Tuberculosis in indigenous peoples in the U.S., 2003-2008

Using Geographic Disaggregation to Compare Tuberculosis Epidemiology Among American Indian and Alaska Native Persons-USA, 2010-2020

BACKGROUND

American Indian and Alaska Native (AIAN) populations are frequently associated with the highest rates of tuberculosis (TB) disease of any racial/ethnic group in the USA. We systematically investigated variation in patterns and potential drivers of TB epidemiology among geographically distinct AIAN subgroups.

METHODS

Using data reported to the National Tuberculosis Surveillance System during 2010-2020, we applied a geographic method of data disaggregation to compare annual TB incidence and the frequency of TB patient characteristics among AIAN persons in Alaska with AIAN persons in other states. We used US Census data to compare the prevalence of substandard housing conditions in AIAN communities in these two geographic areas.

RESULTS

The average annual age-adjusted TB incidence among AIAN persons in Alaska was 21 times higher than among AIAN persons in other states. Compared to AIAN TB patients in other states, AIAN TB patients in Alaska were associated with significantly higher frequencies of multiple epidemiologic TB risk factors (e.g., attribution of TB disease to recent transmission, previous diagnosis of TB disease) and significantly lower frequencies of multiple clinical risk factors for TB disease (e.g., diagnosis with diabetes mellitus, end-stage renal disease). Occupied housing units in AIAN communities in Alaska were associated with significantly higher frequencies of multiple measures of substandard housing conditions compared to AIAN communities in other states.

CONCLUSIONS

Observed differences in patient characteristics and substandard housing conditions are consistent with contrasting syndromes of TB epidemiology in geographically distinct AIAN subgroups and suggest ways that associated public health interventions could be tailored to improve efficacy.

The Many Hosts of Mycobacteria 9 (MHM9): A conference report

The Many Hosts of Mycobacteria (MHM) meeting series brings together basic scientists, clinicians and veterinarians to promote robust discussion and dissemination of recent advances in our knowledge of numerous mycobacterial diseases, including human and bovine tuberculosis (TB), nontuberculous mycobacteria (NTM) infection, Hansen's disease (leprosy), Buruli ulcer and Johne's disease. The 9th MHM conference (MHM9) was held in July 2022 at The Ohio State University (OSU) and centered around the theme of "Confounders of Mycobacterial Disease." Confounders can and often do drive the transmission of mycobacterial diseases, as well as impact surveillance and treatment outcomes. Various confounders were presented and discussed at MHM9 including those that originate from the host (comorbidities and coinfections) as well as those arising from the environment (e.g., zoonotic exposures), economic inequality (e.g. healthcare disparities), stigma (a confounder of leprosy and TB for millennia), and historical neglect (a confounder in Native American Nations). This conference report summarizes select talks given at MHM9 highlighting recent research advances, as well as talks regarding the historic and ongoing impact of TB and other infectious diseases on Native American Nations, including those in Southwestern Alaska where the regional TB incidence rate is among the highest in the Western hemisphere.

Native opportunities to stop hypertension: study protocol for a randomized controlled trial among urban American Indian and Alaska Native adults with hypertension

Introduction

American Indian and Alaska Native (AI/AN) adults experience disproportionate cardiovascular disease (CVD) morbidity and mortality compared to other races, which may be partly attributable to higher burden of hypertension (HTN). Dietary Approaches to Stop Hypertension (DASH) is a high-impact therapeutic dietary intervention for primary and secondary prevention of CVD that can contribute to significant decreases in systolic blood pressure (BP). However, DASH-based interventions have not been tested with AI/AN adults, and unique social determinants of health warrant independent trials. This study will assess the effectiveness of a DASH-based intervention, called Native Opportunities to Stop Hypertension (NOSH), on systolic BP among AI/AN adults in three urban clinics.

Methods

NOSH is a randomized controlled trial to test the effectiveness of an adapted DASH intervention compared to a control condition. Participants will be aged ≥18 years old, self-identify as AI/AN, have physician-diagnosed HTN, and have elevated systolic BP (≥ 130 mmHg). The intervention includes eight weekly, tailored telenutrition counseling sessions with a registered dietitian on DASH eating goals. Intervention participants will be provided $30 weekly and will be encouraged to purchase DASH-aligned foods. Participants in the control group will receive printed educational materials with general information about a low-sodium diet and eight weekly $30 grocery orders. All participants will complete assessments at baseline, after the 8-week intervention, and again 12 weeks post-baseline. A sub-sample of intervention participants will complete an extended support pilot study with assessments at 6- and 9-months post-baseline. The primary outcome is systolic BP. Secondary outcomes include modifiable CVD risk factors, heart disease and stroke risk scores, and dietary intake.

