Tiago Maria Lapa

Vigilância da hanseníase em Olinda, Brasil, utilizando técnicas de análise espacial

In the State of Pernambuco, Brazil, leprosy has been mainly an urban disease, with an uneven geographical distribution related at least partially to the way urban space has been occupied and transformed. Spatial analysis may thus become an important tool to establish an epidemiological surveillance system for leprosy. Homogeneous micro-areas were defined in the city of Olinda through the integration of two databases, the Population Census and SINAN, and through the use of digital maps and geoprocessing techniques. Census tracts were classified according to a social deprivation index (SDI), and micro-area homogeneity was based on similar values for this indicator. Cluster analysis (K-means) was used to define cut-offs between strata. The same procedure was repeated using the income variable only. When the association was tested between the mean SDI value and the mean leprosy detection rate for the period 1991-1996, the value obtained for r2 was 66.1% in the multiplicative model, increasing to 84.3% when the income variable was used. To define different intervention strategies, census tracts were regrouped in three levels of risk: high, moderate, and low. The methodology enabled the identification (within each health district) of groups and/or areas with different risk of leprosy, hence allowing for the definition of control measures.

Epidemiological study of bancroftian filariasis in Recife, Northeastern Brazil

Wuchereria bancrofti in Pernambuco was first documented in 1952 (Azevedo & Dobbin 1952), and since then it has been reported in surveys carried out in selected areas of Recife. Several surveys were carried out from 1981 to 1991 by SUCAM. In the 1985 SUCAMs report the disease is considered under control. The CPqAM Filariasis Research Program was established in 1985 and a filarial survey was carried out in the town of Olinda, Greater Recife. In order to verify the real epidemiological situation, a study was conducted in the city of Recife. 21/36 of the Special Zones of Social Interest (ZEIS), were randomly selected for the present study. From 10,664 persons screened, 683 were positive and the prevalence rate for microfilaraemia (mf) varied from 0.6% to 14.9%. A mean mf prevalence of 6.5%, showed that the infection occurs in a wide geographic distribution in Greater Recife and that the intensity of transmission is a real and potential threat to public health in affected communities. Mf rate among males and females differed significantly. Due to the rapid increase in population, unplanned urban settlements, poor sanitary facilities and the favorable geographical conditions to the development of the vector, filariasis may actually be increasing in Recife.

Aplicação de modelo bayesiano empírico na análise espacial da ocorrência de hanseníase

OBJETIVO: Analisar a distribuicao espacial da hanseniase, identificar areas de possivel sub-registro de casos ou de provavel alta transmissao (risco) e verificar a associacao dessa distribuicao a existencia de casos de formas multibacilares. METODOS: O estudo foi realizado em Recife, PE, de acordo com 94 bairros analisados. A fonte de coleta de dados foi o Sistema de Informacoes sobre Agravos de Notificacao do Ministerio da Saude. Foi adotada uma abordagem ecologica com utilizacao do metodo bayesiano empirico para suavizacao local de taxas, a partir de informacoes de bairros vizinhos por adjacencia. RESULTADOS: A ocorrencia media anual foi de 17,3% de casos novos em menores de 15 anos (28,3% de formas multibacilares), indicando um processo de intensa transmissao da doenca. A analise da distribuicao espacial de hanseniase apontou tres areas onde se concentram bairros com taxas de deteccao elevadas e que possuem baixa condicao de vida. CONCLUSOES: O emprego do modelo bayesiano, baseado em informacoes de unidades espaciais vizinhas, permitiu estimar novamente indicadores epidemiologicos. Foi possivel identificar areas prioritarias para o programa de controle de hanseniase no municipio, tanto pelo elevado numero de ocorrencias correlacionado a presenca de formas multibacilares de doenca em menores de 15 anos quanto pela existencia de subnotificacao.

