The transmission of visceral leishmaniasis in the municipality of Guarujá, on the Coast of São Paulo state, Brazil.

OBJECTIVE: To perform an entomological survey, evaluating the circulation of Leishmania spp. in sand flies captured from the new foci of visceral leishmaniasis (VL) in the coastal region of São Paulo state. METHODS: Sand flies were captured from November 2016 to September 2018 using light traps of the Centers for Disease Control (CDC), in the neighborhood where VL cases were reported. Leishmania spp. circulation was evaluated by gut dissection and molecular analysis of the females captured. RESULTS: Nyssomyia intermedia was the more frequent species (90,7%) within the 1,203 sand flies captured. We found no flagellates in dissected females, but two pools containing females of Ny. intermedia presented DNA of L. infantum. CONCLUSION: Our results suggest that Ny. intermedia might be involved in the establishment of this new VL focus in Sao Paulo. However, before incriminating this species as a L. infantum vector, further studies should investigate other vectorial capacity parameters, including competence, survival, and feeding habits.

The transmission of visceral leishmaniasis in the municipality of Guarujá, on the Coast of São Paulo state, Brazil

ABSTRACT OBJECTIVE To perform an entomological survey, evaluating the circulation of Leishmania spp. in sand flies captured from the new foci of visceral leishmaniasis (VL) in the coastal region of São Paulo state. METHODS Sand flies were captured from November 2016 to September 2018 using light traps of the Centers for Disease Control (CDC), in the neighborhood where VL cases were reported. Leishmania spp. circulation was evaluated by gut dissection and molecular analysis of the females captured. RESULTS Nyssomyia intermedia was the more frequent species (90,7%) within the 1,203 sand flies captured. We found no flagellates in dissected females, but two pools containing females of Ny. intermedia presented DNA of L. infantum. CONCLUSION Our results suggest that Ny. intermedia might be involved in the establishment of this new VL focus in Sao Paulo. However, before incriminating this species as a L. infantum vector, further studies should investigate other vectorial capacity parameters, including competence, survival, and feeding habits.

Natural infection of Lutzomyia longipalpis (Cembrene-1 population) with Leishmania infantum in a new visceral leishmaniasis focus in the eastern region of São Paulo State, Brazil.

INTRODUCTION: Visceral leishmaniasis (VL) transmission has been associated with two different populations of the Lutzomyia longipalpis complex in São Paulo state. METHODS: In a recent focus of VL, we captured and dissected sand flies and investigated Leishmania infantum infection by parasitological, PCR, and sequencing analysis. RESULTS: Flagellates were observed in 2 of 47 (4.2%) cembrene-1 Lu. longipalpis females. The sequences obtained matched those of Le. infantum. CONCLUSIONS: We found that the transmission of Le. infantum by cembrene-1 females may occur at a high rate in this focus of VL and presented new data on the vector capacity of this population.

Natural infection of Lutzomyia longipalpis (Cembrene-1 population) with Leishmania infantum in a new visceral leishmaniasis focus in the eastern region of São Paulo State, Brazil

Abstract INTRODUCTION Visceral leishmaniasis (VL) transmission has been associated with two different populations of the Lutzomyia longipalpis complex in São Paulo state. METHODS In a recent focus of VL, we captured and dissected sand flies and investigated Leishmania infantum infection by parasitological, PCR, and sequencing analysis. RESULTS Flagellates were observed in 2 of 47 (4.2%) cembrene-1 Lu. longipalpis females. The sequences obtained matched those of Le. infantum. CONCLUSIONS We found that the transmission of Le. infantum by cembrene-1 females may occur at a high rate in this focus of VL and presented new data on the vector capacity of this population.

Classificação epidemiológica dos municípios do Estado de São Paulo segundo o Programa de Vigilância e Controle da Leishmaniose Visceral, 2017 / Epidemiological classification of the municipalities of the Stat e of São Paulo according to the Visceral Leishmaniasis Control and Surveillance Program, 2017

Foi realizado um estudo descritivo dos casos de Leishmaniose Visceral (LV) notificados no período de 1999 a 2017 no Estado de São Paulo (ESP). Para a classificação epidemiológica dos municípios com transmissão humana de LV foram seguidas as recomendações do Ministério da Saúde1 que considera: "Municípios com transmissão recente aqueles que apresentaram o primeiro registro da doença nos últimos três anos" e "Municípios endêmicos aqueles que apresentam transmissão contínua de LV humana há pelo menos três anos

A field study of the survival and dispersal pattern of Lutzomyia longipalpis in an endemic area of visceral leishmaniasis in Brazil.

