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Introduction American cutaneous leishmaniasis (ACL) has been reported in every municipality of the State of Mato Grosso, Brazil, but the transmission epidemiology remains poorly understood. Our study was developed in a rural area of the Nova Mutum municipality where four autochthonous cases of ACL were reported in 2009. Our aims were to describe the local phlebotomine sandfly fauna and to investigate the infection rates and infecting Leishmania species in the captured sandflies. Methods Entomological captures were performed bimonthly at 10 fixed sites close to the edge of a forested area between June 2011 and April 2012. Results A total of 3,743 phlebotomine sandflies belonging to 31 distinct species were captured. Approximately 75% of the specimens were females. The most abundant species (45.4%) was Lutzomyia antunesi, which was consistently captured at every site. Species that are epidemiologically important for ACL, such as L. flaviscutellata, L. whitmani and L. umbratilis, were also captured. L. antunesi and L. ubiquitalis were naturally infected by Leishmania braziliensis or Le. guyanensis, with minimum infection rates of 0.88% and 6.67%, respectively. Surprisingly, L. antunesi was infected by Le. infantum (synonym chagasi). Conclusions The natural infection of L. antunesi and L. ubiquitalis by Leishmania sp. suggests that these species might play a role in the zoonotic cycle of ACL in Nova Mutum. The presence of Le. infantum in L. antunesi suggests that there may be a risk of an outbreak of visceral leishmaniasis (VL) in Nova Mutum.

Montes Claros in Minas Gerais State, Brazil, was considered an intense transmission area for visceral leishmaniasis. This study evaluated sand fly fauna after insecticide application. Captures were performed in 10 districts from September 2005 to August 2006 with CDC light traps inside and outside each residence. Cypermethrin was sprayed in two cycles during November/2005 and May/2006. The 636 specimens collected, belonging to 10 species, were predominantly Lutzomyia longipalpis (79%), and most frequently males (70%). The highest percentage of specimens were captured in areas surrounding domiciles (85.8%). The main species were observed to be sensitive to treatment with the insecticide. The results showed a reduction in the number of sand flies collected after use of cypermethrin in homes and annexes, and with residual effect lasting from two to four months.Montes Claros foi considerada área de transmissão intensa para leishmaniose visceral no Estado de Minas Gerais, Brasil. Este trabalho avaliou a fauna de flebotomíneos após a aplicação do inseticida. Entre setembro de 2005 e agosto de 2006, foram realizadas capturas com 20 armadilhas luminosas CDC em 10 bairros do município, no intra e no peridomicílio de cada residência. Dois ciclos de borrifação com cipermetrina foram realizados nos meses de novembro/2005 e maio/2006. Coletou-se 636 exemplares pertencentes a 10 espécies, com predominância de Lutzomyia longipalpis (79%). Machos foram coletados com maior frequência (70%). O peridomicílio apresentou a maior porcentagem dos espécimens capturados (85,8%). Observou-se que as principais espécies foram sensíveis ao tratamento com o inseticida. Os resultados mostraram uma redução do número de flebotomíneos coletados devido ao uso de cipermetrina nos domicílios e seus anexos, mas com efeito residual atuante entre dois e quatro meses.

ABSTRACT Background: Although canine visceral leishmaniasis (CVL) transmission primarily occurs through the bite of phlebotomine sand flies infected with Leishmania infantum, alternative routes may exist. Methods: Thirty-four dogs diagnosed with CVL were sampled for parasitological investigation in tissues from the reproductive tract. Results: Amastigotes of Leishmania sp. were present in 79% (27/34) of the reproductive system samples, with distinct infection rates depending on the tissue. Conclusions: Our data confirms that alternative routes, such as horizontal and vertical transmissions, should be considered in the epidemiological chain of CVL.

Background: Porteirinha is endemic for visceral leishmaniasis (VL), with intense disease transmission of the disease. We evaluated the impact of canine euthanasia as a single control measure on the incidence of VL in humans and canines. Methods: A prospective observational cohort study was carried out over four years (1998–2002) in 8 of the 12 neighborhoods of the city. The dynamics of canine visceral leishmaniasis (CVL) transmission were evaluated for 2 years, before beginning the screening–culling intervention. The comparative morbidity index (CMI) was used to stratify areas with the greatest risk of CVL, and the spatial distribution of human and canine VL cases was compared using univariate and bivariate K-functions. Results: Human cases conglomerated in three neighborhoods. Spatial clusters were detected for CVL in 1998, 2000, and 2001, but not in 1999, when greater spatial dispersion occurred. The screening and culling intervention reduced the number of human VL cases and decreased the incidence of CVL, mainly in neighborhoods with a high CMI. Conclusions: The systematic euthanasia of seropositive dogs was shown to be an effective control action of the Program for Control of Visceral Leishmaniasis (PCLV) in Brazil. The fundamental role of domestic dogs in the epidemiological chain of VL was reaffirmed.

