Margareth Regina Dibo

Study of the relationship between Aedes (Stegomyia) aegypti egg and adult densities, dengue fever and climate in Mirassol, state of Sao Paulo, Brazil

The purpose of this study was to examine the relationship between Aedes aegypti egg and adult density indices, dengue fever and climate in Mirassol, state of São Paulo, Brazil, between November 2004-November 2005. Weekly collections of adults and eggs were made using, respectively, manual aspirators and oviposition traps that produced four entomological indices (positivity and average of females and eggs). Weekly incidence coefficients were calculated based on dengue cases. Each week, the data obtained from entomological indices were related to each other, dengue, and climate variables. The first index to show an association with dengue transmission was the female average, followed by female positivity and egg average. Egg positivity did not show a relationship with risk for dengue, but was sensitive to identifying the presence of the vector, principally in dry seasons. The relationship between climatic factors, the vector and the disease found in this study can be widely employed in planning and undertaking dengue surveillance and control activities, but it is a tool that has not been considered by the authorities responsible for controlling the disease. In fact, this relationship permits the use of information about climate for early detection of epidemics and for establishing more effective prevention strategies than currently exist.

Physiological state of Aedes (Stegomyia) aegypti mosquitoes captured with MosquiTRAPs™ in Mirassol, São Paulo, Brazil

ABSTRACT We examined the best location in a house to install MosquiTRAPs, sticky ovitraps that attract and capture Aedes aegypti females and investigated the physiological state of captured female mosquitoes. The study was performed in a twenty-block area in Mirassol, São Paulo State, Brazil, in which five blocks were randomly chosen for MosquiTRAP installation. In each block, four houses were selected for the installation of eight traps: four indoors (bedroom, living room, bathroom, and kitchen) and four outdoors in the shade (two at the front of the house and two in the backyard). These houses were visited over an eight-week period. The outdoor MosquiTRAPs captured five times more females than indoor traps and appeared to be the best places to install MosquiTRAPs. There were no significant differences among indoor sites or among outdoor sites with respect to the number of females captured. The capacity of the MosquiTRAP to capture a large number of gravid Ae. aegypti females reinforces its potential as an entomological surveillance tool in dengue control programs.

Identification of the best ovitrap installation sites for gravid Aedes (Stegomyia) aegypti in residences in Mirassol, state of São Paulo, Brazil

This study aimed at identifying the best ovitrap installation sites for gravid Aedes aegypti in Mirassol, state of São Paulo, Brazil. Ovitraps were installed in ten houses per block over ten blocks. Four ovitraps were placed per residence, one in the bedroom, one in the living room, and two outdoors with one in a sheltered area and one in an outside site. Each week for eleven weeks, visits were made to examine the ovitraps and to change the paddles used for egg-laying. Eggs were analyzed according to the trap location. The results showed that the outdoor sites received significantly more oviposition than indoor sites. Additionally, in respect to the outdoor sites, the outside site received significantly more oviposition than the sheltered site. A strong correlation was observed between positive traps and egg numbers. The results are discussed with respect to the best installation site of the traps and their implications in surveillance and control of dengue vectors.

Controle do vetor do dengue e participação da comunidade em Catanduva, São Paulo, Brasil

This study aimed to identify changes in knowledge and practices learned to prevent dengue fever in two areas of Catanduva, São Paulo State, from 1999 to 2001: a study area and a control area. The study included an initial quantitative survey, qualitative research, a preliminary diagnosis presented to the community to launch a discussion aimed at defining future actions, implementation of the actions in the study area with community participation (but without changes in the control area), and a final comparison of the two areas. Changes in the study area included: vector control workers began demonstrating preventive measures without removing potential breeding places or using larvicide; use of educational aids specific to the local reality; activities related to the residents priorities; and activities such as music, theater skits, scavenger hunts, and games to demonstrate the vector cycle. Potential domiciliary breeding sites were significantly reduced; the proportion of houses without breeding sites was significantly increased; and there was an increase in the percentage of individuals who recognized the larval form of the vector in the study area as compared to the control area.

