Impact of vector control actions in the abundance of Lutzomyia longipalpis in Montes Claros, Brazil.

Visceral leishmaniasis (VL) is endemic to many states in Brazil. To prevent further expansion of the disease, the Brazilian Ministry of Health adopted integrated measures through the Program of Surveillance and Control of Visceral Leishmaniasis (PSCVL), whose actions include the diagnosis and euthanasia of seropositive dogs (the main domestic reservoirs), the use of residual insecticides, environmental management (EM) to control vector population (mainly Lutzomyia longipalpis phlebotomine), rigorous epidemiological surveillance, and health education. The present study was conducted in areas with recent moderate VL transmission to evaluate the efficacy of vector control activities. The systematic capture of phlebotomine was performed for three consecutive days per month, from August 2015 to July 2017. The number of specimens captured was taken as a representative of the monthly insect population. A total of 38,055 phlebotomine specimens were captured and identified at the species level. Lu. longipalpis was consistently found to be the predominant species (97.7%) each month. In the first year of the study, no intervention was performed. In the second year, two cycles of chemical spraying, EM, or a combination of both were performed before and after the rainy season. All interventions, either individually or in combination, reduced the abundance of Lu. longipalpis in the study area.

Evaluation of chemical spraying and environmental management efficacy in areas with minor previous application of integrated control actions for visceral leishmaniasis in Brazil.

Leishmaniases are vector-borne diseases that are transmitted to humans through the bite of Leishmania-infected phlebotomine sand flies (Diptera:Psychodidae). The main proved vector of visceral leishmaniais (VL) in the New World - Lutzomyia longipalpis - is well-adapted to urban areas and has extensive distribution within the five geographical regions of Brazil. Integrated public health actions directed for the vector, domestic reservoir and humans for the control of VL are preferentially applied in municipalities with higher epidemiological risk of transmission. In this study, we evaluated the individual impact of two main vector control actions - chemical spraying and environmental management - in two districts with no reported cases of human VL. Although belonging to an endemic municipality for VL in Brazil, the integrated control actions have not been applied in these districts due to the absence of human cases. The number of L. longipalpis captured in a two-year period was used as indicator of the population density of the vector. After chemical spraying a tendency of reduction in L. longipalpis was observed but with no statistical significance compared to the control. Environmental management was effective in that reduction and it may help in the control of VL by reducing the population density of the vector in a preventive and more permanent action, perhaps associated with chemical spraying.

Phlebotomine sand fly fauna and leishmania infection in the vicinity of the Serra do Cipó National Park, a natural Brazilian heritage site.

In the New World, the leishmaniases are primarily transmitted to humans through the bites of Leishmania-infected Lutzomyia (Diptera: Psychodidae) phlebotomine sand flies. Any or both of two basic clinical forms of these diseases are endemic to several cities in Brazil--the American cutaneous leishmaniasis (ACL) and the American visceral leishmaniasis (AVL). The present study was conducted in the urban area of a small-sized Brazilian municipality (Jaboticatubas), in which three cases of AVL and nine of ACL have been reported in the last five years. Jaboticatubas is an important tourism hub, as it includes a major part of the Serra do Cipó National Park. Currently, no local data is available on the entomological fauna or circulating Leishmania. During the one-year period of this study, we captured 3,104 phlebotomine sand flies belonging to sixteen Lutzomyia species. In addition to identifying incriminated or suspected vectors of ACL with DNA of the etiological agent of AVL and vice versa, we also detected Leishmania DNA in unexpected Lutzomyia species. The expressive presence of vectors and natural Leishmania infection indicates favorable conditions for the spreading of leishmaniases in the vicinity of the Serra do Cipó National Park.

Epidemiological aspects of vector, parasite, and domestic reservoir in areas of recent transmission and no reported human cases of visceral leishmaniasis in Brazil.

