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The Mato Grosso do Sul State (MS) has the second-largest indigenous population and the highest incidence rates of TB among indigenous people in Brazil. However, little is known about the risk factors associated with active TB in indigenous people in the region, especially regarding socioeconomic factors. The aim of this study is to assess the effect of the Family Allowance Program (BFP) and of other predictors of active TB in a high-risk indigenous population in Brazil. We conducted a case-control study with incident TB cases matched by age and by village of residence (1:2 proportion) between March 2011 and December 2012. We used a conditional logistic regression for data analysis. A total of 153 cases and 306 controls were enrolled. The final model included the following risk factors: alcohol consumption (low-risk use OR=2.2; 95% CI 1.1-4.3; risky use OR=2.4; 95% CI 1.0-6.0; dependent/ damaging use OR=9.1; 95% CI 2.9-29.1); recent contact with a TB patient (OR=2.0; 95% CI 1.2-3.5); and male sex (OR=1.9; 95% CI 1.1-3.2). BFP participation (OR=0.5; 95% CI 0.3-0.6) and BCG vaccination (OR=0.5; 95% CI 0.3-0.9) were found to be protective factors against TB. Although the BFP was not designed to target TB-affected households specifically, our findings reveal the importance of the BFP in preventing one of the most important infectious diseases among adults in indigenous villages in Brazil. This result is in line with the End-TB strategy, which identifies social protection, poverty alleviation and targeting other determinants of TB as key actions.

Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

After nearly a century of vaccination and six decades of drug therapy, tuberculosis (TB) kills more people annually than any other infectious disease. Substantial challenges to disease eradication remain among vulnerable and underserved populations. The Guarani-Kaiowá people are an indigenous population in Paraguay and the Brazilian state of Mato Grosso do Sul. This community, marginalized in Brazilian society, experiences severe poverty. Like other South American indigenous populations, their TB prevalence is high, but the disease has remained largely unstudied in their communities. Herein, Mycobacterium tuberculosis isolates from local clinics were whole genome sequenced, and a population genetic framework was generated. Phylogenetics show M. tuberculosis isolates in the Guarani-Kaiowá people cluster away from selected reference strains, suggesting divergence. Most cluster in a single group, further characterized as M. tuberculosis sublineage 4.3.3. Closer analysis of SNPs showed numerous variants across the genome, including in drug resistance-associated genes, and with many unique changes fixed in each group. We report that local M. tuberculosis strains have acquired unique polymorphisms in the Guarani-Kaiowá people, and drug resistance characterization is urgently needed to inform public health to ensure proper care and avoid further evolution and spread of drug-resistant TB.

Background The Guarani-Kaiowá are Brazil's second-largest indigenous group. Average annual tuberculosis (TB) incidence rates among the Guarani-Kaiowá are nearly 400/100,000 in Mato Grosso do Sul state, ten times the national average. Although stigma is considered crucial for TB control in indigenous communities, few studies have investigated TB stigma among indigenous populations. This study sought to understand the role of TB-related stigma and perceptions of TB in maintaining hyperendemic TB transmission in the Guarani-Kaiowá communities. Methods Various forms of stigma were explored through semi-structured interviews with 19 patients, 11 relatives, and 23 community members. Patients were identified from the registry of the healthcare service. Community members, selected by snowball sampling, were matched by gender and village of residence. Interviews were conducted in Guarani and Portuguese and later translated into English. Framework analysis was performed using NVivo. Results Traditional beliefs of a weakening of the body allowing the disease to enter were common, but the exact mechanism of transmission was unknown. Strong community/public stigma associated TB with uncleanliness, abuse, and irresponsibility. Anticipated stigma led to significant treatment delays for fear of exclusion and losing employment. While most patients felt supported by their families, nearly all patients related experienced/enacted stigma in the community such as gossip, avoidance, and social exclusion, leading to long-lasting internalized/self-stigma. Secondary stigmatization of relatives was widespread, and blanket latent TB infection (LTBI) treatment of patients’ households was a contributing factor in treatment delay. The healthcare service unnecessarily added to stigmatization by enforcing separate utensils and sleeping arrangements for patients. Conclusions Our findings suggest that stigma is a driver for treatment delay and continued transmission of TB in the community. The stigmatization of TB was rooted in a poor understanding of TB transmission, partly because of incorrect orientation by the healthcare service. Interventions to reduce TB-associated stigma are urgently needed.

The spread of H5N1 influenza and the similarity between this avian virus and the Spanish flu virus causes fear of a new influenza pandemic, but data from the Spanish flu may also be of guidance in planning for preventive measures. Using data on influenza cases, influenza deaths and total deaths for Denmark and for Danish towns from 1917 to 1921, and population data from the 1916 and 1921 censuses, we analysed incident cases, cumulative, age-specific and age-standardized rates. Overall, more than 900,000 persons contracted flu during the y 1918-1920, and 1 out of 50 patients died from the disease. An early wave of the flu occurred in the capital and major towns, but not in peripheral towns. Influenza incidence in 1918 peaked at age 5-15 y, closely followed by the age groups 1-5 y and 15-65 y, but the influenza mortality was highest in the age groups 0-1 y and 15-65 y, with a peak mortality at age 20-34 y producing a W curve for mortality by age. The background for the better outcome in children aged 1-15 y as well as for the disease immunity in the elderly population should be further investigated.