Paulo Cesar Basta

Aspectos epidemiológicos da tuberculose na população indígena Suruí, Amazônia, Brasil

Tuberculosis persists as a serious public health problem in Brazil. Prevalence rates are alarming in certain social groups, including indigenous peoples. This article presents an epidemiological analysis of records for the Suruí Indians available at the Tuberculosis Control Program in the Municipality of Cacoal, Rondônia. The study includes a descriptive statistical analysis of cases reported from 1975 to 2002. There is evidence that the Suruí have an increased risk of acquiring and dying from tuberculosis as compared to other indigenous groups in Rondônia as well as non-Indians. The average incidence coefficient for tuberculosis in the Suruí was 2518.9 per 100,000 inhabitants in the period 1991-2002. It was observed that 45% of the cases were diagnosed in children < 15 years old. Over half of the cases (63.3%) were reported in men. Only 43.2% of the cases were confirmed by sputum microscopy. The use of PPD skin tests, histopathological exams or bacteriological culture were not reported throughout the period. Attention is called to the need for prevention and control measures specifically tailored to the reality of indigenous peoples.

Cytokine genes are associated with tuberculin skin test response in a native Brazilian population.

Tuberculosis was a major cause of population decline among Brazilian indigenous peoples and remains a leading cause of morbidity and mortality among them. Despite high BCG coverage, results of Tuberculin Skin Test (TST) reactivity have shown high rates of anergy in Amazonian Indians. Given the high prevalence of anergy in these populations and the fact that genetic host factors play an important role in susceptibility to Mycobacterium tuberculosis (MTB), the aim of this study was to evaluate the association of nineteen polymorphisms in fifteen genes related to immune response and anergy in the Xavante, an indigenous group from Brazil. A total of 481 individuals were investigated. TST anergy was observed in 69% of them. Polymorphisms in four genes showed absence or very low variability: SP110, PTPN22, IL12RB1 and IL6. IFNG +874 A/T heterozygotes and IL4-590 C/C homozygotes were more frequent in those individuals who presented a positive TST (prevalence ratios of 1.9 and 2.0 respectively). The risk of anergy was 1.5 in IL10-1082 G/G homozygotes when compared to carriers for the A allele. In indigenous groups such as the Xavante exposure to a variety of infections, associated with specific genetic factors, may disturb the T-helper 1 and T-helper 2 balance leading to increased immunological susceptibility.

Tuberculosis among the Xavante Indians of the Brazilian Amazon: an epidemiological and ethnographic assessment.

Abstract Background: Despite broad availability of a national tuberculosis (TB) control program that has proved effective in Brazil, TB remains a major cause of morbidity and mortality among indigenous peoples. Aim: We report the results of an interdisciplinary investigation of TB epidemiology, healthcare services, and ethnomedicine among the Xavante Indians of Central Brazil. Subjects and methods: Fieldwork components included clinical assessment of TB (479 subjects, 89.3% of the population = 1 year of age), analysis of medical health records, and ethnographic research. Results: We found TB to constitute a major health risk, with moderately high annual risk of infection (0.94%), moderate prevalence of infection, high percentage of X-ray images suggestive of TB (14.2% in subjects ≥ 10 years of age), and a relatively low percentage of individuals with reactive TB skin tests (16.6% of reactions ≥ 10 mm) despite high BCG vaccine coverage. We also found a high rate of TB patients showing no evidence of prior infection. Ethnographic interviews show that Xavante and biomedical health perspectives are simultaneously divergent in their etiologies but pragmatically compatible. Conclusion: Ineffective diagnosis procedures compromise the efficacy of existing TB prevention efforts and threaten to undermine otherwise favorable institutional and cultural conditions.

Morbidade hospitalar em crianças indígenas Suruí menores de dez anos, Rondônia, Brasil: 2000 a 2004

OBJETIVOS: analisar o perfil de morbidade hospitalar de criancas indigenas atendidas na rede de servicos do Sistema Unico de Saude. METODOS: Foram investigados 380 registros de internacao hospitalar de criancas indigenas Surui menores de 10 anos de idade atendidas na rede hospitalar do municipio de Cacoal, Rondonia, a partir de dados coletados no Hospital Materno-Infantil, instituicao publica, e no Hospital Infantil e Maternidade Menino Jesus, instituicao particular, no periodo de 2000 a 2004. Esses dois hospitais concentram o atendimento a indigenas no municipio. Utilizou-se a Classificacao Internacional de Doencas (CID), 10.a revisao, para a classificacao dos diagnosticos. RESULTADOS: as doencas do aparelho respiratorio - Cap. X (58,2%) figuraram como o principal motivo de internacao hospitalar. Doencas infecciosas e parasitarias (Cap I) apresentaram-se como a segunda maior causa (35,0%) e afeccoes originadas no periodo perinatal (Cap XVI) como a terceira (3,2%). Outras causas contribuiram individualmente com menos de 1,5% do total, que somadas nao atingiram 4%. A maioria das internacoes (65,5%) foram de criancas <2 anos de idade. O tempo medio de internacao foi significativamente superior no hospital publico em relacao ao privado. CONCLUSOES: O perfil de morbidade hospitalar observado nas criancas Surui evidencia nao somente a precariedade das suas condicoes de saude, como tambem problemas estruturais no que tange as acoes de atencao basica. Recomenda-se a realizacao de estudos que visem aprofundar aspectos epidemiologicos relacionados as internacoes hospitalares em populacoes indigenas, fundamentais para o desenvolvimento de acoes de saude mais adequadas.

