Tuberculosis control in a highly endemic indigenous community in Brazil

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing

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.

Factors associated with TB in an indigenous population in Brazil: the effect of a cash transfer program

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.

Impact of mass-screening on tuberculosis incidence in a prospective cohort of Brazilian prisoners

BACKGROUND

Globally, prison inmates are a high-risk population for tuberculosis (TB), but the specific drivers of disease and impact of mass screening interventions are poorly understood.

METHODS

We performed a prospective cohort study to characterize the incidence and risk factors for tuberculosis infection and disease in 12 Brazilian prisons, and to investigate the effect of mass screening on subsequent disease risk. After recruiting a stratified random sample of inmates, we administered a questionnaire to ascertain symptoms and potential risk factors for tuberculosis; performed tuberculin skin testing (TST); collected sera for HIV testing; and obtained two sputum samples for smear microscopy and culture, from participants reporting a cough of any duration. We repeated the questionnaire and all tests for inmates who remained incarcerated after 1 year. TST conversion was defined as TST ≥10 mm and an induration increase of at least 6 mm in an individual with a baseline TST <10 mm. Cox proportional hazard models were performed to identify risk factors associated with active TB. To evaluate the impact of screening on subsequent risk of disease, we compared TB notifications over one year among individuals randomized to screening for active TB with those not randomized to screening.

RESULTS

Among 3,771 inmates recruited, 3,380 (89.6 %) were enrolled in the study, and 1,422 remained incarcerated after one year. Among 1,350 inmates (94.9 %) with paired TSTs at baseline and one-year follow-up, 25.7 % (272/1060) converted to positive. Among those incarcerated for the year, 10 (0.7 %) had TB at baseline and 25 (1.8 %) were diagnosed with TB over the subsequent year. Cases identified through active screening were less likely to be smear-positive than passively detected cases (10.0 % vs 50.9 %; p < 0.01), suggesting early case detection. However, there was no reduction in subsequent disease among individuals actively screened versus those not screened (1.3 % vs 1.7 %; p = 0.88). Drug use during the year (AHR 3.22; 95 % CI 1.05-9.89) and knows somebody with TB were (AHR 2.86; 95 % CI 1.01-8.10) associated with active TB during one year of follow up CONCLUSIONS: Mass screening in twelve Brazilian prisons did not reduce risk of subsequent disease in twelve Brazilian prisons, likely due to an extremely high force of infection. New approaches are needed to control TB in this high-transmission setting.

Ethnic and Racial Inequalities in Notified Cases of Tuberculosis in Brazil

OBJECTIVE

This study analysed clinical and sociodemographic aspects and follow-up for notified cases of tuberculosis (TB) and explored inequalities in incidence rates and outcome by colour or race and the geographic macro-regions of Brazil.

METHODS

This paper reports the results of a population-based descriptive epidemiological study of all notified cases of TB in Brazil during the period from 01/01/2008 to 31/12/2011. We analysed sociodemographic and clinical variables according to colour or race (white, black, Asian, mixed, and indigenous) and geographic macro-regions of the country (North, Northeast, Central-West, South, and Southeast).

RESULTS

During the study period, the average incidence of TB in Brazil was 36.7 cases per 100,000 inhabitants, with the highest rates occurring in the North and Southeast regions. The analysis of TB notifications by colour or race revealed that the indigenous population presented the highest incidence rates in all macro-regions except the South, where higher rates were reported in black patients. 'Cured' was the most frequently reported treatment outcome for all skin colour categories. The highest cure rate occurred among the indigenous population (76.8%), while the lowest cure rate occurred among the black population (70.7%). Rates of treatment default were highest among blacks (10.5%) and lowest among the indigenous population (6.9%). However, the fatality rate was similar across race categories, varying between 2.8% and 3.8% for whites and the indigenous population, respectively. The lowest cure rates were observed when follow-up was inadequate (58.3%), and the highest was observed when the follow-up was classified as excellent (96.8%).

CONCLUSIONS

This study revealed that-apart from the heterogeneous distribution of TB among the Brazilian macro-regions-ethnic-racial inequalities exist in terms of clinical-epidemiological characteristics and incidence rates as well as follow-up for cases undergoing treatment. The highest rates of TB occurred among the indigenous people.

[Pulmonary tuberculosis among residents of municipalities in Mato Grosso do Sul State, Brazil, bordering on Paraguay and Bolivia]

This study analyzed the epidemiological profile of pulmonary tuberculosis from 2007 to 2010 in municipalities (counties) in Mato Grosso do Sul State, Brazil, that border on Paraguay and Bolivia. In the border region, the incidence rate (49.1/100,000 inhabitants), mortality rate (4.0/100,000 inhabitants), and treatment dropout rate (11.3%) were 1.6, 1.8, and 1.5 times higher than in the non-border region. Among indigenous individuals in the border region, the rates for incidence (253.4/100,000 inhabitants), mortality (11.6/100,000 inhabitants), and HIV/TB co-infection (1.9/100,000 inhabitants) were 6.4, 3.2, and 1.9 times higher than in non-indigenous individuals in this region. Living in the border regions was inversely associated with HIV/TB co-infection. Indigenous ethnicity was associated statistically with not abandoning TB treatment. The study concludes that the population residing in these municipalities along the border is exposed to high risk of pulmonary TB and TB mortality and treatment dropout, thus requiring special health surveillance interventions.