Discussion

NOSH is among the first randomized controlled trials to test the impact of a diet-based intervention on HTN among urban AI/AN adults. If effective, NOSH has the potential to inform clinical strategies to reduce BP among AI/AN adults.

Clinical trials registration

https://clinicaltrials.gov/ct2/show/NCT02796313, Identifier NCT02796313.

Time to diagnosis and treatment of pulmonary tuberculosis in indigenous peoples: a systematic review

BACKGROUND

Time to diagnosis and treatment is a major factor in determining the likelihood of tuberculosis (TB) transmission and is an important area of intervention to reduce the reservoir of TB infection and prevent disease and mortality. Although Indigenous peoples experience an elevated incidence of TB, prior systematic reviews have not focused on this group. We summarize and report findings related to time to diagnosis and treatment of pulmonary TB (PTB) among Indigenous peoples, globally.

METHODS

A Systematic review was performed using Ovid and PubMed databases. Articles or abstracts estimating time to diagnosis, or treatment of PTB among Indigenous peoples were included with no restriction on sample size with publication dates restricted up to 2019. Studies that focused on outbreaks, solely extrapulmonary TB alone in non-Indigenous populations were excluded. Literature was assessed using the Hawker checklist. Registration Protocol (PROSPERO): CRD42018102463.

RESULTS

Twenty-four studies were selected after initial assessment of 2021 records. These included Indigenous groups from five of six geographical regions outlined by the World Health Organization (all except the European Region). The range of time to treatment (24-240 days), and patient delay (20 days-2.5 years) were highly variable across studies and, in at least 60% of the studies, longer in Indigenous compared to non-Indigenous peoples. Risk factors associated with longer patient delays included poor awareness of TB, type of health provider first seen, and self-treatment.

CONCLUSION

Time to diagnosis and treatment estimates for Indigenous peoples are generally within previously reported ranges from other systematic reviews focusing on the general population. However among literature examined in this systematic review that stratified by Indigenous and non-Indigenous peoples, patient delay and time to treatment were longer compared to non-Indigenous populations in over half of the studies. Studies included were sparse and highlight an overall gap in literature important to interrupting transmission and preventing new TB cases among Indigenous peoples. Although, risk factors unique to Indigenous populations were not identified, further investigation is needed as social determinants of health among studies conducted in medium and high incidence countries may be shared across both population groups. Trial registration N/a.

Tuberculosis in Indigenous Persons - United States, 2009-2019

BACKGROUND

Populations of indigenous persons are frequently associated with pronounced disparities in rates of tuberculosis (TB) disease compared to co-occurring nonindigenous populations.

METHODS

Using data from the National Tuberculosis Surveillance System on TB cases in U.S.-born patients reported in the United States during 2009-2019, we calculated incidence rate ratios and risk ratios for TB risk factors to compare cases in American Indian or Alaska Native (AIAN) and Native Hawaiian or other Pacific Islander (NHPI) TB patients to cases in White TB patients.

RESULTS

Annual TB incidence rates among AIAN and NHPI TB patients were on average ≥10 times higher than among White TB patients. Compared to White TB patients, AIAN and NHPI TB patients were 1.91 (95% confidence interval (CI): 1.35-2.71) and 3.39 (CI: 1.44-5.74) times more likely to have renal disease or failure, 1.33 (CI: 1.16-1.53) and 1.63 (CI: 1.20-2.20) times more likely to have diabetes mellitus, and 0.66 (CI: 0.44-0.99) and 0.19 (CI: 0-0.59) times less likely to be HIV positive, respectively. AIAN TB patients were 1.84 (CI: 1.69-2.00) and 1.48 (CI: 1.27-1.71) times more likely to report using excess alcohol and experiencing homelessness, respectively.

CONCLUSION

TB among U.S. indigenous persons is associated with persistent and concerning health disparities.