Zoonotic Visceral leishmaniasis (ZVL) is a neglected tropical disease that in the Americas is caused by the infection of Leishmania infantum and the domestic dog (Canis familiaris) is the main parasite reservoir in urban areas. The parasite is mainly transmitted by populations of the sibling species Lutzomyia longipalpis that has been spreading in countries including Brazil, Argentina, Paraguay and more recently Uruguay. Although bionomic parameters such as population survival and the duration of the gonotrophic cycle are critical in evaluating vector capacity, field studies have rarely been applied to sand fly populations. The present study sought to evaluate basic bionomic parameters related to the vectorial capacity of the (S)-9-methylgermacrene-B population of the Lu. longipalpis complex in a visceral leishmaniasis area of Sao Paulo state. The daily survival rate, the duration of the gonotrophic cycle and the dispersal pattern were evaluated through the mark- release-recapture method. A total of 1,547 males and 401 females were marked and released in five experiments carried out between February 2013 and February 2014. The higher recapture rates occurred within 100 meters of the release point and the estimated daily survival rates varied between 0.69 and 0.89 for females and between 0.69 and 0.79 for males. The minimum duration of the gonotrophic cycle observed was five days. The absolute population size, calculated ranged from 900 to 4,857 females and from 2,882 to 9,543 males. Our results demonstrate a high survival rate of this vector population and low dispersal that could be associated with the presence of all necessary conditions for its establishment and maintenance in the peridomiciles of this area. Our findings contribute to the basic data necessary for the understanding of ZVL dynamics and the evaluation of the implementation of prevention and control measures.

Vetor ou vetores? Capacidade vetorial e estratégias de controle / Vector or vectors? Vectorial capacity and control strategies

Variáveis relacionadas a fatores epidemiológicos, ao ambiente, ao agente etiológico, ao vetor e aos reservatórios parecem atuar na determinação dos diferentes cenários de transmissão da leishmaniose visceral no Brasil. No estado de São Paulo a leishmaniose visceral (LV) não apresenta um padrão epidemiológico homogêneo por todas suas regiões, parecendo refletir uma multitude de cenários propícios para a ocorrência da transmissão dentro do território Paulista. Lutzomyia longipalpis é composta por um complexo de espécies das quais duas são encontradas no Estado de São Paulo e parecem possuir diferença na capacidade vetorial. É provável que essa diferença seja o fator determinante na caracterização dos diferentes padrões epidemiológicos observados nas diferentes regiões do Estado. No presente estudo, procuramos determinar a distribuição temporal e geográfica das espécies do complexo Lu. longipalpis, dos casos caninos e dos casos humanos de LV como elementos chave para ajudar na caracterização de alguns cenários de transmissão da doença e apontar áreas de maior risco para a aquisição da doença. Por outro lado, a recente e inesperada ocorrência de transmissão da LV em localidades sem a presença da Lu. longipalpis, caracteriza mais um novo cenário, onde a transmissão da Leishmania infantum ao homem se mostrou possível, configurando um novo desafio para as autoridades da saúde pública. (AU)

Variables related to epidemiological factors, etiologic agent, environment, vector and reservoirs seem to act in determining the different scenarios of transmission of visceral leishmaniasis (VL) in Brazil. In the state of São Paulo, VL does not present a homogeneous epidemiological pattern across all its regions, seeming to reflect a multitude of scenarios conducive to the occurrence of transmission within Paulista territory. Lutzomyia longipalpis is composed of a complex of species of which two are found in the state of São Paulo and appear to have a difference in vector capacity. It is likely that this difference is the determining factor in the characterization of the different epidemiological patterns observed in the different regions of the State. In the present study, we sought to determine the temporal and geographic distribution of Lu. longipalpis species, canine cases and human cases of VL as key elements to help characterize some scenarios of transmission of the disease and to indicate areas of greater risk for disease acquisition. The recent and unexpected occurrence of VL transmission in localities without the presence of Lu. longipalpis characterizes another new scenario, where other species of san flies can transmit Leishmania infantum to man and configuring a new challenge for public health authorities. (AU)

