[Sandflies (Diptera, Psychodidae) from the transmission area for American cutaneous leishmaniasis in the town of Itupeva, the southeastern region of São Paulo state, Brazil]

Sand fly population dynamics in areas of American cutaneous leishmaniasis, Municipality of Paraty, Rio de Janeiro, Brazil

The present study is the second and last part of the study that investigated the fauna and behavior of sand flies in areas prone to cutaneous leishmaniasis outbreaks, in the State of Rio de Janeiro, in the municipality of Paraty. To collect the sand flies, CDC and Shannon light traps were used, installed in the peridomiciliary and forest areas, and manual suction tubes on the walls of the home and in the animal shelters. A total of 102,937 sand flies, belonging to nine genera and 23 species were captured from October 2009 to September 2012. Regarding the monthly frequency of sand flies, the period of highest density was from November to March, with a maximum peak in January. The lowest density was observed in June and July. In the studied area, the species of epidemiological importance, Nyssomyia intermedia, Pintomyia fischeri, Migonemyia migonei and Nyssomyia whitmani, were found in all months of the year, a period in which residents may be in contact with these vectors of the etiological agent of cutaneous leishmaniasis.

Nyssomyia whitmani (Diptera: Psychodidae) Activity From Sunset to Sunrise: A Two-Year Study in a Rural Area in Northeast Argentina

We model the nocturnal patterns of the main vector of Leishmania braziliensis (Vianna) in the Paranaense region of South America, Nyssomyia whitmani (Antunes & Coutinho). Occurrence and abundance variation were analyzed by hourly periods, and in relation to sunrise and sunset to avoid differences in luminosity at fixed times throughout the year. The possible role of climatic and environmental variables on nocturnal activity curves was explored. A rotating light trap was operated biweekly in the peridomestic henhouse of a farm in Puerto Iguazú, from May 2016 to May 2018. Ny. whitmani, is the predominant Phlebotominae species (6,720 specimens captured), and is present throughout the night and seasons. Generalized additive models of nocturnal abundance of Ny. whitmani show a bell shape with an acrophase in the early evening. Models of abundance distribution as a function of total abundance showed significant nonlinear variations, only for the tertile of highest vector abundance, in the curves by hourly periods, and related to dawn, while female abundance relative to total abundance showed an asymptotic increasing curve, suggesting density-dependent events with abundance thresholds. Finally, temperature was the variable that best explained the pattern of abundance distribution of Ny. whitmani during the night, although triggers for scotophase activity due to internal clocks or luminosity could not be ruled out. The relationship of activity and abundance with climatic variables would also explain the nights of extraordinary abundance, and therefore of greater probability of vector-human and vector-reservoir contacts.

Nycthemeral Rhythm of Phlebotominae (Diptera: Psychodidae) in a Craggy Region, Transitioning Between the Wetland and the Plateau, Brazil

Recording the nycthemeral rhythm of sand flies allows the evaluation of the daily activity in different ecotypes, the period of greatest activity, and their degree of anthropophily. We investigated the fauna and the rhythm of sand fly activity in an ecotourism region in Mato Grosso do Sul (MS) state, Brazil. Sand flies were captured monthly, using a Shannon trap for 24 h periods between July 2012 and June 2014. We collected 1,815 sand flies, in which Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati) and Lutzomyia longipalpis were the most abundant species during the dry season, with activity from 5 p.m.-7 a.m. and 6 p.m.-5 a.m., respectively. Both species require particular attention as vectors of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum in several regions of Brazil, including MS. However, Lutzomyia dispar was more anthropophilic, and was most active between January and March, from 5 p.m. to 5 a.m. Lutzomyia misionensis (=Pintomyia misionensis, sensu Galati) was present throughout both years, active from 4 p.m. to 5 a.m. Other species were active from 5 p.m. to 6 a.m. Due to intense tourism in the months that coincide with a high number of vectors for leishmaniases in Piraputanga, it is essential to determine vector-monitoring strategies in the area by investigating sand fly rhythm while not neglecting other periods of the year when the insects are present.