Vigilância de doenças endêmicas em áreas urbanas: a interface entre mapas de setores censitários e indicadores de morbidade

In this article we discuss the methodological issues associated with the creation of a surveillance system for endemic diseases in urban areas based on analysis of populations at risk and on spatially referenced epidemiological indicators. We comment on the systems basic requirements, selection criteria for socioeconomic variables, and methodological steps to combine these variables so as to construct a census-based deprivation index. We also present the ways we solved some operational problems related to generation of digitized census tracts maps and linkage of morbidity data from different sources. This approach, spatial organization into account in surveillance of endemic diseases, exemplified here by tuberculosis and leprosy, allows for the interaction of several official data sets from census and health services in order to geographically discriminate inner-city risk strata. Criteria for constructing these risk strata were considered a useful tool for health planning and management activities for the control of endemic diseases in cities.

Análise da demanda de casos de hanseníase aos serviços de saúde através do uso de técnicas de análise espacial

Hansen disease or leprosy is a major endemic disease in Brazil. Well-designed strategies, including decentralization of basic care, are needed to reduce its prevalence. The article begins by describing the structure and supply of services for treating leprosy cases in the country, after which it analyzes the trends in epidemiological and operational indicators, comparing the periods before and after decentralization of services to the municipal (local) level. Finally, spatial analysis allowed identifying the territorial distribution of this endemic and analyzing the pattern of geographic areas according to care provided by health facilities and its evolution. Based on the location of the geographic centers in the census tracts by place of residence, and using spatial smoothing technique based on Kernel estimation, the study constructed domain areas of care for each health facility or unit. Following municipalization of care, there was an increase in the detection and treatment by the municipalities themselves, reducing patient evasion to neighboring counties and causing changes in demand trends, with an increase in use of services by the clientele and important alterations in the epidemiological and operational indicators.

Intestinal Helminthiasis and Anaemia in Youngsters from Matriz da Luz, District of São Lourenço da Mata, State of Pernambuco, Brazil

A group of youngsters (4-18 years old) in northeast Brazil was studied to establish the prevalence of anaemia and intestinal parasitism, as well as to analyze the correlation between them. Two criteria were used to determine the state of anaemia, the level of haemoglobin and the mean of corpuscular volume. The first was considered a single criterion and the second an associated criteria, used in an attempt to correlate anaemia with iron deficiency. The prevalence of intestinal parasitism was 93%, while the prevalence of anaemia was 43.1% and 16.1% according to the criteria employed (single or associated respectively). Anaemia was significantly associated with both sex and age. No significant statistical difference was observed when the association was made between each parasite and anaemia even with those more related to anaemia.

Perfil epidemiológico da filariose linfática em crianças residentes em áreas endêmicas

OBJECTIVE Lymphatic filariasis still represents a major public health problem in the city of Recife. In spite of the fact that previous surveys had already shown high frequency of microfilaraemia in pediatric population, the prevalence of filarial disease and the microfilaraemic pattern of this group were unknown. This paper describes the clinical-epidemiological pattern of filariasis in children and adolescents living in two highly endemic areas of Recife. METHODS The parasitological survey was done through a census carried out between December 1990 and July 1991. Thick drop technique (45 micro l) was performed on a total of 1,464 children and adolescents between the ages of 5 and 14, of whom 967 were submitted to clinical examination. Positive cases had their blood recollected (60 micro l) to measure the microfilaraemic density. RESULTS The microfilaraemia prevalence was 6.4 %. In the age groups of 5 to 9 and 10 to 14 a microfilaraemia prevalence of respectively 4.6% and 8.3% was observed. The microfilaraemic density varied from 3 to 864 microfilariae per 60 microl of blood, there having been no statistically significant difference between the sexes and age groups (p<0.05). 6 cases (0.6 %) of acute filarial disease and 11 of chronic filarial disease (1.1%) were identified, hydrocele being the principal manifestation found. Lymphadenopathy was found in 22% of the children, statistical association with microfilaraemia being observed (p<0.001). CONCLUSIONS The results of the parasitological survey show the strong presence of children in the contingent of microfilaraemic individuals, indicating an early and intense exposure to filariasis in the population studied.