Chronic symptoms and pulmonary dysfunction in post-tuberculosis Brazilian patients

Background

Questionnaire and spirometry were applied to post-tuberculosis indigenous and non-indigenous individuals from Dourados, Brazil, to investigate the prevalence of chronic respiratory symptoms and pulmonary dysfunction.

Methods

This was a cross-sectional study in cured tuberculosis individuals as reported in the National System on Reportable Diseases (SINAN) from 2002 to 2012.

Results

One hundred and twenty individuals were included in the study and the prevalence of chronic respiratory symptoms was 45% (95% CI, 34–59%). Respiratory symptoms included cough (28%), sputum (23%), wheezing (22%) and dyspnea (8%). These symptoms were associated with alcoholism, AOR: 3.1 (1.2–8.4); less than 4 years of schooling, AOR: 5.0 (1.4–17.7); and previous pulmonary diseases, AOR: 5.4 (1.7–17.3). Forty-one percent (95% CI, 29–56) had pulmonary disorders, of which the most prevalent were obstructive disorders (49%), followed by obstructive disorder with reduced forced vital capacity disorders (46%) and restrictive disorders (5%). The lifestyle difference could not explain differences in chronic symptoms and/or the prevalence of pulmonary dysfunction.

Conclusion

The high prevalence of chronic respiratory symptoms and pulmonary dysfunction in post-tuberculosis patients indicates a need for further interventions to reduce social vulnerability of patients successfully treated for tuberculosis.

[Social inequalities and tuberculosis: an analysis by race/color in Mato Grosso do Sul, Brazil]

OBJECTIVE

To describe the sociodemographic and clinical-epidemiological characteristics of tuberculosis cases and identify associated factors with abandoning treatment and death whilst undergoing treatment.

METHODS

Epidemiological study based on cases of tuberculosis recorded in indigenous and non-indigenous individuals according to race/color in Mato Grosso do Sul, Midwestern Brazil, between 2001 and 2009. Descriptive analysis of the cases was carried out according to the variables of sex, age group, residence, type of test used in the diagnosis, clinical form, supervised treatment and final status, according to race/color. Univariate/multivariate logistic regression analyses were used to identify predictors of abandoning treatment and death, using odds ratio as a measure of association. A time series of incidence according to race/color was constructed.

RESULTS

In the period, 6,962 new cases of tuberculosis were registered, 15.6% being among indigenous. The illness was predominantly found in men and adults (20-44 years old) in all groups. Most of the indigenous patients lived in rural areas (79.8%) and 13.5% of the records in indigenous occurred in children aged < 10 years. The average incidence in the state was 34.5/100,000 inhabitants, being 209.0, 73.1, 52.7, 23.0 and 22.4 in indigenous, and those with yellow, black, white and brown skin, respectively. Patients aged 20 to 44 years (OR = 13.3, 95%CI 1.9;96.8), male (OR = 1.6, 95%CI 1.1;2.3) and of black race/color (OR = 2.5, 95%CI 1.0;6.3) were associated with abandoning treatment, while patients aged > 45 years (OR = 3.0, 95%CI 1.2;7.8) and with the mixed form (OR = 2.3, 95%CI 1.1;5.0) showed association with death. Although they only account for 3.0% of the population, the indigenous were responsible for 15.6% of cases recorded during the period.

CONCLUSIONS

Major inequalities in the tuberculosis illness process were found between the categories studied. Incidence in the indigenous population was consistently higher than recorded in any other group, reaching more than six times the national average. It was among those with black and brown skin that the worst treatment results were observed, as they were twice as likely to abandon treatment as the indigenous. Poor program performance was strongly associated with abandoning treatment and death. It is thought that as long as there is no reduction in poverty inequalities in health indicators will remain.

Health-service performance of TB treatment for indigenous and non-indigenous populations in Brazil: a cross-sectional study

BACKGROUND

Health-service evaluation studies are fundamental for proposing interventions and ensuring improvements in healthcare quality. The present study assesses the performance of health services for indigenous and non-indigenous populations with regard to tuberculosis (TB) control.

METHODS

Interviews with TB patients who underwent treatment between 2009 and 2011 were conducted using the Primary Care Assessment Tool adapted for TB care in Brazil.