Introdução e expansão da Leishmaniose visceral americana em humanos no estado de São Paulo, 1999-2011

OBJECTIVE : To analyze the spread of human American visceral leishmaniasis and identify the key municipalities for developing surveillance and control activities. METHODS : The area of the study was composed of the 316 municipalities in the state of Sao Paulo belonging to the five health districts in which human American visceral leishmaniasis occurs, using data on autochthonous cases and deaths according to the reporting year and municipality in which the death occurred. The incidence, mortality and case fatality rates for each municipality and for the entire area were calculated. An empirical Bayes estimator was used to calculate the local Bayesian incidence and rates of mortality per municipality, and Kriging was used to visualize the spatial distribution of temperature and rainfall. RESULTS : A total of 73 municipalities with transmission of the disease were identified. Human American visceral leishmaniasis was first detected in areas with higher temperatures and lower rainfall, but it also spread in cooler and wetter areas. The expansion of human American visceral leishmaniasis occurred along a main axis of dissemination, from Northwest to Southeast, following the Marechal Rondon highway and the Bolivia-Brazil gas pipeline, and along a secondary axis that was derived from the main axis, which runs both North and South, following the highway network. Rates of incidence according to health district exhibit a peak, followed by a fall, except the Sao Jose do Rio Preto region. Higher concentrations of municipalities with high incidence and mortality rates were observed in the Aracatuba, Presidente Prudente and Marilia health districts. CONCLUSIONS : This study indicates possible determinants of the spread of disease, including the Marechal Rondon highway and the construction of the Bolivia-Brazil gas pipeline. Climatic factors seemed to play no role in the spread. The use of spatial analysis techniques allowed the municipalities where cases and deaths are possibly underreported to be identified, which indicated the municipalities which should be prioritized for the development of surveillance and control activities.OBJECTIVE To analyze the spread of human American visceral leishmaniasis and identify the key municipalities for developing surveillance and control activities. METHODS The area of the study was composed of the 316 municipalities in the state of Sao Paulo belonging to the five health districts in which human American visceral leishmaniasis occurs, using data on autochthonous cases and deaths according to the reporting year and municipality in which the death occurred. The incidence, mortality and case fatality rates for each municipality and for the entire area were calculated. An empirical Bayes estimator was used to calculate the local Bayesian incidence and rates of mortality per municipality, and Kriging was used to visualize the spatial distribution of temperature and rainfall. RESULTS A total of 73 municipalities with transmission of the disease were identified. Human American visceral leishmaniasis was first detected in areas with higher temperatures and lower rainfall, but it also spread in cooler and wetter areas. The expansion of human American visceral leishmaniasis occurred along a main axis of dissemination, from Northwest to Southeast, following the Marechal Rondon highway and the Bolivia-Brazil gas pipeline, and along a secondary axis that was derived from the main axis, which runs both North and South, following the highway network. Rates of incidence according to health district exhibit a peak, followed by a fall, except the Sao Jose do Rio Preto region. Higher concentrations of municipalities with high incidence and mortality rates were observed in the Araçatuba, Presidente Prudente and Marília health districts. CONCLUSIONS This study indicates possible determinants of the spread of disease, including the Marechal Rondon highway and the construction of the Bolivia-Brazil gas pipeline. Climatic factors seemed to play no role in the spread. The use of spatial analysis techniques allowed the municipalities where cases and deaths are possibly underreported to be identified, which indicated the municipalities which should be prioritized for the development of surveillance and control activities.