Abstract INTRODUCTION: Canine visceral leishmaniasis (CVL) is an endemic disease in Brazil, and integrated control actions have been adopted by the Brazilian Ministry of Health to control its spread. However, the transmission profile is unknown in areas with recent CVL cases, including Itaúna, located in the Brazilian state of Minas Gerais, where the present study was carried out. METHODS: A total of 2,302 dogs from 12 neighborhoods were serologically tested for canine VL using the current diagnostic protocol adopted by the Brazilian Ministry of Health. Test positivity rate (TPR) and CVL prevalence were determined for each neighborhood. The presence of Leishmania was assessed in 60 seropositive dogs which had been recommended for euthanasia. Twenty-two of them (37%) were asymptomatic, and 38 (63%) were symptomatic for CVL. Parasitological (myeloculture and smear/imprint) and molecular (PCR) methods were employed for Leishmania detection in bone marrow, spleen, mesenteric lymph nodes, and ear skin. The infecting Leishmania species was identified by DNA sequencing. RESULTS: CVL prevalence (per 1,000 dogs) varied from 0.0-166.67, depending on the neighborhood, with a mean of 68.96 (SD 51.38). Leishmania DNA was detected in at least one tissue from all seropositive dogs, with comparable TPR among tissues. Leishmania parasites were identified in most (54/60) seropositive dogs, and the infecting parasite was identified as Leishmania infantum in all of these. CONCLUSIONS: Prevalence of CVL is a contributor to the spread of visceral leishmaniasis in Itaúna.

Abstract INTRODUCTION: Leishmaniasis constitutes a serious but neglected tropical disease. Recently, socio-environmental, biological and physical changes have altered the range of leishmaniasis, causing it to spread into urban areas. In Minas Gerais, the disease is endemic, exhibiting regional differences and reaching urban centers. The purpose of this study was to evaluate entomological aspects related to the ecoepidemiology of leishmaniasis in Itaúna. METHODS: Monthly catches with HP traps were carried out from June 2017 to May 2018, in three ecological areas (urban, rural, and forest). The adaptability of the species to anthropic environments was assessed using the synanthropy index (SI). RESULTS: We collected 1306 specimens of phlebotomine sand flies. Of the species of medical importance, Lutzomyia longipalpis, the vector of Leishmania infantum, represented 90.4% of the specimens identified at species level (n=1260). Nyssomyia whitmani, the vector of Leishmania braziliensis, represented 1.6% of the total. Lu. longipalpis displayed an SI of +95.8, a value that denotes a marked preference for human environments. For Ny. whitmani, the SI was -25, expressing the tendency of this species to occupy uninhabited areas. The population of the three most numerous species captured increased with rain, high temperatures, and high relative humidity. Although captured at low numbers, Ny. whitmani showed a different profile concerning the climate variables analyzed. CONCLUSIONS: Understanding the epidemiology of the disease may assist the health services in formulating effective control measures for improving community health and contributing to the establishment of a dynamic relationship and a global awareness of the health/disease process.

Visceral leishmaniasis (VL) is a neglected tropical disease, caused by Leishmania (Kinetoplastida, Trypanosomatidae) species. In Brazil, the transmission of this parasite essentially occurs through the bite of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) previously infected with Leishmania infantum. Aiming at preventing VL expansion over the country, integrated control actions have been implemented through a Visceral Leishmaniasis Surveillance and Control Program (VLSCP). Among the actions currently adopted by the program, the screening-culling of seropositive dogs for canine VL (CVL) is particularly polemic. Dogs with negative or divergent serology for CVL remain in their owner's domicile and are monitored by public health agents. In the present study, we determined the prevalence of CVL and analyzed the implementation of the VLSCP screening-culling action, in an area in Brazil where there has been a recent expansion of VL. Canine census surveys were conducted semiannually for two years (Aug/2015 to Feb/2017). Serological diagnosis of CVL was performed in accordance with current VLSCP protocol: immunochromatography (TR-DPP) followed by enzyme-linked immunosorbent assay (ELISA EIE). 6,667 dogs were serologically screened for CVL, of which 567 (8.5%) were positive in both tests and 641 (9.6%) had divergent results. A variable percentage (6.3% to 65.4%) of the dogs in the latter group became positive within nine months from the first result. Xenodiagnosis was conducted in canine samples belonging to any of the three possible serological statuses for CVL-positive, divergent or negative. Leishmania spp. DNA was detected in Lu. longipalpis that fed on 50.0% (5/10) of dogs with positive serology and on 29.4% (5/17) of dogs with divergent serological status for CVL. Therefore, dogs with divergent serology for CVL may be as Leishmania-infective to Lu. longipalpis as seropositive ones. Even with the adoption of euthanasia for seropositive dogs, part of the canine population will continue to serve as a source of Leishmania infection for phlebotomine sand flies.

