Publications by authors named "Wayner V Souza"

17 Publications

  • Page 1 of 1

Acute Chagas disease in Brazil from 2001 to 2018: A nationwide spatiotemporal analysis.

PLoS Negl Trop Dis 2020 08 3;14(8):e0008445. Epub 2020 Aug 3.

Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Salvador, Bahia, Brazil.

Background: In Brazil, acute Chagas disease (ACD) surveillance involves mandatory notification, which allows for population-based epidemiological studies. We conducted a nationwide population-based ecological analysis of the spatiotemporal patterns of ACD notifications in Brazil using secondary surveillance data obtained from the Notifiable Diseases Information System (SINAN) maintained by Brazilian Ministry of Health.

Methodology/principal Findings: In this nationwide population-based ecological all cases of ACD reported in Brazil between 2001 and 2018 were included. Epidemiological characteristics and time trends were analyzed through joinpoint regression models and spatial distribution using microregions as the unit of analysis. A total of 5,184 cases of ACD were recorded during the period under study. The annual incidence rate in Brazil was 0.16 per 100,000 inhabitants/year. Three statistically significant changes in time trends were identified: a rapid increase prior to 2005 (Period 1), a stable drop from 2005 to 2009 (Period 2), followed by another increasing trend after 2009 (Period 3). Higher frequencies were noted in males and females in the North (all three periods) and in females in Northeast (Periods 1 and 2) macroregions, as well as in individuals aged between 20-64 years in the Northeast, and children, adolescents and the elderly in the North macroregion. Vectorial transmission was the main route reported during Period 1, while oral transmission was found to increase significantly in the North during the other periods. Spatiotemporal distribution was heterogeneous in Brazil over time. Despite regional differences, over time cases of ACD decreased significantly nationwide. An increasing trend was noted in the North (especially after 2007), and significant decreases occurred after 2008 among all microregions other than those in the North, especially those in the Northeast and Central-West macroregions.

Conclusions/significance: In light of the newly identified epidemiological profile of CD transmission in Brazil, we emphasize the need for strategically integrated entomological and health surveillance actions.
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http://dx.doi.org/10.1371/journal.pntd.0008445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7425982PMC
August 2020

Early epilepsy in children with Zika-related microcephaly in a cohort in Recife, Brazil: Characteristics, electroencephalographic findings, and treatment response.

Epilepsia 2020 03 17;61(3):509-518. Epub 2020 Feb 17.

University of Pernambuco, Recife, Brazil.

Objective: To estimate the incidence of epilepsy in children with Zika-related microcephaly in the first 24 months of life; to characterize the associated clinical and electrographic findings; and to summarize the treatment responses.

Methods: We followed a cohort of children, born during the 2015-2016 Zika virus (ZIKV) epidemic in Brazil, with congenital microcephaly and evidence of congenital ZIKV infection on neuroimaging and/or laboratory testing. Neurological assessments were performed at ≤3, 6, 12, 15, 18, 21, and 24 months of life. Serial electroencephalograms were performed over the first 24 months.

Results: We evaluated 91 children, of whom 48 were female. In this study sample, the cumulative incidence of epilepsy was 71.4% in the first 24 months, and the main type of seizure was infantile spasms (83.1%). The highest incidence of seizures occurred between 3 and 9 months of age, and the risk remained high until 15 months of age. The incidence of infantile spasms peaked between 4 and 7 months and was followed by an increased incidence of focal epilepsy cases after 12 months of age. Neuroimaging results were available for all children, and 100% were abnormal. Cortical abnormalities were identified in 78.4% of the 74 children evaluated by computed tomography and 100% of the 53 children evaluated by magnetic resonance imaging. Overall, only 46.1% of the 65 children with epilepsy responded to treatment. The most commonly used medication was sodium valproate with or without benzodiazepines, levetiracetam, phenobarbital, and vigabatrin.

Significance: Zika-related microcephaly was associated with high risk of early epilepsy. Seizures typically began after the third month of life, usually as infantile spasms, with atypical electroencephalographic abnormalities. The seizure control rate was low. The onset of seizures in the second year was less frequent and, when it occurred, presented as focal epilepsy.
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http://dx.doi.org/10.1111/epi.16444DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7155083PMC
March 2020

Spatiotemporal Analysis of the Population Risk of Congenital Microcephaly in Pernambuco State, Brazil.

Int J Environ Res Public Health 2020 01 21;17(3). Epub 2020 Jan 21.

Centro de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz, Recife PE, 50740-465, Brazil.

