Is it better to be rich in a poor area or poor in a rich area? A multilevel analysis of a case-control study of social determinants of tuberculosis

Neighbourhood factors and tuberculosis incidence in Cape Town: A negative binomial regression and spatial analysis

OBJECTIVES

Although the link between poverty and tuberculosis (TB) is widely recognised, limited studies have investigated the association between neighbourhood factors and TB incidence. Since the factors influencing different episodes of TB might be different, this study focused on the first episode of TB disease (first-episode TB).

METHODS

All first episodes in previously linked and geocoded TB notification data from 2007 to 2015 in Cape Town, South Africa, were aggregated at the neighbourhood level and merged with the 2011 census data. We conducted an ecological study to assess the association between neighbourhood incidence of first-episode TB and neighbourhood factors (total TB burden [all episodes] in the previous year, socioeconomic index, mean household size, mean age, and percentage males) using a negative binomial regression. We also examined the presence of hotspots in neighbourhood TB incidence with the Global Moran's I statistic and assessed spatial dependency in the association between neighbourhood factors and TB incidence using a spatial lag model.

RESULTS

The study included 684 neighbourhoods with a median first-episode TB incidence rate of 114 (IQR: 0-345) per 100,000 people. We found lower neighbourhood socioeconomic index (SEI), higher neighbourhood total TB burden, lower neighbourhood mean household size, and lower neighbourhood mean age were associated with increased neighbourhood first-episode TB incidence. Our findings revealed a hotspot of first-episode TB incidence in Cape Town and evidence of spatial dependency in the association between neighbourhood factors and TB incidence.

CONCLUSION

Neighbourhood TB burden and SEI were associated with first-episode TB incidence, and there was spatial dependency in this association. Our findings can inform targeted interventions to reduce TB in high-risk neighbourhoods, thereby reducing health disparities and promoting health equity.

The environmental and socioeconomic effects of tuberculosis patients in the southwest of China: a population-based study

OBJECTIVE

The objective of this study was to assess the incidence of tuberculosis (TB) and find the risk factors of TB patients with a high burden of TB in socioeconomic level, the high level of TB incidence and the great changes of economic and social factors, explore the possible factors, construct scientific and robust prediction model, and analyse whether the task of stopping TB can be accomplished by the expected global deadline.

STUDY DESIGN

This was an ecological study.

METHODS

Descriptive analysis, spatial and space-time scan, correlation analysis, and regression analysis were carried out, based on cases of TB in Sichuan Province and ecological data from 2006 to 2017, to explore the characters of TB and ecological factors, using the transfer function-noise model to forecast the trend of TB until 2035.

RESULTS

Factors affecting the incidence of TB, increasing per capita green area, reporting status of TB among Tibetans and Yi minorities, comprehensive treatment management, total cost of TB per capita for urban residents, proportion of males with high school education, 20 to 20 h of 24-h accumulated precipitation, reducing HIV at the same time as AIDS deaths, the increase in the proportion of males in junior high school education, and the increase in the number of registered TB cases can reduce the incidence of TB.

CONCLUSIONS

There was concentration mainly on enhanced control of the environment and society measures, helpful in guiding government planning to control TB. Reinforcement is required to reduce the TB of population aged 15-24 and aged 25-64 in socioeconomic level by 2035.

The Relation Between Trace Elements and Latent Tuberculosis Infection: a Study Based on National Health and Nutritional Examination Survey 2011-2012

This study aimed to analyze the potential association between trace elements and latent tuberculosis infection (LTBI) based on the data from the National Health and Nutritional Examination Survey (NHANES) during 2011-2012. In this cross-sectional study, tuberculin skin testing (TST) and QuantiFERON®-TB Gold In-Tube (QFT-GIT) were utilized to screen for LTBI. Participants with positive results of TST or/and QFT-GIT were defined as LTBI. Weighted univariate and multivariate logistic regression analyses were used to explore the association between trace elements and LTBI. Subgroup analyses were conducted according to gender, age, birthplace, race, and health insurance holding status. A total of 6064 participants were included in this study, of whom 655 (10.80%) participants were with positive results of LTBI. Weighted multivariable analysis demonstrated that zinc [odds ratio (OR) = 0.89; 95% confidence interval (CI), 0.82-0.97] and selenium (OR = 0.31; 95%CI, 0.13-0.70) in the serum may be associated with a reduced risk of LTBI. In different concentrations of zinc and selenium, serum zinc concentration of 12.56-13.99 μmol/l (vs. < 11.23 μmol/l; OR = 0.37, 95% CI, 0.20-0.67) was related to a reduced risk of LTBI, while no significant difference was observed under different selenium levels (P > 0.05). Subgroup analyses indicated that the role of zinc and selenium in reducing TB risk may be more significant in males, people aged 21-64, people born in the USA, people with health insurance, and non-Hispanic Whites. Maintaining serum zinc and selenium levels may help reduce the risk of LTBI and indirectly help people prevent TB.

Screening of latent tuberculosis infection among patients with diabetes mellitus from a high-burden area in Brazil

Although several cohort studies have raised the important association between diabetes mellitus (DM) and latent tuberculosis infection (LTBI), evidences are limited and controversial. Furthermore, it is well documented that the poor glycemic control may exacerbate the risk for active TB. Thus, the monitoring of diabetic patients living in high-incidence areas for TB is an important concern in views of available diagnostic tests for LTBI. In this cross-sectional study, we estimate the association of DM and LTBI among diabetic patients classified as type-1 DM (T1D) or type-2 DM (T2D) living in Rio de Janeiro, RJ, Brazil - considered a high TB burden region of these country. Non-DM volunteers were included as endemic area healthy controls. All participants were screened for DM using glycosylated-hemoglobin (HbA_1c) and for LTBI using the QuantiFERON-TB Gold in Tube (QFT-GIT). Demographic, socioeconomic, clinical and laboratorial data were also assessed. Among 553 included participants, 88 (15.9%) had QFT-GIT positive test, of which 18 (20.5%) were non-DM, 30 (34.1%) T1D and 40 (45.4%) T2D. After adjustments for potential baseline confounders, age, self-reported non-white skin color and an active TB case in the family were significantly associated with LTBI among the studied population by using a hierarchical multivariate logistic regression analysis. Additionally, we verified that T2D patients were able to produce significant increased interferon-gamma (IFN-γ) plasma levels in response to Mycobacterium tuberculosis-specific antigens, when compared to non-DM individuals. Altogether, our data showed an increased prevalence of LTBI among DM patients, albeit non-statistically significant, and point out to important independent factors associated with LTBI, which deserve attention in monitoring patients with DM. Moreover, QFT-GIT test seems to be a good tool to screening LTBI in this population, even in a high TB burden area.

Spatial pattern of tuberculosis (TB) and related socio-environmental factors in South Korea, 2008-2016

Tuberculosis (TB) incidence and corresponding mortality rates in S. Korea are unusual and unique compared to other economically developed countries. Korea has the highest TB incidence rate in Organization for Economic Co-operation and Development (OECD) countries. TB is known as a disease reflecting socio-economic and environmental conditions of a society. Besides, TB is an infectious disease spread through the air, naturally forming spatial dependence of its incidence. This study investigates TB incidences in Korea in socio-economic and environmental perspectives. Eigenvector spatial filtering applied accounts for spatial autocorrelation in the TB incidence, and Getis-Ord Gi* statistic tracks the changes of TB clusters at given time. The results show that population composition ratio, population growth rate, health insurance payment, and public health variables are significant throughout the study period. Environmental variables make minor effects on TB incidence. This study argues that unique demographic features of Korea are a potential threat to TB control in the future.

