens were collected and 48 species were detected. Among the species found, 22 are first records in the state and seven are considered important vectors of leishmaniases. Lutzomyia longipalpis, the vector of American Visceral Leishmaniasis (AVL) showed higher frequency in urban compared to rural areas, and Nyssomyia whitmani, the vector of American Cutaneous Leishmaniasis (ACL), predominated in rural areas. The frequency and habits of sand fly vectors are discussed considering environmental characteristics and climatic factors. CONCLUSIONS/SIGNIFICANCE: The construction of dams requires a great amount of labor, therefore attracting people from elsewhere. Increased migration, without adequate structure, leads to bad living conditions in new and unplanned settlements. It also leads to deforestation associated with environmental impacts, which can facilitate the spread of leishmaniases. This study discusses the importance of Lu. longipalpis and Ny. whitmani on the transmission cycles of leishmaniases in Porto Nacional and the record of Bi. flaviscutellata in periurban area of the city.

The phlebotomine fauna (Diptera: Psychodidae) of Guarai, state of Tocantins, with an emphasis on the putative vectors of American cutaneous leishmaniasis in rural settlement and periurban areas

Phlebotomine sandflies were captured in rural settlement and periurban areas of the municipality of Guaraí in the state of Tocantins (TO), an endemic area of American cutaneous leishmaniasis (ACL). Forty-three phlebotomine species were identified, nine of which have already been recognised as ACL vectors. Eleven species were recorded for the first time in TO. Nyssomyia whitmani was the most abundant species, followed by Evandromyia bourrouli, Nyssomyia antunesi and Psychodopygus complexus. The Shannon-Wiener diversity index and the evenness index were higher in the rural settlement area than in the periurban area. The evaluation of different ecotopes within the rural area showed the highest frequencies of Ev. bourrouli and Ny. antunesi in chicken coops, whereas Ny. whitmani predominated in this ecotope in the periurban area. In the rural settlement area, Ev. bourrouli was the most frequently captured species in automatic light traps and Ps. complexus was the most prevalent in Shannon trap captures. The rural settlement environment exhibited greater phlebotomine biodiversity than the periurban area. Ps. complexus and Psychodopygus ayrozai naturally infected with Leishmania (Viannia) braziliensis were identified. The data identified Ny. whitmani as a potential ACL vector in the periurban area, whereas Ps. complexus was more prevalent in the rural environment associated with settlements.

Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Orgäos, Estado do Rio de Janeiro: V. Preferências alimentares (Diptera, Psychodidae, Phlebotominae) / Ecological aspects of sandflies of the National Park of Serra dos Orgäos, State of Rio de Janeiro: V. Food preferences (Diptera, Psychodidae, Phlebotominae)

Realizamos capturas simultâneas de flebótomos, no Parque Nacional da Serra dos Orgäos, Estado do Rio de Janeiro, utilizando três iscas: homem, gambá e galo. Em 298h capturamos 1.155 fêmeas de seis espécies do gênero Lutzomya. L. ayrozai e L. hirsuta foram as espécies mais numerosas; ambas sugaram somente próximo ao solo, sendo decididamente antropofílicas e mais ativas entre 17 e 24h. L. fischeri foi a espécie mais freqüente na copa e a que demonstrou maior ecletismo quanto ao hospedeiro, hora e local; na copa sugou mais o galo, especialmente entre 0 e 5h e, no solo, picou com maior intensidade o homem, principalmente entre 20 e 24h

Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Orgäos, Rio de Janeiro: III. Freqüência horária (Diptera, Psychodidae, Phlebotominae) / Phlebotomus ecology of the Parque Nacional da Serra dos Orgäos, Rio de Janeiro : III - Time frequency (Diptera, Psychodidae, Phlebotominae)