Since an outbreak in Brazil, which started in 2015, Zika has been recognized as an important cause of microcephaly. The highest burden of this outbreak was in northeast Brazil, including the state of Pernambuco. The prevalence of congenital microcephaly in Pernambuco state was estimated from the RESP (Registro de Eventos em Saúde Pública) surveillance system, from August 2015 to August 2016 inclusive. The denominators were estimated at the municipality level from official demographic data. Microcephaly was defined as a neonatal head circumference below the 3rd percentile of the Intergrowth standards. Smoothed maps of the prevalence of microcephaly were obtained from a Bayesian model which was conditional autoregressive (CAR) in space, and first order autoregressive in time. A total of 742 cases were identified. Additionally, high and early occurrences were identified in the Recife Metropolitan Region, on the coast, and in a north-south band about 300 km inland. Over a substantial part of the state, the overall prevalence, aggregating over the study period, was above 0.5%. The reasons for the high occurrence in the inland area remain unclear.
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http://dx.doi.org/10.3390/ijerph17030700DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7037094PMC
January 2020

Perinatal analyses of Zika- and dengue virus-specific neutralizing antibodies: A microcephaly case-control study in an area of high dengue endemicity in Brazil.

PLoS Negl Trop Dis 2019 03 11;13(3):e0007246. Epub 2019 Mar 11.

Aggeu Magalhães Institute, Oswaldo Cruz Foundation (FIOCRUZ), Recife, Pernambuco, Brazil.

Laboratory confirmation of Zika virus (ZIKV) infection during pregnancy is challenging due to cross-reactivity with dengue virus (DENV) and limited knowledge about the kinetics of anti-Zika antibody responses during pregnancy. We described ZIKV and DENV serological markers and the maternal-fetal transfer of antibodies among mothers and neonates after the ZIKV microcephaly outbreak in Northeast Brazil (2016). We included 89 microcephaly cases and 173 neonate controls at time of birth and their mothers. Microcephaly cases were defined as newborns with a particular head circumference (2 SD below the mean). Two controls without microcephaly were matched by the expected date of delivery and area of residence. We tested maternal serum for recent (ZIKV genome, IgM and IgG3 anti-NS1) and previous (ZIKV and DENV neutralizing antibodies [NAbs]) markers of infection. Multiple markers of recent or previous ZIKV and DENV infection in mothers were analyzed using principal component analysis (PCA). At delivery, 5.6% of microcephaly case mothers and 1.7% of control mothers were positive for ZIKV IgM. Positivity for ZIKV IgG3 anti-NS1 was 8.0% for case mothers and 3.5% for control mothers. ZIKV NAbs was slightly higher among mothers of cases (69.6%) than that of mothers of controls (57.2%; p = 0.054). DENV exposure was detected in 85.8% of all mothers. PCA discriminated two distinct components related to recent or previous ZIKV infection and DENV exposure. ZIKV NAbs were higher in newborns than in their corresponding mothers (p<0.001). We detected a high frequency of ZIKV exposure among mothers after the first wave of the ZIKV outbreak in Northeast Brazil. However, we found low sensitivity of the serological markers to recent infection (IgM and IgG3 anti-NS1) in perinatal samples of mothers of microcephaly cases. Since the neutralization test cannot precisely determine the time of infection, testing for ZIKV immune status should be performed as early as possible and throughout pregnancy to monitor acute Zika infection in endemic areas.
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http://dx.doi.org/10.1371/journal.pntd.0007246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428350PMC
March 2019

Zika virus and microcephaly - Authors' reply.

Lancet Infect Dis 2016 12 15;16(12):1332. Epub 2016 Nov 15.

Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.

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http://dx.doi.org/10.1016/S1473-3099(16)30457-1DOI Listing
December 2016

Pyriproxyfen and the microcephaly epidemic in Brazil - an ecological approach to explore the hypothesis of their association.

Mem Inst Oswaldo Cruz 2016 Dec 31;111(12):774-776. Epub 2016 Oct 31.

London School of Hygiene and Tropical Medicine, London, UK.