Environmental Niche Modelling of Phlebotomine Sand Flies and Cutaneous Leishmaniasis Identifies Lutzomyia intermedia as the Main Vector Species in Southeastern Brazil

Cutaneous leishmaniasis (CL) is caused by a protozoan of the genus Leishmania and is transmitted by sand flies. The state of Espírito Santo (ES), an endemic area in southeast Brazil, has shown a considerably high prevalence in recent decades. Environmental niche modelling (ENM) is a useful tool for predicting potential disease risk. In this study, ENM was applied to sand fly species and CL cases in ES to identify the principal vector and risk areas of the disease. Sand flies were collected in 466 rural localities between 1997 and 2013 using active and passive capture. Insects were identified to the species level, and the localities were georeferenced. Twenty-one bioclimatic variables were selected from WorldClim. Maxent was used to construct models projecting the potential distribution for five Lutzomyia species and CL cases. ENMTools was used to overlap the species and the CL case models. The Kruskal-Wallis test was performed, adopting a 5% significance level. Approximately 250,000 specimens were captured, belonging to 43 species. The area under the curve (AUC) was considered acceptable for all models. The slope was considered relevant to the construction of the models for all the species identified. The overlay test identified Lutzomyia intermedia as the main vector of CL in southeast Brazil. ENM tools enable an analysis of the association among environmental variables, vector distributions and CL cases, which can be used to support epidemiologic and entomological vigilance actions to control the expansion of CL in vulnerable areas.

The phlebotomine sand flies fauna in Parque Estadual do Rio Doce, Minas Gerais, Brazil

Background

Phlebotomine sand flies are dipterans of the family Psychodidae. They are very important to veterinary medicine because some species are vectors of infective forms of Leishmania spp., the etiological agents of leishmaniasis. The Parque Estadual do Rio Doce is located in an area with constant reports of cases of leishmaniasis. In order to better understanding the phlebotamine sand fly fauna of the park, the present work was undertaken with the goal of analyzing phlebotomine sand flies collected there, verifying their seasonality and correlating their presence with forest and/or anthropic areas.

Methods

To analyze the fauna of phlebotomine sand flies, HP-type, model CDC light traps were distributed along the Juquita trail of PERD. Twelve traps were installed between September 2012 and February 2014, and captured specimens were identified to species.

Results and discussions

A total of 1993 phlebotomine sand flies of 30 species were captured. The most abundant species were Pressatia choti, Psychodopygus davisi and Nyssomyia intermedia. The high number of Nyssomyia intermedia captured drew attention because they are considered one of the vectors of the infective Leishmania braziliensis present at PERD. No seasonality was observed in the occurrence of phlebotomine sand flies captured at PERD. The number of captured specimens of vector species, and the distance of traps from the forest boarder, were negatively correlated, showing that these vectors (Nyssomyia intermedia, Nyssomyia whitmani and Migonemyia migonei) were less common inside the forest area and that attention should be drawn to other potential vector species in the forest.

Conclusion

These results can contribute to leishmaniasis prevention strategies directed at the visitors and professionals at or near PERD. The finding of the presence of Leishmania vectors in the park area must be given attention, since disease transmission can threaten people who visit PERD and its surroundings. Therefore, information on the prevention of leishmaniasis needs to be provided to all people who go there.

Comparison of the phlebotomine (Diptera: Psychodidae) fauna of urban, transitional, and wild areas in northern Minas Gerais, Brazil

BACKGROUND

Phlebotomines are directly related to the study of leishmaniases, and so the study of their distribution plays an important role in the epidemiology of these diseases. Collections of phlebotomines were made with the intent of comparing the distribution, richness, diversity, and abundance of species in three distinct environments in an area endemic for tegumentary and visceral leishmaniasis in Minas Gerais State, Brazil.