Clinical and radiological study of Suruí indigenous children and adolescents, Amazon Region, Brazil

INTRODUCTION The average incidence coefficient of tuberculosis in Suruí Indians from Rondônia was 2.500/100.000 inhabitants in 1991-2002. About 50% of these cases were reported in children < 15 years-old. METHODS This study aimed to describe the clinical and radiological characteristics of children and adolescents identified as TB case contacts. A score system for the diagnosis of childhood TB was used and the procedures adopted by local health services were in accordance with national guidelines. RESULTS 52 chest X-rays of 37 indigenous subjects were analyzed; of these, 51.9% were abnormal. Some X-rays showed more than two lesions, making a total of 36 independent events. Infiltrates (38.9%), calcifications (38.9%), cavitations (11.1%) and atelectasis/pleural effusion (11.1%) were observed. Among the abnormal images, 22.2% were probably indicated active TB and 33.3% showed sequelae. Confrontation with the guidelines revealed 52.6% of divergent procedures. CONCLUSIONS The presence of latent tuberculosis infection (LTBI) and active TB between children and adolescents are indicators of active and progressive transmission of Mycobacterium tuberculosis. The X-rays showed high frequencies of infiltrates and calcifications, which are compatible with primary infection in early childhood. However, these lesions are not different from those observed among other groups and do not suggest immune deficiencies. The divergences presented show that the best moment for the treatment of LTBI went unnoticed by local personnel. In conclusion, the use of a score system is fundamental for the correct diagnosis of TB in childhood, as is conducting bacilloscopy and sputum culture in adolescents able to expectorate.

Distribuição espacial e temporal da tuberculose em indígenas e não indígenas de Rondônia, Amazônia Ocidental, Brasil

This study analyzed the spatial and temporal distribution of crude and adjusted rates of incidence of tuberculosis (TB) between 1997 and 2006, identifying areas of greatest risk to the indigenous and non-indigenous population of Rondônia State, Brazil. An ecological study was conducted analyzing municipalities and Indian reserves, using the local empirical Bayesian method. The crude average rate of incidence of TB among the non-indigenous population was 35.6/100,000 inhabitants, while for the indigenous population it was 415.0/100,000. Rates greater than 600/100,000 were reported in the Karipuna, Sete de Setembro, Igarapé, Ribeirão and Karitiana reserves. We observed a greater number of cases in under 15 year-olds with little schooling in contrast to the situation in the non-indigenous population. After making adjustments, the rates in some Indian reserves exceeded 240/100,000 inhabitants, while in coinciding municipalities incidence was between the range of 61-120/100,000. The Bayesian method led to decreased overall heterogeneity in rates. Evidence suggests that the indigenous population is more vulnerable to contracting TB and highlighted areas that require further attention to ensure the adequate control of TB in Rondônia.

Tuberculosis in indigenous children in the Brazilian Amazon

OBJECTIVE Assess the epidemiological aspects of tuberculosis in Brazilian indigenous children and actions to control it. METHODS An epidemiological study was performed with 356 children from 0 to 14 years of age in Rondônia State, Amazon, Brazil, during the period 1997-2006. Cases of TB reported to the Notifiable Diseases Surveillance System were divided into indigenous and non-indigenous categories and analyzed according to sex, age group, place of residence, clinical form, diagnostic tests and treatment outcome. A descriptive analysis of cases and hypothesis test (χ²) was carried out to verify if there were differences in the proportions of illness between the groups investigated. RESULTS A total of 356 TB cases were identified (125 indigenous, 231 non-indigenous) of which 51.4% of the cases were in males. In the indigenous group, 60.8% of the cases presented in children aged 0-4 years old. The incidence mean was much higher among indigenous; in 2001, 1,047.9 cases/100,000 inhabitants were reported in children aged < 5 years. Pulmonary TB was reported in more than 80% of the cases, and in both groups over 70% of the cases were cured. Cultures and histopathological exams were performed on only 10% of the patients. There were 3 cases of TB/HIV co-infection in the non-indigenous group and none in the indigenous group. The case detection rate was classified as insufficient or fair in more than 80% of the indigenous population notifications, revealing that most of the diagnoses were performed based on chest x-ray. CONCLUSIONS The approach used in this study proved useful in demonstrating inequalities in health between indigenous and non-indigenous populations and was superior to the conventional analyses performed by the surveillance services, drawing attention to the need to improve childhood TB diagnosis among the indigenous population.