The microcephaly epidemic in Brazil generated intense debate regarding its causality, and one hypothesised cause of this epidemic, now recognised as congenital Zika virus syndrome, was the treatment of drinking water tanks with pyriproxyfen to control Aedes aegypti larvae. We present the results of a geographical analysis of the association between the prevalence of microcephaly confirmed by Fenton growth charts and the type of larvicide used in the municipalities that were home to the mothers of the affected newborns in the metropolitan region of Recife in Pernambuco, the state in Brazil where the epidemic was first detected. The overall prevalence of microcephaly was 82 per 10,000 live births in the three municipalities that used the larvicide Bti (Bacillus thuringiensis israelensis) instead of pyriproxyfen, and 69 per 10,000 live births in the eleven municipalities that used pyriproxyfen. The difference was not statistically significant. Our results show that the prevalence of microcephaly was not higher in the areas in which pyriproxyfen was used. In this ecological approach, there was no evidence of a correlation between the use of pyriproxyfen in the municipalities and the microcephaly epidemic.
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http://dx.doi.org/10.1590/0074-02760160291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5146741PMC
December 2016

From re-emergence to hyperendemicity: the natural history of the dengue epidemic in Brazil.

PLoS Negl Trop Dis 2011 Jan 4;5(1):e935. Epub 2011 Jan 4.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.

Background: dengue virus (DENV) was reintroduced into Brazil in 1986 and by 1995 it had spread throughout the country. In 2007 the number of dengue hemorrhagic fever (DHF) cases more than doubled and a shift in the age distribution was reported. While previously the majority of DHF cases occurred among adults, in 2007 53% of cases occurred in children under 15 years old. The reasons for this shift have not been determined.

Methods And Findings: age stratified cross-sectional seroepidemiologic survey conducted in Recife, Brazil in 2006. Serostatus was determined by ELISA based detection of Dengue IgG. We estimated time-constant and time-varying forces of infection of DENV between 1986 and 2006. We used discrete-time simulation to estimate the accumulation of monotypic and multitypic immunity over time in a population previously completely susceptible to DENV. We projected the age distribution of population immunity to dengue assuming similar hazards of infection in future years. The overall prevalence of DENV IgG was 0.80 (n = 1427). The time-constant force of infection for the period was estimated to be 0.052 (95% CI 0.041, 0.063), corresponding to 5.2% of susceptible individuals becoming infected each year by each serotype. Simulations show that as time since re-emergence of dengue goes by, multitypic immunity accumulates in adults while an increasing proportion of susceptible individuals and those with monotypic immunity are among young age groups. The median age of those monotypically immune can be expected to shift from 24 years, 10 years after introduction, to 13 years, 50 years after introduction. Of those monotypically immune, the proportion under 15 years old shifts from 27% to 58%. These results are consistent with the dengue notification records from the same region since 1995.

Interpretation: assuming that persons who have been monotypically exposed are at highest risk for severe dengue, the shift towards younger patient ages observed in Brazil can be partially explained by the accumulation of multitypic immunity against DENV-1, 2, and 3 in older age groups, 22 years after the re-introduction of these viruses. Serotype specific seroepidemiologic studies are necessary to accurately estimate the serotype specific forces of infection.
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http://dx.doi.org/10.1371/journal.pntd.0000935DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3014978PMC
January 2011

A dynamic analysis of tuberculosis dissemination to improve control and surveillance.

PLoS One 2010 Nov 30;5(11):e14140. Epub 2010 Nov 30.

Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, Recife, Pernambuco, Brazil.

Background: Detailed analysis of the dynamic interactions among biological, environmental, social, and economic factors that favour the spread of certain diseases is extremely useful for designing effective control strategies. Diseases like tuberculosis that kills somebody every 15 seconds in the world, require methods that take into account the disease dynamics to design truly efficient control and surveillance strategies. The usual and well established statistical approaches provide insights into the cause-effect relationships that favour disease transmission but they only estimate risk areas, spatial or temporal trends. Here we introduce a novel approach that allows figuring out the dynamical behaviour of the disease spreading. This information can subsequently be used to validate mathematical models of the dissemination process from which the underlying mechanisms that are responsible for this spreading could be inferred.

Methodology/principal Findings: The method presented here is based on the analysis of the spread of tuberculosis in a Brazilian endemic city during five consecutive years. The detailed analysis of the spatio-temporal correlation of the yearly geo-referenced data, using different characteristic times of the disease evolution, allowed us to trace the temporal path of the aetiological agent, to locate the sources of infection, and to characterize the dynamics of disease spreading. Consequently, the method also allowed for the identification of socio-economic factors that influence the process.

Conclusions/significance: The information obtained can contribute to more effective budget allocation, drug distribution and recruitment of human skilled resources, as well as guiding the design of vaccination programs. We propose that this novel strategy can also be applied to the evaluation of other diseases as well as other social processes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0014140PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994743PMC
November 2010

An entomological surveillance system based on open spatial information for participative dengue control.