METHODS

Phlebotomines were collected with automatic light traps in urban, transitional, and wild areas from March 2013 to February 2014 in the district of Barra do Guaicuí, municipality of Várzea da Palma, Minas Gerais. The distribution patterns of these species of insects, as well as species richness, evenness, and abundance among the different areas, were analyzed.

RESULTS

A total of 3,365 phlebotomines belonging to 15 species were collected. The urban area had the greatest abundance whereas the transitional area had the greatest diversity and evenness of species. Nyssomyia intermedia was the most abundant species in the urban area, whereas Evandromyia evandroi was the most abundant in the transitional area and Ev. lenti in the wild area.

CONCLUSION

The analysis of our results showed that the distribution of the collected species had distinct profiles between the environments studied. Furthermore our study indicates the potential risk of transmission of leishmaniasis in the urban environment where it was observed had the highest population density and abundance of important vector species of Leishmania.

Phlebotomine fauna in the urban area of Timóteo, State of Minas Gerais, Brazil

This work is characterized by an entomological research and an investigation on whether seasonal behaviours can be associated to the phlebotomine fauna found in the urban area of Timóteo-MG - an endemic focus of tegumentary leishmaniasis (TL). The analysis of the seasonal behaviour of sand flies has taken into account the following climatic variables: rainfall, relative humidity and temperature. Automatic light traps were installed in households between 2009 and 2010. The sand fly species with the highest number captured was Lutzomyia whitmani (66.5%), a TL vector species, whose abundance has provided strong evidences that this species is the main vector of TL in the municipality of Timóteo, with its cycle of transmission developing in its urban area. Amongst the results observed in the analyses of seasonal behaviour, only temperature conveyed particular association between seasonal occurrence of sand flies and climate variables. The findings of this study may assist the local epidemiological surveillance agency in defining strategies and directing efforts for controlling these insects.

Ecological aspects of the Phlebotominae fauna (Diptera: Psychodidae) in the Xakriabá Indigenous Reserve, Brazil

Background

Sand fly collections were performed to study ecological aspects of the Phlebotominae fauna of the Xakriabá Indigenous Reserve, an area with endemic cutaneous leishmaniasis, located in the state of Minas Gerais, Brazil.

Methods

The collections were performed in peridomicile areas and along trails previously selected for the study of wild and synanthropic Leishmania hosts. Differences in the distribution patterns of the sand fly species as well as in species richness and abundance between the different ecotopes were investigated during both rainy and dry seasons over the course of the study period.

Results

A total of 8,046 sand flies belonging to 11 genera and 28 species were collected. Lutzomyia longipalpis and Nyssomyia intermedia were the most abundant species in peridomicile areas, whereas Martinsmyia minasensis and Lutzomyia cavernicola were the most abundant species among the different trail ecotopes.

Conclusion

The different composition of the sand fly fauna observed in the peridomicile areas and in the trails during the study, reinforces the importance of sampled different areas in a phlebotomine fauna survey. The presence of Lutzomyia longipalpis and Ny. Intermedia most abundant in peridomicile can be important to Leishmania infantum and Leishmania braziliensis transmission in the Imbaúbas native village.

Magnitude and trend of American Tegumentary Leishmaniasis in the State of São Paulo, Brazil, 1975 to 2008

The aim of this study was to analyze the magnitude and trend of American Tegumentary Leishmaniasis (ATL) in the State of São Paulo from 1975 to 2008. An ecological study that classified municipalities according to the magnitude of transmission was performed. From 1975 to 1985, 1,281 cases of ATL were registered in 45 municipalities, rising to 258 municipalities and 4,093 cases from 1986 to 1995; and reaching 385 municipalities and 7,604 cases from 1996 to 2008. Lutzomyia intermedia s.l. was collected in most of the entomological surveys. In the classification of municipalities according to magnitude, 67.5% were observed to have a "small magnitude," 19.2% "moderate magnitude" and 13.3% "high magnitude." The highest incidences of ATL have been restricted to underserved areas close to the Atlantic forest. There was an increase in the number of municipalities with small occurrence of cases and expansion in the area of risk.