Presença de culicídeos em município de porte médio do Estado de São Paulo e risco de ocorrência de febre do Nilo Ocidental e outras arboviroses

INTRODUCAO: O objetivo deste estudo foi mensurar a diversidade de especies de culicideos, descrever sua abundância e variacao sazonal em areas urbanas e matas de Sao Jose do Rio Preto, SP, e discutir o risco de ocorrencia de arboviroses. METODOS: Coletas de larvas e de mosquitos adultos foram realizadas mensalmente, em 2006 e 2007, em area urbana e em quatro fragmentos de mata. No perimetro urbano, coletaram-se larvas nos sitios mais provaveis de oviposicao para mosquitos do genero Culex e nas matas foi realizada a coleta de mosquitos adultos, sendo que em duas utilizaram-se armadilhas CDC a noite e, em duas, aspirador de Nasci de dia. RESULTADOS: Na area urbana identificaram-se 34 especies de culicideos em um total de 8.683 exemplares; destes, 80,7% corresponderam ao Culex quinquefasciatus, 9,6% ao Culex grupo Coronator, 3,2% ao Aedes albopictus (3,2%) e 1,1% ao Ochlerotatus fluviatilis. A abundância de larvas de Cx. quinquefasciatus correlacionou-se negativamente com a chuva. Nas quatro matas, foram coletados 2.268 mosquitos distribuidos entre 10 generos, 46 especies ou grupos. As mais abundantes foram Aedeomyia squamipennis, Culex. coronator, Culex (Mel.) secao Melanoconion, Culex declarator, Ochlerotatus scapularis, Anopheles triannulatus, Culex bidens/interfor e Culex habilitator/pseudojhantinosoma. CONCLUSOES: A abundância de Cx. quinquefasciatus na area urbana e a presenca de outros culicideos nas areas urbanas e de matas apontam para a possibilidade de transmissao do virus do Nilo Ocidental e de outras arboviroses em Sao Jose do Rio Preto e outras cidades do Brasil, sendo fundamental o estabelecimento de medidas visando a vigilância destas arboviroses.

Assessment of entomological indicators of Aedes aegypti (L.) from adult and egg collections in São Paulo, Brazil

ABSTRACT We compared the presence and mean number of eggs from oviposition traps with the mean number of Aedes aegypti females captured by manual aspirators and by MosquiTRAPs™ to determine the sensitivity of each method and to standardize each indicator. The collections of adults and eggs were performed over 23 weeks in six neighborhoods of Mirassol, state of São Paulo, Brazil. A better assessment of indicators required larger number of MosquiTRAPs, but to quantify the number of females per house, one trap was sufficient. The sensitivities of MosquiTRAPs and manual aspirations to detect the presence of A. aegypti females were similar, but were lower compared to oviposition traps. The correlation coefficients between the number of females captured by MosquiTRAPs and manual aspirations and the number of eggs from oviposition traps were low, which may be a consequence of each method showing different stages of the mosquito life cycle.

Estabelecimento de metodologia para alimentação de Aedes aegypti (Diptera-Culicidae) em camundongos swiss e avaliação da toxicidade e do efeito residual do óleo essencial de Tagetes minuta L (Asteraceae) em populações de Aedes aegypti

The objectives here were to develop a procedure for feeding females of Aedes aegypti that does not cause stress in Swiss mice and to evaluate the toxicity and residual effect of essential oil from Tagetes minuta L. (Asteraceae) in Aedes aegypti populations. Two mice were anesthetized: one was used to observe the duration of sedation and the other was placed in a cage to feed the female mosquitoes. Essential oil was diluted in acetone and used in bioassays to assess the lethal concentrations in larvae from the Cities of Bauru (SP) and São José do Rio Preto (SP) that were sensitive and resistant to temephos, respectively. The data obtained were compared with the American Rockefeller strain. The procedure with mice was approved. There was no difference between the populations regarding susceptibility to Tagetes minuta, and the assays showed LC50 of 0.24, 0.25 and 0.21 ml/l and LC99.9 of 0.35, 0.39 and 0.42 ml/l, for Rockefeller, Bauru and São José do Rio Preto, respectively. The solution did not show any residual effect.