The possible impact of socioeconomic, income, and educational status on adverse effects of drug and their therapeutic episodes in patients targeted with a combination of tuberculosis interventions

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Socio-economic status is very important in patient receiving DOT therapy.

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Income influences disease occurrence as well as adverse events.

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Occupation increases the risk of diseases and results increase risk of adverse events.

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Low income results mal nutrition and increased risk of drug intolerance or adverse events.

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DOTS is an effective treatment strategy for MTB patients.

First-line antituberculosis (anti-TB) compounds have been considered as proven components of the Directly Observed Treatment-Short course (DOTS). Drug therapy against tuberculosis has been categorized as I, II, or III following the Revised National Tuberculosis Control Program guidelines. Anti-TB are drugs are quite common and show limited adverse effects. However, first-line anti-TB compounds mediated DOTS therapy and were found with several complications. Thus, those drugs have been discontinued. Therefore, the present study was designed to find out the possible impact of socioeconomic, income, and educational status on the adverse effects of drugs and their therapeutic episodes in patients targeted with a combination of tuberculosis intervention. This study found that an increased incidence of tuberculosis was found in patients who have finished high school, contributing to a high percentage of adverse effects. Notably, adverse events were shown maximally in poor patients compared with rich- or high-income patients. On the contrary, a high prevalence of adverse events was shown to be increased in partially skilled workers compared with full-skilled workers. Consequently, adversely considerable events were implicated to be raised in patients associated with minimal socioeconomic class. Such interesting factors would help in monitoring such events in experimental patients.

Zika-related adverse outcomes in a cohort of pregnant women with rash in Pernambuco, Brazil

Background

While Zika virus (ZIKV) is now widely recognized as a teratogen, the frequency and full spectrum of adverse outcomes of congenital ZIKV infection remains incompletely understood.

Methods

Participants in the MERG cohort of pregnant women with rash, recruited from the surveillance system from December/2015-June/2017. Exposure definition was based on a combination of longitudinal data from molecular, serologic (IgM and IgG3) and plaque reduction neutralization tests for ZIKV. Children were evaluated by a team of clinical specialists and by transfontanelle ultrasound and were classified as having microcephaly and/or other signs/symptoms consistent with congenital Zika syndrome (CZS). Risks of adverse outcomes were quantified according to the relative evidence of a ZIKV infection in pregnancy.

Findings

376 women had confirmed and suspected exposure to ZIKV. Among evaluable children born to these mothers, 20% presented with an adverse outcome compatible with exposure to ZIKV during pregnancy. The absolute risk of microcephaly was 2.9% (11/376), of calcifications and/or ventriculomegaly was 7.2% (13/180), of additional neurologic alterations was 5.3% (13/245), of ophthalmologic abnormalities was 7% (15/214), and of dysphagia was 1.8% (4/226). Less than 1% of the children experienced abnormalities across all of the domains simultaneously. Interpretation: Although approximately one-fifth of children with confirmed and suspected exposure to ZIKV in pregnancy presented with at least one abnormality compatible with CZS, the manifestations presented more frequently in isolation than in combination. Due to the rare nature of some outcomes and the possibility of later manifestations, large scale individual participant data meta-analysis and the long-term evaluation of children are imperative to identify the full spectrum of this syndrome and to plan actions to reduce damages.

The ability to meaningfully quantify the absolute and relative risks of Congenital Zika Syndrome is contingent on the accurate identification of ZIKV infections in pregnant women and the long-term follow-up of children at risk. This study builds on the evidence base on ZIKV in pregnancy by not only examining pregnancy and birth outcomes, but also considering later onset manifestations of Congenital Zika Syndrome, conducting a deep and standardized investigation of infant outcomes. In addition, it used unprecedented repeated testing and the use of multiple diagnostic platforms, including qRT-PCR, IgM and IgG3 ELISAs, and PRNTs to identify ZIKV cases. The absolute risk of microcephaly was 2.9%, of calcifications and/or ventriculomegaly was 7.2%, of additional neurologic alterations was 5.3%, of ophthalmologic abnormalities was 7% and of dysphagia was 1.8%. The manifestations presented more frequently in isolation than in combination (i.e., less than 1% of the children experienced abnormalities across all of the domains simultaneously). Although approximately one-fifth of children with confirmed and suspected exposure to ZIKV in pregnancy presented with at least one abnormality compatible with CZS, the manifestations presented more frequently in isolation than in combination

The socio-economic distribution of exposure to Ebola: Survey evidence from Liberia and Sierra Leone

Socio-economic factors are widely believed to have been an important driver of the transmission of Ebola Virus Disease (EVD) during the West African outbreak of 2014–16, however, studies that have investigated the relationship between socio-economic status (SES) and EVD have found inconsistent results. Using nationally representative household survey data on whether respondents knew a close friend or family member with Ebola, we explore the SES determinants of EVD exposure along individual, household, and community lines in Liberia and Sierra Leone. While we find no overall association between household wealth and EVD exposure, we find that pooled data mask important differences observed within countries with higher wealth households more likely to have been exposed to EVD in Sierra Leone and the opposite relationship in Liberia. Finally, we also generally find a positive association between education and EVD exposure both at the individual and the community levels in the full sample. There is an urgent need to better understand these relationships to examine both why the outbreak spread and to help prepare for future outbreaks.

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Socio-economic status (SES) was believed to be an important driver of exposure Ebola in the West African outbreak.

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Previous studies of the relationship between SES and Ebola show inconsistent associations.

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We find that higher wealth households were more likely to be exposed to Ebola in Sierra Leone but not Liberia.

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We also find higher SES communities were less likely to have been exposed.

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We also find a positive association with education at the individual and community levels.

[Individual and contextual determinants of infant mortality in Brazilian state capitals: a multilevel approach]

The study sought to identify individual and contextual risk factors in healthcare and their interactions and regional differences in the determination of infant mortality in Brazilian state capitals. This was a case-control study that analyzed 7,470 infant deaths in 2012 in the 27 state capitals, recorded in the Brazilian Mortality Information System (SIM) and matched with the Brazilian Information System on Live Births (SINASC) through linkage and 24,285 controls obtained by sampling the surviving liveborn infants from 2011 to 2012 from the total of 1,424,691 births. The individual explanatory variables corresponded to information available in the SINASC database, and the contextual variable consisted of a quality index for hospital care in the 702 healthcare services where the births occurred. A multilevel logistic model was used to analyze interaction. The principal determinants of infant mortality were biological factors (low birthweight, prematurity, congenital malformations, severe/moderate asphyxia, and race/color), mediated by maternal socioeconomic factors (schooling, marital status, and occupation) and insufficiency of prenatal care. Low number of prenatal visits was a risk factor for infant mortality, independently of the service's quality, except in the state capitals in the South of Brazil. In the interaction between income and prenatal care, few prenatal visits and birth in high-income state capitals showed a higher risk when compared to births in low-income state capitals (OR = 0.68). Multilevel analysis evidenced regional inequalities in the risk models and reiterated the importance of biological determinants in the mediation of socioeconomic and healthcare factors in infant mortality.