An Acad Bras Cienc 2009 12;81(4):655-62

Departamento de Entomologia, Centro de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz, Cidade Universitária, Recife, PE, Brasil.

Aedes aegypti is a very efficient disseminator of human pathogens. This condition is the result of evolutionary adaptations to frequent haematophagy, as well as to the colonization of countless types of habitats associated with environmental and cultural factors that favor the proliferation of this mosquito in urban ecosystems. Studies using sensitive methods of monitoring demonstrate that the methods of surveillance used in the Brazilian program do not show the high degrees of the infestation of cities by this vector. To increase the capacity of the health sector, new tools are needed to the practice of surveillance, which incorporate aspects of the vector, place and human population. We describe here the SMCP-Aedes - Monitoring System and Population Control of Aedes aegypti, aiming to provide an entomological surveillance framework as a basis for epidemiological surveillance of dengue. The SMCP-Aedes is uphold in the space technology information, supported by the intensive use of the web and free software to collect, store, analyze and disseminate information on the spatial-temporal distribution of the estimated density for the population of Aedes, based on data systematically collected with the use of ovitraps. Planned control interventions, intensified where and when indicated by the entomological surveillance, are agreed with the communities, relying on the permanent social mobilization.
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http://dx.doi.org/10.1590/s0001-37652009000400004DOI Listing
December 2009

Is it better to be rich in a poor area or poor in a rich area? A multilevel analysis of a case-control study of social determinants of tuberculosis.

Int J Epidemiol 2009 Oct 4;38(5):1285-96. Epub 2009 Aug 4.

Departamento de Medicina Tropical, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.

Background: Tuberculosis is known to have socio-economic determinants at individual and at area levels, but it is not known whether they are independent, whether they interact and their relative contributions to the burden of tuberculosis.

Methods: A case-control study was conducted in Recife, Brazil, to investigate individual and area social determinants of tuberculosis, to explore the relationship between determinants at the two levels and to calculate their relative contribution to the burden of tuberculosis. It included 1452 cases of tuberculosis diagnosed by the tuberculosis services and 5808 controls selected at random from questionnaires completed for the demographic census. Exhaustive information on social factors was collected from cases, using the questionnaire used in the census. Socio-economic information for areas was downloaded from the census. Multilevel logistic regression investigated individual and area effects.

Results: There was a marked and independent influence of social variables on the risk of tuberculosis, both at individual and area levels. At individual level, being aged >or=20, being male, being illiterate, not working in the previous 7 days and possessing few goods, all increased the risk of tuberculosis. At area level, living in an area with many illiterate people and where few households own a computer also increased this risk; individual and area levels did not appear to interact. Twice as many cases were attributable to social variables at individual level than at area level.

Conclusions: Although individual characteristics are the main contributor to the risk of tuberculosis, contextual characteristics make a substantial independent contribution.
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http://dx.doi.org/10.1093/ije/dyp224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2755128PMC
October 2009

Spatial point analysis based on dengue surveys at household level in central Brazil.

BMC Public Health 2008 Oct 20;8:361. Epub 2008 Oct 20.

Institute of Tropical Pathology and Public Health, Federal University of Goias, Department of Collective Health, Goias, Brazil.

Background: Dengue virus (DENV) affects nonimunne human populations in tropical and subtropical regions. In the Americas, dengue has drastically increased in the last two decades and Brazil is considered one of the most affected countries. The high frequency of asymptomatic infection makes difficult to estimate prevalence of infection using registered cases and to locate high risk intra-urban area at population level. The goal of this spatial point analysis was to identify potential high-risk intra-urban areas of dengue, using data collected at household level from surveys.

Methods: Two household surveys took place in the city of Goiania (approximately 1.1 million population), Central Brazil in the year 2001 and 2002. First survey screened 1,586 asymptomatic individuals older than 5 years of age. Second survey 2,906 asymptomatic volunteers, same age-groups, were selected by multistage sampling (census tracts; blocks; households) using available digital maps. Sera from participants were tested by dengue virus-specific IgM/IgG by EIA. A Generalized Additive Model (GAM) was used to detect the spatial varying risk over the region. Initially without any fixed covariates, to depict the overall risk map, followed by a model including the main covariates and the year, where the resulting maps show the risk associated with living place, controlled for the individual risk factors. This method has the advantage to generate smoothed risk factors maps, adjusted by socio-demographic covariates.