Vetor ou vetores? Capacidade vetorial e estratégias de controle / Vector or vectors? Vectorial capacity and control strategies

Variáveis relacionadas a fatores epidemiológicos, ao ambiente, ao agente etiológico, ao vetor e aos reservatórios parecem atuar na determinação dos diferentes cenários de transmissão da leishmaniose visceral no Brasil. No estado de São Paulo a leishmaniose visceral (LV) não apresenta um padrão epidemiológico homogêneo por todas suas regiões, parecendo refletir uma multitude de cenários propícios para a ocorrência da transmissão dentro do território Paulista. Lutzomyia longipalpis é composta por um complexo de espécies das quais duas são encontradas no Estado de São Paulo e parecem possuir diferença na capacidade vetorial. É provável que essa diferença seja o fator determinante na caracterização dos diferentes padrões epidemiológicos observados nas diferentes regiões do Estado. No presente estudo, procuramos determinar a distribuição temporal e geográfica das espécies do complexo Lu. longipalpis, dos casos caninos e dos casos humanos de LV como elementos chave para ajudar na caracterização de alguns cenários de transmissão da doença e apontar áreas de maior risco para a aquisição da doença. Por outro lado, a recente e inesperada ocorrência de transmissão da LV em localidades sem a presença da Lu. longipalpis, caracteriza mais um novo cenário, onde a transmissão da Leishmania infantum ao homem se mostrou possível, configurando um novo desafio para as autoridades da saúde pública.

Variables related to epidemiological factors, etiologic agent, environment, vector and reservoirs seem to act in determining the different scenarios of transmission of visceral leishmaniasis (VL) in Brazil. In the state of São Paulo, VL does not present a homogeneous epidemiological pattern across all its regions, seeming to reflect a multitude of scenarios conducive to the occurrence of transmission within Paulista territory. Lutzomyia longipalpis is composed of a complex of species of which two are found in the state of São Paulo and appear to have a difference in vector capacity. It is likely that this difference is the determining factor in the characterization of the different epidemiological patterns observed in the different regions of the State. In the present study, we sought to determine the temporal and geographic distribution of Lu. longipalpis species, canine cases and human cases of VL as key elements to help characterize some scenarios of transmission of the disease and to indicate areas of greater risk for disease acquisition. The recent and unexpected occurrence of VL transmission in localities without the presence of Lu. longipalpis characterizes another new scenario, where other species of san flies can transmit Leishmania infantum to man and configuring a new challenge for public health authorities.

Insights into the epidemiological link between biting flies and pemphigus foliaceus in southeastern Brazil.

BACKGROUND: Black fly and sandfly bites are related to the endemicity of pemphigus foliaceus (PF); however, an immune reaction against the salivary proteins from these flies still requires confirmation in the case of PF patients living in southeastern Brazil. PURPOSE: To georeference the distribution of Simuliidae (Diptera: Simuliidae) and Phlebotominae (Diptera: Psychodidae) and of PF cases in the northeastern region of São Paulo State, and to assess the humoral immune response against salivary gland extracts (SGEs) from biting flies in PF patients, relatives, and neighbours. METHODS: PF patients' medical information recorded between 1965 and 2014 were obtained from the database of the University Hospital. Data on the distribution of fly species were collected from scientific reports and epidemiological databases. Spatial maps relating the distribution of biting flies with PF cases were plotted. Serum IgG antibodies against the SGEs from Simulium nigrimanum, Nyssomyia neivai, and Aedes aegypti (as control) were determined by ELISA. RESULTS: Two hundred and eighty-five PF cases were distributed in 60 municipalities with a prevalence of 57.5 per million inhabitants, revealing well-defined geographical clusters. S. nigrimanum and N. neivai specimens were registered in eight (13.3%) and 26 (43.3%) of these municipalities, respectively. PF patients, and their relatives presented higher levels of IgG against the SGEs of S. nigrimanum and N. neivai (P<0.001 for both), but not against the SGE from A. aegypti (P=0.115 and P=0.552, respectively), as compared to controls. IgG against the SGEs from S. nigrimanum and N. neivai but not against the SGE from A. aegypti correlated with levels of anti-Desmoglein 1 in PF patients (r=0.3848, P=0.039; and r=0.416, P=0.022, respectively). CONCLUSION: An epidemiological link between biting flies and PF in southeastern Brazil is proposed, implying a possible role of the salivary proteins from these flies in PF etiopathogenesis.