Determinants associated with areas with higher tuberculosis mortality rates: an ecological study

OBJECTIVE

To characterise tuberculosis deaths in a region of northeast Brazil during the period from 2006 to 2017 and to identify determinants associated with areas with higher tuberculosis mortality rates.

METHODS

Ecological descriptive study of deaths from tuberculosis with multivariate mapping and logistic regression, carried out from 2006 to 2017 in the 75 municipalities of Sergipe, Brazil. The focus of the analysis was the mean mortality rate from tuberculosis, dichotomised according to the median. The independent variables were selected based on the conceptual model of the social determinants of health.

RESULTS

Mortality due to tuberculosis in Sergipe, Brazil, was most prevalent among males, mixed-race people, and people over 40 years old and with a low level of education. Multivariate logistic regression identified the mean incidence rate for tuberculosis (aOR: 1.06), the proportion of HIV testing (aOR: 7.10), people without primary education and with informal occupation (aOR: 1.26) and people living in urban households without waste collection service (aOR: 0.10) as determinants associated to municipalities with higher tuberculosis mortality rates, with area under the ROC curve of 84% (P-value 0.000). Mapping revealed evident spatial variability.

CONCLUSIONS

The tuberculosis epidemic in Brazil is determined by access to health services, especially the provision of HIV testing among those diagnosed with tuberculosis, accelerated urbanisation with large pockets of poverty and unsanitary housing conditions, corroborating global trends.

Association of social deprivation and outdoor air pollution with pulmonary tuberculosis in spatiotemporal analysis

The objective of this study was to identify the association between social deprivation, outdoor air pollution, and tuberculosis (TB) incidence rate or mortality rate. The study sample comprised 25 districts in Seoul, Korea. We used two public data derived from the Community Health Survey and Seoul Statistics. The geographic information system analysis and random effects Poisson regression were applied to explore the association of social deprivation and air pollution with TB incidence and mortality. An 1 ppb increase in sulfur dioxide (SO₂) concentration was significantly associated with the risk of TB incidence (risk ratio [RR] = 1.046, 95% confidence interval [CI]: 1.028, 1.065). An 1 unit increase in the deprivation index was significantly related to a6% increase in the mortality of TB (RR = 1.063, 95% CI: 1.031, 1.097). : Our results imply that social deprivation and air pollution may affect the different TB outcomes. Effective policy-making for TB control should reflect the differing outcomes between TB incidence and mortality.

Family health and conditional cash transfer in Brazil and its effect on tuberculosis mortality

BACKGROUND

Social protection can reduce poverty and act on the determinants of tuberculosis (TB).

OBJECTIVE

To evaluate the impact of the Family Health Strategy (FHS) and the Bolsa Família Programme on TB-related mortality in Brazil.

METHODS

This was an ecological study in which the units of analysis were Brazilian municipalities between 2001 and 2012. The principal independent variables were the levels of coverage of the primary health care system and the conditional cash transfer programme. The dependent variable was TB mortality rate (obtained from national databases). Descriptive analysis and negative binomial regression based on panel data using fixed-effects models were performed. Crude and adjusted estimates were calculated for continuous and categorical variables.

RESULTS

A high FHS coverage was significantly associated with a reduction in the TB mortality rate (RR 0.80, 95%CI 0.72-0.89). An increase in the coverage of the Brazilian cash transfer programme was significantly associated with a reduction in the TB mortality rate (RR 0.87, 95%CI 0.81-0.96).

CONCLUSION

FHS and the Bolsa Família conditional cash transfer programme had a positive impact on the TB mortality rate in Brazil. Public policies should include economic support combined with health promotion.

Inequality in the global incidence and prevalence of tuberculosis (TB) and TB/HIV according to the human development index

Background: Tuberculosis (TB) is one of the ten leading causes of death, especially in developing countries. We aimed to assess the inequality in the incidence and prevalence of TB and TB/HIV based on the human development index (HDI) globally.

Methods: In this ecological study, the data on the incidence and prevalence of TB, HIV, and TB/HIV co-infection in 168 countries were obtained from the World Health Organization (WHO). The HDI of these countries in 2000, 2005, 2010, and 2015 was also obtained from the United Nations Development Program (UNDP). The concentration index was used to assess the inequality of the incidence and prevalence of TB and TB/HIV based on the HDI globally.

Results: The concentration index for the incidence of TB according to the HDI was -0.32 (95% CI: -0.46, -0.17), -0.36 (95% CI: -0.49, -0.23), -0.37 (95% CI: -0.52, -0.22), and -0.36 (-0.52, -0.21) in 2000, 2005, 2010, and 2015, respectively. The same pattern was observed for the incidence and prevalence of TB/HIV. The results showed that TB and TB/HIV mainly concentrated in countries with a lower HDI.

Conclusion: According to the results of this study, the incidence of TB and TB/HIV and the prevalence of TB/HIV concentrated in the countries with a lower HDI. In addition, inequality in TB and HIV based on the HDI did not change from 2000 to 2015. Therefore, it seems that public health programs, especially in low-income countries, should be revised and the World Health Organization and the United Nations should provide more technical and financial help for these countries.

Tuberculosis incidence inequalities and its social determinants in Manaus from 2007 to 2016

Background

Brazil is among the 30 countries with high-burden of tuberculosis worldwide, and Manaus is the capital with the highest tuberculosis incidence. The accelerated economic and population growth in Manaus in the last 30 years has strengthened the process of social stratification that may result in population groups that are less favored in terms of healthcare and are vulnerable to infection and illness due to tuberculosis. This study aimed to characterize inequalities associated with tuberculosis incidence in relation to the socioeconomic and demographic characteristics of the resident population of Manaus and to identify their determinants from 2007 to 2016.

Methods

An ecological study was conducted using the data from the Diseases Notification Information System. Tuberculosis incidence rates by population characteristics (gender, ethnicity, and socioeconomic level) were calculated for each year, studied, and represented in equiplot charts. To measure the disparity of tuberculosis incidence in the resident population in Manaus, the Gini index of tuberculosis in each neighborhood was calculated based on the incidence rates of the census sectors. A thematic map was constructed to represent the spatial distribution of tuberculosis incidence inequality. Linear regression models were used to identify the relationship between the tuberculosis incidence inequality and its social determinants.

Results

From 2007 to 2016, there was an increase in the tuberculosis incidence in Manaus, together with an increase in incident inequality among genders, ethnic groups, and socioeconomic level. The incidence of tuberculosis inequality was associated with the inequalities of its possible determinants (Gini of the proportion of male population, Gini of the proportion of indigenous population, Gini of the proportion of illiteracy, Gini of income, Gini of the proportion of households connected to the water network, and Gini of the mean number of bathrooms per inhabitant), the per capita income, and the proportion of cases with laboratory confirmation.