Tuberculosis Among Native Hawaiian and Other Pacific Islander Persons: United States and U.S.-Affiliated Pacific Islands, 2010-2019

Background

In recent years, tuberculosis (TB) incidence in the United States has declined overall but remained high among Native Hawaiian and Other Pacific Islander (NH/PI) persons. Few studies have examined the epidemiology of TB among NH/PI persons, particularly in the U.S.-Affiliated Pacific Islands (USAPI). We describe TB incidence and characteristics of NH/PI patients during 2010-2019.

Methods

We used data from the National Tuberculosis Surveillance System to characterize TB cases reported among NH/PI persons born in the 50 U.S. states (defined to include District of Columbia) and the USAPI. We calculated annual TB incidence among NH/PI patients, stratified by place of birth (U.S. states or USAPI). Using Asian persons born outside the United States-persons historically grouped with NH/PI persons as one racial category-as the reference, we compared demographic, clinical, and socio-behavioral characteristics of NH/PI TB patients.

Results

During 2010-2019, 4359 TB cases were reported among NH/PI patients born in the U.S. states (n=205) or the USAPI (n=4154). Median annual incidence per 100,000 persons was 6.5 cases (persons born in the U.S. states) and 150.7 cases (persons born in the USAPI). The proportion of TB patients aged <15 years was higher among NH/PI persons (U.S. states: 54%, USAPI: 24%) than among Asian persons born outside the United States (1%).

Conclusions

TB incidence among NH/PI persons is high, particularly among persons born in the USAPI, emphasizing the need to enhance TB prevention strategies in these communities. Interventions should be tailored toward those who experience the highest risk, including NH/PI children and adolescents.

Incidence of socially significant infectious diseases (HIV, TB and HIV/TB coinfection) in the Arctic regions of Russia)

The study is aimed to evaluate the HIV, TB, and HIV/TB coinfection incidence per 100,000 population/year in Russian Arctic, based on official statistical data. The epidemics' incidence in Russian Arctic is uneven. The highest HIV incidence in 2019 was registered in Krasnoyarsk region (94,6), and the highest TB incidence in ChAD (136,1). ChAD was also identified as the region with the worst indicators, where the HIV incidence in 2007-2019 was evaluated at (315,8%), TB (136,1%), HIV/TB coinfection (150,0%). Despite the significant reduction in TB incidence in Arkhangelsk oblast (-63,9%), Karelia (-57,3%) and Komi (-56,2%) republics, it is alarming to observe dramatic increases in HIV incidence in the aforementioned regions (592,3%, 331,8%, 156,5% respectively). External factors influence HIV and TB incidence in most regions. Prevailing in men, HIV and TB incidence disparities between the general population and permanent residents occurred in all regions, except in ChAD and NAD, where the infections were diagnosed only among permanent residents. It is necessary to provide more detailed studies focusing on HIV, TB, and HIV/TB coinfection features in each circumpolar district in order to determine the main risk factors, especially among indigenous peoples as a vulnerable group, and to evaluate the HIV/TB collaborative services' capacity.

The contribution of stigma to the transmission and treatment of tuberculosis in a hyperendemic indigenous population in Brazil

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.

Epidemiology of tuberculosis among children and adolescents in the USA, 2007-17: an analysis of national surveillance data

BACKGROUND

Understanding tuberculosis epidemiology among children and adolescents informs treatment and prevention efforts, and efforts to eliminate disparities in tuberculosis incidence and mortality. We sought to describe the epidemiology of children and adolescents with tuberculosis disease in the USA, including tuberculosis incidence rates by parental country of birth and for US territories and freely associated states, which have not been previously described.

METHODS

We analysed data for children aged younger than 15 years and adolescents aged 15-17 years with tuberculosis disease reported to the National Tuberculosis Surveillance System during 2007-17, and calculated tuberculosis incidence rates using population estimates from the US Census Bureau.

FINDINGS

During 2010-17, 6072 tuberculosis cases occurred among children and adolescents; of these, 5175 (85%) of 6072 occurred in the 50 US states or the District of Columbia and 897 (15%) of 6072 in US-affiliated islands. In US states, 3520 (68%) of 5175 cases occurred among US-born people overall, including 2977 (76%) of 3896 children and 543 (42%) of 1279 adolescents. The incidence rate among children and adolescents was 1·0 per 100 000 person-years during 2007-17 and declined 47·8% (95% CI -51·4 to -44·1) during this period. We observed disproportionately high tuberculosis rates among children and adolescents of all non-white racial or ethnic groups, people living in US-affiliated islands, and children born in or with parents from tuberculosis-endemic countries.