Abstract Background Given the increase in cases of visceral leishmaniasis in recent years, associated with the socio-economic impact of this disease, as well as the wide distribution of Lutzomyia longipalpis in Brazil and the likelihood that this vector may develop resistance to insecticides used for control, the Ministry of Health considers as crucial the creation of a network in order to study and monitor the resistance of this vector to insecticides used for control. In this sense, this study aimed: 1) to characterize the susceptibility of L. longipalpis from Lapinha Cave (Lagoa Santa, MG - Brazil) to Alfateck SC200 in field bioassays, and 2) to define the susceptibility baseline to alpha-cypermethrin in laboratory bioassays, checking the possibility of using it as susceptibility reference lineage (SRL). Findings The field bioassays revealed that the tested population was highly susceptible to alpha-cypermethrin in all time periods with high mortality (~100 %) in all treated surfaces before six months after spraying. In the laboratory bioassays, the studied population presented LD50, LD95 and LD99 to 0.78013, 10.5580 and 31.067 mg/m2, respectively. The slope was 1.454121. Conclusions The studied population of L. longipalpis was considered as adequate for SRL according criterion recommended by Pan-American Health Organization and has proven susceptibility to tested insecticide in the field. One cannot rule out the possibility of finding populations of L. longipalpis more susceptible to alpha-cypermethrin; therefore, further research is necessary on other populations with potential use as a SRL.

Introduction Dogs play a primary role in the zoonotic cycle of visceral leishmaniasis (VL). Therefore, the accurate diagnosis of infected dogs, primarily asymptomatic dogs, is crucial to the efficiency of VL control programs. Methods We investigated the agreement of four diagnostic tests for canine visceral leishmaniasis (CVL): parasite detection, either after myeloculture or by direct microscopic examination of tissue imprints; kinetoplast-deoxyribonucleic acid-polymerase chain reaction (kDNA-PCR); and an immunochromatographic test (ICT). An enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence test (IFAT), both of which were adopted as part of the screening-culling program in Brazil, were used as reference tests. Our sample set consisted of 44 seropositive dogs, 25 of which were clinically asymptomatic and 19 were symptomatic for CVL according to ELISA-IFAT. Results The highest and lowest test co-positivities were observed for ICT (77.3%) and myeloculture (58.1%), respectively. When analyzed together, the overall percentage of co-positive tests was significantly higher for the symptomatic group compared to the asymptomatic group. However, only ICT was significantly different based on the results of a separate analysis per test for each group of dogs. The majority (93.8%) of animals exhibited at least one positive test result, with an average of 2.66 positive tests per dog. Half of the symptomatic dogs tested positive for all four tests administered. Conclusions The variability between test results reinforces the need for more efficient and reliable methods to accurately diagnose canine VL, particularly in asymptomatic animals.

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.

INTRODUÇÃO: A leishmaniose visceral tem sido notificada em quase todos os estados do Brasil, e principalmente no norte de Minas Gerais, onde a doença é endêmica. Este estudo visou detectar a infecção natural de Lutzomyia longipalpis e identificar através da técnica de PCR/RFLP a espécie de Leishmania encontrada nos flebotomíneos do município de Janaúba. MÉTODOS: Utilizando-se armadilhas luminosas, foram capturadas 1.550 fêmeas de L. longipalpis, que agrupadas em pool de 10 exemplares foram submetidas à extração e amplificação de DNA, através das técnicas de PCR genérico e cacofonia. RESULTADOS: Dos 155 pools, seis apresentaram-se positivos para Leishmania sp., sendo a taxa de infecção do município de 3,9%. Através da PCR/RFLP determinou-se que o padrão de digestão das amostras positivas foi semelhante ao da cepa referência Leishmania chagasi (MHOM/BR/74/PP75). CONCLUSÕES: A detecção de infecção natural associada a estudos sobre a epidemiologia da LV sugere que L. longipalpis esteja envolvida na transmissão de L. infantum chagasi em Janaúba, principalmente nas áreas de intensa transmissão de LV.