Conclusions

Disparities in tuberculosis incidence in the resident population in neighborhoods can be explained by the sociodemographic and economic heterogeneity. Our findings recommend that public policies and tuberculosis control strategies consider differences in the determinants of tuberculosis inequality for the development of specific actions for each population group.

Is there association between human development index and tuberculosis mortality risk? Evidence from a spatial analysis study in the south of Brazil

The goal of this study was to analyse the spatial pattern of tuberculosis (TB) mortality using different approaches, namely: mortality rates (MR), spatial relative risks (RR) and Bayesian rates (Global and Local) and their association with human development index (HDI), Global and its three dimensions: education, longevity and income. An ecological study was developed in Curitiba, Brazil based on data from Mortality Information System (2008-2014). Spatial scan statistics were used to compute RR and identify high-risk clusters. Bivariate Local Indicator of Spatial Associations was used to assess associations. MR ranged between 0 and 25.24/100.000 with a mean (standard deviation) of 1.07 (2.66). Corresponding values for spatial RR were 0-27.46, 1.2 (2.99) and for Bayesian rates (Global and Local) were 0.49-1.66, 0.90 (0.19) and 0-6.59, 0.98 (0.80). High-risk clusters were identified for all variables, except for HDI-income and Global Bayesian rate. Significant negative spatial relations were found between MR and income; between RR and HDI global, longevity and income; and Bayesian rates with all variables. Some areas presented different patterns: low social development/low risk and high risk/high development. These results demonstrate that social development variables should be considered, in mortality due TB.

Socio-economic gradients in prevalent tuberculosis in Zambia and the Western Cape of South Africa

Objective

To describe the associations between socio‐economic position and prevalent tuberculosis in the 2010 ZAMSTAR Tuberculosis Prevalence Survey, one of the first large tuberculosis prevalence surveys in Southern Africa in the HIV era.

Methods

The main analyses used data on 34 446 individuals in Zambia and 30 017 individuals in South Africa with evaluable tuberculosis culture results. Logistic regression was used to estimate adjusted odds ratios for prevalent TB by two measures of socio‐economic position: household wealth, derived from data on assets using principal components analysis, and individual educational attainment. Mediation analysis was used to evaluate potential mechanisms for the observed social gradients.

Results

The quartile with highest household wealth index in Zambia and South Africa had, respectively, 0.55 (95% CI 0.33–0.92) times and 0.70 (95% CI 0.54–0.93) times the adjusted odds of prevalent TB of the bottom quartile. College or university‐educated individuals in Zambia and South Africa had, respectively, 0.25 (95% CI 0.12–0.54) and 0.42 (95% CI 0.25–0.70) times the adjusted odds of prevalent TB of individuals who had received only primary education. We found little evidence that these associations were mediated via several key proximal risk factors for TB, including HIV status.

Conclusion

These data suggest that social determinants of TB remain important even in the context of generalised HIV epidemics.

Risks for tuberculosis in Kazakhstan: implications for prevention

SETTING

Four regions in Kazakhstan where participants were recruited from June 2012 to May 2014.

OBJECTIVE

To examine associations between incarceration history and tobacco, alcohol, and drug consumption, and human immunodeficiency virus (HIV) infection and diabetes mellitus (DM) with TB.

DESIGN

This matched case-control study included 1600 participants who completed a survey on sociodemographics, history of incarceration, tobacco, alcohol and drug use, and HIV and DM diagnosis. Conditional logistic regression analysis was used to examine associations between a TB diagnosis and risk factors.

RESULTS

Participants who had ever smoked tobacco (aOR 1.73, 95%CI 1.23-2.43, P  0.01), ever drank alcohol (aOR 1.41, 95%CI 1.03-1.93, P  0.05), were HIV-positive (aOR 36.37, 95%CI 2.05-646.13, P  0.05) or had DM (aOR 13.96, 95%CI 6.37-30.56, P  0.01) were more likely to have TB.

CONCLUSIONS

The association between TB and tobacco use, alcohol use, HIV and DM in Kazakhstan suggests a need for comprehensive intervention and prevention approaches that also address tobacco and alcohol use, DM and HIV.

Active Case Finding Among Homeless People as a Means of Reducing the Incidence of Pulmonary Tuberculosis in General Population

The incidence of tuberculosis (TB) declined more than two-fold, compared with the national average, in the northeastern region of Poland in the period of 2003-2012. During that time, four programs of active case finding of TB were conducted as part of which a total of 944 homeless individuals were examined and 21 cases of active TB were detected. The objective of the present study was to find out whether the observed beneficial epidemiological trend could be a result of those programs. We addressed the issue of how the active case finding programs in the homeless community affected the TB incidence in the general population using a modified crisscross SIS-type (Susceptible - Infected - Susceptible) model which describes the dynamics of TB spread between the homeless and non-homeless populations. The values calculated from our model proved highly congruent with the actual epidemiological data. Our analysis showed a significant decline in TB incidence within 1 year of completion of each active case finding program. The model shows that each identified and cured case in the homeless community reduced the number of new cases in the general population by 3-4 within 1 year and by up to 20 within 5 years.

High Zika Virus Seroprevalence in Salvador, Northeastern Brazil Limits the Potential for Further Outbreaks

During 2015 to 2016, Brazil reported more Zika virus (ZIKV) cases than any other country, yet population exposure remains unknown. Serological studies of ZIKV are hampered by cross-reactive immune responses against heterologous viruses. We conducted serosurveys for ZIKV, dengue virus (DENV), and Chikungunya virus (CHIKV) in 633 individuals prospectively sampled during 2015 to 2016, including microcephaly and non-microcephaly pregnancies, HIV-infected patients, tuberculosis patients, and university staff in Salvador in northeastern Brazil using enzyme-linked immunosorbent assays (ELISAs) and plaque reduction neutralization tests. Sera sampled retrospectively during 2013 to 2015 from 277 HIV-infected patients were used to assess the spread of ZIKV over time. Individuals were georeferenced, and sociodemographic indicators were compared between ZIKV-positive and -negative areas and areas with and without microcephaly cases. Epidemiological key parameters were modeled in a Bayesian framework. ZIKV seroprevalence increased rapidly during 2015 to 2016, reaching 63.3% by 2016 (95% confidence interval [CI], 59.4 to 66.8%), comparable to the seroprevalence of DENV (75.7%; CI, 69.4 to 81.1%) and higher than that of CHIKV (7.4%; CI, 5.6 to 9.8%). Of 19 microcephaly pregnancies, 94.7% showed ZIKV IgG antibodies, compared to 69.3% of 257 non-microcephaly pregnancies (P = 0.017). Analyses of sociodemographic data revealed a higher ZIKV burden in low socioeconomic status (SES) areas. High seroprevalence, combined with case data dynamics allowed estimates of the basic reproduction number R0 of 2.1 (CI, 1.8 to 2.5) at the onset of the outbreak and an effective reproductive number Reff of <1 in subsequent years. Our data corroborate ZIKV-associated congenital disease and an association of low SES and ZIKV infection and suggest that population immunity caused cessation of the outbreak. Similar studies from other areas will be required to determine the fate of the American ZIKV outbreak.IMPORTANCE The ongoing American Zika virus (ZIKV) outbreak involves millions of cases and has a major impact on maternal and child health. Knowledge of infection rates is crucial to project future epidemic patterns and determine the absolute risk of microcephaly upon maternal ZIKV infection during pregnancy. For unknown reasons, the vast majority of ZIKV-associated microcephaly cases are concentrated in northeastern Brazil. We analyzed different subpopulations from Salvador, a Brazilian metropolis representing one of the most affected areas during the American ZIKV outbreak. We demonstrate rapid spread of ZIKV in Salvador, Brazil, and infection rates exceeding 60%. We provide evidence for the link between ZIKV and microcephaly, report that ZIKV predominantly affects geographic areas with low socioeconomic status, and show that population immunity likely caused cessation of the outbreak. Our results enable stakeholders to identify target populations for vaccination and for trials on vaccine efficacy and allow refocusing of research efforts and intervention strategies.