Os resultados obtidos de outubro de 1980 a setembro de 1982, confirmaram a preferência dos flebótomos pelos horários crepuscular e noturno para hematofagia. Somente foram capturados durante o dia quando o tempo estava encoberto ou nos meses de veräo com escurecimento repentino, ocasionado por prenúncios de grandes precipitaçöes, muito comuns nessa época do ano. Nos três períodos por nós estudados - matutino, vespertino e noturno - observamos um equilíbrio entre L. ayrozai e L. hirsuta e um certo ecletismo, quanto à hora de sugar, de L. shannoni e L. fischeri, especialmente a primeira. Com as capturas de 24 horas consecutivas constatamos a predileçäo de L. ayrozai pela hematofagia nas horas mais avançadas da noite, entre 23h e 2h, enquanto L. hirsuta foi mais freqüente entre 18h e 23h. Ambas, contudo, podem picar durante todo o período desde que as condiçöes de temperatura e umidade sejam favoráveis

Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Orgäos, Rio de Janeiro: II. Distribuiçäo vertical (Diptera, Psychodidae, Phlebotominae) / Aspects of the ecology of sandflies of the Serra dos Orgäos National Park, State of Rio de Janeiro: II. Vertical distribution

Durante um ano completo efetuamos capturas de flebótomos em isca humana, simultaneamente no solo e na copa da floresta em plataforma a dez metros de altura. Lutzomyia fischeri foi a espécie mais numerosa na copa. L.sp. 1 (espécie ainda näo descrita) também foi mais freqüente neste nivel; L.shannoni, apesar de ser mais ativa ao nivel do solo, compareceu várias vezes na copa; L.pessoai, L.ayrozai, L.davisi. L.sp.2 (espécie também näo identificada), L.microps e L.monticola só picaram iscas situadas no solo; L.hirsuta esteve pouco representada na copa, porém sua maior densidade foi no solo, onde figura como espécie dominante nos meses mais frios e secos do ano. Dois aspectos devem ser enfatizados com relaçäo à distribuiçäo vertical: a acrodendrofilia de L. fischeri e, ao contrário, o fato de L.ayrozai alimentar-se exclusivamente ao nível do solo. Este comportamento de L.ayrozai e sua preferência em sugar nas partes mais baixas do corpo fazem supor que seus abrigos naturais sejam as folhas caídas no solo florestal. Dentre os fatores mesológicos que influenciam na estratificaçäo dos flebótomos consideramos que a luminosidade seja preponderante, pois em noites mais claras (lua crescente ou cheia) a atividade foi nula, todos os flebotomíneos capturados na copa das árvores foram obtidos em noites mais escuras (lua nova ou minguante)

Microbiota do trato digestivo de fêmeas de Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) provenientes de colônia alimentadas com sangue e com sangue e sacarose / Digestive tract microbiota in female Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidade) feeding on blood meal and sacarose plus blood meal

Há poucos estudos sobre a microbiota do trato digestivo de flebotomíneos, considerando-se que o sangue näo é o único alimento ingerido. Os flebotomíneos, tanto os machos como as fêmeas, alimentam-se de açúcares, provenientes de várias fontes, possibilitando a ingestäo de microrganismos. As chances de contaminaçäo aumentam nos insetos criados em laboratório e pode interferir no desenvolvimento da Leishmania spp. Foi separado um total de 300 fêmeas, divididas em dois lotes, das quais extraímos o trato digestivo. No lote 1 (fêmeas alimentadas com sangue e sacarose) das 10 espécies bacterianas isoladas, a família Enterobacteriaceae esteve representada pelos gêneros Serratia, Enterobacter e Yokenella, e o grupo dos näo fermentadores pelos gêneros Pseudomonas, Acinetobacter e Stenotrophomonas. No lote 2 (fêmeas alimentadas apenas com sanue) das 8 espécies isoladas o grupo dos näo fermentadores esteve representado pelos gêneros Acinetobacter, Stenotrophomonas, Burkolderia e Pseudomonas, e a família Enterobacteriaceae, pelos gêneros Enterobacter e Serratia.