Detec����o de Aedes aegypti e Aedes albopictus, na zona urbana do munic��pio de Catanduva-SP, ap��s controle de epidemia de dengue

Ap��s a realiza����o dos trabalhos de controle visando �� interrup����o da transmiss��o do v��rus do dengue, iniciou-se um trabalho de monitoriza����o de Aedes aegypti e Aedes albopictus com dois m��todos de vigil��ncia entomol��gica: ��ndice de Breteau (IB) e ovitrampas. Pretendeu-se avaliar o tempo necess��rio para que as esp��cies envolvidas fossem novamente detectadas na ��rea urbana do munic��pio de Catanduva, SP. As ovitrampas apresentaram positividade para Aedes aegypti dois meses ap��s os trabalhos de controle, enquanto o ��ndice de Breteau veio a positivar-se somente no quarto m��s ap��s o t��rmino dos referidos trabalhos.

Education in primary school as a strategy to control dengue

The proliferation of Aedes aegypti, a species of mosquito that is the vector of the dengue pathogen, is being augmented by the population's lack of care in allowing the formation of larval habitats. One form of controlling dengue is the distribution of information on the mosquito to improve awareness and to provide the means necessary for the elimination of its reproductive habitats. To evaluate a teaching method concerning the vector and dengue, students from the 5th and 6th years of primary education were compared before and after didactic intervention with a group of control students. The students who received intervention were more successful in identifying the stages of the cycle, biological and morphological characteristics of the adult insect and the importance of the mosquito in health issues. The didactic intervention was successful in developing knowledge leading to increased awareness of the importance of preventative measures that should be taken against the vector and the disease.

Aedes albopictus (S) na regi��o de S��o Jos�� do Rio Preto, SP: estudo da sua infesta����o em ��rea j�� ocupada pelo Aedes aegypti e discuss��o de seu papel como poss��vel vetor de dengue e febre amarela

Os objetivos deste trabalho foram estudar a evolu����o da infesta����o pelo Aedes albopictus na regi��o de S��o Jos�� do Rio Preto, ��rea j�� ocupada pelo Aedes aegypti e discutir seu papel na transmiss��o de doen��as. Com informa����es obtidas em medidas de densidade larv��ria realizadas em ��reas urbanas dos munic��pios, analisaram-se: ano e local de ocorr��ncia, composi����o e localiza����o das amostras larv��rias; recipientes e ��ndices de Breteau. At�� maio de 2001, o vetor j�� se encontrava em 96 dos 100 munic��pios da regi��o. O Aedes albopictus, comparativamente ao Aedes aegypti, ocupou em maior propor����o o peridomic��lio e apresentou maior grau de associa����o com recipientes naturais e descart��veis. O comportamento end��mico do dengue, a ocorr��ncia de casos aut��ctones de febre amarela silvestre na regi��o e a reconhecida compet��ncia do vetor para estas doen��as implicam em considerar a possibilidade de sua participa����o na transmiss��o do dengue e na reurbaniza����o da febre amarela.

Isolation of dengue 2 virus from a patient with central nervous system involvement (transverse myelitis)

A dengue fever case is described in a 58-year-old male patient with febrile illness and thrombocytopenia complicated by neurological involvement characterized by transverse myelitis followed by weakness of both legs and flaccid paralysis. Muscle strength was much diminished and bilateral areflexia was observed. Dengue 2 (DEN-2) virus was isolated and the patient sero-converted by hemagglutination-inhibition and IgM-ELISA tests. The RT-PCR test was positive to DEN-2 in acute phase serum and culture supernatant, but negative in the cerebrospinal fluid. After three weeks of hospitalization the patient was discharged. No other infectious agent was detected in the blood and cerebrospinal fluid samples. The patient had full recovery from paralysis six months after the onset of DEN-2 infection.

Susceptibility of Aedes aegypti (L) to the insect growth regulators diflubenzuron and methoprene in Uberl��ndia, State of Minas Gerais

Aedes aegypti (L) (Diptera: Culicidae) was reared in several concentrations of diflubenzuron and methoprene under laboratory conditions in Uberl��ndia, State of Minas Gerais, southeastern Brazil. Characteristics such as LC50 and LC95, the susceptibility of immature stages of different ages to these insect growth regulators and their residual effects were studied. The LC50 and LC95 of diflubenzuron and methoprene were 5.19 and 12.24 ppb; 19.95 and 72.08 ppb, respectively. While diflubenzuron caused great mortality in all larval instars, methoprene was more effective when the mosquito was exposed from the start of the fourth larval instar onwards. Commercial concentrations of these two insect growth regulators close to LC95 presented greater residual activity than did their respective technical formulations. The parameters were compared with those obtained elsewhere. The characteristics investigated here indicate that these insect growth regulators are effective alternatives for controlling the dengue vector in the Uberl��ndia region.