Determinants of tuberculosis transmission and treatment abandonment in Fortaleza, Brazil

Background

Tuberculosis (TB) remains a public health problem, despite recent achievements in reducing incidence and mortality rates. In Brazil, these achievements were above the worldwide average, but marked by large regional heterogeneities. In Fortaleza (5th largest city in Brazil), the tuberculosis cure rate has been declining and treatment abandonment has been increasing in the past decade, despite a reduction in incidence and an increase in directly observed therapy (DOT). These trends put efforts to eliminate tuberculosis at risk. We therefore sought to determine social and programmatic determinants of tuberculosis incidence and treatment abandonment in Fortaleza.

Methods

We analyzed sociodemographic and clinical data for all new tuberculosis cases notified in the Notifiable Diseases Information System (SINAN) from Fortaleza between 2007 and 2014. We calculated incidence rates for 117 neighborhoods in Fortaleza, assessed their spatial clustering, and used spatial regression models to quantify associations between neighborhood-level covariates and incidence rates. We used hierarchical logistic regression models to evaluate how individual- and neighborhood-level covariates predicted tuberculosis treatment abandonment.

Results

There were 12,338 new cases reported during the study period. Case rates across neighborhoods were significantly positively clustered in two low-income areas close to the city center. In an adjusted model, tuberculosis rates were significantly higher in neighborhoods with lower literacy, higher sewerage access and homicide rates, and a greater proportion of self-reported black residents. Treatment was abandoned in 1901 cases (15.4%), a rate that rose by 71% between 2007 and 2014. Abandonment was significantly associated with many individual sociodemographic and clinical factors. Notably, being recommended for DOT was protective for those who completed DOT, but associated with abandonment for those who did not.

Conclusion

Low socioeconomic status areas have higher tuberculosis rates, and low socioeconomic individuals have higher risk of treatment abandonment, in Fortaleza. Treatment abandonment rates are growing despite the advent of universal DOT recommendations in Brazil. Proactive social policies, and active contact tracing to find missed cases, may help reduce the tuberculosis burden in this setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4435-0) contains supplementary material, which is available to authorized users.

Household crowding as a potential mediator of socioeconomic determinants of tuberculosis incidence in Brazil

Although many studies have identified social conditions associated with tuberculosis, contextual and individual factors have rarely been analysed simultaneously. Consequently, we aimed to identify contextual and individual factors associated with tuberculosis incidence in general population in Brazil in 2010. We also assessed whether household crowding mediates the association between socioeconomic determinants and tuberculosis incidence. Individual data of tuberculosis cases were obtained from 5,565 municipalities in Brazil in 2010 (last year of national census), and merged with contextual variables. The associations were evaluated in a multilevel analysis using negative binomial regression. After adjusting for individual factors (age, sex and race) and geographic region, the following contextual factors were associated with tuberculosis incidence rate: AIDS incidence rate [incidence rate ratio (IRR), 1.21; 95% confidence interval (CI), 1.18–1.24], unemployment rate (IRR, 1.16; 95% CI, 1.13–1.19), Gini coefficient (IRR, 1.05; 95% CI, 1.02–1.08), proportion of inmates (IRR, 1.11; 95% CI, 1.09–1.14), mean per capita household income (IRR, 0.94; 95% CI, 0.91–0.97) and primary care coverage (IRR, 0.94; 95% CI, 0.92–0.96). Inclusion of household crowding in the multivariate model led to a loss of the associations of both Gini coefficient and mean per capita household income. In conclusion, our findings suggest that income inequality and poverty, as determinants of tuberculosis incidence, can be mediated by household crowding. Moreover, prison population can represent a potential social reservoir of tuberculosis in Brazil and should be addressed as a priority for disease control. Finally, the negative association between primary health coverage and tuberculosis incidence highlights the importance of this level of care as a strategy to control this disease.

Tuberculosis as a marker of inequities in the context of socio-spatial transformation

OBJECTIVE

This study aims to analyze the association between the incidence of tuberculosis and different socioeconomic indicators in a territory of intense transformation of the urban space.

METHODS

This is an ecological study, whose analysis units were the neighborhoods of the city of Itaboraí, state of Rio de Janeiro, Brazil. The data have been analyzed by generalized linear models. The response variable was incidence of tuberculosis from 2006 to 2011. The independent variables were the socio-demographic indicators. The spatial distribution of tuberculosis was analyzed with the elaboration of thematic maps.

RESULTS

The results have shown a significant association between the incidence of tuberculosis and variables that reflect different dimensions of living conditions, such as consumer goods, housing conditions and its surroundings, agglomeration of population, and income distribution.

CONCLUSIONS

The disproportionate incidence of tuberculosis in populations with worse living conditions highlights the persistence of socioeconomic determinants in the reproduction of the disease. Different municipal public sectors need to better articulate with local tuberculosis control programs to reduce the social burden of the disease.

Two decades of tuberculosis in a city in Northeastern Brazil: advances and challenges in time and space

INTRODUCTION This study presents two decades of epidemiological data on tuberculosis (TB), in order to understanding the disease profile and its spatiotemporal dynamics. METHODS This descriptive study was performed in the City of Olinda/Pernambuco, Brazil, from 1991-2010, and it analyzed new patients with TB living in the city. We used the χ²-test with a p-value <0.05 to identify differences in trends. Incidence and cluster distribution were identified using spatial scan statistics. RESULTS In total, 6202 new cases were recorded during the two decades. The highest incidence occurred in 1995 (110 cases/100,000 inhabitants), and the lowest occurred in 2009 (65 cases/100,000 inhabitants) (β=-1.44; R²=0.43; p=0.0018). The highest mortality occurred in 1998 (16 deaths/100,000 inhabitants), and the lowest occurred in 2008 (5 deaths/100,000 inhabitants) (β=-0.19; R²=0.17; p=0.07). There was a male predominance (65%), and ages ranged from 20-49 years (65%). There was a substantial increase in the number of patients that were cured after treatment (60% to 67%; p<0.001) as well as those tested for HIV (1.9% to 58.5%; p<0.001). During the first decade, clusters with p-values <0.05 included 29% of the total notified cases, and in the second decade, that percentage was 12%. CONCLUSIONS We observed a decreasing trend in incidence, which was significant, and mortality rates, which was not significant. The increased number of laboratory tests performed reflects advances in surveillance, and a reduction in the proportion of cases in primary clusters suggests, among other things, that the disease is spreading across the region.