Ecological parameters of the (S)-9-methylgermacrene-B population of the Lutzomyia longipalpis complex in a visceral leishmaniasis area in São Paulo state, Brazil.

BACKGROUND: Visceral leishmaniasis (VL) is an important public health challenge in Brazil because of the high number of human and canine cases reported annually. Leishmania infantum is the etiological agent of VL and Lutzomyia longipalpis is its main vector. However, evidence suggests that this taxon constitutes a species complex. In Sao Paulo state, there are two populations of Lu. longipalpis, each secreting distinct pheromones, (S)-9-methylgermacrene-B and Cembrene 1; both have been associated with different patterns of VL transmission. The aim of the present study was to investigate the temporal distribution and natural infection of the (S)-9-methylgermacrene-B population of the Lu. longipalpis complex in a highly VL endemic area of Sao Paulo state to obtain information that may contribute to the surveillance of this zoonosis and to the planning of preventive and control measures. METHODS: The study was carried out in Panorama municipality, Sao Paulo State. Captures were made during 24 months in seven domiciles. The relation between sand fly abundance and climatic variables, temperature and humidity, was analyzed and natural infection by Leishmania spp. in sand fly females was investigated by nested PCR. RESULTS: A total of 4120 sand flies, with predominance of Lu. longipalpis (97.2%) were captured. The highest averages of sand flies/night/trap occurred in the rainy season (November-March) and a positive, significant correlation between sand fly abundance and the temperature and humidity 20 days before the capture days was found. Leishmania infantum DNA was detected in three out of 250 pools of females analyzed, giving an estimated minimum infection rate of 1.2%. CONCLUSION: The identification of the climatic association between the high abundance of the vector in this highly endemic VL focus constitutes a fundamental point for evaluating future vector and dog control measures and this information increases the data of VL foci in Sao Paulo state that could contribute to the public health authorities in planning prevention and control measures. The identification of natural infection by Le. infantum in Lu. longipalpis specimens reinforces the importance of entomological surveillance activities in this municipality.

Maxadilan-simile expression in Nyssomyia neivai, a sandfly vector in an endemic region of Brazil, and its immunogenicity in patients with American tegumentary leishmaniasis.

BACKGROUND: Maxadilan (Max) is a salivary component in the sandfly Lutzomyia longipalpis (Lutz & Neiva 1912), a vector of visceral leishmaniasis. Max has a powerful vasodilatory effect and is a candidate vaccine that has been tested in experimental leishmaniasis. Nyssomyia neivai (Pinto 1926) is a vector of the pathogen responsible for American tegumentary leishmaniasis (ATL) in Brazil. OBJECTIVE: We searched for Max expression in Ny. neivai and for antibodies against Max in ATL patients. METHODS: cDNA and protein were extracted from the cephalic segment, including salivary glands, of Ny. neivai and analysed by polymerase chain reaction, DNA sequencing, and blotting assays. The results were compared with data obtained from Lu. longipalpis samples. We quantified antibodies against Max in serum samples from 41 patients with ATL (31 and 10 with the cutaneous and mucocutaneous forms, respectively) and 63 controls from the endemic northeastern region of São Paulo state, using enzyme-linked immunosorbent assay. FINDINGS: Recognition of a Max-simile peptide by specific antibodies confirmed expression of a Max sequence in Ny. neivai (GenBank EF601123.1). Compared to controls, patients with ATL presented higher levels of antibodies against Max (p = 0.004); 24.4% of the patients with ATL and 3.2% of the controls presented anti-Max levels above the cutoff index (p = 0.014). The anti-Max levels were not associated with the specific clinical form of ATL, leishmanin skin test response, absence or presence of amastigotes in histopathologic exam, results of indirect immunofluorescence testing for leishmaniasis, or duration of cutaneous form disease. MAIN CONCLUSION: High serum anti-Max levels did not protect patients against ATL, but confirmed previous natural exposure to Ny. neivai bites in this ATL endemic region.