Ecological aspects of phlebotomine fauna (Diptera, Psychodidae) of Serra da Cantareira, Greater São Paulo Metropolitan region, state of São Paulo, Brazil

Human cases of American cutaneous leishmaniasis (ACL) have been recorded in Serra da Cantareira, in the Greater São Paulo Metropolitan Region, where two conservation units are situated, the Parque Estadual da Cantareira and the Parque Estadual Alberto Löfgren. The present study aimed to identify the sandfly fauna and some of its ecological aspects in these two parks and their surrounding area to investigate Leishmania sp. vectors. The captures were undertaken monthly from January to December 2009, from 6:00 p.m. to 6:00 a.m., with automatic light traps installed in forests and peridomicile areas and with modified black/white Shannon traps in the peridomicile. A total of 12 species and 5,436 sandflies were captured: with automatic light traps (141), Shannon traps (5,219) and attempting to bite the researchers while they were conducting the collection in Shannon traps (76). Pintomyia fischeri and Migonemyia migonei were the most abundant species. Pi. fischeri predominated in all three kinds of captures (49%, 88.8% and 65.8%, respectively). Mg. migonei was the second most prevalent in Shannon traps (10.0%) and attempting to bite the researchers (22.4%). Pi. fischeri females were significantly more attracted to black and those of Mg. migonei to white Shannon traps. A positive and significant correlation was observed between the numbers of Pi. fischeri and the mean of minimum relative humidity values on the fifteen days prior to capture, while there was a negative and significant correlation between the relative humidity on the capture day and the two most abundant species. The anthropophilia and high frequencies of Pi. fischeri and Mg. migonei suggest that both species may be transmitting ACL agents in this region.

Lista de espécies de Phlebotominae (Diptera, Psychodidae) do Estado de São Paulo, Brasil, com comentários sobre sua distribuição geográfica

Os flebotomíneos são insetos de interesse médico, responsáveis pela transmissão de protozoários parasitas do gênero Leishmania entre animais reservatórios humanos e não-humanos, os quais são encontrados em todo o Estado de São Paulo, Brasil. As 69 espécies de flebotomíneos registradas no Estado de São Paulo, incluindo 7 espécies registradas aqui pela primeira vez, estão organizadas em uma lista de espécies utilizando a classificação filogenética de Galati (2003). Nossa lista de espécies incorpora e atualiza os dados publicados por Barretto (1947) e Martins et al. (1978), e inclui registros para mais 33 espécies retirados da literatura publicada desde então, e também da observação de espécimes depositados em coleções entomológicas. Para cada espécie de flebotomíneo, a distribuição geográfica por município é fornecida, com comentários sobre a distribuição de seis vetores de leishmaniose cutânea, bem como de Lutzomyia longipalpis, o principal vetor de leishmaniose visceral.

Phlebotomine sandflies (Diptera: Psychodidae) in Governador Valadares, a transmission area for American tegumentary leishmaniasis in State of Minas Gerais, Brazil

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.

Spatial and temporal patterns of occurrence of Lutzomyia sand fly species in an endemic area for cutaneous leishmaniasis in the Atlantic Forest region of northeast Brazil

Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly population's abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurrence.

Species structure of sand fly (Diptera: Psychodidae) fauna in the Brazilian western Amazon

We surveyed areas of the state of Rondônia in western Amazon for phlebotomine, which are potential vectors of leishmaniasis. A total of 5,998 specimens were captured, resulting in the identification of 48 species within the Lutzomyia (99.98%) and Brumptomyia (0.02%) genera. The predominant species was Lutzomyia davisi, followed by Lutzomyia umbratilis, Lutzomyia llanosmartinsi, Lutzomyia c. carrerai, Lutzomyia dendrophyla, Lutzomyia nevesi and Lutzomyia whitmani. All sand flies identified as vectors for cutaneous leishmaniasis in Brazil, i.e., Lu. davisi, Lu. umbratilis, Lu. c. carrerai and Lu. whitmani, were found in the surveyed areas.