Din��mica populacional de Aedes aegypti (L) em ��rea urbana de alta incid��ncia de dengue

Aspectos da din��mica populacional de Aedes aegypti foram investigados a partir de coletas no decorrer de dois anos na ��rea urbana de Uberl��ndia, MG. A din��mica populacional do mosquito foi influenciada por fatores f��sicos como temperatura e pluviosidade. Altas densidades larvais tamb��m influenciaram no desenvolvimento do mosquito.

Associa����o entre incid��ncia de dengue, pluviosidade e densidade larv��ria de Aedes aegypti, no Estado de Goi��s

INTRODU����O: A densidade larv��ria de Aedes aegypti flutua de acordo com as varia����es clim��ticas sazonais, elevando-se nas esta����es de maior pluviosidade, em fun����o do n��mero de potenciais criadouros dispon��veis, o que predisp��e ao aumento da incid��ncia de dengue. Este estudo teve o objetivo de mostrar a associa����o entre os casos de dengue, a pluviosidade e o ��ndice de infesta����o predial. M��TODOS: Os munic��pios foram estratificados de acordo com transmiss��o e risco de dengue, e infestados ou n��o pelo mosquito. Utilizou-se o ��ndice de infesta����o predial larv��rio (IIP) como indicador de risco de transmiss��o. RESULTADOS: Houve correla����o positiva entre o IIP, o n��mero de casos de dengue e a pluviosidade. A transmiss��o da doen��a foi maior nos quatro primeiros meses de cada ano estudado, per��odo de elevada pluviosidade, diminuindo, nos meses de junho a setembro, ��poca de poucas chuvas. Os casos de dengue mostraram-se cont��nuos e crescentes nos meses de janeiro a mar��o de cada ano, declinando nos meses de abril e maio, quando ocorreu a interrup����o na maioria dos munic��pios. A regi��o metropolitana de Goi��nia foi respons��vel por mais de 80% dos casos de dengue em Goi��s e a transmiss��o foi cont��nua em todos os meses, embora baixa no per��odo de maio a dezembro, mas com aumento nos tr��s ��ltimos meses, os quais, normalmente, apresentam ��ndices baixos de transmiss��o. CONCLUS��ES: A correla����o positiva entre o IIP e a pluviosidade, e o IIP e a incid��ncia de casos, apontaram para uma associa����o significativa crescente na transmiss��o e no n��mero de casos de dengue.

A list of mosquito species of the Brazilian State of Pernambuco, including the first report of Haemagogus janthinomys (Diptera: Culicidae), yellow fever vector and 14 other species (Diptera: Culicidae)

INTRODUCTION: Besides mosquito species adapted to urban environments (Culex quinquefasciatus, Aedes aegypti and Aedes albopictus), only 15 species of Anopheles had been recorded in the State of Pernambuco. METHODS: Human-landing mosquitoes were collected in Dois Irm��os Park, in Recife. RESULTS: The first report for the state of Haemagogus janthinomys, an important vector of yellow fever virus, and 14 other species, including Trichoprosopon lampropus, a first reported for Brazil. CONCLUSIONS: The mosquito fauna in the area is diversified and has potential medical and veterinary importance.

Aedes aegypti and Aedes albopictus (Diptera: Culicidae): coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization

INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paran�� and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion). Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paran��. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paran�� and Santa Catarina) presented survival when exposed to the organophosphate temephos.

Genomic and environmental factors influence Wolbachia-Drosophila symbiosis

Intracellular, vertically transmitted bacteria form complex and intimate relationships with their hosts. Wolbachia, maternally transmitted ��- proteobacteria, live within the cells of numerous arthropod species. Wolbachia are famous master manipulators of insect reproduction: to favour their own spread they can induce male killing, parthenogenesis or cytoplasmic incompatibility. Wolbachia can also protect various insects from pathogens, which makes them a promising tool for the control of vector-borne diseases. Mosquitoes with Wolbachia have already been released in the wild to eliminate dengue. Yet, how Wolbachia manipulate their hosts remains largely unknown.(...)

