Dengue is a vector-borne disease transmitted by the mosquito Aedes aegypti. The incidence of dengue disease shows a clear dependence on seasonal variation. How does the temperature affect the incidence? We addressed this question indirectly by estimating the size of the A. aegypti population for different temperatures applying population dynamics theory. In order to achieve this objective we designed temperature-controlled experiments to assess the entomological parameters regarding the mosquito's life-cycle at different temperatures. By obtaining the mortality, transition and oviposition rates for different stages of the life-cycle of the mosquito we were able to calculate the basic offspring number Q(0), which is the capacity of vector reproduction and ultimately gives the size of the vector population.

The incidence of dengue infection, a vector-borne disease transmitted by the mosquito Aedes aegypti, shows clear dependence on seasonal variation. Based on the quantification method that furnishes the size of the A. aegypti population in terms of the estimated entomological parameters for different temperatures, we assessed the risk of dengue outbreaks. The persistence and severity of epidemics can be assessed by the basic reproduction number R(0), which varies with temperature. The expression for R(0) obtained from 'true' and 'pseudo' mass action laws for dengue infection is discussed.

Introduction:The 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 São Paulo, the Superintendência 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 fi eld control was evaluated for vector populations that showed resistance in laboratory assays. Methods: Field effi cacy tests with larvicides and adulticides were performed over a 13-year period, using World Health Organization protocols. Results: Data from the fi eld tests showed a reduction in the residual effect of temephos on populations with a resistance ratio of 3. For adults, fi eld control was less effective in populations characterized as resistant in laboratory qualitative assays, and this was confi rmed using qualitative assays and fi eld evaluation. Conclusions: Our 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.

The present study was effected aiming the verification of the seasonal, spatial and hourly of the phlebotominic species found in the county of Itupeva. Captures were performed fortnightly and 864 sand flies were collected between april/94 and march/95. 81.3% of the captured specimens belonged to 4 species: L. migonei (32.4%), L. whitmani (26.0%), L. intermedia (12.0%) e L. fischeri (10.9%). Such species showed larger densities during the cold and dry season of the year (from april to september/94) and were more active between the second and the fifth hour after twilight. L. migonei predominated almost in all the investigated surroundings being followed by L. whitmani and L. longipalpis in the domestic environments. In conclusion it is thought that in conjunction with L. intermedia, a suspect vector in the State of São Paulo, L. migonei and L. whitmani may have an important role in the transmission of cutaneous leishmaniasis in the area under study.

Sandflies were captured in a secondary forest zone in the county of Teodoro Sampaio, São Paulo, during 12 months as from May 1994. Two houses located respectively at 240 m and 850 m from the semi-deciduous forest were selected. Night Center of Disease Control trap captures were performed fortnightly from twilight to dawn intradomiciliarily, in the edge and the interior of the forest and in the peridomicile of each one of the houses. Captures were realized as well in the peridomicile using Shannon traps during 6 hour for 24 captures and 4 quarter captures from twilight to dawn. The dominant species was Lutzomyia intermedia (93.5%). A larger number of insects were captured in the traps located in the edge of the forest. In the peridomicile of both houses an equivalent number of insects were captured, although a clear predominance of males was observed in the more distant located house. In the interior of the house located near the forest a larger number of specimens predominantly female were captured. L. intermedia and L. whitmani peaks occurred in the first hour and were characteristically more abundant in May, September and December when the mean temperature varied from 21 to 25.7 degrees C and the pluviometric index as from 66.7 to 195.1 mm.

METHODS: This is a descriptive study of a sylvatic yellow fever outbreak in the Southwestern region of the state from February to April 2009. Suspected and confirmed cases in humans and in non-human primates were evaluated. Entomological investigation in sylvatic environment involved capture at ground level and in the tree canopy to identify species and detect natural infections. Control measures were performed in urban areas to control Aedes aegypti. Vaccination was directed at residents living in areas with confirmed viral circulation and also at nearby cities according to national recommendation. RESULTS:Twenty-eight human cases were confirmed (39.3% case fatality rate) in rural areas of Sarutaiá, Piraju, Tejupá, Avaré and Buri. The deaths of 56 nonhuman primates were also reported, 91.4% were Allouatta sp. Epizootics was confirmed in two non-human primates in the cities of Itapetininga and Buri. A total of 1,782 mosquitoes were collected, including Haemagogus leucocelaenus, Hg. janthinomys/capricornii, and Sabethes chloropterus, Sa. purpureus and Sa. undosus. Yellow fever virus was isolated from a group of Hg. Leucocelaenus from Buri. Vaccination was carried out in 49 cities, with a total of 1,018,705 doses. Nine serious post-vaccination adverse events were reported. CONCLUSIONS:The cases occurred between February and April 2009 in areas with no recorded yellow fever virus circulation in over 60 years. The outbreak region occurred outside the original recommended vaccination area with a high percentage of susceptible population. The fast adoption of control measures interrupted the human transmission within a month and the confirmation of viral circulation in humans, monkeys and mosquitoes. The results allowed the identification of new areas of viral circulation but further studies are required to clarify the dynamics of the spread of this disease.

À memona de meu pai que, inteligentemente, soube fornecer-me as bases da minha formação e ensinar-me a encarar o trabalho com o mais elevado espírito de integridade. À minha mãe, que sempre me estimulou a continuar este projeto substituindo-me junto ao Juninho e ao Luiz Felipe nos momentos de ausência. Ao Wanderley, que comigo dividiu as angústias e ansiedades durante a realização deste trabalho. RESUMO O controle da transmissão da doença de Chagas no Estado de São Paulo, delineado" no presente estudo, foi equacionado e solucionado e não constitui, nos dias atuais, problema de saúde pública. O risco de ocorrência de casos agudos fica restrito a eventos isolados. Este quadro, portanto, autoriza otimismo, podendo-se supor que a atual incidência da doença no Estado seja próxima de zero e esperar que a incidência futura se mantenha nesse nível. Sob a ótica da transmissão vetorial, as ações de vigilância sobre as espécies peridomiciliares presentes atualmente no Estado têm respondido de maneira eficaz à possibilidade de infecção por Trypanosoma cruzi a partir do contato homem-vetor.A casa rural paulista não constitui hoje ecótopo adequado para a domiciliação de tais espécies de triatomíneos. O comportamento invasor, característico principalmente dos indivíduos adultos fêmeas, não tem passado despercebido à população que prontamente coleta e encaminha o inseto para análise utilizando-se, na maioria das vezes, do Centro de Saude local, numa integração da vigilância vetorial à rede de atenção à · saude. O pronto atendimento a cada notificação serve de estímulo à participação. Em síntese, a vigilância vetorial está consolidada junto à comunidade e à rede de saúde local.A transmissão transfusional constitui fenômeno raro dadas as condições com que se pratica a hemoterapia no Estado de São Paulo. As ações de controle do sangue foram implementadas pela Secretaria de Saúde a partir de 1988, com índices de cobertura de seleção de doadores próximos de 100% já em 1990.Mais recentemente, com a instalação da Hemo-rede estadual e a ampliação da cobertura dos Hemocentros incluindo os pequenos municípios, pode-se observar uma melhora da qualidade da hemoterapia. O descarte do candidato à doação quando procedente de área endêmica de doença de Chagas, tem contribuído para a obtenção de baixos percentuais de prevalência na triagem sorológica, situado~ próximos a 1%.A transmissão congênita, entendida como mecanismo residual de perpetuação da infecção, ocorre em níveis discretos e pode ser perfeitamente controlada desde que se realizem provas sorológicas para doença de Chagas em gestantes com epidemiologia compatível e se pesquise a infecção na criança ao nascer e seguimento até os 6 meses. A persistência da positividade sorológica deve orientar para tratamento especifico.Outros mecanismos de transmissão não apresentam qualquer importância no contexto da endemia.Resta ao sistema de saúde, portanto, olhar de frente os indivíduos infectados que merecerão atenção médica e previdenciária e cujo direito à saúde está garantido pela carta consti...

With the urbanisation of the population in developing countries and the process of globalisation, Chagas has become an emerging disease in the urban areas of endemic and non-endemic countries. In 2006, it was estimated that the prevalence of Chagas disease among the general Bolivian population was 6.8%. The aim of the present study was to determine the prevalence of Trypanosoma cruzi infection among Bolivian immigrants living in São Paulo, Brazil. This study had a sample of 633 volunteers who were randomly selected from the clientele of primary care units located in the central districts of São Paulo, Brazil. Infection was detected by two different ELISA assays with epimastigote antigens, followed by an immunoblot with trypomastigote antigens as a confirmatory test. The prevalence of the infection was 4.4%. Risk factors independently associated with the infection were: a history of rural jobs in Bolivia, knowledge of the vector involved in transmission, and having relatives with Chagas disease. Brazil has successfully eliminated household vector transmission of T. cruzi, as well as its transmission by blood transfusion. The arrival of infected immigrants represents an additional challenge to primary care clinics to manage chronic Chagas disease, its vertical transmission, and the blood derivatives and organ transplant programs.