Maxadilan-simile expression in Nyssomyia neivai, a sandfly vector in an endemic region of Brazil, and its immunogenicity in patients with American tegumentary leishmaniasis

BACKGROUND Maxadilan (Max) is a salivary component in the sandfly Lutzomyia longipalpis (Lutz & Neiva 1912), a vector of visceral leishmaniasis. Max has a powerful vasodilatory effect and is a candidate vaccine that has been tested in experimental leishmaniasis. Nyssomyia neivai (Pinto 1926) is a vector of the pathogen responsible for American tegumentary leishmaniasis (ATL) in Brazil. OBJECTIVE We searched for Max expression in Ny. neivai and for antibodies against Max in ATL patients. METHODS cDNA and protein were extracted from the cephalic segment, including salivary glands, of Ny. neivai and analysed by polymerase chain reaction, DNA sequencing, and blotting assays. The results were compared with data obtained from Lu. longipalpis samples. We quantified antibodies against Max in serum samples from 41 patients with ATL (31 and 10 with the cutaneous and mucocutaneous forms, respectively) and 63 controls from the endemic northeastern region of São Paulo state, using enzyme-linked immunosorbent assay. FINDINGS Recognition of a Max-simile peptide by specific antibodies confirmed expression of a Max sequence in Ny. neivai (GenBank EF601123.1). Compared to controls, patients with ATL presented higher levels of antibodies against Max (p = 0.004); 24.4% of the patients with ATL and 3.2% of the controls presented anti-Max levels above the cutoff index (p = 0.014). The anti-Max levels were not associated with the specific clinical form of ATL, leishmanin skin test response, absence or presence of amastigotes in histopathologic exam, results of indirect immunofluorescence testing for leishmaniasis, or duration of cutaneous form disease. MAIN CONCLUSION High serum anti-Max levels did not protect patients against ATL, but confirmed previous natural exposure to Ny. neivai bites in this ATL endemic region.

Distribution of Lutzomyia longipalpis chemotype populations in São Paulo state, Brazil.

BACKGROUND: American visceral leishmaniasis (AVL) is an emerging disease in the state of São Paulo, Brazil. Its geographical expansion and the increase in the number of human cases has been linked to dispersion of Lutzomyia longipalpis into urban areas. To produce more accurate risk maps we investigated the geographic distribution and routes of expansion of the disease as well as chemotype populations of the vector. METHODOLOGY/PRINCIPAL FINDINGS: A database, containing the annual records of municipalities which had notified human and canine AVL cases as well as the presence of the vector, was compiled. The chemotypes of L. longipalpis populations from municipalities in different regions of São Paulo State were determined by Coupled Gas Chromatography - Mass Spectrometry. From 1997 to June 2014, L. longipalpis has been reported in 166 municipalities, 148 of them in the Western region. A total of 106 municipalities were identified with transmission and 99 were located in the Western region, where all 2,204 autochthonous human cases occurred. Both the vector and the occurrence of human cases have expanded in a South-easterly direction, from the Western to central region, and from there, a further expansion to the North and the South. The (S)-9-methylgermacrene-B population of L. longipalpis is widely distributed in the Western region and the cembrene-1 population is restricted to the Eastern region. CONCLUSION/SIGNIFICANCE: The maps in the present study show that there are two distinct epidemiological patterns of AVL in São Paulo State and that the expansion of human and canine AVL cases through the Western region has followed the same dispersion route of only one of the two species of the L. longipalpis complex, (S)-9-methylgermacrene-B. Entomological vigilance based on the routes of dispersion and identification of the chemotype population could be used to identify at-risk areas and consequently define the priorities for control measures.

Colonization of palm trees by Rhodnius neglectus and household and invasion in an urban area, Araçatuba, São Paulo State, Brazil.

The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a "Munck" truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.

COLONIZATION OF PALM TREES BY Rhodnius neglectus AND HOUSEHOLD AND INVASION IN AN URBAN AREA, ARAÇATUBA, SÃO PAULO STATE, BRAZIL / Colonização de palmeiras por Rhodnius neglectus e invasão domiciliar em área urbana, Araçatuba, São Paulo, Brasil

The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a “Munck” truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.