Results: The prevalence of antibody against dengue infection was 37.3% (95%CI [35.5-39.1]) in the year 2002; 7.8% increase in one-year interval. The spatial variation in risk of dengue infection significantly changed when comparing 2001 with 2002, (ORadjusted = 1.35; p < 0.001), while controlling for potential confounders using GAM model. Also increasing age and low education levels were associated with dengue infection.

Conclusion: This study showed spatial heterogeneity in the risk areas of dengue when using a spatial multivariate approach in a short time interval. Data from household surveys pointed out that low prevalence areas in 2001 surveys shifted to high-risk area in consecutive year. This mapping of dengue risks should give insights for control interventions in urban areas.
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http://dx.doi.org/10.1186/1471-2458-8-361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576465PMC
October 2008

Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination.

BMC Med Res Methodol 2007 Feb 23;7:11. Epub 2007 Feb 23.

Department of Mother and Child Health, Federal University of Pernambuco, Recife, Brasil.

Background: In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases.

Methods: A comparison of two control groups in a case control study of the efficacy of BCG revaccination. One group was selected from subjects presenting to the heath unit the case attended for routine prevention and care; the second group was selected from the neighbourhood of cases. All Health Units from which controls were selected offered BCG revaccination. Efficacy estimated in a randomized control trial of BCG revaccination was used to establish that the neighbourhood control group was the one that gave unbiased results.

Results: The proportion of controls with scars indicating BCG revaccination was higher among the control group selected from Health Unit attenders than among neighbourhood controls. This excess was not removed after control for social variables and history of exposure to tuberculosis, and appears to have resulted from the fact that people attending the Health Unit were more likely to have been revaccinated than neighbourhood controls, although we can not exclude an effect of other unmeasured variables.

Conclusion: In this study, controls selected from people presenting to a Health Unit overrepresented exposure to BCG revaccination. Had the results from the HU attenders control group been accepted this would have resulted in overestimation of vaccine efficacy. When the exposure of interest is offered in a health facility, selection of controls from attenders at the facility may result in over representation of exposure in controls and selection bias.
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http://dx.doi.org/10.1186/1471-2288-7-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1810541PMC
February 2007

Tuberculosis in intra-urban settings: a Bayesian approach.

Trop Med Int Health 2007 Mar;12(3):323-30

Aggeu Magalhães Research Centre, Oswaldo Cruz Foundation, Recife, Brazil.

Objective: To model the effect of socio-economic deprivation and a few transmission-related indicators of the tuberculosis (TB) incidence at small area level, to discuss the potential of each indicator in targeting places for developing preventive action.

Methods: Ecological spatial study of TB incidence in Olinda, a city in the north-east of Brazil, during the period 1996-2000. Three socio-economic indicators (mean number of inhabitants per household; percentage of heads of household with <1 year's formal education; percentage of heads of households with monthly income lower than the minimum wage) and two transmission-related indicators (number of cases of retreatment; number of households with more than one case during the period under study), all calculated per census tract, were used. We adopted four different full hierarchical Bayesian models to estimate the relative risk of the occurrence of TB via Markov chain Monte Carlo.

Results: The best specified model includes all the selected covariates and the spatially structured random effect. The gain in goodness-of-fit statistic when the spatial structure was included confirms the clustered spatial pattern of disease and poverty. In this model, the covariates within the non-zero credibility interval were the number of persons per house, the number of cases of retreatment and the number of households with more than one case (all with relative risk > or = 1.8) in each census tract.

Conclusions: The possibility to estimate in the same framework both the contribution of covariates at ecological level and the spatial pattern should be encouraged in epidemiology, and may help with establishing Epidemiological Surveillance Systems on a territorial basis, that allows rational planning of interventions and improvement of the Control Programme effectiveness.
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http://dx.doi.org/10.1111/j.1365-3156.2006.01797.xDOI Listing
March 2007

Risk factors for treatment delay in pulmonary tuberculosis in Recife, Brazil.

BMC Public Health 2005 Mar 18;5:25. Epub 2005 Mar 18.

Departamento de Medicina Tropical, Universidade Federal de Pernambuco, Brazil.

Background: Tuberculosis is still a great challenge to public health in Brazil and worldwide. Early detection followed by effective therapy is extremely important in controlling the disease. Recent studies have investigated reasons for delays in treatment, but there is no agreed definition of what constitutes an "acceptable" delay. This study investigates factors associated with total delay in treatment of tuberculosis.

Methods: A cohort of adult cases of pulmonary tuberculosis diagnosed over a two-year period was studied. Patients were interviewed on entry, reporting the duration of symptoms before the start of treatment, and sputum and blood samples were collected. It was decided that sixty days was an acceptable total delay. Associations were investigated using univariable and multivariable analysis and the population attributable fraction was estimated.