American cutaneous leishmaniasis in the Pontal of Paranapanema - SP, Brazil: ecological and entomological aspects

American cutaneous leishmaniasis (ACL) occurs in epidemic outbreaks and in sporadic cases with small annual variation in the Pontal of Paranapanema, SP. There is little research on the sandfly fauna of this region. The last outbreaks were related to the Movement of the Landless Workers (MST) and with the ecological tourism in preserved forest of the Parque Estadual do Morro do Diabo (PEMD). AIM: identification of the sandfly fauna within the PEMD, mainly anthropophilic species already incriminated as vectors of ACL, as well as their seasonality, hourly frequency and data of the behavior. M&M: The captures were undertaken with CDC light and Shannon traps from 6:00 pm to 10:00 pm, monthly from May 2000 to December 2001. The temperature and relative humidity data were registered at hourly intervals. RESULTS: The captured species were: Brumptomyia brumpti, Nyssomyia neivai, Nyssomyia whitmani, Pintomyia fischeri and Pintomyia pessoai. The P. pessoai predominated (34.39%) and N. neivai was less found (0.74%), only being captured in CDC traps. Shannon trap captured more sandflies (63.01%) than the CDC traps (36.99%). Despite the environmental degradation anthropophilic species, indicates favorable bioecological conditions for persistence of vectors and potential transmission of leishmaniasis.

Phlebotomine sand flies (Diptera, Psychodidae) in an American tegumentary leishmaniasis transmission area in northern Espírito Santo State, Brazil

American tegumentary leishmaniasis is endemic to the Espírito Santo State, Brazil, where it is widely distributed. The composition of the phlebotomine sand fly fauna in an American tegumentary leishmaniasis focus was determined by monthly sampling, using Shannon light traps in an Atlantic Forest reserve and adjacent habitat that had been modified by human activity. Seasonal fluctuations in numbers of the most abundant species were also monitored from June 2004 to May 2006. Of the 6,176 specimens collected, 47.4% were captured in the forest and 52.6% in the disturbed habitat. Although Lutzomyia davisi (60.8%) predominated in specimens from the forest, those captured near human dwellings consisted almost entirely of Lu. choti (72%) and Lu. intermedia (24.3%). All three species occurred throughout the year. Based on our findings, Lu. intermedia probably acts as the principal domestic Leishmania vector in the study area.

[Sand flies in the Aguapeí river floodplain, northwest area of State of São Paulo, Brazil]

OBJECTIVE

To investigate the seasonal variation of sand flies regarding their occurrences and densities.

METHODS

The study was conducted in the Aguapeí river floodplain in the state of São Paulo, southeastern Brazil. Sand flies were monthly captured with automatic light traps set up between 18:00 and 7:00 hours, over a period of one year (2004-2005), at two sites: veranda of a domicile and in a forest on the banks of Aguapeí River. The Williams' average was used for estimating the seasonal variation and the Chi-square test for comparison.

RESULTS

A total of 35,995 specimens were captured: five Brumptomyia avellari, one Psathyromyia (Xiphomyia) hermanlenti and the rest Nyssomyia neivai, which had the highest frequency during the winter. Ps. hermanlenti is first recorded in state of São Paulo.

CONCLUSIONS

The high density of Nyssomyia neivai, a suspected vector of cutaneous leishmaniasis, points out to the risk of transmission of this disease in this setting, especially during drier periods of the year.

