Prevalence and factors associated with latent tuberculosis infection in an indigenous population in the Brazilian Amazon.

INTRODUCTION: Recent studies have shown a high incidence and prevalence of latent tuberculosis infection (LTBI) in indigenous populations around the World. We aimed to estimate the prevalence and annual risk of infection (ARI) as well as to identify factors associated with LTBI in an indigenous population from the Brazilian Amazon. METHODS: We conducted a cross-sectional study in 2011. We performed tuberculin skin tests (TSTs), smears and cultures of sputum samples, and chest radiographs for individuals who reported cough for two or more weeks. Associations between LTBI (TST ≥5mm) and socio-demographic, clinical, and epidemiological characteristics were investigated using Poisson regression with robust variance. Prevalence ratio (PR) was used as the measure of association. RESULTS: We examined 263 individuals. The prevalence of LTBI was 40.3%, and the ARI was 2.4%. Age ≥15 years [PR=5.5; 95% confidence interval (CI): 3.5-8.6], contact with tuberculosis (TB) patients (PR=3.8; 95% CI: 1.2-11.9), previous TB history (PR=1.4; 95% CI: 1.2-1.7), and presence of Bacillus Calmette-Guérin (BCG) scar (PR=1.9, 95% CI: 1.2-2.9) were associated with LTBI. CONCLUSIONS: Although some adults may have been infected years prior, the high prevalence of infection and its strong association with age ≥15 years, history of TB, and recent contact with TB patients suggest that the TB transmission risk is high in the study area.

Prevalence and factors associated with latent tuberculosis infection in an indigenous population in the Brazilian Amazon

Abstract: INTRODUCTION Recent studies have shown a high incidence and prevalence of latent tuberculosis infection (LTBI) in indigenous populations around the World. We aimed to estimate the prevalence and annual risk of infection (ARI) as well as to identify factors associated with LTBI in an indigenous population from the Brazilian Amazon. METHODS We conducted a cross-sectional study in 2011. We performed tuberculin skin tests (TSTs), smears and cultures of sputum samples, and chest radiographs for individuals who reported cough for two or more weeks. Associations between LTBI (TST ≥5mm) and socio-demographic, clinical, and epidemiological characteristics were investigated using Poisson regression with robust variance. Prevalence ratio (PR) was used as the measure of association. RESULTS We examined 263 individuals. The prevalence of LTBI was 40.3%, and the ARI was 2.4%. Age ≥15 years [PR=5.5; 95% confidence interval (CI): 3.5-8.6], contact with tuberculosis (TB) patients (PR=3.8; 95% CI: 1.2-11.9), previous TB history (PR=1.4; 95% CI: 1.2-1.7), and presence of Bacillus Calmette-Guérin (BCG) scar (PR=1.9, 95% CI: 1.2-2.9) were associated with LTBI. CONCLUSIONS Although some adults may have been infected years prior, the high prevalence of infection and its strong association with age ≥15 years, history of TB, and recent contact with TB patients suggest that the TB transmission risk is high in the study area.

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.

[Tuberculosis in indigenous peoples in the Brazilian Amazon: an epidemiological study in the Upper Rio Negro region]. / Tuberculose em indígenas da Amazônia brasileira: estudo epidemiológico na região do Alto Rio Negro.

OBJECTIVE: To describe the sociodemographic, clinical, and epidemiological characteristics of reported tuberculosis cases among indigenous individuals of São Gabriel de Cachoeira, State of Amazonas, Brazil, and to identify the factors associated with mortality during treatment; and to estimate the prevalence of latent tuberculosis infection (LTBI) and associated factors and obtain information on the therapeutic course and the individual perceptions regarding acquistion of tuberculosis in the district of Iauaretê. METHODS: Firstly, a retrospective epidemiological study (1997 to 2007) was conducted using data from the Brazilian Notifiable Diseases Surveillance System (SINAN). Next, a cross-sectional study (2010) was conducted with respiratory symptomatic subjects and contacts of Iauaretê. RESULTS: Seven hundred and twenty-three new cases were reported, with incidence of 273.4/100 000 and mortality of 13.2/100 000. There was a predominance of males (57%), aged > 45 years (37.6%), people with no schooling (42.7%), and cases from rural areas (76.9%). Patients aged 0 to 20 years were at lower risk of death when compared to those aged > 45 years (OR = 0.3; IC95%: 0.1 a 0.9). In Iauaretê, with 15.3% of the reported cases, 184 people were interviewed. A prevalence of LTB of 76.1% was reported. Tuberculin skin test > 5 mm was associated with the > 15-year old age group, history of active tuberculosis, and radiological alterations. A previous history of tuberculosis was cited by 54 people (29.3%). The main explanation for the disease was "puffing/poisoning" (24.1%). The therapeutic course included industrialized drugs (42.6%), medicinal plants/roots, shamanism, and prayer (42.7%). CONCLUSIONS: The risk of tuberculosis infection and disease in this population was high. Despite the reduced incidence resulting from recent efforts, tuberculosis control requires closer surveillance of contacts and improvement in communication strategies between health teams and indigenous populations.