The American visceral leishmaniasis (AVL) is caused by parasites belonging to the genus Leishmania (Trypanosomatidae) and is transmitted to humans through the bite of certain species of infected phlebotomine sand flies. In this study, we investigated the natural infection ratio of Lutzomyia longipalpis, the main vector species of AVL in Brazil, in Várzea Grande, Mato Grosso State. Between July 2004 and June 2006, phlebotomine sand flies were captured in peridomestic areas using CDC light-traps. Four hundred and twenty (420) specimens of Lu. longipalpis were captured. 42 pools, containing 10 specimens of Lu. longipalpis each, were used for genomic DNA extraction and PCR (polymerase chain reaction) amplification. Leishmania spp. DNA was detected in three out of the 42 pools tested, resulting in a minimal infection ratio of 0.71%. Restriction fragment length polymorphism (RFLP) analysis indicated that Leishmania (L.) chagasi was the infective agent in the positive pools.A leishmaniose visceral americana (LVA) é causada por parasitos pertencentes ao gênero Leishmania (Trypanosomatidae) e transmitida ao homem através da picada de certas espécies de flebotomíneos, previamente infectados. Neste trabalho, investigamos o índice de infecção natural de Lutzomyia longipalpis, principal vetor da LVA no Brasil, em Várzea Grande, Estado do Mato Grosso. De julho de 2004 a junho de 2006, foram feitas capturas de flebotomíneos em áreas peridomésticas utilizando armadilhas de luz CDC. Foram capturadas 420 espécimens de Lu. longipalpis. Quarenta e dois grupos, formados por 10 espécimens de Lu. longipalpis cada um, foram submetidos à extração de DNA genômico e amplificação por PCR (reação em cadeia da polimerase). DNA de Leishmania spp. foi detectado em 3 dos 42 grupos testados, resultando em um índice mínimo de infecção de 0,71%. A análise de polimorfismos de fragmentos de restrição (RFLP) indicou Leishmania (L.) chagasi como a espécie infectante nos grupos positivos.

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.

INTRODUÇÃO: O município de Jaciara foi classificado em 2003, como área de transmissão de leishmaniose visceral em situação de surto. O trabalho objetivou determinar evidência de transmissão de Leishmania (Leishmania) infantum chagasi por Lutzomyia cruzi no município de Jaciara, Estado de Mato Grosso, Brasil. MÉTODOS: O município situa-se a 127km da capital Cuiabá e é um importante ponto de atração para os praticantes de eco-turismo. Fêmeas de Lutzomyia cruzi, capturadas com armadilha de CDC, foram dissecadas para confirmação da espécie e armazenadas a -20ºC em pools de 10 indivíduos para extração de DNA, PCR genérico, RFLP específico e eletroforese em gel de poliacrilamida. RESULTADOS: O levantamento entomológico demonstrou a ocorrência abundante de Lutzomyia cruzi e ausência de Lutzomyia longipalpis, principal vetora da Leishmania (Leishmania) infantum chagasi. Uma das três amostras analisadas apresentou banda característica de DNA de Leishmania (120pb) em PCR genérico. Para confirmação da espécie de Leishmania, na RFLP utilizaram-se controles positivos de Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis e Leishmania (Leishmania) infantum chagasi digeridas com enzima de restrição HaeIII. Constatou-se um padrão de bandas semelhante à Leishmania (Leishmania) infantum chagasi em uma amostra, confirmando a detecção de infecção natural de Leishmania (Leishmania) infantum chagasi em Lutzomyia cruzi. CONCLUSÕES: A ocorrência de casos humanos e cães positivos, a presença da Lutzomyia cruzi e a ausência de Lutzomyia longipalpis, bem como a detecção de infecção natural por Leishmania (Leishmania) infantum chagasi, evidenciam a participação de Lutzomyia cruzi na transmissão da leishmaniose visceral em Jaciara, Estado de Mato Grosso, Brasil.

In the present paper, we evaluate the relationship between climate variables and population density of Lutzomyia longipalpis in Montes Claros, an area of active transmission of American visceral leishmaniasis (AVL) in Brazil. Entomological captures were performed in 10 selected districts of the city, between September 2002-August 2003. A total of 773 specimens of L. longipalpiswere captured in the period and the population density could be associated with local climate variables (cumulative rainfall, average temperature and relative humidity) through a mathematical linear model with a determination coefficient (Rsqr) of 0.752. Although based on an oversimplified statistical analysis, as far as the vector is concerned, this approach showed to be potentially useful as a starting point to guide control measures for AVL in Montes Claros.