A urbanização da leishmaniose tegumentar americana no município de Campinas - São Paulo (SP) e região: magnitude do problema e desafios

FUNDAMENTOS - A leishmaniose tegumentar americana ocupa o segundo lugar entre as protozoonoses por vetores no Brasil. OBJETIVOS - Descrever a distribuição da doença na macrorregião de Campinas-SP e identificar as principais dificuldades em sua prevenção. MÉTODOS - A área estudada abrange 42 municípios. Os dados foram coletados no Sistema Nacional de Agravos e de Notificação do Grupo de Vigilância Epidemiológica, de 1998 a 2004, da Superintendência de Controle de Endemias, do Centro de Zoonoses e foi feita revisão da literatura. RESULTADOS - Foram registrados 458 casos, de caráter endêmico e com maior ocorrência em Campinas e Jundiaí. A doença predominava na área urbana (57%), no sexo masculino (62%) e acometia todas as faixas etárias. As espécies vetoras encontradas foram Lutzomyia intermedia sl, L. neivai, L. migonei, L. whitmani, L. fisheri, e L. pessoai. CONCLUSÕES - A leishmaniose tegumentar está distribuída amplamente na região (81% dos municípios estudados) e predominava na área urbana (57%). As dificuldades encontradas em seu controle foram a crescente adaptação do vetor ao peridomicílio, a multiplicidade dos fatores envolvidos na transmissão e a resposta insuficiente às medidas de controle atuais. O acompanhamento do ambiente e da doença, o diagnóstico e o tratamento precoces, a notificação compulsória e o seguimento dos casos, além de investimento em pesquisas, campanhas e ações diretas junto aos pacientes são importantes para o controle da doença.

Phlebotomine fauna (Diptera: Psychodidae) and species abundance in an endemic area of American cutaneous leishmaniasis in southeastern Minas Gerais, Brazil

This study was undertaken to identify the phlebotomine fauna and species abundance in domiciliary and peridomiciliary (hen-house and guava-tree) environments, on a lake shore, a cultivated area of coffee and banana, and a forested area of Conceição da Aparecida municipality, southeastern the state of Minas Gerais, to provide information for the control and epidemiological surveillance of leishmaniasis in this area. The captures were carried out monthly between May 2001 and November 2002, with automatic light and Shannon traps. A total of 1444 sand flies were captured, 951 (76.5%) with automatic light traps and 493 (23.5%) with the Shannon trap. Thirteen species were captured, the most frequent being Nyssomyia whitmani (62.7%), Migonemyia migonei (21.4%), Pintomyia fischeri (6.9%), and Evandromyia lenti (3.6%). Species abundance was determined using the automatic light traps installed in the six environments. The most abundant species according to the standardized index of species abundance were Ny. whitmani (1.0) and Mg. migonei (0.82). In view of the dominance of these two species, known vectors of cutaneous leishmaniasis in other Brazilian areas, their participation in the transmission of the disease in this county is suggested. The diversity and evenness indexes in the domicile were the lowest due to the high frequency (83%) of Ny. whitmani. The capture of Lutzomyia longipalpis, rarely recorded in the south-eastern and southern regions of Minas Gerais, is also noteworthy.

Leishmaniose tegumentar americana: flebotomíneos em área de transmissão no Município de Uberlândia, MG

De maio de 2000 a janeiro de 2001, foram realizadas 4 capturas de flebotomíneos em área de transmissão da leishmaniose tegumentar americana na bacia do rio Araguari, no Município de Uberlândia, MG, com duração de 15 horas consecutivas cada, para observar o comportamento dos insetos. A primeira captura foi em maio de 2000 (frio e úmido), a segunda em junho de 2000 ( frio e seco), a terceira em outubro de 2000 (quente e seco) e a quarta em janeiro de 2001 (quente e chuvoso). Utilizaram-se para capturar os flebótomos armadilhas Center on Disease Control e Shannon. Foram capturados e identificados 6551 flebótomos, sendo 1990 machos e 4561 fêmeas distribuídos em 2 gêneros (Lutzomyia e Brumptomyia) e 8 espécies. A Lutzomyia intermedia predominou com o maior número de espécimens (6531), representando 99,7% dos flebótomos capturados. Nas quatro capturas observou-se a preferência de Lutzomyia intermedia pelo mês que precede o período chuvoso (outubro), com temperaturas e umidade relativa do ar altas.