Tuberculosis in indigenous children in the Brazilian Amazon / Tuberculose em crianças indígenas da Amazônia brasileira / Tuberculosis en niños indígenas en el Amazonas Brasileño

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.

OBJETIVO: Avaliar os aspectos epidemiológicos da tuberculose em crianças indígenas brasileiras e as ações para seu controle. MÉTODOS: Estudo epidemiológico com 356 crianças de 0 a 14 anos de idade, em Rondônia, Amazônia, Brasil, de 1997 a 2006. Os casos, registrados no Sistema de Informação de Agravos de Notificação, foram classificados em indígenas e não indígenas, e analisados segundo sexo, faixa etária, local de residência, forma clínica, exames diagnósticos e resultado do tratamento. Foi realizada análise descritiva dos casos e teste de hipótese (χ²) para verificar se houve diferenças nas proporções de adoecimento entre os grupos investigados. RESULTADOS: Foram identificados 356 casos de tuberculose (125 indígenas e 231 não indígenas), dos quais 51,4% em meninos. Nos indígenas, 60,8% dos casos foram notificados em < 5 anos. A incidência média foi maior entre os indígenas: 1.047,9 casos/100.000 habitantes < 5 anos, no ano de 2001. A forma pulmonar foi registrada em mais de 80,0% dos casos e a cura ultrapassou 70,0% em ambos os grupos. Cultura e exame histopatológico foram utilizados em apenas 10,0% dos pacientes. Houve três casos de coinfecção com HIV em não indígenas e nenhum em indígenas. A detecção dos casos foi classificada como insuficiente e/ou regular em mais de 80,0% das notificações em indígenas, mostrando que a maioria dos diagnósticos foi baseada na radiografia de tórax. CONCLUSÕES: A abordagem empregada mostrou-se útil para ilustrar desigualdades em saúde entre indígenas e não indígenas, demonstrando-se superior às análises convencionais realizadas nos serviços de vigilância. Fica evidente a necessidade de um aprimoramento da investigação diagnóstica entre as crianças indígenas.

OBJETIVO: Evaluar los aspectos epidemiológicos de la tuberculosis en niños indígenas brasileños y las acciones para su control. MÉTODOS: Estudio epidemiológico con [356] niños de 0 a 14 años de edad, en Rondonia, Amazonas, Brasil, de 1997 a 2006. Los casos registrados en el Sistema de Información de Agravios de Notificación, se clasificaron en indígenas y no indígenas, y se analizaron según sexo, grupo etario, lugar de residencia, forma clínica, exámenes diagnósticos y resultado del tratamiento. Se realizó análisis descriptivo de los casos y prueba de hipótesis (χ²) para verificar si hubo diferencias en las proporciones de la enfermedad entre los grupos investigados. RESULTADOS: Se identificaron 356 casos de tuberculosis (125 indígenas y 231 no indígenas), de los cuales, 51,4% en niños varones. En los indígenas, 60,8% de los casos fueron notificados en < 5 años. La incidencia promedio fue mayor entre los indígenas: 1.047,9 casos/100.000 habitantes < 5 años, en el año de 2001. La forma pulmonar fue registrada en más de 80,0% de los casos y la cura ultrapasó 70,0% en ambos grupos. Cultivo y examen histopatológico fueron utilizados en sólo 10,0% de los pacientes. Hubo tres casos de coinfección con VIH en no indígenas e ninguno en indígenas. La detección de los casos fue clasificada como insuficiente y/o regular en más de 80,0% de las notificaciones en indígenas, mostrando que la mayoría de los diagnósticos estuvo basada en la radiografía de tórax. CONCLUSIONES: El abordaje empleado se evidenció útil para ilustrar desigualdades en salud entre indígenas y no indígenas, demostrándose superior a los análisis convencionales realizados en los servicios de vigilancia. Se hace incuestionable la necesidad de perfeccionar la investigación diagnóstica entre los niños indígenas.

