Aedes albopictus in bromeliads of anthropic environment in São Paulo State, Brazil

OBJECTIVE: Aedes albopictus populations can breed in several kinds of containers, and its presence has also been reported in Bromeliaceae. The purpose of this study was to evaluate the epidemiological importance of the Bromeliaceae plants as potential breeding sites of Aedes albopictus and to document the associated Culicidae entomofauna found in this micro-habitat. METHODS: Collections of Culicidae larvae were carried out fortnightly in aquatic content of bromeliads during 1998 and 1999. Collections took place in urban and periurban areas of Ilhabela island and periurban area of Ilha Comprida island, Brazil. RESULTS: A total of 26,647 Culicidae larvae were collected at both study sites, 14,575 in the urban area and 10,987 in the periurban area of Ilhabela and the remaining 1,085 in the periurban area of Ilha Comprida. There was no statistical difference between the amount of larvae collected in urban and periurban areas of Ilhabela. Regarding the Ae. albopictus, there was found a higher frequency and amount of larvae in the urban area of Ilhabela, followed by the periurban area in the same site, whereas in the periurban area of Ilha Comprida, its presence was considered accidental, since it was reported only in the first three months. CONCLUSIONS: The results show that bromeliads, largely used in landscaping, may contribute to the spread of Ae. albopictus. The presence of this species in domesticated and domiciled bromeliads allows us to suggest that the Culicidae larva is part of the regional fauna and facilitate the contact between humans and etiological agents of the natural ecosystem.     

Aedes albopictus seasonality in a protected area in the city of São Paulo, Brazil

The study had the objective of assessing the seasonality of Aedes albopictus and the impact of environmental factors on breeding sites in a protected urban area. Immature individuals were collected through fluid aspiration from nine tree holes, in the Ecological Park of Tietê in the city of S?o Paulo, Southern Brazil, from 2001 to 2002. The index of positivity and number of individuals results were as follows: positivity x precipitation (rho=0.69, p<0.001), positivity x temperature (rho=0.35, p<0.001), number of individuals x precipitation (rho=0.29, p<0.001) and number of individuals x temperature (rho=0.13, p<0.05). These correlations suggest rainfalls had greater impact than temperature.     

Changes in susceptibility of Aedes aegypti to organophosphates in municipalities in the state of São Paulo, Brazil

Baseline data on susceptibility of Aedes aegypti to organophosphates detected alterations in cities of the state of S. Paulo, Brazil     

Simplifying the sampling method for evaluating the larval density of Aedes aegypti in S?o Paulo State, Brazil]

OBJECTIVE: To suggest changes in the sampling procedures for estimating the larval density of Aedes aegypti in the state of S?o Paulo, Brazil, by assessing the efficacy and level of complexity of the current procedures. METHODS: The "Superintendência de Controle de Endemias do Estado de S?o Paulo" - SUCEN's (Superintendence for Endemic Control of the State of S?o Paulo) sampling procedures for estimating the density of Aedes aegypti larvae was assessed. The Breteau index with one-stage cluster sampling was applied. An average of 35 blocks, 14 buildings per block, of a total of 510 buildings per sample, were assessed. One hundred and eleven samples were obtained in 6 municipalities of S?o José do Rio Preto. RESULTS: The Breteau index estimates higher than 3 had coefficients of variation smaller than 30% in 71% of the samples. The design effect was 1.19 and 1.79 for indexes lower and higher than 5, respectively. The estimates were obtained in less than 3 days, requiring a daily average of 5.5 men per sampling. CONCLUSION: This sampling design revealed to be a simplified one: fast, economic and easily managed. The operational easiness was due to the use of the one-stage cluster sampling, when there was not need to prepare lists of addresses and then sort and locate the buildings. Though the design effect shows a slight loss of the estimates' accuracy with the use of one-stage cluster sampling, this was proven to be under acceptable range. Simplifying changes in the process of determining the sample size and assessing sampling errors are proposed.     

Occurrence of schistosomiasis mansoni vectors on the Northern coast of the State of São Paulo, Brazil

This article comments on the detection of Biomphalaria tenagophila (d'Orbigny, 1835) infected with Schistosoma mansoni Sambon, 1907 in Caraguatatuba and the introduction of Biomphalaria straminea (Dunker, 1848) in Ilha Bela, two municipalities on the Northern coast of the State of S?o Paulo, Brazil. Infected snails were collected from a ditch located in the Olaria district. B. straminea and B. tenagophila were living in syntopy in a stream situated in Barra Velha. Such epidemiological findings indicate the risk of spread of schistosomiasis mansoni in the region, a consequence of inadequate basic sanitation.     

Spatial distribution of endemic diseases in Ribeirão Preto, São Paulo State

The perception that some diseases happen in certain places is old. The concern in studying the relation between the human being and the environment resulted in several studies of medical geography, directed to the analysis of diseases spatial distribution. This sectional study was carried out in Ribeir?o Preto, S?o Paulo State, and aimed to illustrate, through health problems (dengue, leprosy and tuberculosis), how a Geographic Information System tool allows the identification of heterogeneous areas, providing support for the choice of strategies and specific interventions according to the need of residents, as well as, priority of resources to more vulnerable groups. The population comprised cases of dengue, leprosy and tuberculosis notified in Ribeir?o Preto in 2000. Data were collected in the Health Secretary Epidemiological Surveillance of the city. In order to obtain the thematic maps, data were geo-codified with the software MapInfo 7.8 e Spring 4.3. The thematic maps showed the density distribution of dengue, leprosy and tuberculosis cases in the city as a way to complement the analysis of health information, pointing priority areas for the control of these diseases.     