Evolução espaço-temporal do sobrepeso e da obesidade em adolescentes masculinos Brasileiros, 1980 a 2005

Analysis of the temporal trend in obesity shows the increasing risk posed by this condition worldwide. This article aims to verify and compare the prevalence rates for overweight and obesity in male adolescents in all States of Brazil, from 1980 to 2005. We used the Brazilian Armys database, with 8,989,508 males 17-19 years of age. We defined overweight as body mass index (BMI) from 25kg/m2 to 29,9kg/m2 and obesity as BMI > 30kg/m2. The analysis showed an increasing trend in the prevalence of overweight and obesity in all States of Brazil for the period studied. There was a three-fold increase in adolescents with overweight and a six-fold increase in obesity. The absolute numbers for overweight were higher than for obesity, but the rate of increase over the period was greater for obesity. Analyzing the trend in prevalence rates by five-year period, we observed that from 1980 to 2005, as the prevalence of overweight decreased, that of obesity increased in all States of Brazil.

Comparison of the burden of diarrhoeal illness among individuals with and without household cisterns in northeast Brazil.

BackgroundLack of access to safe and secure water is an international issue recognized by the United Nations. To address this problem, the One Million Cisterns Project was initiated in 2001 in Brazil’s semi-arid region to provide a sustainable source of water to households. The objectives of this study were to determine the 30-day period prevalence of diarrhoea in individuals with and without cisterns and determine symptomology, duration of illness and type of health care sought among those with diarrhoea. A subgroup analysis was also conducted among children less than five years old.MethodsA face-to-face survey was conducted between August 20th and September 20th, 2007 in the Agreste Central Region of Pernambuco State, Brazil. Households with and without a cistern that had at least one child under the age of five years were selected using systematic convenient sampling. Differences in health outcomes between groups were assessed using Pearson’s Chi-squared and two-way t-tests. Demographic variables were tested for univariable associations with diarrhoea using logistic regression with random effects. P-values of 0.05 or less were considered statistically significant.ResultsA total of 3679 people from 774 households were included in the analysis (1863 people from 377 households with cisterns and 1816 people from 397 households without cisterns). People from households with a cistern had a significantly lower 30-day period prevalence of diarrhoea (prevalence = 11.0%; 95% CI 9.5-12.4) than people from households without a cistern (prevalence = 18.2%; 95% CI 16.4-20.0). This significant difference was also found in a subgroup analysis of children under five years old; those children with a cistern had a 30-day period prevalence of 15.6% (95% CI 12.3-18.9) versus 26.7% (95% CI 22.8-30.6) in children without a cistern. There were no significant differences between those people with and without cisterns in terms of the types of symptoms, duration of illness and health care sought for diarrhoea.ConclusionsOur results indicate that the use of cisterns for drinking water is associated with a decreased occurrence of diarrhoea in this study population. Further research accounting for additional risk factors and preventative factors should be conducted.

Impacto do uso da água de cisternas na ocorrência de episódios diarréicos na população rural do agreste central de Pernambuco, Brasil

OBJECTIVES: to evaluate the impact of the use of water-tanks on the occurrence of episodes of diarrhea, comparing the number and duration of episodes among the residents of households with and without water-tanks in the same geographical area. METHODS: a longitudinal prospective study, nested in a cross-section study comparing two groups (households with and without water-tanks), was carried out in 21 municipalities in the Central Agreste region of the Brazilian State of Pernambuco, in 2007. Data was gathered over 60 days and included 1,765 individuals. Descriptive analysis was carried out using mixed hierarchical models, Mann-Whitney and Kaplan-Meyer with the level of significance set at 5%. RESULTS: among the 949 individuals with water-tanks, there was a reduction in the risk of the occurrence of episodes of diarrhea of 73% compared with the 816 individuals without water-tanks (RR=0.27; p<0.001). The mean number of episodes registered among residents of households without water-tanks was 0.48 (SC=1.17), compared with 0.08 (SC=0.32) among households with water-tanks (z=-10.26; p<0.001). The mean during of episodes was 1.5 times greater in households without water-tanks (χ2=8.99; p=0.003). CONCLUSIONS: the findings of this study point to the importance of access to drinking water for the reduction of disease. The occurrence of diarrhea and its concomitant severity indicators-number of episodes and duration-were consistently higher among residents of households without water-tanks.