Phlebotomine sand flies in Porteirinha, an area of American visceral leishmaniasis transmission in the State of Minas Gerais, Brazil

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmaniasis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predominant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed.

A periurbanização de Lutzomyia whitmani em área de foco de leishmaniose cutânea, no Estado do Maranhão, Brasil

Em um inquérito entomológico realizado em 2000, na zona periurbana do município de Dom Pedro-MA, pretendia-se estimar a abundância de Lutzomyia longipalpis, por conta da ocorrência de um óbito suspeito de calazar. Entretanto, constatou-se que do total de 2.961 flebótomos capturados no peridomicílio, 82,4% (2.440 espécimes) eram de Lutzomyia whitmani. Esta associação vem determinando um novo padrão de transmissão da leishmaniose cutânea (o urbano), como vem acontecendo com o calazar nordestino.

Epidemiological and clinical features of Leishmania (Viannia) braziliensis American cutaneous and mucocutaneous leishmaniasis in the State of Espírito Santo, Brazil

Between 1985 and 2000, epidemiological surveys of the American tegumentary leishmaniasis (ATL) were carried out in several rural and urban communities in Espírito Santo, Brazil. A total of 100 stocks of Leishmania (comprising isolates from both human and canine hosts with ATL) were identified by two methods of molecular characterization, using specific monoclonal antibodies and multilocus enzyme electrophoresis. Parasite isolates from 19 municipalities were found to belong to the same zymodeme and serodeme type as of the Leishmania (Viannia) braziliensis reference strain. In contrast, our genotyping studies have shown intra-specific variation among these parasites (comparisons of the variability of the internal transcribed spacers between the small and large subunits of the rRNA genes of the 22 stocks studied revealed at least 11 genotypes). Two main clusters of L. (V.) braziliensis genotypes were observed, representing parasites collected from different endemic regions in the state, where transmission reflects distinct eco-epidemiological features. Infection with this pathogen was associated with the characteristic disease forms, but neither the clinical outcome nor the response to treatment could be related to the genetic polymorphism of the isolates, as defined by using the proposed methodology.

Lutzomyia vectors for cutaneous leishmaniasis in Southern Brazil: ecological niche models, predicted geographic distributions, and climate change effects

Geographic and ecological distributions of three Lutzomyia sand flies that are cutaneous leishmaniasis vectors in South America were analysed using ecological niche modelling. This new tool provides a large-scale perspective on species' geographic distributions, ecological and historical factors determining them, and their potential for change with expected environmental changes. As a first step, the ability of this technique to predict geographic distributions of the three species was tested statistically using two subsampling techniques: a random-selection technique that simulates 50% data density, and a quadrant-based technique that challenges the method to predict into broad unsampled regions. Predictivity under both test schemes was highly statistically significant. Visualisation of ecological niches provided insights into the ecological basis for distributional differences among species. Projections of potential geographic distributions across scenarios of global climate change suggested that only Lutzomyia whitmani is likely to be experiencing dramatic improvements in conditions in south-eastern Brazil, where cutaneous leishmaniasis appears to be re-emerging; Lutzomyia intermedia and Lutzomyia migonei may be seeing more subtle improvements in climatic conditions, but the implications are not straightforward. More generally, this technique offers the possibility of new views into the distributional ecology of disease, vector, and reservoir species.