Atividades de controle do dengue na visão de seus agentes e da população atendida, São José do Rio Preto, São Paulo, Brasil

The aim of this article was to identify daily situations experienced by dengue control agents in their relationship to local residents. A cross-sectional study applied questionnaires among vector control agents, community health workers, and a sample of local women. The answers by the dengue control agents and community health workers were grouped in the categories of work, private life, and community. The women were asked about the relationship with the vector control and community health workers. The difficulties cited in the private and work areas by the vector control agents were different from those reported by community health workers. At the community level they coincided and showed that neither group is adequately prepared to deal with these issues. Of the local women interviewed, 87.0% reported that they were well-informed or very well-informed about dengue, 84.0% stated that the work by the vector control agents and community health workers was always helpful, and 54.0% identified inappropriate visiting hours by vector control agents and community health workers as a difficulty. The study identified the need for a new job profile that would recognize and respect the specificities of the areas where their activities are conducted, integrating the communitys socio-environmental issues.

Introduction and expansion of human American visceral leishmaniasis in the state of Sao Paulo, Brazil, 1999-2011

OBJECTIVE : To analyze the spread of human American visceral leishmaniasis and identify the key municipalities for developing surveillance and control activities. METHODS : The area of the study was composed of the 316 municipalities in the state of Sao Paulo belonging to the five health districts in which human American visceral leishmaniasis occurs, using data on autochthonous cases and deaths according to the reporting year and municipality in which the death occurred. The incidence, mortality and case fatality rates for each municipality and for the entire area were calculated. An empirical Bayes estimator was used to calculate the local Bayesian incidence and rates of mortality per municipality, and Kriging was used to visualize the spatial distribution of temperature and rainfall. RESULTS : A total of 73 municipalities with transmission of the disease were identified. Human American visceral leishmaniasis was first detected in areas with higher temperatures and lower rainfall, but it also spread in cooler and wetter areas. The expansion of human American visceral leishmaniasis occurred along a main axis of dissemination, from Northwest to Southeast, following the Marechal Rondon highway and the Bolivia-Brazil gas pipeline, and along a secondary axis that was derived from the main axis, which runs both North and South, following the highway network. Rates of incidence according to health district exhibit a peak, followed by a fall, except the Sao Jose do Rio Preto region. Higher concentrations of municipalities with high incidence and mortality rates were observed in the Aracatuba, Presidente Prudente and Marilia health districts. CONCLUSIONS : This study indicates possible determinants of the spread of disease, including the Marechal Rondon highway and the construction of the Bolivia-Brazil gas pipeline. Climatic factors seemed to play no role in the spread. The use of spatial analysis techniques allowed the municipalities where cases and deaths are possibly underreported to be identified, which indicated the municipalities which should be prioritized for the development of surveillance and control activities.OBJECTIVE To analyze the spread of human American visceral leishmaniasis and identify the key municipalities for developing surveillance and control activities. METHODS The area of the study was composed of the 316 municipalities in the state of Sao Paulo belonging to the five health districts in which human American visceral leishmaniasis occurs, using data on autochthonous cases and deaths according to the reporting year and municipality in which the death occurred. The incidence, mortality and case fatality rates for each municipality and for the entire area were calculated. An empirical Bayes estimator was used to calculate the local Bayesian incidence and rates of mortality per municipality, and Kriging was used to visualize the spatial distribution of temperature and rainfall. RESULTS A total of 73 municipalities with transmission of the disease were identified. Human American visceral leishmaniasis was first detected in areas with higher temperatures and lower rainfall, but it also spread in cooler and wetter areas. The expansion of human American visceral leishmaniasis occurred along a main axis of dissemination, from Northwest to Southeast, following the Marechal Rondon highway and the Bolivia-Brazil gas pipeline, and along a secondary axis that was derived from the main axis, which runs both North and South, following the highway network. Rates of incidence according to health district exhibit a peak, followed by a fall, except the Sao Jose do Rio Preto region. Higher concentrations of municipalities with high incidence and mortality rates were observed in the Araçatuba, Presidente Prudente and Marília health districts. CONCLUSIONS This study indicates possible determinants of the spread of disease, including the Marechal Rondon highway and the construction of the Bolivia-Brazil gas pipeline. Climatic factors seemed to play no role in the spread. The use of spatial analysis techniques allowed the municipalities where cases and deaths are possibly underreported to be identified, which indicated the municipalities which should be prioritized for the development of surveillance and control activities.