O objetivo deste trabalho é relatar a colonização de palmeiras por Rhodnius neglectus, sua invasão em área urbana, na cidade de Araçatuba - São Paulo, o controle e as medidas de vigilância instituídas. As pesquisas de triatomíneos nos domicílios ocorreram nos apartamentos quando da notificação pelo morador. Os insetos coletados foram identificados, examinados quanto à infecção natural e teste de precipitina. Na pesquisa das palmeiras foram utilizados lonas para forração do chão e caminhão Munck equipado com moto poda. O controle químico foi realizado com a utilização de compressor manual. No ano de 2009, foram coletados pela população 81 exemplares de Rhodnius neglectus em domicílios. O teste de precipitina acusou presença de sangue humano em 2,7% das amostras. Pesquisas entomológicas foram realizadas nestas edificações e naquelas situadas em um raio de 200 metros onde ocorreram as invasões. A pesquisa realizada nas palmeiras resultou na captura de 882 exemplares de triatomíneos, negativos para tripanosomatídeos. Foi realizado controle mecânico e químico. Novas pesquisas realizadas nas palmeiras avaliadas no mesmo ano resultaram na coleta de seis exemplares. Os controles mecânicos e químicos das palmeiras aliado ao trabalho de participação popular mostraram-se factíveis impedindo a colonização destes insetos nos domicílios da cidade.

Spatial and seasonal distribution of Lutzomyia longipalpis in Dracena, a city in the western region of the State of São Paulo, Brazil, that is endemic with visceral leishmaniasis

Introduction Vector seasonality knowledge is important for monitoring and controlling of vector-borne diseases. Lutzomyia longipalpis (Lu. longipalpis) is the main vector of Leishmania (Leishmania) infantum Nicolle, 1908, which is the causative agent of visceral leishmaniasis in the Americas. Methods Lu. longipalpis was monitored for 3 consecutive nights each month using light traps from the Centers for Disease Control in the peridomiciles and intradomiciles of 18 residences from January 2005 to December 2012 in the urban area of Dracena, a medium-sized city located in the western region of São Paulo, Brazil. Results A total of 54,820 Lu. longipalpis specimens were collected, and the proportion of positive samples was significantly higher in the peridomiciles than in the intradomiciles (p<0.05) in all 8 years of the study, except for 2005. The vector was present in all study years in the 9 sub-regions of the city, and the male/female ratio ranged from 3.19 to 4.26. The greatest vector abundance occurred in the first semester and peaked in March, confirming its seasonality. Conclusions The maintenance of this high abundance over an 8-year surveillance period demonstrates the vector adaptation to the urban conditions of the city. These characteristics present a major challenge for preventing human and canine contact with the vector and, consequently, controlling the spread of disease. .

Larval breeding sites of Lutzomyia longipalpis (Diptera: Psychodidae) in visceral leishmaniasis endemic urban areas in Southeastern Brazil.

BACKGROUND: The scarcity of information on the immature stages of sand flies and their preferred breeding sites has resulted in the focus of vectorial control on the adult stage using residual insecticide house-spraying. This strategy, along with the treatment of human cases and the euthanasia of infected dogs, has proven inefficient and visceral leishmaniasis continues to expand in Brazil. Identifying the breeding sites of sand flies is essential to the understanding of the vector's population dynamic and could be used to develop novel control strategies. METHODOLOGY/PRINCIPAL FINDING: In the present study, an intensive search for the breeding sites of Lutzomyia longipalpis was conducted in urban and peri-urban areas of two municipalities, Promissão and Dracena, which are endemic for visceral leishmaniasis in São Paulo State, Brazil. During an exploratory period, a total of 962 soil emergence traps were used to investigate possible peridomiciliary breeding site microhabitats such as: leaf litter under tree, chicken sheds, other animal sheds and uncovered debris. A total of 160 sand flies were collected and 148 (92.5%) were L. longipalpis. In Promissão the proportion of chicken sheds positive was significantly higher than in leaf litter under trees. Chicken shed microhabitats presented the highest density of L. longipalpis in both municipalities: 17.29 and 5.71 individuals per square meter sampled in Promissão and Dracena respectively. A contagious spatial distribution pattern of L. longipalpis was identified in the emergence traps located in the chicken sheds. CONCLUSION: The results indicate that chicken sheds are the preferential breeding site for L. longipalpis in the present study areas. Thus, control measures targeting the immature stages in chicken sheds could have a great effect on reducing the number of adult flies and consequently the transmission rate of Leishmania (Leishmania) infantum chagasi.