Effective surveillance of vector dynamics of Aedes aegypti in a hospital setting in Cuiabá, Mato Grosso, Brazil.

INTRODUCTION: Hospitals are important for vector control of endemic diseases. METHODOLOGY: To investigate the presence of dengue vectors, 30 locations at a university hospital in Cuiabá, Mato Grosso, Brazil, were monitored from January to December 2009 for mosquito eggs using ovitraps placed in high-traffic internal and external areas. RESULTS: A total of 2,302 eggs were obtained. Positivity rate at different sites ranged from 50.0% to 0.0%, with the highest indices in external areas. The presence of eggs correlated with increasing humidity (r = 9.81; p = 0.0013). DISCUSSION: The study aimed to detect and verify the infestation level of the dengue vector and the influence of abiotic factors. CONCLUSIONS: The results indicate that this hospital may be considered an environment for the spread of dengue and hence strategic actions, including control measures and programs aimed at preventing the transmission of this vector, must be implemented.

Spatial distribution and temporal variability of phlebotominae at the Cuiabá campus of the Federal University of Mato Grosso, Brazil

Phlebotomine sand flies are vectors of Leishmania to humans and other animals. The aim of thisstudy was to verify the spatial distribution and effect of some abiotic factors on the abundance andtemporal variability of Phlebotominae at the Cuiabá campus of the Federal University of MatoGrosso (600,000 m2). CDC traps were installed at distances of 1,000 to 300 m s from each other andat a height of 1.5 m from the ground, between 17:00 and 07:00, distributed at six sites on the campus.Monthly collections were made on three consecutive days from December 2008 to December 2011.The living sand flies captured were sacrificed in ethyl acetate and then screened under a stereoscopicmicroscope. The insects were then subjected to clarification and identified. The abiotic data oftemperature and average relative humidity during the times when the traps remained at the insectcollection sites were determined with a digital thermometer-hygrometer. A non-linear mathematicalmodel was used to evaluate the association between the abiotic variables and the number of insectscaught. Species of Phlebotominae with and without the capacity to transmit Leishmania werecaptured at the site during the study period. The abundance of phlebotominae presented spatial andtemporal variability by virtue of abiotic and other variables. The most favourable conditions forthe occurrence of Phlebotominae at the site were a temperature of 23.2 ºC and a relative humidityof 70 percent. Temperatures above 35 °C or below 18 °C and a relative humidity lower than 18 percent wereunfavourable for the Phlebotominae.

Flebotomíneos são insetos vetores de Leishmanias para humanos e outros animais. O objetivo dotrabalho foi verificar a distribuição espacial e o efeito de alguns fatores abióticos sobre a abundânciae a variabilidade temporal de flebotomíneos no campus de Cuiabá da Universidade Federal de MatoGrosso (600.000 m2). Armadilhas CDC foram instaladas com distâncias entre si de 1.000 a 300 m,a 1,5 m de altura, das 17 h às 7 h, distribuídas em seis locais do campus para coletas mensais e emtrês dias consecutivos, de dezembro de 2008 a dezembro de 2011. Os flebótomos capturados vivosforam encaminhados ao Laboratório de Entomologia da UFMT, colocados em acetato de etila e, emseguida, foram triados sob observação em microscópio estereoscópico. Após esse procedimento,os insetos foram submetidos ao processo de clarificação e identificados. Os dados abióticos detemperatura e umidade relativa médias dos horários em que as armadilhas permaneceram nos locaisde coleta de insetos foram determinados com um termohigrômetro digital. Para avaliar o efeitodas variáveis abióticas sobre o número de insetos capturados, utilizou-se um modelo matemáticonão linear. Espécies de flebotomíneos com e sem a capacidade de transmissão das Leishmaniasforam capturadas no local durante o período estudado. A abundância de flebotomíneos apresentouvariabilidade espacial e temporal em razão de variáveis abióticas e de outras variáveis. As condiçõesmais favoráveis à ocorrência de flebotomíneos no local foram: temperatura de 23,2ºC e umidaderelativa de 70 por cento. Temperaturas acima de 35°C ou abaixo de 18°C e umidade relativa inferior a 18 por centoforam desfavoráveis para os flebotomíneos.