Variation in Aedes aegypti (Linnaeus) (Diptera, Culicidae) infestation in artificial containers in Caxias, state of Maranh��o, Brazil

INTRODUCTION: Dengue is a serious public health problem worldwide, with cases reported annually in tropical and subtropical regions. Aedes aegypti (Linnaeus, 1762), the main vector of dengue, is a domiciliary species with high dispersal and survival capacities and can use various artificial containers as breeding sites. We assessed potential container breeding sites of A. aegypti in the municipality of Caxias, Maranh��o, Brazil. METHODS: In the initial phase, we analyzed 900 properties in 3 neighborhoods during the dry and rainy seasons (August-October 2005 and February-April 2006, respectively). During the second sampling period, September 2006-August 2007, we used 5 assessment cycles for 300 properties in a single neighborhood. RESULTS: During the dry and rainy seasons, water-storage containers comprised 55.7% (n = 1,970) and 48.5% (n = 1,836) of the total containers inspected, and showed the highest productivity of immature A. aegypti; we found 23.7 and 106.1 individuals/container, respectively, in peridomicile sites. In intradomicile sites, water-storage containers were also the most important breeding sites with 86.4% (n = 973) and 85.6% (n = 900) of all containers and a mean of 7.9 and 108.3 individuals/container in the dry and rainy seaso-October 2006 (1,342). The highest number of positives (70) was recorded in May, mostly (94%) in storage containers. CONCLUSIONS: Storage containers are the principal and most productive A. aegypti breeding sites and are a major contributing factor to the maintenance of this vector in Caxias.

Bioactivity of plant extracts on the larval and pupal stages of Aedes aegypti (Diptera, Culicidea)

Introduction Aedes aegypti is responsible for the transmission of the dengue and yellow fever viruses. This study evaluated the effects of extracts from Cnidosculos phyllacanthus, Ricinus communis, and Coutarea hexandra on the developmental periods of A.aegypti larvae and pupae. Crude extracts of C. phyllacanthus and C. hexandra and oil from R. communis and C. phyllacanthus were used. Methods Bioassays of the larvicidal and pupicidal effects of these products at different concentrations and times of exposure were evaluated. The lethal and sublethal effects were determined using different concentrations in larvicidal tests. Mortality data were evaluated by Probit analysis to determine the LC50 and LC90 values. Results The vegetable oils from C. phyllacanthus and R. communis demonstrated greater efficiency for larval control with an LC50=0.28µl/mL and an LC90=1.48µl/mL and LC50=0.029µl/mL and a LC90=0.26µl/mL, respectively. In pupal tests toxic effects for all insects were verified after exposure to the products at significant LC50 and LC90 values for 24 and 48h. The effects of sublethal concentrations of C. phyllacanthus (oil) were more effective on the insects. Conclusions The vegetables oils from C. phyllacanthus and R. communis demonstrated greater potential from the control of different developmental periods in the life cycle of this insect.

Impact of insecticide resistance on the field control of Aedes aegypti in the State of S��o Paulo

IntroductionThe need to control dengue transmission by means of insecticides has led to the development of resistance to most of the products used worldwide against mosquitoes. In the State of S��o Paulo, the Superintend��ncia de Controle de Endemias(SUCEN) has annually monitored the susceptibility of Aedes aegypti to insecticides since 1996; since 1999, surveys were conducted in collaboration with the National Network of Laboratories (MoReNAa Network) and were coordinated by the Ministry of Health. In this study, in addition to the biological characterization of insecticide resistance in the laboratory, the impact of resistance on field control was evaluated for vector populations that showed resistance in laboratory assays.MethodsField efficacy tests with larvicides and adulticides were performed over a 13-year period, using World Health Organization protocols.ResultsData from the field tests showed a reduction in the residual effect of temephos on populations with a resistance ratio of 3. For adults, field control was less effective in populations characterized as resistant in laboratory qualitative assays, and this was confirmed using qualitative assays and field evaluation.ConclusionsOur results indicated that management of resistance development needs to be adopted when insect populations show reduced susceptibility. The use of insecticides is a self-limiting tool that needs to be applied cautiously, and dengue control requires more sustainable strategies.

Knowledge and practices related to dengue and its vector: a community-based study from Southeast Brazil

Abstract INTRODUCTION: This study investigated the knowledge of users of primary healthcare services living in Ribeir��o Preto, Brazil, about dengue and its vector. METHODS: A cross-sectional survey of 605 people was conducted following a major dengue outbreak in 2013. RESULTS: Participants with higher levels of education were more likely to identify correctly the vector of the disease. CONCLUSIONS: The results emphasize the relevance of health education programs, the continuous promotion of educational campaigns in the media, the role of the television as a source of information, and the importance of motivating the population to control the vector.