An��lise espacial do padr��o de introdu����o e dissemina����o da dengue nos munic��pios do Esp��rito Santo

O n��mero de munic��pios infestados pelo Aedes aegypti no Estado do Esp��rito Santo vem aumentando gradativamente, levando a altas taxas de incid��ncia de dengue ao longo dos anos. Apesar das tentativas de combate �� doen��a, esta se tornou uma das maiores preocupa����es na sa��de p��blica do Estado. Este estudo se prop��e a descrever a din��mica da expans��o da doen��a no Estado a partir da associa����o entre vari��veis ambientais e populacionais, utilizando dados operacionalizados por meio de t��cnicas de geoprocessamento. O estudo utilizou como fonte de dados a infesta����o pelo mosquito vetor e o coeficiente de incid��ncia da doen��a, as dist��ncias rodovi��rias intermunicipais do Estado, a altitude dos munic��pios e as vari��veis geoclim��ticas (temperatura e sufici��ncia de ��gua), incorporadas a uma ferramenta operacional, as Unidades Naturais do Esp��rito Santo (UNES), representadas em um ��nico mapa operacionalizado em Sistema de Informa����o Geogr��fica (SIG), obtido a partir do Sistema Integrado de Bases Georreferenciadas do Estado do Esp��rito Santo. Para an��lise dos dados, foi realizada a Regress��o de Poisson para os dados de incid��ncia de dengue e Regress��o Log��stica para os de infesta����o pelo vetor. Em seguida, os dados de infesta����o pelo mosquito e incid��ncia de dengue foram georreferenciados, utilizando como ferramenta operacional o SIG ArcGIS vers��o 9.2. Observou-se que a pluviosidade �� um fator que contribui para o surgimento de mosquito em ��reas n��o infestadas. Altas temperaturas contribuem para um alto coeficiente de incid��ncia de dengue nos munic��pios capixabas. A vari��vel dist��ncia em rela����o a munic��pios populosos �� um fator de prote����o para a incid��ncia da doen��a. A grande variabilidade encontrada nos dados, que n��o �� explicada pelas vari��veis utilizadas no modelo para incid��ncia da doen��a, refor��a a premissa de que a dengue �� condicionada pela intera����o din��mica entre muitas vari��veis que o estudo n��o abordou. A espacializa����o dos dados de infesta����o pelo mosquito e incid��ncia de dengue e as Zonas Naturais do ES permitiu a visualiza����o da influ��ncia das vari��veis estatisticamente significantes nos modelos utilizados no padr��o da introdu����o e dissemina����o da doen��a no Estado.

Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species

Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis) and Aedes albopictus (Dengue) (both laboratory and field strains); laboratory strains of Aedes aegypti (Dengue), Anopheles slephensi and Anopheles culicifacies (Malaria), and Culex tritaeniorhynchus (Japanese encephalitis) in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain) against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai)/m�� on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch). Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 9- Synanthropy and epidemiological vector role of Aedes scapularis in South-Eastern Brazil

Behaviour comparisons of Aedes scapularis and Ae. serratus are presented. Results were obtained by sampling Aedes adult mosquitoes at several places in the rural anthropic environment in the Ribeira Valley region of S. Paulo State, Brazil. Aedes dominance was shared by those two species, but Ae. scapularis Sshowed a clear tendency to frequent the modified environment, while Ae. serratus was to be found in the more preserved ones, here represented by the vestigial patchy forests. Regarding the open cultivated land and the dwelling environments, Ae. scapularis preponderates. Considering the regional developmental phases, this mosquito showed a remarkable increase in the modified environment differently from Ae. serratus that underwent a considerable decrease in migrating from the forest to the anthropic environment. As a consequence of these results it is reasonable to conclude that Ae. scapularis may be considered as an epidemiologically efficient vector and that it quite probably played this role in the Rocio encephalitis and other arbovirus epidemics.

Popula����o de Aedes aegypti (l.) em ��rea end��mica de dengue, Sudeste do Brasil