RESULTS

Primary healthcare (PHC) was the first treatment for most patients at symptom onset, and the diagnoses were typically performed by specialized services. Many patients experienced delayed TB diagnoses that required more than three medical appointments (51% and 47% for indigenous and non-indigenous populations, respectively). Indigenous people received social support, such as basic-needs grocery packages (2.19 ± 1.63 vs. 1.13 ± 0.49 for non-indigenous people, p < 0.01) and home visits from health professionals, with an emphasis on the performance of directly observed treatment strategies (DOT; 4.57 ± 0.89 vs. 1.68 ± 1.04 for non-indigenous people, p < 0.01).

CONCLUSIONS

Regardless of the differences between indigenous and non-indigenous populations, the time needed to receive a TB diagnosis was unsatisfactory for both groups. Furthermore, DOT must be performed with better coverage among non-indigenous patients.

The 2014 FIFA World Cup: communicable disease risks and advice for visitors to Brazil--a review from the Latin American Society for Travel Medicine (SLAMVI)

The next FIFA World Cup will be held in Brazil in June-July 2014. Around 600,000 international visitors and participants (as well over 3 million domestic travelers) are expected. This event will take place in twelve cities. This event poses specific challenges, given its size and the diversity of attendees, including the potential for the transmission of imported or endemic communicable diseases, especially those that have an increased transmission rate as a result of close human proximity, eg, seasonal influenza, measles but also tropical endemic diseases. In anticipation of increased travel, a panel of experts from the Latin American Society for Travel Medicine (SLAMVI) developed the current recommendations regarding the epidemiology and risks of the main communicable diseases in the major potential destinations, recommended immunizations and other preventives measures to be used as a basis for advice for travelers and travel medicine practitioners. Mosquito-borne infections also pose a challenge. Dengue poses a significant risk in all states, including the host cities. Vaccination against yellow fever is recommended except for travelers who will only visit coastal areas. Travelers visiting high-risk areas for malaria (Amazon) should be assessed regarding the need for chemoprophylaxis. Chikunguya fever may be a threat for Brazil, given the presence of Aedes aegypti, vector of dengue, and the possibility of travelers bringing the virus with them when attending the event. Advice on the correct timing and use of repellents and other personal protection measures is key to preventing these vector-borne infections. Other important recommendations for travelers should focus on preventing water and food-borne diseases such as hepatitis A, typhoid fever, giardiasis and traveler's diarrhea. Sexually transmitted diseases (STD) should be also mentioned and the use of condoms advocated. This review addresses pre-travel, preventive strategies to reduce the risk of acquiring communicable diseases during a mass gathering such as the World Cup and also reviews the spectrum of endemic infections in Brazil to facilitate the recognition and management of infectious diseases in travelers returning to their countries of origin.

Incidence and transmission patterns of tuberculosis among indigenous populations in Brazil

Approximately 10% of the Brazilian indigenous population lives in the state of Mato Grosso do Sul (MS), where a large number of new cases of tuberculosis (TB) are reported. This study was conducted to assess TB occurrence, transmission and the utility of TB diagnosis based on the Ogawa-Kudoh (O-K) culture method in this remote population. The incidence of TB was estimated by a retrospective review of the surveillance data maintained by the Notifiable Diseases Surveillance System for the study region. The TB transmission pattern among indigenous people was assessed by genotyping Mycobacterium tuberculosis isolates using the IS 6110 restriction fragment length polymorphism (RFLP) technique. Of the 3,093 cases identified from 1999-2001, 610 (~20%) were indigenous patients (average incidence: 377/100,000/year). The use of the O-K culture method increased the number of diagnosed cases by 34.1%. Of the genotyped isolates from 52 indigenous patients, 33 (63.5%) belonged to cluster RFLP patterns, indicating recently transmitted TB. These results demonstrate high, on-going TB transmission rates among the indigenous people of MS and indicate that new efforts are needed to disrupt these current transmissions.

A spatial analysis of social and economic determinants of tuberculosis in Brazil

We investigated the spatial distribution, and social and economic correlates, of tuberculosis in Brazil between 2002 and 2009 using municipality-level age/sex-standardized tuberculosis notification data. Rates were very strongly spatially autocorrelated, being notably high in urban areas on the eastern seaboard and in the west of the country. Non-spatial ecological regression analyses found higher rates associated with urbanicity, population density, poor economic conditions, household crowding, non-white population and worse health and healthcare indicators. These associations remained in spatial conditional autoregressive models, although the effect of poverty appeared partially confounded by urbanicity, race and spatial autocorrelation, and partially mediated by household crowding. Our analysis highlights both the multiple relationships between socioeconomic factors and tuberculosis in Brazil, and the importance of accounting for spatial factors in analysing socioeconomic determinants of tuberculosis.

Impact of latent infection treatment in indigenous populations

The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN) database, and the contacts’ data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI) multidisciplinary teams, according to SESAI’s instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02–1.04) and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59–3.22). The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST) ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07–1.17), age (RR: 1.01, 95% CI: 1.00–1.03), and treatment of latent infection (RR: 0.03, 95% CI: 0.01–0.27). The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33–182). In contacts with TST ≥10 mm, 10 (95% CI: 6–19) latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities.