[An increase in Hansen's disease in northeastern Brazil]

Path of infectious diseases in Brazil in the last 50 years: an ongoing challenge

In this article, we comment on the main features of infectious diseases in Brazil in the last 50 years, highlighting how much of this path Revista de Saúde Pública could portray. From 1967 to 2016, 1,335 articles focusing on infectious diseases were published in Revista de Saúde Pública. Although the proportion of articles on the topic have decreased from about 50.0% to 15.0%, its notability remained and reflected the growing complexity of the research required for its control. It is noteworthy that studies design and analysis strategies progressively became more sophisticated, following the great development of epidemiology in Brazil in the recent decades. Thus, the journal has followed the success of public health interventions that permitted to control or eliminate numerous infectious diseases - which were responsible, in the past, for high rates of morbidity and mortality -, and also followed the reemergence of diseases already controlled and the emergence of until then unknown diseases, with a strong impact on the Brazilian population, establishing a little predictable and very challenging path. RESUMO Neste artigo, comentamos as principais características das doenças infecciosas no Brasil, nos últimos 50 anos, destacando o quanto a Revista de Saúde Pública conseguiu capturar essa trajetória. De 1967 a 2016, foram publicados 1.335 artigos na Revista de Saúde Pública com foco em doenças infecciosas. Ainda que a proporção de artigos sobre esse tema tenha declinado de cerca de 50,0% para 15,0%, seu destaque se manteve e refletiu a crescente complexidade das pesquisas necessárias para o seu controle. Nota-se que os desenhos dos estudos e as estratégias de análise ganharam progressivamente maior sofisticação, acompanhando o grande desenvolvimento da epidemiologia no Brasil, nas últimas décadas. Assim, foi registrado não apenas o sucesso de intervenções de saúde pública que permitiram o controle ou a eliminação de inúmeras doenças infecciosas responsáveis, no passado, por elevadas taxas de morbimortalidade, como também a reemergência de males já controlados e o surgimento de doenças até então desconhecidas, com forte impacto na população brasileira, desenhando uma trajetória pouco previsível e muito desafiadora.

Epidemiological situation of leprosy in Salvador from 2001 to 2009

Mycobacterium leprae was first described as the bacillus that causes leprosy, a chronic granulomatous infectious disease, in 1873 by Amauer Hansen. Leprosy is part of a group of 10 neglected diseases and Bahia has endemic levels of this illness, varying between high and very high. The detection of 52 new cases of leprosy in children under 15 years old in Salvador in 2006 is alarming, and suggests an early contact with the disease. The aim of this review is to analyze the epidemiological situation, the detection rate and evaluate the clinical and epidemiological profile of leprosy in Salvador, in the period 2001-2009. A retrospective cross-sectional study was performed using secondary data collected at Notifiable Diseases Information System Database (SINAN) through the notification of patients with leprosy. Over these nine years 3,226 patients were reported, with a predominance of: females (51.5%), and clinical multibacillary forms in the general population (51.7%), but when we analyze those under 15 years old, paucibacillary forms (tuberculoid + indeterminate) prevailed. The tuberculoid form was the most diagnosed type of presentation. The annual detection rate in Salvador remained at a very high level of endemicity during the studied period and for those under 15 years old it ranged between high and very high. Grade 2 disabilities both at the time of diagnosis and at discharge after cure, varied between low and medium. Based on these data we conclude that the high levels of leprosy detection rates in the general population, plus the variation between high and very high levels in those under 15 years old, associated with the medium level of grade 2 disabilities at the time of diagnosis and discharge, demonstrate the need for improvement on the existing services, investment in active case finding and training of the healthcare professionals in Salvador.

[Leprosy in Espírito Santo State, Brazil: a growing endemic?]

This study provides a trend analysis of leprosy among patients in the State of Espírito Santo, Brazil, from 1980 to 2003. Using temporal series statistical models, an upward trend was identified throughout the period in the overall detection rate (p<0.05), with an apparent stabilization at the end of the period. We also observed an upward trend for the following periods: (i) 1980-1987 in the <15 and >or=50-year age groups and for paucibacillary forms; (ii) 1988-1995 for the 15-19, 20-29, and >or=50-year groups and for multibacillary forms; and (iii) 1996-2003 in the 20-29-year group and paucibacillary forms. The indicators for evaluation of the endemic indicate: stable levels in grade 2 disability (mean of 6%); a proportion of less than 10% of cases in individuals<15 years of age; and a treatment dropout rate of approximately 6%. Prevalence showed a sharp decline. The upward trend can be explained partially by greater surveillance sensitivity, but the high proportion of individuals<15 highlights the need for studies aimed at better knowledge of residual sources of infection, especially in the household.

Hanseníase no município de Fortaleza, CE, Brasil: aspectos epidemiológicos e operacionais em menores de 15 anos (1995-2006)

Estudo transversal que objetiva analisar a ocorrência de casos de hanseníase em menores de 15 anos de idade residentes no Município de Fortaleza e notificados no SINAN. Os indicadores epidemiológicos nesta população mostram hiperendemicidade. Operacionalmente observa-se a manutenção da concentração de atendimento em algumas unidades de referência, apesar de alguns avanços. Diagnóstico tardio, elevado grau de incapacidade no diagnóstico e baixo grau de avaliação de contatos registrados revelam a fragilidade das ações de controle. Ressalta-se a possibilidade de erro diagnóstico frente às características da infecção nesta população. A ocorrência de casos de hanseníase nesta população representa um indicador epidemiológico de grande relevância e sua análise amplia a discussão sobre problemas operacionais na rede de serviços de saúde.

[Social reproduction of leprosy: a study of patients profile with leprosy in the city of São Paulo]

This study discusses the relationship between work and living conditions among leprosy patients enrolled in the São Paulo municipal public health system in 1996. Social patterns were studied based on the theory of social determination of the health-disease process. The main purpose of the study was to emphasize evidence of the disease determination network, seeking new knowledge to improve public policies on leprosy. Data were gathered from a sample of leprosy patients registered in the city's public health system. Although patients' families are characterized by a common social thread, different work/life possibilities allow for a classification of patients into three social groups. The majority belong to groups that are marginalized from social production, living in areas where social exclusion is more extreme, on the outskirts of the city. If the trends in this study persist, incident leprosy cases will result from the social exclusion of migrants from Brazil's Southeast and Northeast. The study also discusses the position of young people and female patients in the determination network of this infectious disease in the city of São Paulo.

[Empirical bayesian model applied to the spatial analysis of leprosy occurrence]

OBJECTIVE

To analyze the spatial distribution of leprosy, identify areas of potential case underreporting or high transmission risk, and to assess the ecological association of leprosy distribution with multibacillary cases.

METHODS

This study was carried out in 94 neighborhoods of Recife, Brazil. Data was obtained from the Ministry of Health's Disease Reporting System. An ecological approach with the empirical Bayesian method was applied for local rate flattening, using data from a neighborhood matrix.

RESULTS

The mean annual occurrence was 17.3% of new cases in individuals under the age of 15 (28.3% corresponded to multibacillary forms), revealing an intense disease transmission. The spatial distribution of leprosy indicated three areas where there was a concentration of high detection rates and low-income neighborhoods.

CONCLUSIONS

The Bayesian method allowed to reassess epidemiological indicators based on data from neighboring spatial units. This enabled to identify areas that should be prioritized in municipal control programs, either because of underreporting of cases or the higher number of occurrences related to multibacillary forms in individuals under 15.

[Leprosy surveillance in Olinda, Brazil, using spatial analysis techniques]

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.