OBJETIVO: Estudar a popula����o de Aedes aegypti em ��rea de transmiss��o de dengue sob o ponto de vista de freq����ncia, distribui����o espacial, paridade, desenvolvimento ovariano e conte��do do intestino m��dio. M��TODOS: O estudo foi realizado na cidade de S��o Jos�� do Rio Preto, SP. Foram selecionados dois setores, um com n��vel socioecon��mico baixo e outro com n��vel m��dio. As observa����es foram realizadas entre 1996 e 1997. Foram feitas capturas no intra e peridomic��lios com capturadores el��tricos manuais. S��o dados detalhes das dissec����es para estudo do estado fisiol��gico das f��meas e da classifica����o utilizada. RESULTADOS: Capturaram-se 188 machos e 189 f��meas. Obteve-se um ��ndice de 0,46 f��meas por casa. Dos machos e das f��meas capturados, estavam no intradomic��lio, respectivamente, 82,4% e 87,3%. Encontrou-se maior propor����o de f��meas no setor de n��vel socioecon��mico mais baixo e com maior concentra����o populacional. Foram analisadas 148 f��meas, sendo 27,0% nul��paras e 10,1% on��paras. As demais foram classificadas nas fases III a V de Christophers e Mer (C & M) com 28,0% destas contendo sangue de colora����o vermelha no intestino m��dio. Das f��meas, 87,9% j�� haviam praticado a hematofagia. CONCLUS��ES: A esp��cie revelou grande tend��ncia �� endofilia. A propor����o de nul��paras foi superior a de on��paras, apesar da maioria das f��meas ser classificada nas fases III a V de C & M. Chama aten����o o elevado percentual das f��meas que praticaram a hematofagia e a ocorr��ncia de n��o concord��ncia gonotr��fica.

Dengue and the risk of urban yellow fever reintroduction in S��o Paulo State, Brazil

OBJECTIVE: To propose a mathematical method for the estimation of the Basic Reproduction Number, R0, of urban yellow fever in a dengue-infested area. METHODS: The method is based on the assumption that, as the same vector (Aedes aegypti) causes both infections, all the quantities related to the mosquito, estimated from the initial phase of dengue epidemic, could be applied to yellow fever dynamics. It is demonstrated that R0 for yellow fever is, on average, 43% lower than that for dengue. This difference is due to the longer dengue viremia and its shorter extrinsic incubation period. RESULTS: In this study the analysis was expanded to the epidemiological situation of dengue in S��o Paulo in the year 2001. The total number of dengue cases increased from 3,582 in 2000 to 51,348 in 2001. It was then calculated R0 for yellow fever for every city which have shown R0 of dengue greater than 1. It was also estimated the total number of unprotected people living in highly risky areas for urban yellow fever. CONCLUSIONS: Currently there is a great number of non-vaccinated people living in Aedes aegypti infested area in the state of S��o Paulo.

Infesta����o pelo Aedes aegypti e ocorr��ncia da dengue em Belo Horizonte, Minas Gerais

OBJETIVO: Analisar a associa����o entre a propor����o de im��veis prediais positivos para larvas de Aedes aegypti, por meio do ��ndice de infesta����o predial, e a taxa de incid��ncia da dengue. M��TODOS: Foram selecionados casos aut��ctones de dengue e valores de infesta����o predial verificados nas ��reas de abrang��ncia dos distritos sanit��rios de Belo Horizonte, MG, no per��odo de outubro de 1997 a maio de 2001. Ap��s grupamento dos valores de infesta����o predial segundo sua distribui����o em quartis, as m��dias das taxas de incid��ncias da dengue (referentes ao m��s subseq��ente �� realiza����o dos levantamentos de infesta����o predial) foram comparadas pelo teste ANOVA. RESULTADOS: Observou-se uma correla����o fraca, por��m estatisticamente significativa, entre a taxa de incid��ncia mensal da doen��a e os valores de infesta����o predial para os distritos sanit��rios (r=0,21; p=0,02) e ��reas de abrang��ncia (r=0,14; p=0,00) no per��odo analisado. Ap��s grupamento dos valores de infesta����o predial em quartis, as ��reas de abrang��ncia com infesta����o predial entre 0,46% e 1,32% (2º quartil) apresentaram, em rela����o ��s ��reas com infesta����o predial, menor ou igual a 0,45% (1º quartil), taxa de incid��ncia mensal m��dia da doen��a duas vezes maior. Para as ��reas com infesta����o predial entre 1,33% e 2,76% (3º quartil) e maior ou igual a 2,77%, as taxas de incid��ncias mensais m��dias foram, respectivamente, cinco e sete vezes maiores em rela����o ��s ��reas com 0,45% ou menos. CONCLUS��ES: Apesar das conhecidas limita����es do ��ndice de infesta����o predial para estimar a infesta����o vetorial e predizer a ocorr��ncia de epidemias de dengue, os resultados indicam que maiores ��ndices se associaram a maior risco de transmiss��o da doen��a nos distritos sanit��rios e ��reas de abrang��ncia de Belo Horizonte.