Predictors of opportunistic illnesses incidence in post combination antiretroviral therapy era in an urban cohort from Rio de Janeiro, Brazil

Background

Opportunistic illnesses still account for a huge proportion of hospitalizations and deaths among HIV-infected patients in the post combination antiretroviral therapy (cART) era, particularly in middle- and low-income countries. The aim of this study was to assess predictors of the top four most incident opportunistic illnesses (tuberculosis, esophageal candidiasis, cerebral toxoplasmosis and Pneumocystis jiroveci pneumonia) in an HIV clinical cohort from a middle-income country in the post cART era.

Methods

A total of 2835 HIV infected participants aged ≥ 18 years at enrollment were followed from January 2000 to December 2012 until the occurrence of their first opportunistic illness, death or end of study, whichever occurred first. Extended Cox proportional hazards regression models, stratified by use of cART, were fitted to assess predictors of opportunistic illness incidence during follow-up.

Results

The incidence rates of tuberculosis, esophageal candidiasis, cerebral toxoplasmosis and Pneumocystis jiroveci pneumonia were 15.3, 8.6, 6.0, 4.8 per 1000 persons-year, respectively. Disease specific adjusted Cox models showed that presence of an opportunistic illness at enrollment significantly increased disease incidence while higher nadir CD4+ T lymphocyte count had a significant protective effect in patients not in use of cART. Duration of cART use also significantly reduced disease incidence.

Conclusions

Our findings show that, still in the post-cART era, prevention of opportunistic infections can be achieved by preventing immune deterioration by instituting early use of cART. Interventions focusing on early diagnosis and linkage to care in addition to the prompt initiation of cART are essential to reduce the incidence of opportunistic illnesses among HIV infected patients in post-cART era.

School life expectancy and risk for tuberculosis in Europe

OBJECTIVE

This study aims to investigate the effect of country-level school life expectancy on Tuberculosis (TB) incidence to gain further understanding of substantial variation in TB incidence across Europe.

METHODS

An ecological study examined the prospective association between baseline country-level education in 2000 measured by school life expectancy and TB incidence in 2000-2010 in 40 countries of the WHO European region using quantile regression. Subsequently, to validate the ecological associations between education and TB incidence, an individual-level analysis was performed using case-based data in 29 EU/EEA countries from the European Surveillance System (TESSy) and simulating a theoretical control group.

RESULTS

The ecological analysis showed that baseline school life expectancy had a negative prospective association with TB incidence. We observed consistent negative effects of school life expectancy on individuals' TB infections prospectively.

CONCLUSIONS

These findings suggests that country-level education is an important determinant of individual-level TB infection in the region, and in the absence of a social determinants indicator that is routinely collected for reportable infectious diseases, the adoption of country-level education for reportable infectious diseases would significantly advance the field.

Social determinants of nonadherence to tuberculosis treatment in Buenos Aires, Argentina

This study aimed to identify the individual and environmental determinants of nonadherence to tuberculosis (TB) treatment in selected districts in the Buenos Aires Metropolitan Area, in Argentina. We conducted a cross-sectional study using a hierarchical model. Using primary and secondary data, logistic regression was performed to analyze two types of determinants. The likelihood of nonadherence to treatment was greatest among male patients. The following factors led to a greater likelihood of nonadherence to treatment: patients living in a home without running water; head of household without medical insurance; need to use more than one means of transport to reach the health center; place of residence in an area with a high proportion of households connected to the natural gas network; place of residence in an area where a large proportion of families fall below the minimum threshold of subsistence capacity; place of residence in an area where a high proportion of households do not have flushing toilets and basic sanitation. Our results show that social and economic factors - related to both individual and environmental characteristics - influence adherence to TB treatment.

Spatial analysis of the tuberculosis treatment dropout, Buenos Aires, Argentina

OBJECTIVE

Identify spatial distribution patterns of the proportion of nonadherence to tuberculosis treatment and its associated factors.

METHODS

We conducted an ecological study based on secondary and primary data from municipalities of the metropolitan area of Buenos Aires, Argentina. An exploratory analysis of the characteristics of the area and the distributions of the cases included in the sample (proportion of nonadherence) was also carried out along with a multifactor analysis by linear regression. The variables related to the characteristics of the population, residences and families were analyzed.

RESULTS

Areas with higher proportion of the population without social security benefits (p = 0.007) and of households with unsatisfied basic needs had a higher risk of nonadherence (p = 0.032). In addition, the proportion of nonadherence was higher in areas with the highest proportion of households with no public transportation within 300 meters (p = 0.070).

CONCLUSIONS

We found a risk area for the nonadherence to treatment characterized by a population living in poverty, with precarious jobs and difficult access to public transportation.

Spatial and non-spatial determinants of successful tuberculosis treatment outcomes: An implication of Geographical Information Systems in health policy-making in a developing country

This retrospective study aimed to address whether or to what extent spatial and non-spatial factors with a focus on a healthcare delivery system would influence successful tuberculosis (TB) treatment outcomes in Urmia, Iran. In this cross-sectional study, data of 452 new TB cases were extracted from Urmia TB Management Center during a 5-year period. Using the Geographical Information System (GIS), health centers and study subjects' locations were geocoded on digital maps. To identify the statistically significant geographical clusters, Average Nearest Neighbor (ANN) index was used. Logistic regression analysis was employed to determine the association of spatial and non-spatial variables on the occurrence of adverse treatment outcomes. The spatial clusters of TB cases were concentrated in older, impoverished and outskirts areas. Although there was a tendency toward higher odds of adverse treatment outcomes among urban TB cases, this finding after adjusting for distance from a given TB healthcare center did not reach statistically significant. This article highlights effects of spatial and non-spatial determinants on the TB adverse treatment outcomes, particularly in what way the policies of healthcare services are made. Accordingly, non-spatial determinants in terms of low socio-economic factors need more attention by public health policy makers, and then more focus should be placed on the health delivery system, in particular men's health.

Risk factors for tuberculosis in older children and adolescents: a matched case-control study in Recife, Brazil

Background

Tuberculosis is a major disease worldwide and most research focus on risk factors for adults, although there is a marked adolescent peak in incidence. The objective of this study was to identify risk factors for tuberculosis in children aged 7 to 19.

Methods

A case control study matched by age with 169 cases and 477 controls. The study population consisted of adolescents and older children from Recife, Brazil. Cases were individuals diagnosed with tuberculosis in the control programme and controls were selected in the neighborhood of cases. Conditional logistic regression was used to identify risk factors.

Results

Cigarette smoking increased by 50% the risk of tuberculosis but that this was not statistically significant (OR = 1.6). Other risk factors were sleeping in the same house as a case of tuberculosis (OR = 31.6), living in a house with no piped water (OR = 7.7) (probably as a proxy for bad living conditions), illiteracy (OR = 3.7) and male sex (OR = 1.8). The increase in risk with living in houses with no piped water was much more marked in males. The proportion of cases of tuberculosis attributed to contact with someone with TB was 38% and to illiteracy, lack of piped water and smoking, 20%.