Results: Of 1105 patients, 62% had a delay of longer than 60 days. Age, sex, alcoholism and difficulty of access were not associated with delays, but associations were found in the case of unemployment, having given up smoking, having lost weight and being treated in two of the six health districts. The proportion attributable to: not being an ex-smoker was 31%; unemployment, 18%; weight loss, 12%, and going to the two worst health districts, 25%.

Conclusion: In this urban area, delays seem to be related to unemployment and general attitudes towards health. Although they reflect the way health services are organized, delays are not associated with access to care.
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http://dx.doi.org/10.1186/1471-2458-5-25DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1084352PMC
March 2005

Household survey of dengue infection in central Brazil: spatial point pattern analysis and risk factors assessment.

Am J Trop Med Hyg 2004 Nov;71(5):646-51

Brazilian Ministry of Health, 7o Andra Sala 715 70 070, 040 Brasilia, DF, Brazil.

Urban dengue fever is now considered a major public health threat in most American countries. A household survey was conducted in the city of Goiania in central Brazil in 2001 to assess prevalence of dengue infection and individual and area-based risk factors. Spatial point pattern analysis was performed using the dual Kernel method. A total of 1,610 households were surveyed; 1,585 individuals more than five years old had blood and data collected. Sera were tested for IgM/IgG antibodies by an enzyme-linked immunoassay. Area-based indicators derived from census data were linked to geocoded residential address. The seroprevalence of dengue was 29.5% and the estimate prevalence surface reached 50% in the outskirts areas. The risk of infection was significantly associated with older age (P < 0.01), low education (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.82-6.55), and low income (OR = 1.32, 95% CI = 1.02-1.71) in multivariate analysis. This study highlighted the heterogeneity of dengue transmission within the city and can assist in spatial targeting control interventions.
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November 2004

Antibody isotype responses to egg antigens in human chronic Schistosomiasis mansoni before and after treatment.

Mem Inst Oswaldo Cruz 2002 ;97 Suppl 1:111-2

Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães, Fiocruz, Recife, PE, 50670-420, Brasil.

In the present communication we analyzed the levels of IgG1, IgG2, IgG3, IgG4 and IgE isotypes to soluble egg antigen of Schistosoma mansoni by ELISA in individuals from an endemic area for schistosomiasis in Northeast Brazil. The analysis was performed before and after treatment to evaluate the age-dependent pattern, and to identify differences in the reactivities to antigens. Our results suggest that schistosomiasis treatment would not interfere with this sort of immune response.
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http://dx.doi.org/10.1590/s0074-02762002000900022DOI Listing
February 2003

Evaluation of PCR for diagnosis of American cutaneous leishmaniasis in an area of endemicity in northeastern Brazil.

J Clin Microbiol 2002 Oct;40(10):3572-6

Centro de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz, Av. Prof. Moraes Rego s/n, Cidade Universitária, 50670-420 Recife, Brazil.

PCR-based approaches targeting kinetoplast DNA were evaluated for the diagnosis of American cutaneous leishmaniasis (ACL) in regions of endemicity in northeastern Brazil. A total of 119 cutaneous biopsy specimens from patients with ACL and nonleishmaniasis cutaneous lesions were studied. Two PCR-based systems were used; one was specific for the subgenus Viannia, and the other was specific for the genus Leishmania. The PCR specific for the subgenus Viannia had a sensitivity of 95.4%, whereas the genus-specific PCR detected the target DNA in 88.2% of the samples tested. The specificities of the assays, determined with samples from a group with nonleishmaniasis cutaneous lesions, was 100%. The results of the conventional tests indicate that the sensitivities of the PCR-based methods were significantly higher than those of smear examination, histological staining, and isolation by culture (P < 0.05). Antibodies specific for Leishmania braziliensis were detected by indirect immunofluorescence in 82.9% of the patients tested. Parasites were isolated from 40 of 86 patients (46.5%). Sixty-seven percent of dermal scrapings and 66.2% of stained tissue sections were positive by microscopy. Amplified products from the subgenus-specific PCR hybridized with the Leishmania panamensis minicircle, confirming infection consistent with L. braziliensis. The evidence available at present incriminates L. braziliensis as the only causative agent of ACL in the state of Pernambuco in Brazil.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC130853PMC
http://dx.doi.org/10.1128/JCM.40.10.3572-3576.2002DOI Listing
October 2002
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