Oviposici��n diaria de Aedes aegypti en Or��n, Salta, Argentina

El objetivo del estudio fue determinar los horarios de m��xima actividad de oviposici��n de Aedes aegypti en la ciudad de Or��n (noroeste argentino). Se realizaron muestreos quincenales entre noviembre de 2006 y febrero de 2007 (primavera-verano). La ciudad fue dividida en tres zonas (norte, centro, sur), donde fueron seleccionadas al azar las viviendas para colocar dos ovitrampas en el exterior de las mismas. Las ovitrampas fueron reemplazadas cada cuatro horas, desde la ma��ana (8h) hasta el atardecer (20h). Se registr�� la mayor cantidad de huevos entre las 16 y 20 h (81%). Estos datos aportan al conocimiento del vector y, por lo tanto, de la posibilidad de control, pudiendo realizarse las fumigaciones en la franja horaria con mayor actividad de oviposici��n.

Resistance of Aedes aegypti to temephos and adaptive disadvantages

OBJECTIVE To evaluate the resistance of Aedes aegypti to temephos Fersol 1G (temephos 1% w/w) associated with the adaptive disadvantage of insect populations in the absence of selection pressure. METHODS A diagnostic dose of 0.28 mg a.i./L and doses between 0.28 mg a.i./L and 1.40 mg a.i./L were used. Vector populations collected between 2007 and 2008 in the city of Campina Grande, state of Paraíba, were evaluated. To evaluate competition in the absence of selection pressure, insect populations with initial frequencies of 20.0%, 40.0%, 60.0%, and 80.0% resistant individuals were produced and subjected to the diagnostic dose for two months. Evaluation of the development of aquatic and adult stages allowed comparison of the life cycles in susceptible and resistant populations and construction of fertility life tables. RESULTS No mortality was observed in Ae. aegypti populations subjected to the diagnostic dose of 0.28 mg a.i./L. The decreased mortality observed in populations containing 20.0%, 40.0%, 60.0%, and 80.0% resistant insects indicates that temephos resistance is unstable in the absence of selection pressure. A comparison of the life cycles indicated differences in the duration and viability of the larval phase, but no differences were observed in embryo development, sex ratio, adult longevity, and number of eggs per female. CONCLUSIONS The fertility life table results indicated that some populations had reproductive disadvantages compared with the susceptible population in the absence of selection pressure, indicating the presence of a fitness cost in populations resistant to temephos.

Brote de dengue en San Jose de Guaribe, Venezuela: reporte preliminar

Comunicamos nuestra experiencia de un brote de dengue en el Municipio San Jos�� de Guaribe, Estado Gu��rico a mediados de Septiembre y comienzo de Octubre de 1990. Un total de 97 casos sin muertes y el estudio serol��gico en una muestra problacional mostr�� virus tipo 2. La pronta intervenci��n y la efectividad de las medidas de control, una atenci��n m��dica oportuna y un diagn��stico scrol��gico temprano contribuyeron al control del brote. Esta es la primera descripci��n de un brote de dengue en el Estado Gu��rico, Venezuela.

Residual effect of two Bacillus thuringiensis var. israelensis products assayed against Aedes aegypti (Diptera: Culicidae) in laboratory and outdoors at Rio de Janeiro, Brazil

Resistance of the dengue vector to temephos stimulated its substitution for Bacillus thuringiensis var. israelensis (Bti) since 2001 in Brazil. The persistence of the two Bti formulations employed at that time by the Health Ministry, Vectobac G and Aquabac G, was assayed under laboratory and outdoor conditions. Both formulations were tested at 0.2 g/10 liters of water, the same concentration applied in the field for vector control. The tests were done against Ae. aegypti third instar larvae (Rockefeller strain). In the laboratory, Vectobac G and Aquabac G caused at least 95% mortality until 101 and 45 days after treatment, respectively. In the outdoor assays, test containers of different materials were treated with either formulation and placed in a shaded area. Larvae were introduced each 3-6 days and mortality was recorded 24 and 48 hours later. In the first set of assays, performed in June 2001, mortality levels of 70% or more were attained for 2-5 weeks for both formulations in all containers. The exception was for the iron one that rusted, resulting in low mortality after seven days. In the second set of assays (August 2001), 70% mortality was attained for just 1-2 weeks for all the containers and both formulations.

Diterpenos de Copaifera reticulata Ducke com atividade larvicida contra Aedes aegypti (L.) (Diptera, Culicidae)

The objective of this study was to evaluate the larvicidal activity of diterpenoids obtained from the oil-resin of Copaifera reticulata against Aedes aegypti larvae, the principal vector of dengue and urban yellow fever. Four diterpenes were obtained from oil-resin extraction with organic solvents and subsequent chromatographic and spectroscopic procedures allowed to isolation and identification of these compounds as 3-b-acetoxylabdan-8(17)-13-dien-15-oic acid (1), alepterolic acid (2), 3-b-hidroxylabdan-8(17)-en-15-oic acid (3), and ent-agatic acid (4). Each compound was previously dissolved in dimethylsulphoxide, and distilled water was added to obtain the desired concentrations. Twenty larvae of third instars were placed into plastic beckers, containing the solution test (25 mL), in a five repetitions scheme, and their mortality, indicated by torpor and darkening of the cephalic capsule, was recorded after 48h. Probit analyses were used to determine lethal concentrations (LC50 and LC90) and their respective 95% confidence intervals. This study showed that only diterpenoids 1 and 2 exhibited larvicidal properties with LC50 of 0.8 ppm and 87.3 ppm, respectively, revealing the former as the most toxic compound against third instars of Ae. aegypti. Therefore, this compound seems to be an interesting source for new metabolite to be exploited.

LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES

Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.

Express��o em Escherichia coli de antig��nios do Cell fusing agent virus (Flaviviridae: Flavivirus) como prote��na de fus��o

RESUMO: O Cell Fusing Agent V��rus (CFAV), considerado como o primeiro ���flaviv��rus espec��ficos de insectos��� (ISF), parece estar exclusivamente adaptado aos seus hospedeiros, n��o replicando em c��lulas de vertebrados. Apesar de ter sido identificado h�� mais de tr��s d��cadas (1975), a verdade �� que muito pouco se conhece sobre a sua biologia. Dado o seu parentesco filogen��tico com alguns outros flaviv��rus encontrados naturalmente em mosquitos de diferentes g��neros colhidos em diferentes regi��es do globo, este v��rus poder�� ser usado como modelo para o estudo de ISF. No entanto, necessitam do desenvolvimento de ferramentas b��sicas, tais como clones moleculares ou baterias de soros contendo anticorpos que reconhe��am uma ou mais prote��nas codificadas pelo genoma viral, produzidas, por exemplo, a partir de antig��nios virais produzidos de forma recombinante. Com este trabalho pretendeu-se a optimiza����o de protocolos que permitiram a express��o e purifica����o parcial de quatro prote��nas [duas prote��nas estruturais (C e E) e duas n��o estruturais (NS3hel e NS5B)] do CFAV em E. coli, todas elas produzidas como prote��nas de fus��o com ���caudas��� (tags) de hexahistidina nos seus extremos carboxilo. Para a expans��o do CFAV foram utilizadas c��lulas Aedes albopictus (C6/36). Ap��s a realiza����o da extrac����o do RNA viral e a obten����o de cDNA, procedeu-se amplifica����o, por RT-PCR, das regi��es codificantes das prote��nas C, E, NS3hel e NS5B, utilizando primers espec��ficos. Os quatro fragmentos de DNA foram independentemente inseridos no vector pJTE1.2/blunt usando E. coli NovaBlue como hospedeira de clonagem e, posteriormente, inseridos em vectores de express��o pET-28b e pET-29b usando E. coli BL21(DE3)pLysS e Rosetta(DE3)pLysS como hospedeiras de express��o. Ap��s da indu����o, express��o e purifica����o das prote��nas recombinantes C, E, NS3hel e NS5B, foi confirmada a autenticidade destas prote��nas produzidas atrav��s do m��todo Western Blot com um anticorpo anti-histidina. --------- ABSTRACT: The Cell Fusing Agent virus (CFAV) considered as the first "insect- specific flavivirus" (ISF) and seems to be uniquely adapted to their hosts, not replicating in vertebrate cells. Although it has been known for more than three decades (1975), the truth is very little is known about its biology. Given its close phylogenetic relationship with other flavivirus naturally circulating in various genera of mosquitoes collected from different regions of the globe, this virus could be used as a model for the study of ISF. However, such studies require the development of experimental basic tools, such as molecular clones or serum batteries containing antibodies that recognize one or more proteins encoded by the viral genome, produced, for example, from viral antigens recombinant produced. In this work, we carried out the optimization of protocols that allowed the expression and partial purification of four proteins [two structural proteins (C and E) and two nonstructural proteins (NS3hel and NS5B)] CFAV in E. coli as fusion protein for c-terminal hexahistidine tags. For the expansion of the CFAV we used Aedes albopictus (C6/36) cells. After completion of the viral RNA extraction and cDNA obtained, amplification of the coding regions of the C, E, NS5B and NS3hel proteins was carried out by RT-PCR using specific primers. The four DNA fragments were independently inserted into the vector pJTE1.2/blunt using E. coli NovaBlue as cloning host and then inserted into expression vectors pET-28b and pET-29b using E. coli BL21(DE3)pLysS and Rosetta(DE3)pLysS as expression host. After induction, expression and purification of recombinant C, E, NS3hel and NS5B proteins Western Blot analyses with an anti-histidine antibody confirmed the authenticity of these proteins produced.