About 97% of the human cases of the American visceral leishmaniasis (VL) occur in Brazil. In the last few years, the disease expanded to medium- and large-sized cities, in which surveillance and control actions have been intensified, in an effort to control VL spreading. Our two-year study was conducted in Belo Horizonte, the sixth most populous city in Brazil, which is endemic for VL. We focused in two particular districts of recent transmission of the disease, with no reported human cases and submitted to minor surveillance and control actions. Our aim was to draw an epidemiological profile of the local situation concerning Lutzomyia vector, Leishmania parasites, and the main domestic reservoirs (dogs). Lutzomyia longipalpis comprised 96.5% of the total phlebotomine sand flies captured and displayed an expressive minimal infection rate by Leishmania infantum (16.7%). Positive correlations were found between the population densities of L. longipalpis, rainfall and temperature. L. infantum was also detected in the cortelezzii complex and, for the first time, in Lutzomyia lloydi. Leishmania braziliensis, an etiological agent of the American cutaneous leishmaniasis, was also identified in L. longipalpis. Among the 1408 dogs serologically tested by standard enzyme-linked and fluorescence immune assays (ELISA/IFA) 3.6% were positive for VL. L. infantum DNA and Leishmania parasites were identified in 100% and 72.5% of the seropositive dogs, respectively. The co-positivity of other diagnostic tests for VL-Leishmania-nested PCR, imprint and myeloculture-was compared to the standard serology. Both symptomatic or asymptomatic dogs displayed an equal average number of positive diagnostic tests for VL. The districts studied display favorable conditions for the rapid spreading of human infection, in terms of L. longipalpis population density, and presence of L. infantum in both vector and main reservoir.

Rattus norvegicus (Rodentia: Muridae) Infected by Leishmania (Leishmania) infantum (syn. Le. chagasi) in Brazil.

In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL) is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL) was also captured at high proportion (12.8%). Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares.

Ovos de enterobius vermicularis em salas de espera e banheiros de unidades básicas de saúde (UBS) do município de Nova Serrana-MG: contribuições para o controle / Enterobius vermicularis eggs in waiting rooms and bathrooms basic health units (BHU) in the municipality of Nova Serrana-MG: contributions to control

Neste trabalho, avaliou-se, utilizando a técnica de Graham (1941), a presença de ovos de helmintos intestinais em amostras coletadas em objetos de cinco Unidades Básicas de Saúde (UBS) da cidade de Nova Serrana-MG. No total de oito coletas, foram amostrados, nas recepções, 40 mesas de atendimento e 40 assentos de cadeiras e, nos banheiros, 64 maçanetas internas e 64 maçanetas externas de portas. Todas as lâminas foram analisadas por microscopia óptica nos aumentos de 10X e 40X no Laboratório de Microscopia da FUNEDI/UEMG e reexaminadas no Laboratório de Helmintologia e Malacologia Médica do Centro de Pesquisas René Rachou (FIOCRUZ-Minas). Os resultados indicaram a presença de ovos de Enterobius vermicularis, em sua maioria, viáveis, sendo os percentuais de ocorrência calculados por meio de proporção simples. Na recepção, a porcentagem de contaminação foi de 25,0 por cento nas mesas de atendimento e de 17,9 por cento no assento das cadeiras; nos banheiros, 35,7 por cento das maçanetas internas e 21,4 por cento das maçanetas externas apresentaram ovos. Não foram encontrados ovos e larvas de outros helmintos, apenas grãos de pólen, fibras vegetais e esporos de fungos. Foram realizadas palestras direcionadas aos funcionários destas UBS para apresentar-lhes os resultados e discutir medidas para evitar a contaminação de pessoas que frequentam e trabalham nestes locais. Os dados evidenciaram que as salas de espera das UBS podem ser importantes veículos de dispersão e contaminação de enteroparasitos. Medidas de educação em saúde são importantes e devem ser realizadas entre os usuários e funcionários dos postos, pois levam as pessoas a conhecer o problema, mudar seus hábitos e discutir soluções para prevenção e controle desta e de outras endemias...

In this study, the presence of intestinal helminth eggs was evaluated in samples collected from five Basic Health Units (BHU) using the Graham’s technique (1941), in the city of Nova Serrana (MG). In the total of 8 collections, 40 chair seats and 40 attendance tables were sampled in the reception and, on the toilet doors, 64 internal door handles and 64 external door handles. All the slides were analyzed by light optic microscopy with 10X and 40X magnifications in the Microscopy Laboratory FUNEDI / UEMG and re-examined in the Medical Malacology and Helminthology Laboratory of the Research Center René Rachou (FIOCRUZ-Minas). The results indicated the presence of Enterobius vermicularis eggs, mostly viable, with infection rates calculated by simple proportion. In the reception the contamination percentage was 25.0 percent on attendance tables and 17.9 percent on chair seats; in the toilets, 35.7 perecent of internal door handles and 21.4 percent of external door handles presented eggs. There were no eggs and larvae of other helminths, only pollen grains, vegetable fibers and fungal spores. Lectures were held with employees of BHU to present the results and discuss measures that can be taken to prevent contamination of people who attend and work at these sites. The data showed that the BHU toilets and waiting rooms can be important vehicles of dispersal and contamination with enteroparasites. Health education measures are important and must be undertaken among the health center users and employees as they lead people to understand the problem, change their habits and discuss solutions to prevent and control this and other diseases...