Conclusion

Household contact with tuberculosis, social factors and male sex play the biggest role in determining risk of TB disease among children and adolescents in the study. We recommend further research on the relationship of cigarette smoking on tuberculosis in adolescents, and on whether the sex differentials are more marked in bad living conditions. Separate studies should be conducted in older children and in adolescents.

Neighborhood socioeconomic position and tuberculosis transmission: a retrospective cohort study

Background

Current understanding of tuberculosis (TB) genotype clustering in the US is based on individual risk factors. This study sought to identify whether area-based socioeconomic status (SES) was associated with genotypic clustering among culture-confirmed TB cases.

Methods

A retrospective cohort analysis was performed on data collected on persons with incident TB in King County, Washington, 2004–2008. Multilevel models were used to identify the relationship between area-level SES at the block group level and clustering utilizing a socioeconomic position index (SEP).

Results

Of 519 patients with a known genotyping result and block group, 212 (41%) of isolates clustered genotypically. Analyses suggested an association between lower area-based SES and increased recent TB transmission, particularly among US-born populations. Models in which community characteristics were measured at the block group level demonstrated that lower area-based SEP was positively associated with genotypic clustering after controlling for individual covariates. However, the trend in higher clustering odds with lower SEP index quartile diminished when additional block-group covariates.

Conclusions

Results stress the need for TB control interventions that take area-based measures into account, with particular focus on poor neighborhoods. Interventions based on area-based characteristics, such as improving case finding strategies, utilizing location-based screening and addressing social inequalities, could reduce recent rates of transmission.

The effects of socioeconomic status, clinical factors, and genetic ancestry on pulmonary tuberculosis disease in northeastern Mexico

Diverse socioeconomic and clinical factors influence susceptibility to tuberculosis (TB) disease in Mexico. The role of genetic factors, particularly those that differ between the parental groups that admixed in Mexico, is unclear. The objectives of this study are to identify the socioeconomic and clinical predictors of the transition from latent TB infection (LTBI) to pulmonary TB disease in an urban population in northeastern Mexico, and to examine whether genetic ancestry plays an independent role in this transition. We recruited 97 pulmonary TB disease patients and 97 LTBI individuals from a public hospital in Monterrey, Nuevo León. Socioeconomic and clinical variables were collected from interviews and medical records, and genetic ancestry was estimated for a subset of 142 study participants from 291,917 single nucleotide polymorphisms (SNPs). We examined crude associations between the variables and TB disease status. Significant predictors from crude association tests were analyzed using multivariable logistic regression. We also compared genetic ancestry between LTBI individuals and TB disease patients at 1,314 SNPs in 273 genes from the TB biosystem in the NCBI BioSystems database. In crude association tests, 12 socioeconomic and clinical variables were associated with TB disease. Multivariable logistic regression analyses indicated that marital status, diabetes, and smoking were independently associated with TB status. Genetic ancestry was not associated with TB disease in either crude or multivariable analyses. Separate analyses showed that LTBI individuals recruited from hospital staff had significantly higher European genetic ancestry than LTBI individuals recruited from the clinics and waiting rooms. Genetic ancestry differed between individuals with LTBI and TB disease at SNPs located in two genes in the TB biosystem. These results indicate that Monterrey may be structured with respect to genetic ancestry, and that genetic differences in TB susceptibility in parental populations may contribute to variation in disease susceptibility in the region.

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.

Association between socioeconomic position and tuberculosis in a large population-based study in rural Malawi

SETTING

There is increasing interest in social structural interventions for tuberculosis. The association between poverty and tuberculosis is well established in many settings, but less clear in rural Africa. In Karonga District, Malawi, we found an association between higher socioeconomic status and tuberculosis from 1986-1996, independent of HIV status and other factors.

OBJECTIVE

To investigate the relationship in the same area in 1997-2010.

DESIGN

All adults in the district with new laboratory-confirmed tuberculosis were included. They were compared with community controls, selected concurrently and frequency-matched for age, sex and area.

RESULTS

1707 cases and 2678 controls were interviewed (response rates >95%). The odds of TB were increased in those working in the cash compared to subsistence economy (p<0.001), and with better housing (p-trend=0.006), but decreased with increased asset ownership (p-trend=0.003). The associations with occupation and housing were partly mediated by HIV status, but remained significant.

CONCLUSION

Different socioeconomic measures capture different pathways of the association between socioeconomic status and tuberculosis. Subsistence farmers may be relatively unexposed whereas those in the cash economy travel more, and may be more likely to come forward for diagnosis. In this setting "better houses" may be less well ventilated and residents may spend more time indoors.

Epidemiology of pulmonary tuberculosis in Wenchuan earthquake stricken area: population-based study

OBJECTIVES

To explore spatio-temporal distribution and associated factors of pulmonary tuberculosis in Wenchuan earthquake stricken area.

METHODS

Case count, county's location, demographic, health, and social economics data were collected. Longitudinal multilevel model of extra-Poisson and spatial clustering analysis Besag and Newell's method were used.

RESULTS

The incidence rate decreased from 117.59 to 81.04/100,000, and the associated factors included time, latitude of the county, proportion of people aged no more than 29 years, and the disaster-affected severity of the county. The temporal distribution of mortality rate was parabolic, with a summit in 2008. The associated factors included time, whether or not the county is minority inhabited area, and the disaster-affected severity of the county. Two clustered regions of incidence rate were detected with little variations before and after the quake, which were Aba-Ganzi region and Liangshan-Leshan border region. The clustered regions of mortality rate detected were five counties located in Aba-Ganzi region in 2008, and no cluster was detected during other years.

CONCLUSIONS

Tuberculosis epidemiology demonstrates a special spatio-temporal distribution pattern. Wenchuan earthquake has effects especially on mortality rate. Natural, demographic, and social factors also contribute.

Tuberculosis and poverty: why are the poor at greater risk in India?

Background

Although poverty is widely recognized as an important risk factor for tuberculosis (TB) disease, the specific proximal risk factors that mediate this association are less clear. The objective of our study was to investigate the mechanisms by which poverty increases the risk of TB.

Methods

Using individual level data from 198,754 people from the 2006 Demographic Health Survey (DHS) for India, we assessed self-reported TB status, TB determinants and household socioeconomic status. We used these data to calculate the population attributable fractions (PAF) for each key TB risk factor based on the prevalence of determinants and estimates of the effect of these risk factors derived from published sources. We conducted a mediation analysis using principal components analysis (PCA) and regression to demonstrate how the association between poverty and TB prevalence is mediated.

Results

The prevalence of self-reported TB in the 2006 DHS for India was 545 per 100,000 and ranged from 201 in the highest quintile to 1100 in the lowest quintile. Among those in the poorest population, the PAFs for low body mass index (BMI) and indoor air pollution were 34.2% and 28.5% respectively. The PCA analysis also showed that low BMI had the strongest mediating effect on the association between poverty and prevalent TB (12%, p = 0.019).

Conclusion

TB control strategies should be targeted to the poorest populations that are most at risk, and should address the most important determinants of disease—specifically low BMI and indoor air pollution.