INTERPRETATION

Overall, tuberculosis incidence among children and adolescents in the USA is low and steadily declining, but additional efforts are needed to eliminate disparities in incidence and mortality.

FUNDING

US Centers for Disease Control and Prevention.

[Tuberculosis in indigenous children and adolescents in Brazil: factors associated with death and treatment dropout]

The study aimed to describe clinical and sociodemographic characteristics, estimate incidence, and analyze factors associated with dropout and death during treatment of TB cases reported in indigenous children and adolescents in Brazil from 2006 to 2016. A historical case series was performed on incidence according to age bracket and major geographic region, and multinomial logistic regression was used to explain factors associated with treatment dropout and death. Of the 2,096 reported cases, 88.2% evolved to cure, 7.2% dropped out of treatment, and 4.6% evolved to death. There was a predominance of cases in boys 15-19 years of age and a higher proportion of deaths (55.7%) in children < 4 years. Considering indigenous children and adolescents with TB in Brazil as a whole, mean incidence was 49.1/100,000, ranging from 21.5/100,000 to 97.6/100,000 in the Northeast and Central, respectively. Cases with insufficient and irregular follow-up showed higher odds of dropout (OR = 11.1; 95%CI: 5.2-24.8/OR = 4.4; 95%CI: 1.9-10.3) and death (OR = 20.3; 95%CI: 4.9-84.9/OR = 5.1; 95%CI: 1.2-22.7). Cases in retreatment (OR = 2.4; 95%CI: 2.08-8.55) and with HIV coinfection (OR = 8.2; 95%CI: 2.2-30.9) were also associated with dropout. Extrapulmonary (OR = 1.8; 95%CI: 1.1-3.3) and mixed clinical forms (OR = 5.6; 95%CI: 2.8-11.4), age < 4 years (OR = 3.1; 95%CI: 1.5-6.4), and cases from the North (OR = 2.8; 95%CI: 1.1-7.1) and Central (OR = 2.8; 95%CI: 1.1-7.0) were associated with death. TB control in indigenous children and adolescents cannot be achieved without investments in research and development and without reducing social inequalities.

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.

Incorporation of Social Determinants of Health in the Peer-Reviewed Literature: A Systematic Review of Articles Authored by the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

OBJECTIVES

Social determinants of health (SDHs) are the complex, structural, and societal factors that are responsible for most health inequities. Since 2003, the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) has researched how SDHs place communities at risk for communicable diseases and poor adolescent health. We described the frequency and types of SDHs discussed in articles authored by NCHHSTP.

METHODS

We used the MEDLINE/PubMed search engine to systematically review the frequency and type of SDHs that appeared in peer-reviewed publications available in PubMed from January 1, 2009, through December 31, 2014, with a NCHHSTP affiliation. We chose search terms to identify articles with a focus on the following SDH categories: income and employment, housing and homelessness, education and schooling, stigma or discrimination, social or community context, health and health care, and neighborhood or built environment. We classified articles based on the depth of topic coverage as "substantial" (ie, one of ≤3 foci of the article) or "minimal" (ie, one of ≥4 foci of the article).

RESULTS

Of 862 articles authored by NCHHSTP, 366 (42%) addressed the SDH factors of interest. Some articles addressed >1 SDH factor (366 articles appeared 568 times across the 7 categories examined), and we examined them for each category that they addressed. Most articles that addressed SDHs (449/568 articles; 79%) had a minimal SDH focus. SDH categories that were most represented in the literature were health and health care (190/568 articles; 33%) and education and schooling (118/568 articles; 21%).

CONCLUSIONS

This assessment serves as a baseline measurement of inclusion of SDH topics from NCHHSTP authors in the literature and creates a methodology that can be used in future assessments of this topic.