Genetic polymorphism and immune response to tuberculosis in indigenous populations: a brief review

We systematically reviewed studies of the immune response to tuberculosis and the genetic polymorphisms associated with Th1- or Th2-mediated cytokine expression in indigenous populations. A bibliographic search was performed on the Medline and ISI databases and included studies published between January 1980 and October 2011. The search terms were tuberculosis, American Indians, Amerindian, indigenous, Indians, native people, aboriginal, immun*, host immune, immune response, cytokine*, polymorphism*, and gene. Regardless of their design, studies that evaluated immunoglobulin, cytokine levels and genetic polymorphisms that altered cytokine expression were included. Thirteen studies met the inclusion criteria. The majority of studies were performed in Latin America, and five investigated the Warao ethnic group of Venezuela. Most of the investigations indirectly evaluated the immune response. Higher anergy to the tuberculin skin test, higher IgG4 and IgM levels, higher IL-5 production and lower TNF-α, IL-12p40 and IFN-γ production were found in the indigenous populations. The studies also reported a predominantly Th2-type response in these populations and a possibly higher susceptibility to tuberculosis. A better understanding of the relevant genetic polymorphisms and their role in immune regulation would help to clarify the immunogenetic mechanisms of TB infection in these populations. This information would be useful for identifying new treatments and preventing infection and progression to active disease.

Leprosy in indigenous populations of Amazonas State, Brazil: an epidemiological study in the counties of Autazes, Eirunepé and São Gabriel da Cachoeira (2000 to 2005)

In 2005, Amazonas State, Brazil, showed hyperendemic leprosy detection coefficients and prevalence with medium endemicity. Although this State has the largest indigenous population in Brazil, there are no data on the leprosy profile in these groups. This study aimed to describe and analyze the epidemiological characteristics of leprosy case reporting in the municipalities (counties) of Autazes, Eirunepé, and São Gabriel da Cachoeira, comparing indigenous and non-indigenous findings according to target variables. A total of 386 cases reported to SINAN from 2000 to 2005 were analyzed. Mean detection rates were 3.55, 14.94, and 2.13/10,000 (among non-indigenous) and 10.95, 1.93, and 0.78/10,000 (among indigenous peoples) in Autazes, Eirunepé, and São Gabriel da Cachoeira, respectively. Paucibacillary cases predominated among both indigenous and non-indigenous populations; however, dimorphous cases represented one-third of notifications. Despite coverage limitations and underreporting, the findings suggest that leprosy is a major public health problem for indigenous populations in Amazonas State. Classification according to race/ethnicity has been a useful tool for solving health inequalities.

Tuberculose em indígenas da Amazônia brasileira: estudo epidemiológico na região do Alto Rio Negro

OBJETIVO: Descrever as caracteristicas sociodemograficas e clinico-epidemiologicas dos casos de tuberculose notificados na populacao indigena do Municipio de Sao Gabriel de Cachoeira, Estado do Amazonas, Brasil, e identificar fatores associados ao obito durante o tratamento; e estimar a prevalencia de infeccao latente por tuberculose (ILTB) e fatores associados e obter informacoes sobre o itinerario terapeutico e a percepcao acerca do adoecimento dos indigenas do Distrito de Iauarete. METODOS: Primeiramente, realizou-se um estudo epidemiologico retrospectivo (1997 a 2007) com base nos dados do Sistema de Informacao de Agravos de Notificacao. Posteriormente, realizou-se um estudo transversal (2010) em sintomaticos respiratorios e contatos no Distrito Indigena de Iauarete. RESULTADOS: Registraram-se 723 casos novos, com incidencia de 273,4/100 000 e mortalidade de 13,2/100 000. Houve predominio em homens (57%), idade > 45 anos (37,6%), pessoas sem escolaridade (42,7%) e na area rural (76,9%). Doentes de 0 a 20 anos apresentaram menor chance de obito quando comparados a idade > 45 anos (OR = 0,3; IC95%: 0,1 a 0,9). Em Iauarete, que concentrou 15,3% das notificacoes, foram entrevistados 184 indigenas. Revelou-se prevalencia de ILTB de 76,1%. Prova tuberculinica > 5 mm associou-se com idade > 15 anos, historia de tuberculose ativa e alteracoes radiologicas. Tuberculose anterior foi citada por 54 indigenas (29,3%). A principal explicacao para o adoecimento foi sopro/envenenamento (24,1%). O itinerario terapeutico incluiu medicamentos industrializados (42,6%), plantas medicinais/raizes, pajelanca/xamanismo e reza (42,7%). CONCLUSOES: A prevalencia de infeccao tuberculosa e doenca ativa nessa populacao foi elevada. As estrategias de controle tiveram resultados positivos, com reducao na incidencia em tempos recentes. Entretanto, para controlar a tuberculose e necessario intensificar a vigilância dos contatos e aperfeicoar as estrategias de comunicacao das equipes com a populacao indigena.