Paulo Basta

The radiographic patterns of 23/33 (69.7%) Suruí indians, of the Brazilian Amazon, treated in 2003-2004 were analyzed. The analysis showed that 44.8% presented unspecific infiltrates, 10.3% presented cavitations and 39.1% presented multiple parenchymal involvements. Although 36% of the patients presented normal radiographs, they underwent anti-tuberculous treatment without having been submitted for other possible means of diagnosis.

O B J E C T I V E : To estimate the prevalence and the annual risk of infection (ARI) of tuberculosis (TB) in an indigenous population in Brazil. M E T H O D S : We applied a method to estimate the prevalence of TB infection in populations with high bacille Calmette-Guérin (BCG) vaccine coverage. The method consisted of comparing levels of skin test reactivity in individuals tested with purified protein derivative (PPD) before and after stimulation with intradermal BCG. Fieldwork was carried out among the Suruí Indians (n 993) in two phases, 3 months apart. R E S U L T S : A total of 645 subjects were tested. In pre-BCG revaccination, tuberculin skin test (TST) indura-tions averaged 5.9 mm (33.5% 10 mm). In post-BCG revaccination TST, indurations averaged 9.4 mm (48.7% 10 mm). Conversion from non-reactor to reactor was 54.4%. The ARI ranged from 1.2% to 2.2%. In the logistic regression, age and history of TB were the strongest independent predictors of TB infection. BCG scar and the number of individuals per house were also associated with infection. C O N C L U S I O N : Tuberculous transmission is very high in the Suruí, surpassing the ARI reported for Brazil (0.6%). The epidemiology of TB in this indigenous population is related to unfavourable social and economic conditions, as well as to deficient health care services.

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. 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. 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. The presence of latent tuberculosis infection (LTBI)...

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 Tuber-culin 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 þ874 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.

A cross-sectional survey was carried out in 2003 to investigate the epidemiology of tuberculosis (TB) among the Suruí Indians, Brazilian Amazon. A total of 736 subjects (50.7% females) were examined (80% of the total population). TB suspects underwent standardised evaluation for the presence of signs and/or symptoms of active TB, including chest radiography, PPD skin test, sputum microscopy examination for acid-fast bacilli and mycobacterial culture. A Bacillus Calmette—Guerin vaccine scar was detected in 699 individuals (95.0%). Of all the individuals examined, 120 (16.3%) had undergone previous TB treatment (46.7% females). One hundred and nine individuals were assessed as TB suspects (52.3% females). The survey identified six new cases of TB in the Suruí (three men and three women). Five of the six cases came from only two of the ten villages. Mycobacterium tuberculosis colonies grew from 5 (4.6%) samples (only two of which were also smear-positive) and mycobacteria other than M. tuberculosis were isolated from 14 (12.8%) samples. Diagnosis of TB based exclusively on clinical grounds was established only in the case of a 4-year-old girl. Based on this survey, the prevalence of active TB in the sampled group (N = 736) was 815.2 per 100 000. This study highlights the urgent need to review and strengthen control strategies directed at indigenous peoples in the country, taking into consideration their social, cultural and environmental differences.

ABSTRACT 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. 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. 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%). 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.

This investigation aimed at the detection of Mycobacterium tuberculosis (MTB) in the sputum of Suruí Indian subjects from Amazonia, Brazil. Polymerase chain reaction analyses were positive for 12 samples, five of which were also culture-positive (N = 147). Four MTB genotypes were identified, one of which showed resistance to rifampicin and isoniazid. The study also highlighted one village complex as of particular importance, considering the relatively high number of tuberculosis cases reported and of MTB isolates obtained.

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. We report the results of an interdisciplinary investigation of TB epidemiology, healthcare services, and ethnomedicine among the Xavante Indians of Central Brazil. 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. 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 > or = 10 years of age), and a relatively low percentage of individuals with reactive TB skin tests (16.6% of reactions > or = 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. Ineffective diagnosis procedures compromise the efficacy of existing TB prevention efforts and threaten to undermine otherwise favorable institutional and cultural conditions.