Epidemiology of Nontuberculous Mycobacterial Lung Disease and Tuberculosis, Hawaii, USA

Previous studies found Hawaiians and Asian-Americans/Pacific Islanders to be independently at increased risk for nontuberculous mycobacterial pulmonary disease (NTMPD) and tuberculosis (TB). To better understand NTM infection and TB risk patterns in Hawaii, USA, we evaluated data on a cohort of patients in Hawaii for 2005–2013. Period prevalence of NTMPD was highest among Japanese, Chinese, and Vietnamese patients (>300/100,000 persons) and lowest among Native Hawaiians and Other Pacific Islanders (50/100,000). Japanese patients were twice as likely as all other racial/ethnic groups to have Mycobacterium abscessus isolated (adjusted odds ratio 2.0, 95% CI 1.2–3.2) but were not at increased risk for infection with other mycobacteria species. In contrast, incidence of TB was stable and was lowest among Japanese patients (no cases) and highest among Filipino, Korean, and Vietnamese patients (>50/100,000). Substantial differences exist in the epidemiology of NTMPD by race/ethnicity, suggesting behavioral and biologic factors that affect disease susceptibility.

Individual- and neighborhood-level contextual factors are associated with Mycobacterium tuberculosis transmission: genotypic clustering of cases in Michigan, 2004-2012

PURPOSE

Using genotyping data of Mycobacterium tuberculosis isolates from new cases reported to the tuberculosis (TB) surveillance program, we evaluated risk factors for recent TB transmission at both the individual- and neighborhood- levels among U.S.-born and foreign-born populations.

METHODS

TB cases (N = 1236) reported in Michigan during 2004 to 2012 were analyzed using multivariable Poisson regression models to examine risk factors for recent transmission cross-sectionally for U.S.-born and foreign-born populations separately. Recent transmission was defined based on spoligotype and 12-locus-mycobacterial interspersed repetitive unit-variable number tandem repeat typing matches of bacteria from cases that were diagnosed within 1 year of each other. Four classes of predictor variables were examined: demographic factors, known TB risk factors, clinical characteristics, and neighborhood-level factors.

RESULTS

Overall, 22% of the foreign-born cases resulted from recent transmission. Among the foreign-born, race and being a contact of an infectious TB case were significant predictors of recent transmission. More than half (52%) of U.S.-born cases resulted from recent transmission. Among the U.S.-born, recent transmission was predicted by both individual- and neighborhood-level sociodemographic characteristics.

CONCLUSIONS

Interventions aimed at reducing TB incidence among foreign-born should focus on reducing reactivation of latent infection. However, reducing TB incidence among the U.S.-born will require decreasing transmission among socially disadvantaged groups at the individual- and neighborhood- levels. This report fills an important knowledge gap regarding the contemporary social context of TB in the United States, thereby providing a foundation for future studies of public health policies that can lead to the development of more targeted, effective TB control.

Infectious Disease Issues in Underserved Populations

Infectious disease has a major impact on the health outcomes of underserved populations and is reported at significantly higher rates among these populations compared with the general population. Overcoming barriers and obstacles to health care access is key to addressing the disparity regarding the prevalence of infectious disease. Enhancing cultural competency and educating practitioners about underserved populations' basic health needs; optimizing health insurance for the underserved; increasing community resources; and improving access to comprehensive, continuous, compassionate, and coordinated health care are strategies for diminishing the burden of infectious disease in underserved populations.

Recent Transmission of Tuberculosis - United States, 2011-2014

Tuberculosis is an infectious disease that may result from recent transmission or from an infection acquired many years in the past; there is no diagnostic test to distinguish the two causes. Cases resulting from recent transmission are particularly concerning from a public health standpoint. To describe recent tuberculosis transmission in the United States, we used a field-validated plausible source-case method to estimate cases likely resulting from recent transmission during January 2011–September 2014. We classified cases as resulting from either limited or extensive recent transmission based on transmission cluster size. We used logistic regression to analyze patient characteristics associated with recent transmission. Of 26,586 genotyped cases, 14% were attributable to recent transmission, 39% of which were attributable to extensive recent transmission. The burden of cases attributed to recent transmission was geographically heterogeneous and poorly predicted by tuberculosis incidence. Extensive recent transmission was positively associated with American Indian/Alaska Native (adjusted prevalence ratio [aPR] = 3.6 (95% confidence interval [CI] 2.9–4.4), Native Hawaiian/Pacific Islander (aPR = 3.2, 95% CI 2.3–4.5), and black (aPR = 3.0, 95% CI 2.6–3.5) race, and homelessness (aPR = 2.3, 95% CI 2.0–2.5). Extensive recent transmission was negatively associated with foreign birth (aPR = 0.2, 95% CI 0.2–0.2). Tuberculosis control efforts should prioritize reducing transmission among higher-risk populations.