Parity and influence of abiotic factors on Anopheles in the Manso dam, State of Mato Grosso, Brazil.

INTRODUCTION: This study examined the parity of Anopheles mosquitoes and the influence of abiotic factors on the distribution of these mosquitoes in the Manso dam, Mato Grosso, Brazil. METHODS: The anophelines were captured using the Human Attraction Technique for 12 h, while recording the temperature and relative humidity. Parity was determined by examining the conditions of the fi laments. RESULTS: Anopheles darlingi and Anopheles triannulatus accounted for 98.5% of the anophelines, with 88% of these being parous. CONCLUSIONS: Sudden variations in weather could be the cause of shifts from the total absence of mosquitoes to the appearance of females in abundance over a three-day period.

Phlebotomine sand flies and canine infection in areas of human visceral leishmaniasis, Cuiabá, Mato Grosso.

Visceral leishmaniasis is a systemic infectious disease that can cause to a severe, potentially life-threatening chronic condition in humans. Risk factors for infection in urban areas have been associated with poor living conditions, the presence of sand fly vectors and infected pets. This study aimed to describe sand fly and canine infection in the neighborhoods of human visceral leishmaniasis occurrence in the city of Cuiabá, Mato Grosso State, central-western Brazil, reported between January 2005 and December 2006. A total of 1,909 sand flies were collected. They were predominantly males and the most frequent species were Lutzomyia cruzi (81.25%), Lutzomyia whitmani (13.88%) and Lutzomyia longipalpis (2.62%). The sand fly density was not significantly correlated with the variation of environmental factors. The prevalence of canine visceral leishmaniasis in the neighborhoods studied was 26.82% and it was found that areas with high density of vectors coincided with areas of high prevalence of dogs and those with the highest rates of human cases. The study of vectors and other potential hosts are essential for a good understanding of visceral leishmaniasis and the related public health concerns, aiming at the prevention and control of leishmaniasis in the city of Cuiabá, Mato Grosso State.

Phlebotomine sand flies and canine infection in areas of human visceral leishmaniasis, Cuiabá, Mato Grosso / Flebotomíneos e infecção canina em áreas de leishmaniose visceral humana, Cuiabá, Mato Grosso

Visceral leishmaniasis is a systemic infectious disease that can cause to a severe, potentially life-threatening chronic condition in humans. Risk factors for infection in urban areas have been associated with poor living conditions, the presence of sand fly vectors and infected pets. This study aimed to describe sand fly and canine infection in the neighborhoods of human visceral leishmaniasis occurrence in the city of Cuiabá, Mato Grosso State, central-western Brazil, reported between January 2005 and December 2006. A total of 1,909 sand flies were collected. They were predominantly males and the most frequent species were Lutzomyia cruzi (81.25 percent), Lutzomyia whitmani (13.88 percent) and Lutzomyia longipalpis (2.62 percent). The sand fly density was not significantly correlated with the variation of environmental factors. The prevalence of canine visceral leishmaniasis in the neighborhoods studied was 26.82 percent and it was found that areas with high density of vectors coincided with areas of high prevalence of dogs and those with the highest rates of human cases. The study of vectors and other potential hosts are essential for a good understanding of visceral leishmaniasis and the related public health concerns, aiming at the prevention and control of leishmaniasis in the city of Cuiabá, Mato Grosso State.