Tuberculosis in Kazakhstan: analysis of risk determinants in national surveillance data

BACKGROUND

Development of tuberculosis (TB) is determined by various risk factors and the interactions of temporal and spatial distributions. The aim of this study was to identify the most salient risk factors for TB disease as well as multidrug resistant TB (MDR-TB) at the oblast (provincial) level in Kazakhstan.

METHODS

Correlational and descriptive analyses were conducted at the oblast and national level using data provided by the country's National Institute of Geography (NIG) and the National Tuberculosis Program (NTP). Reported incident case notification rates (CNRs) and prevalence vary by oblast, thus the study investigated which determinants contributed to this regional variation and compared burdens among oblasts.

RESULTS

The results showed that while tuberculosis CNRs decreased over the study period, MDR-TB conversely increased. Two oblasts -Atyrauskaya and Mangystauskaya - presented especially significant anomalies with large decreases in TB incident CNRs coupled with comparatively large increases in MDR-TB incident CNRs.

CONCLUSION

Understanding the distribution of TB and MDR-TB cases and associated risk factors, especially the "unknown risk factor" categorization points to the need for future research.

Socio economic position in TB prevalence and access to services: results from a population prevalence survey and a facility-based survey in Bangladesh

BACKGROUND

In Bangladesh DOTS has been provided free of charge since 1993, yet information on access to TB services by different population group is not well documented. The objective of this study was to assess and compare the socio economic position (SEP) of actively detected cases from the community and the cases being routinely detected under National Tuberculosis Control Programme (NTP) in Bangladesh.

METHODS AND FINDINGS

SEP was assessed by validated asset item for each of the 21,427 households included in the national tuberculosis prevalence survey 2007-2009. A principal component analysis generated household scores and categorized in quartiles. The distribution of 33 actively identified cases was compared with the 240 NTP cases over the identical SEP quartiles to evaluate access to TB services by different groups of the population. The population prevalence of tuberculosis was 5 times higher in the lowest quartiles of population (95.4, 95% CI: 48.0-189.7) to highest quartile population (19.5, 95% CI: 6.9-55.0). Among the 33 cases detected during survey, 25 (75.8%) were from lower two quartiles, and the rest 8 (24.3%) were from upper two quartiles. Among TB cases detected passively under NTP, more than half of them 137 (57.1%) were from uppermost two quartiles, 98 (41%) from the second quartile, and 5 (2%) in the lowest quartile of the population. This distribution is not affected when adjusted for other factors or interactions among them.

CONCLUSIONS

The findings indicate that despite availability free of charge, DOTS is not equally accessed by the poorer sections of the population. However, these figures should be interpreted with caution since there is a need for additional studies that assess in-depth poverty indicators and its determinants in relation to access of the TB services provided in Bangladesh.

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

OBJECTIVES

We examined trends and epidemiology of tuberculosis (TB) across racial/ethnic groups to better understand TB disparities in the United States, with particular focus on American Indians/Alaska Natives (AI/ANs) and Native Hawaiians/other Pacific Islanders (NH/PIs).

METHODS

We analyzed cases in the U.S. National Tuberculosis Surveillance System and calculated TB case rates among all racial/ethnic groups from 2003 to 2008. Socioeconomic and health indicators for counties in which TB cases were reported came from the Health Resources and Services Administration Area Resource File.

RESULTS

Among the 82,836 TB cases, 914 (1.1%) were in AI/ANs and 362 (0.4%) were in NH/PIs. In 2008, TB case rates for AI/ANs and NH/PIs were 5.9 and 14.7 per 100,000 population, respectively, rates that were more than five and 13 times greater than for non-Hispanic white people (1.1 per 100,000 population). From 2003 to 2008, AI/ANs had the largest percentage decline in TB case rates (-27.4%) for any racial/ethnic group, but NH/PIs had the smallest percentage decline (-3.5%). AI/ANs were more likely than other racial/ethnic groups to be homeless, excessively use alcohol, receive totally directly observed therapy, and come from counties with a greater proportion of people living in poverty and without health insurance. A greater proportion of NH/PIs had extrapulmonary disease and came from counties with a higher proportion of people with a high school diploma.

CONCLUSIONS

There is a need to develop flexible TB-control strategies that address the social determinants of health and that are tailored to the specific needs of AI/ANs and NH/PIs in the U.S.

The association between household socioeconomic position and prevalent tuberculosis in Zambia: a case-control study

Background

Although historically tuberculosis (TB) has been associated with poverty, few analytical studies from developing countries have tried to: 1. assess the relative impact of poverty on TB after the emergence of HIV; 2. explore the causal mechanism underlying this association; and 3. estimate how many cases of TB could be prevented by improving household socioeconomic position (SEP).

Methods and Findings

We undertook a case-control study nested within a population-based TB and HIV prevalence survey conducted in 2005–2006 in two Zambian communities. Cases were defined as persons (15+ years of age) culture positive for M. tuberculosis. Controls were randomly drawn from the TB-free participants enrolled in the prevalence survey. We developed a composite index of household SEP combining variables accounting for four different domains of household SEP. The analysis of the mediation pathway between household SEP and TB was driven by a pre-defined conceptual framework. Adjusted Population Attributable Fractions (aPAF) were estimated.

Prevalent TB was significantly associated with lower household SEP [aOR = 6.2, 95%CI: 2.0–19.2 and aOR = 3.4, 95%CI: 1.8–7.6 respectively for low and medium household SEP compared to high]. Other risk factors for prevalent TB included having a diet poor in proteins [aOR = 3.1, 95%CI: 1.1–8.7], being HIV positive [aOR = 3.1, 95%CI: 1.7–5.8], not BCG vaccinated [aOR = 7.7, 95%CI: 2.8–20.8], and having a history of migration [aOR = 5.2, 95%CI: 2.7–10.2]. These associations were not confounded by household SEP. The association between household SEP and TB appeared to be mediated by inadequate consumption of protein food. Approximately the same proportion of cases could be attributed to this variable and HIV infection (aPAF = 42% and 36%, respectively).

Conclusions

While the fight against HIV remains central for TB control, interventions addressing low household SEP and, especially food availability, may contribute to strengthen our control efforts.

Successes and failures in the control of infectious diseases in Brazil: social and environmental context, policies, interventions, and research needs

Despite pronounced reductions in the number of deaths due to infectious diseases over the past six decades, infectious diseases are still a public health problem in Brazil. In this report, we discuss the major successes and failures in the control of infectious diseases in Brazil, and identify research needs and policies to further improve control or interrupt transmission. Control of diseases such as cholera, Chagas disease, and those preventable by vaccination has been successful through efficient public policies and concerted efforts from different levels of government and civil society. For these diseases, policies dealt with key determinants (eg, the quality of water and basic sanitation, vector control), provided access to preventive resources (such as vaccines), and successfully integrated health policies with broader social policies. Diseases for which control has failed (such as dengue fever and visceral leishmaniasis) are vector-borne diseases with changing epidemiological profiles and major difficulties in treatment (in the case of dengue fever, no treatment is available). Diseases for which control has been partly successful have complex transmission patterns related to adverse environmental, social, economic, or unknown determinants; are sometimes transmitted by insect vectors that are difficult to control; and are mostly chronic diseases with long infectious periods that require lengthy periods of treatment.