Health of Indigenous Peoples

Indigenous populations worldwide are experiencing social, cultural, demographic, nutritional, and psychoemotional changes that have a profound impact on health. Regardless of their geographical location or sociopolitical situation, health indicators are always poorer for indigenous populations than for nonindigenous ones. The determinants of this gap are multiple and interactive, and their analysis requires a biocultural framework. Indigenous populations suffer from lower life expectancy, high infant and child mortality, high maternal morbidity and mortality, heavy infectious disease loads, malnutrition, stunted growth, increasing levels of cardiovascular and other chronic diseases, substance abuse, and depression. The devastating effects of colonization, the loss of ancestral land, and language and cultural barriers for access to health care are among the most salient themes characterizing the poor health situation of indigenous people. Anthropology is extremely well suited to address the interplay among social, economic, and political forces that shape the local experiences of illness.

Death rates from human immunodeficiency virus and tuberculosis among American Indians/Alaska Natives in the United States, 1990-2009

OBJECTIVES

We used race-corrected data and comprehensive diagnostic codes to better compare HIV and tuberculosis (TB) mortality from 1999 to 2009 between American Indian/Alaska Natives (AI/ANs) and Whites.

METHODS

National Vital Statistics Surveillance System mortality data were adjusted for AI/AN racial misclassification through linkage with Indian Health Service registration records. We compared average annual 1990 to 2009 HIV and TB death rates (per 100,000 people) for AI/AN persons with those for Whites; Hispanics were excluded.

RESULTS

Although death rates from HIV in AI/AN persons were significantly lower than those in Whites from 1990 to 1998 (4.2 vs 7.0), they were significantly higher than those in Whites from 1999 to 2009 (3.6 vs 2.0). Death rates from TB in AI/AN persons were significantly higher than those in Whites, with a significant disparity during both 1990 to 1998 (3.3 vs 0.3) and 1999 to 2009 (1.5 vs 0.1).

CONCLUSIONS

The decrease in death rates from HIV and TB was greater among Whites, and death rates remained significantly higher among AI/AN individuals. Public health interventions need to be prioritized to reduce the TB and HIV burden and mortality in AI/AN populations.

Infectious disease mortality among American Indians and Alaska Natives, 1999-2009

OBJECTIVES

We described death rates and leading causes of death caused by infectious diseases (IDs) in American Indian/Alaska Native (AI/AN) persons. Methods. We analyzed national mortality data, adjusted for AI/AN race by linkage with Indian Health Service registration records, for all US counties and Contract Health Service Delivery Area (CHSDA) counties. The average annual 1999 to 2009 ID death rates per 100,000 persons for AI/AN persons were compared with corresponding rates for Whites.

RESULTS

The ID death rate in AI/AN populations was significantly higher than that of Whites. A reported 8429 ID deaths (rate 86.2) in CHSDA counties occurred among AI/AN persons; the rate was significantly higher than the rate in Whites (44.0; rate ratio [RR] = 1.96; 95% confidence interval [CI] = 1.91, 2.00). The rates for the top 10 ID underlying causes of death were significantly higher for AI/AN persons than those for Whites. Lower respiratory tract infection and septicemia were the top-ranked causes. The greatest relative rate disparity was for tuberculosis (RR = 13.51; 95% CI = 11.36, 15.93).

CONCLUSIONS

Health equity might be furthered by expansion of interventions to reduce IDs among AI/AN communities.

Risk for tuberculosis in child contacts. Development and validation of a predictive score

RATIONALE

Contact investigation of persons exposed to tuberculosis (TB) is resource intensive. To date, no clinical prediction rule for TB risk exists for use as a guide during contact investigation.

OBJECTIVES

We sought to develop and validate a simple and easy-to-use predictive score for TB risk, using data routinely available during contact investigation.