A leishmaniose visceral é uma doença infecciosa sistêmica, de evolução crônica grave, potencialmente fatal para o homem. Os fatores de risco para a infecção em áreas urbanas têm sido associados às precárias condições de moradia, à presença de flebotomíneos vetores e de animais domésticos infectados. O presente trabalho objetivou descrever a fauna flebotomínica e infecção canina nos bairros de ocorrência da leishmaniose visceral humana no município de Cuiabá, Mato Grosso, notificados no período de janeiro de 2005 a dezembro de 2006. Foram coletados 1.909 flebotomíneos, as espécies mais frequentes foram Lutzomyia cruzi (81,25 por cento), Lutzomyia whitmani (13,88 por cento) e Lutzomyia longipalpis (2,62 por cento). A densidade de flebotomíneos não apresentou correlação significativa com a variação dos fatores ambientais. A prevalência de leishmaniose visceral canina nos bairros foi de 26,82 por cento e observou-se que as regiões com grande densidade de vetores coincidem com áreas de alta prevalência em cães e áreas nas quais foi detectado o maior número de casos humanos. O estudo de vetores e outros possíveis hospedeiros são imprescindíveis para um bom entendimento da doença a fim de gerar benefícios para a saúde pública, visando à prevenção e o controle das leishmanioses no município de Cuiabá e no Estado de Mato Grosso.

Temporal distribution of Aedes aegypti Linnaeus (Diptera, Culicidae), in a Hospital in Cuiabá, State of Mato Grosso, Brazil / Distribuição Temporal de Aedes aegypti Linnaeus (Diptera, Culicidae), em um Hospital de Cuiabá, Mato Grosso, Brasil

This study aimed at registering and monitoring the presence of Aedes aegypti in the University Hospital Júlio Muller, Cuiabá-MT, as well as investigating the influence of temperature and rainfall on its temporal distribution and egg densities in ovitraps. The study was performed from April/2007 to March/2008, utilizing ovitraps with 10 percent of hay infusion and a wood paddle as an oviposition substrate. For surveillance, one ovitrap was placed in each of the 12 points distributed throughout the hospital. Ovitraps were collected monthly at the end of a 5-day installation period. After egg counting, wood paddles were immersed in water to allow larval eclosion for species identification through optical microscopy. Egg Density Index (EDI), Positive Ovitraps Index (POI), and Mean Number of Eggs (MNE) were used for data analysis. The presence of A. aegypti in the hospital was registered throughout the study period, except in July. The MNE was proportionally higher in the internal area (n= 8.47 eggs/paddle) when compared to the external area (n= 5.46 eggs/paddle), and was higher in September/October 2007 and January/February 2008. A significant increase in EDI, POI and MNE was registered in periods where the average temperature was higher, and the increase in POI was also concomitant with an increase in rainfall. The continuous presence of A. aegypti in the hospital throughout the study period, points out the need of including this mosquito in the arthropod control list in this environment. This is particularly important, considering that A. aegypti is an important vector of several arboviroses.

Esse estudo objetivou registrar e monitorar a presença de Aedes aegypti no Hospital Universitário Júlio Muller, Cuiabá - MT, bem como investigar a influência da temperatura e pluviosidade sobre sua distribuição temporal e densidade de ovos em ovitrampas. O estudo foi realizado de abril/2007 a março/2008, usando ovitrampas com 10 por cento de infusão de gramínea e uma palheta de madeira como substrato para oviposição. Para o monitoramento, uma ovitrampa foi colocada em cada um dos doze pontos distribuídos nas dependências do hospital. Mensalmente, as armadilhas eram recolhidas ao final do quinto dia de instalação. Após a contagem dos ovos, as palhetas foram imersas em água para eclosão das larvas e identificação da espécie alvo em microscopia óptica. Índice de Densidade de Ovos (IDO), Índice de Positividade de Ovitrampas (IPO) e Número Médio de Ovos (NMO) foram usados para análise dos dados. A presença do mosquito no hospital foi registrada ao longo de todo experimento, exceto em julho. A densidade média de ovos foi proporcionalmente maior na área interna (n= 8,47 ovos/palheta) comparada à externa (n= 5,46 ovos/palheta). O NMO foi mais elevado nos meses de setembro e outubro de 2007, janeiro e fevereiro de 2008. Aumentos significativos do NMO, IPO e IDO, foram registrados com a elevação da temperatura, e no IPO com aumento da pluviosidade. A constante presença do mosquito A. aegypti no hospital, indica a necessidade de incluir esse mosquito na lista de controle de artrópodes nesse ambiente. Isso é particularmente importante, considerando que o A. aegypti é importante vetor de várias arboviroses.