Tuberculose em indígenas da Amazônia brasileira: estudo epidemiológico na região do Alto Rio Negro / Tuberculosis in indigenous peoples in the Brazilian Amazon: an epidemiological study in the Upper Rio Negro region

OBJETIVO: Descrever as características sociodemográficas e clínico-epidemiológicas dos casos de tuberculose notificados na população indígena do Município de São Gabriel de Cachoeira, Estado do Amazonas, Brasil, e identificar fatores associados ao óbito durante o tratamento; e estimar a prevalência de infecção latente por tuberculose (ILTB) e fatores associados e obter informações sobre o itinerário terapêutico e a percepção acerca do adoecimento dos indígenas do Distrito de Iauaretê. MÉTODOS: Primeiramente, realizou-se um estudo epidemiológico retrospectivo (1997 a 2007) com base nos dados do Sistema de Informação de Agravos de Notificação. Posteriormente, realizou-se um estudo transversal (2010) em sintomáticos respiratórios e contatos no Distrito Indígena de Iauaretê. RESULTADOS: Registraram-se 723 casos novos, com incidência de 273,4/100 000 e mortalidade de 13,2/100 000. Houve predomínio em homens (57%), idade > 45 anos (37,6%), pessoas sem escolaridade (42,7%) e na área rural (76,9%). Doentes de 0 a 20 anos apresentaram menor chance de óbito quando comparados à idade > 45 anos (OR = 0,3; IC95%: 0,1 a 0,9). Em Iauaretê, que concentrou 15,3% das notificações, foram entrevistados 184 indígenas. Revelou-se prevalência de ILTB de 76,1%. Prova tuberculínica > 5 mm associou-se com idade > 15 anos, história de tuberculose ativa e alterações radiológicas. Tuberculose anterior foi citada por 54 indígenas (29,3%). A principal explicação para o adoecimento foi sopro/envenenamento (24,1%). O itinerário terapêutico incluiu medicamentos industrializados (42,6%), plantas medicinais/raízes, pajelança/xamanismo e reza (42,7%). CONCLUSÕES: A prevalência de infecção tuberculosa e doença ativa nessa população foi elevada. As estratégias de controle tiveram resultados positivos, com redução na incidência em tempos recentes. Entretanto, para controlar a tuberculose é necessário intensificar a vigilância dos contatos e aperfeiçoar as estratégias de comunicação das equipes com a população indígena.

OBJECTIVE: To describe the sociodemographic, clinical, and epidemiological characteristics of reported tuberculosis cases among indigenous individuals of São Gabriel de Cachoeira, State of Amazonas, Brazil, and to identify the factors associated with mortality during treatment; and to estimate the prevalence of latent tuberculosis infection (LTBI) and associated factors and obtain information on the therapeutic course and the individual perceptions regarding acquistion of tuberculosis in the district of Iauaretê. METHODS: Firstly, a retrospective epidemiological study (1997 to 2007) was conducted using data from the Brazilian Notifiable Diseases Surveillance System (SINAN). Next, a cross-sectional study (2010) was conducted with respiratory symptomatic subjects and contacts of Iauaretê. RESULTS: Seven hundred and twenty-three new cases were reported, with incidence of 273.4/100 000 and mortality of 13.2/100 000. There was a predominance of males (57%), aged > 45 years (37.6%), people with no schooling (42.7%), and cases from rural areas (76.9%). Patients aged 0 to 20 years were at lower risk of death when compared to those aged > 45 years (OR = 0.3; IC95%: 0.1 a 0.9). In Iauaretê, with 15.3% of the reported cases, 184 people were interviewed. A prevalence of LTB of 76.1% was reported. Tuberculin skin test > 5 mm was associated with the > 15-year old age group, history of active tuberculosis, and radiological alterations. A previous history of tuberculosis was cited by 54 people (29.3%). The main explanation for the disease was "puffing/poisoning" (24.1%). The therapeutic course included industrialized drugs (42.6%), medicinal plants/roots, shamanism, and prayer (42.7%). CONCLUSIONS: The risk of tuberculosis infection and disease in this population was high. Despite the reduced incidence resulting from recent efforts, tuberculosis control requires closer surveillance of contacts and improvement in communication strategies between health teams and indigenous populations.

Tuberculose entre os indígenas de São Gabriel da Cachoeira, AM: estudo epidemiológico com base em casos notificados e dados provenientes do Distrito Indígena de Iauaretê / Tuberculosis among the Indians of San Gabriel da Cachoeira, AM: epidemiological study based on data from reported cases and the District of Indigenous Iauaretê

A tuberculose (TB) se mantém como um dos principais problemas de saúde para os povos indígenas no Brasil. Realizou-se um estudo que caracterizou o perfil epidemiológico dos casos de TB notificados no SINAN, em São Gabriel da Cachoeira (SGC), no período 1997-2007, e analisaram-se os dados provenientes de uma investigação de indivíduos com sintomas respiratórios realizada no Distrito Indígena de Iauaretê, em 2010. Observaram-se altas taxas de incidência (216,1 / 100.000 habitantes) e de mortalidade (8,9/100.000) por TB entre a população de SGC com uma expressiva proporção de casos (15,6 por cento) diagnosticados em Iauaretê. A análise das notificações revelou que houve concentração de casos em homens (56,9 por cento), em maiores de 45 anos (37,1 por cento), em pessoas sem escolaridade (41,6 por cento), e na zona rural (74,8 por cento). De acordo com o modelo de regressão logística, a variável faixa etária de 20-45 anos foi considerada preditora para o óbito nos pacientes que iniciaram tratamento para TB (OR: 3,0; IC95 por cento: 1,1-8,3). A análise dos dados provenientes de Iauaretê mostrou alta prevalência de infecção pelo Mycobacterium tuberculosis (...) e antecedente de TB (...) mostraram associação com respostas à prova tuberculínica (..) 5 mm. Dos 184 entrevistados em Iauaretê, 54 (29,8 por cento) referiram história anterior de TB. Esse subgrupo narrou como principal causa para o adoecimento sopro e/ou envenenamento (13/54; 24,1 por cento), e o itinerário terapêutico inicial utilizado foi uso de plantas medicinais e/ou pajelança / xamanismo, seguido do uso de medicamentos farmacêuticos (42,6 por cento e 42,7 por cento, respectivamente). Os resultados indicam que a transmissão da TB em SGC se mantém em altos patamares ao longo do tempo, fazendo com que a população esteja submetida a um permanente risco de infecção e doença. Por fim, as evidências indicam que outros problemas devem ser considerados no diagnóstico diferencial ou como fatores de risco para TB mostrando a necessidade de estabelecer protocolos específicos para o controle da TB em indígenas, sobretudo no que tange à detecção, ao diagnóstico, ao tratamento e acompanhamento dos casos identificados, e também aos problemas relacionados ao acesso aos serviços de saúde.

[Clinical and radiological study of Suruí indigenous children and adolescents, Amazon Region, Brazil]. / Estudo clínico-radiológico de crianças e adolescentes indígenas Suruí, Região Amazônica.

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.

Estudo clínico-radiológico de crianças e adolescentes indígenas Suruí, Região Amazônica / Clinical and radiological study of Suruí indigenous children and adolescents, Amazon Region, Brazil

INTRODUÇÃO: Entre os Suruí de Rondônia foram registradas incidências médias de TB > 2.500/100.000 habitantes, entre 1991-2002. Aproximadamente 50 por cento desses casos foram notificados em < 15 anos. MÉTODOS: Trata-se de um estudo clínico-epidemiológico que teve como objetivo descrever as características clínico-radiológicas em crianças e adolescentes identificados como contatos de doentes de TB. Além disto, aplicar o sistema de pontuação para o diagnóstico de TB na infância e verificar se as condutas adotadas no nível local foram concordantes com as diretrizes nacionais. RESULTADOS: Foram analisados 52 Rx de 37 indígenas. Deste conjunto, 48,1 por cento foram normais e 51,9 por cento anormais. Alguns dos Rx apresentaram duas ou mais alterações, totalizando 36 eventos independentes. Observou-se infiltrados (38,9 por cento), calcificações (38,9 por cento), cavitações (11,1 por cento) e atelectasias/derrame pleural (11,1 por cento). Nas imagens anormais, 22,2 por cento eram TB provavelmente ativa e 33,3 por cento sequelas. A confrontação com as diretrizes constatou 52,6 por cento de condutas discordantes. CONCLUSÕES: A presença da infecção tuberculosa latente (ITBL) e TB ativa, entre crianças e adolescentes, são indicadores de transmissão ativa e continuada do Mycobacterium tuberculosis. Os Rx mostrando alta frequência de infiltrados e calcificações é compatível com primo-infecção em idade precoce. Entretanto, essas alterações não são diferentes daquelas observadas entre outros grupos, não sugerindo comprometimento imunológico. As discordâncias apontadas indicam que o momento ideal para o tratamento da ITBL passou despercebido. Conclui-se que é fundamental a utilização do sistema de pontuação para o correto diagnóstico de TB na infância, assim como a realização de baciloscopia e cultura de escarro em adolescentes capazes de expectorar.

INTRODUCTION: The average incidence coefficient of tuberculosis in Suruí Indians from Rondônia was 2.500/100.000 inhabitants in 1991-2002. About 50 percent 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 percent were abnormal. Some X-rays showed more than two lesions, making a total of 36 independent events. Infiltrates (38.9 percent), calcifications (38.9 percent), cavitations (11.1 percent) and atelectasis/pleural effusion (11.1 percent) were observed. Among the abnormal images, 22.2 percent were probably indicated active TB and 33.3 percent showed sequelae. Confrontation with the guidelines revealed 52.6 percent 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.