METHODS

The derivation cohort consisted of 9,411 children aged 0 to 12 years from 2008 to 2009 national contacts cohort. We used a multivariate Cox proportional hazards model to predict the risk of developing active TB. The validation cohort consisted of 2,405 children from the 2005 national contacts cohort. We calculated area under the receiver operating characteristic curves of the model as well as the predicted risk of TB for contacts with different scores.

MEASUREMENTS AND MAIN RESULTS

An 8-point scoring system was developed, including reaction to tuberculin skin test of the contacts, as well as smear-positivity, residence in high-incidence areas, and sex of the index cases. Area under the receiver operating characteristic curve was 0.872 (95% confidence interval, 0.810-0.935) for the derivation cohort and 0.900 (95% confidence interval, 0.830-0.969) for the validation cohort. The risk of developing active TB within 3 years is 100, 7.8, 4.3, 1.0, 0.7, and 0.2% for contacts with risk scores of 7, 6, 5, 4, 3, and 2, respectively.

CONCLUSIONS

A risk predictive score was developed and validated to identify child contacts aged 0 to 12 years at increased risk for active TB. This predictive score can help to prioritize active case finding or isoniazid preventive therapy among children exposed to TB.

Burden of tuberculosis in indigenous peoples globally: a systematic review

BACKGROUND

The burden of tuberculosis (TB) in the estimated 370 million indigenous peoples worldwide is unknown.

OBJECTIVE

To conduct a literature review to summarize the TB burden in indigenous peoples, identify gaps in current knowledge, and provide the foundation for a research agenda prioritizing indigenous health within TB control.

METHODS

A systematic literature review identified articles published between January 1990 and November 2011 quantifying TB disease burden in indigenous populations worldwide.

RESULTS

Among the 91 articles from 19 countries included in the review, only 56 were from outside Australia, Canada, New Zealand and the United States. The majority of the studies showed higher TB rates among indigenous groups than non-indigenous groups. Studies from the Amazon generally reported the highest TB prevalence and incidence, but select populations from South-East Asia and Africa were found to have similarly high rates of TB. In North America, the Inuit had the highest reported TB incidence (156/100000), whereas the Metis of Canada and American Indians/Alaska Natives experienced rates of <10/100000. New Zealand's Maori and Pacific Islanders had higher TB incidence rates than Australian Aborigines, but all were at greater risk of developing TB than non-indigenous groups.

CONCLUSION

Where data exist, indigenous peoples were generally found to have higher rates of TB disease than non-indigenous peoples; however, this burden varied greatly. The paucity of published information on TB burden among indigenous peoples highlights the need to implement and improve TB surveillance to better measure and understand global disparities in TB rates.

Continuous and discontinuous cigarette smoke exposure differentially affects protective Th1 immunity against pulmonary tuberculosis

Pulmonary tuberculosis (TB), caused by Mycobacterium tuberculosis, is the leading cause of death due to a bacterial pathogen. Emerging epidemiologic evidence suggests that the leading risk factor associated with TB mortality is cigarette smoke exposure. Despite this, it remains poorly understood what is the effect of cigarette smoke exposure on anti-TB immunity and whether its potential detrimental effect can be reversed by cigarette smoking cessation. In our current study, we have investigated the impact of both continuous and discontinuous cigarette smoke exposure on the development of anti-mycobacterial type 1 immunity in murine models. We find that while continuous cigarette smoke exposure severely impairs type 1 immunity in the lung, a short-term smoking cessation allows rapid restoration of anti-mycobacterial immunity. The ability of continuous cigarette smoke exposure to dampen type 1 protective immunity is attributed locally to its affects on innate immune cells in the lung. Continuous cigarette smoke exposure locally, by not systemically, impairs APC accumulation and their production of TNF, IL-12, and RANTES, blunts the recruitment of CD4+IFN-γ+ T cells to the lung, and weakens the formation of granuloma. On the other hand, smoking cessation was found to help restore type 1 immunity by rapidly improving the functionality of lung APCs, enhancing the recruitment of CD4+IFN-γ+ T cells to the lung, and promoting the formation of granuloma. Our study for the first time demonstrates that continuous, but not discontinuous, cigarette smoke exposure severely impedes the lung expression of anti-TB Th1 immunity via inhibiting innate immune activation and lung T cell recruitment. Our findings thus suggest cigarette smoking cessation to be beneficial to the control of pulmonary TB.