Phlebotominae (Diptera: Psychodidae) em área de transmissão de leishmaniose tegumentar americana no litoral norte do Estado de São Paulo, Brasil

A região do litoral norte do Estado de São Paulo registrou 14, 30 e 104 casos de leishmaniose tegumentar americana nos anos de 1993, 1994 e 1995 respectivamente. Com objetivo de caracterizar a fauna e a distribuição sazonal e horária das espécies de flebotomíneos foram realizadas coletas quinzenais de formas adultas durante o período de dezembro de 1995 a novembro de 1996, utilizando-se armadilhas luminosas do tipo CDC, no interior da residência, no peridomicílio e na mata durante 12 horas a partir do crepúsculo vespertino. No peridomicílio foi utilizada, durante 6 horas também a partir do crepúsculo vespertino, armadilha de Shannon instalada a 100 metros da casa. A cada 3 meses esta armadilha foi utilizada durante 12 horas. Foram observadas flutuações das densidades populacionais, bem como as ocorrências intra e extradomiciliar das espécies predominantes. Lutzomyia intermedia foi a espécie mais abundante nas diferentes armadilhas utilizadas e nos ambientes investigados.

Distribution of sand flies (Diptera: Psychodidae) at different altitudes in an endemic region of American cutaneous leishmaniasis in the State of Espírito Santo, Brazil

The involvement of different sand fly species in the transmission of American cutaneous leishmaniasis (ACL) at different altitudes was evaluated in the municipality of Afonso Cláudio in the State of Espírito Santo, Brazil, from November 1995 to February 1997. CDC light traps and Shannon traps baited with human volunteers were hung simultaneously at three altitudes of a river valley: (a) 650-750 m in an area of active ACL transmission; (b) 750-850 m in a transitional area; and (c) 850-950 m in an area where no ACL transmission occurred. A total of 13,363 specimens belonging to 28 species was collected. The five most abundant man-biting species were Lutzomyia intermedia, which constituted 24.3% of the total, Lu. migonei (22.3%), Lu. whitmani (15.4%), Lu. fischeri (14.9%) and Lu. monticola (5.8%). Analysis of the distribution of these species at the three altitudes provided evidence that Lu. fischeri and Lu. monticola were not involved in ACL transmission, whereas Lu. migonei and Lu. whitmani might act as secondary vectors of Leishmania (Viannia) braziliensis and Lu. intermedia was probably the principal vector of the parasite. These results reinforce those published in the existing literature, which indicate that Lu. intermedia is the main vector of Le. (V.) braziliensis in Southeast Brazil, while Lu. migonei and Lu. whitmani are of secondary importance.

[Phlebotomine sand flies in the State of Tocantins, Brazil (Diptera: Psychodidae)]

Between 1997-1998, the authors carried out sporadic collection of sand flies in the municipalities of Paraíso de Tocantins, Monte do Carmo, Porto Nacional and Monte Santo all in the Tocantins State of northern Brazil. Human bait was used in Monte Santo and a battery operated light trap in other municipalities. The ecotypes chosen for the traps were in the peridomiciles, inside the houses, in the forest and the orchard. We identified 2,677 sand flies, belonging to 32 species. The most abundant species of sand flies were Lutzomyia whitmani, Lutzomyia longipalpis, Lutzomyia carmelinoi, Lutzomyia evandroi, Lutzomyia longipennis and Lutzomyia antunesi. Collections from the forest showed greater diversity of species, while the largest number of sand flies were caught around the houses. Several species known or suspected to be vectors of Leishmania in other regions of Brazil were captured.

Study of a cutaneous leishmaniasis outbreak in General Vedia, Province of Chaco, 1996

Between March and July 1996, a focalized epidemic outbreak of cutaneous leishmaniasis in General Vedia, province of Chaco, associated to the gallery forest of the Oro river was verified. The incidence rate in the area, which was 0-2/000 cases in preceding years, reached 8/000 cases in 1996. The risk of symptomatic infection was similar between sexes, but was different when analyzing the different age groups by sex, suggesting a greater relative importance of the peridomestic transmission for the females and of the transmission in the subtropical forest for the males. Specimens of Lutzomyia intermedia, a species already incriminated as a vector of Leishmaniasis in other provinces of northern Argentina, were captured and identified in the focus locality in May 1996. The possible causes of the outbreak related to the climatic variables and the vector abundance are analyzed and the results in the framework of possible preventive and control activities are discussed.