Social representations concerning dengue, dengue vectors, and control activities among residents of São Sebastião on the northern coast of São Paulo State, Brazil

This study sought to identify people's knowledge on dengue and its vector biology, aimed at promoting a communications channel between technical and lay reasoning in order to foster community involvement in dengue and dengue vector control activities. A survey was conducted in an Aedes aegypti-infested area with dengue transmission in S?o Sebasti?o on the northern coast of S?o Paulo State, Brazil. One hundred interviews were held, with five open questions on topics related to dengue and vector control. Collective Subject Discourse methodology was used in the analysis. People were not able to properly identify the kinds of accumulated water sources that serve as breeding places for mosquitoes and were unaware of the egg phase in vector development. There was inadequate awareness of vector biology and a need for greater government-community integration. Educational activities should incorporate the study results as insight for improving the social efficiency and efficacy of joint actions to fight dengue and control the mosquito vector.     

Impact of rotavirus vaccination on diarrhea-related hospitalizations in São Paulo State,Brazil

IntroductionFollowing introduction of routine infant rotavirus vaccination, severe diarrhea hospitalization rates declined among children aged <5 years throughout Brazil. Ensuring equity of rotavirus vaccine impact is important in countries that self-finance immunization programs. The objective of this study was to examine rotavirus vaccine impact on diarrhea admission rates among children aged <5 years in Brazil's public health system, according to area-based measures of human development in the state of São Paulo, Brazil.MethodsEcological analysis of public health system hospitalization rates for acute gastroenteritis among children aged <5 years in the state of São Paulo, Brazil, according to five categories of municipal development based on a modified Human Development Index for municipalities. Acute gastroenteritis hospitalization rates among children aged <5 years after national rotavirus vaccine introduction (2008–2011) were compared to rates in pre-vaccine years (2000–2005) to calculate percent decline in rates (1 − rate ratio) and 95% confidence intervals (CI) for each municipal development category. Direct hospitalization costs during the two periods were compared.ResultsAnnual rates declined by 40% (95% CI, 39–42%) from 631 diarrhea hospitalizations per 100,000 person years pre-rotavirus vaccination to 377 per 100,000 post-vaccination among children aged <5 years and 50% (95% CI, 48–52%) from 1009 to 505 per 100,000 among infants. Highest rates were observed in least developed municipalities. Significant declines of 26–52% among children <5 years and 41–63% among infants were observed in all categories of municipal development. Lower diarrhea hospitalization rates resulted in annual savings of approximately 2 million USD for the state of São Paulo. Savings in direct hospitalization costs benefitted municipalities in all five categories.ConclusionThe introduction of rotavirus vaccination was associated with substantial reductions of diarrhea-related admissions at all levels of municipal development in São Paulo State, Brazil.     

Dengue and the risk of urban yellow fever reintroduction in São 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.     

Inequality of workers' survival in Botucatu, São Paulo State, Brazil

The aim of this observational study was to estimate the survival function and risk of death in Botucatu, Southeast Brazil, by occupation. The occupational history of inhabitants of Botucatu who died after their 10th birthday from January 1, 1997, to March 31, 1998, was analyzed, as were the occupational histories of workers' spouses. A total of 992 subjects were studied. Data were analyzed by fitting a proportional hazards model where the time variable was age at death or at time of interview and the main co-variable was occupation. Results showed that risk of death increased consistently as the level of occupational specialization decreased, displaying a 12-year increase in life expectancy for professional as compared to unskilled workers.     

Spotted fever in Campinas region,State of São Paulo,Brazil

Brazilian spotted fever was detected for the first time in the State of S o Paulo in 1929. However, there is no systematic reporting of the disease in the State. In 1985, three cases of the disease occurred in the municipality of Pedreira, located in the Campinas Region, belonging to the 5th Administrative Region, in the Northeast part of the State, including 88 municipalities. An investigation was conducted at the time, but the lack of case registry limited its scope. The present study was undertaken with the aim of recovering the history of the disease in the Region. Data recovered from several public health services for 1985-2000 were used to analyze incidence patterns. It was observed that the transmission area expanded and the number of suspected cases increased, especially after 1996, when mandatory reporting was established. Deaths due to spotted fever were observed in most of the years under study. The study concluded that spotted fever incidence is increasing in the Campinas Region. Complementary bio-ecological studies are currently under way to better understand the epidemiology of this disease, recognized worldwide as an emerging public health problem.     

Parity and wind impact on the frequency of Anopheles marajoara,São Paulo,Brazil

OBJECTIVE: To evaluate the impact of wind velocity on the behavior of An. marajoara population and its parity. METHODS: Collections were made bimonthly from January 1999 to February 2000 in the municipality of Ilha Comprida, Brazil. Adult mosquitoes were captured with a battery hand aspirator. Mann-Whitney test was applied to verify the wind impact on mosquito behavior. Polovodova technique and Christophers and Mer's follicular development analysis were used to determine parity. RESULTS: A total of 11,833 mosquitoes were captured, including 3,072 An. marajoara specimens. The peak of activity of An. marajoara occurred from 2 to 5 AM. Amongst 1,006 An. marajoara females who had their ovarioles dissected, it was found 530 (52.7%) nulliparous, 432 (42.9%) uniparous, 24 (2.4%) biparous and 1 multiparous. According to Christophers and Mer analysis, 982 (97.6%) had their follicles in phases I and II, 7 in phases III and IV, and 17 in phase V. The frequency of An. marajoara was significantly lower when wind velocity was 3 km/h or more or below 3 km/h. CONCLUSIONS: An. marajoara mosquitoes were more active at night. About 50% of dissected An. marajoara females were oniparous. Another important finding was the high proportion of females (97.6%) with follicles in the Christophers and Mer's phases I and II, suggesting the presence of gonotrophic concordance. Wind velocity equal or higher than 3 km/h considerably reduced the frequency of An. marajoara.