Gender differentials of pulmonary tuberculosis transmission and reactivation in an endemic area

Current approaches for diagnosis of subclinical pulmonary tuberculosis, clinical implications and future perspectives: a scoping review

INTRODUCTION

Subclinical tuberculosis (TB) is the presence of TB disease among people who are either asymptomatic or have minimal symptoms.

AREAS COVERED

Currently, there are no accurate diagnostic tools and clear treatment approaches for subclinical TB. In this study, a comprehensive literature search was conducted across major databases. This review aimed to uncover the latest advancements in diagnostic approaches, explore their clinical implications, and outline potential future perspectives. While innovative technologies are in development to enable sputum-free TB tests, there remains a critical need for precise diagnostic tools tailored to the unique characteristics of subclinical TB. Given the complexity of subclinical TB, a multidisciplinary approach involving clinicians, microbiologists, epidemiologists, and public health experts is essential. Further research is needed to establish standardized diagnostic criteria and treatment guidelines specifically tailored for subclinical TB, acknowledging the unique challenges posed by this elusive stage of the disease.

EXPERT OPINION

Efforts are needed for the detection, diagnosis, and treatment of subclinical TB. In this review, we describe the importance of subclinical TB, both from a clinical and public health perspective and highlight the diagnostic and treatment gaps of this stage.

Sex-based tuberculosis mortality in Newfoundland, 1900-1949: Implications for populations in transition

OBJECTIVE

During the second epidemiological transition, tuberculosis (TB) is one disease that declined substantially enough to reduce all-cause mortality. Sex-based differences in TB mortality may reveal an important dimension of population health transitions between the urbanizing and rural regions of Newfoundland.

MATERIALS AND METHODS

For the island of Newfoundland, yearly age-standardized sex-based TB mortality rates were calculated using individual death records from 1900 to 1949 (n = 30 393). Multiple linear regression models predict the relative rates (RR) of sex-based mortality and the absolute difference between males and females while controlling for time and region (the urbanizing Avalon Peninsula or rural Newfoundland). Multiple linear regression models also predict the median age at death from TB while controlling for time, region, and sex to assess if TB was shifting to an older adult disease compared to those typically afflicted in ages 20-44.

RESULTS

Female TB mortality was relatively and absolutely higher than males; additionally, RR and absolute differences between male and female mortality were significantly lower in rural Newfoundland than the Avalon Peninsula. Median age at death for males was significantly higher than females, and differences in median age at death increased over time.

DISCUSSION

The historically high prevalence of TB throughout Newfoundland, including domestic, social, and public health responsibilities of women, likely contributed to increased exposure and transmission, leading to higher observed mortality. Sex-based TB outcomes should be considered in the discussion of the progression of the epidemiological transition as dynamic inequalities that do not necessarily fit contemporary generalizations of sex-based TB epidemiology.

Epidemiology of tuberculosis in Kazakhstan: data from the Unified National Electronic Healthcare System 2014-2019

OBJECTIVES

This study aims to estimate tuberculosis (TB) incidence, mortality rates and survival HRs in Kazakhstan, using large-scale administrative health data records during 2014-2019.

DESIGN

A retrospective cohort study.

SETTINGS

Data for patients with TB in Kazakhstan during 2014-2019, reported in the Unified National Electronic Healthcare System.

PARTICIPANTS

Patients with TB in Kazakhstan (ICD-10 (The International Classification of Diseases, 10th revision) codes: A15-A19).

OUTCOME MEASURES

Demographic factors, diagnoses and comorbidities were analysed using descriptive, bivariate and multivariable statistical analyses. TB incidence and mortality rates were calculated, and Cox regression and Kaplan-Meier survival analysis were performed to assess risk factors for survival rates.

RESULTS

Of the 149 122 patients with TB, 91 437 (61%) were males, and 139 931 (94%) had respiratory TB. From 2014 to 2019, TB incidence declined from 227 to 15.2 per 100 000 individuals, while all-cause mortality increased from 8.4 to 15.2 per 100 000. Age-specific TB incidence was lowest for 0-10 years of age and highest for 20 years of age. Being older, man, urban residence versus rural, retired versus employed, having HIV and having diabetes versus no comorbidities were associated with lower survival rates.

CONCLUSION

To date, this is the largest TB published study for Kazakhstan, characterising TB incidence and mortality trends by demographic factors, and risk factors for survival rates. The findings highlight the need for targeted interventions to address the growing burden of TB, particularly among older adults, men, urban residents and those with HIV and diabetes. The study underscores the importance of using administrative health data to inform policy and health system responses to TB in Kazakhstan.

Epidemiological features and temporal trends of HIV-negative tuberculosis burden from 1990 to 2019: a retrospective analysis based on the Global Burden of Disease Study 2019

OBJECTIVE

This study aimed to analyse the burden and temporal trends of tuberculosis (TB) incidence and mortality globally, as well as the association between mortality-to-incidence ratio (MIR) and Socio-Demographic Index (SDI).

DESIGN

A retrospective analysis of TB data from 1990 to 2019 was conducted using the Global Burden of Disease Study database.

RESULTS

Between 1990 and 2019, there was a declining trend in the global incidence and mortality of TB. High SDI regions experienced a higher declining rate than in low SDI regions during the same period. Nearly half of the new patients occurred in South Asia. In addition, there is a sex-age imbalance in the overall burden of TB, with young males having higher incidence and mortality than females. In terms of the three subtypes of TB, drug-sensitive (DS)-TB accounted for more than 90% of the incidents and deaths and experienced a decline over the past 30 years. However, drug-resistant TB (multidrug-resistant (MDR)-TB and extensively drug-resistant (XDR)-TB) showed an overall increasing trend in age-standardised incidence rates and age-standardised mortality rates, with an inflection point after the year 2000. At the regional level, South Asia and Eastern Europe remained a high burden of drug-resistant TB incidence and mortality. Interestingly, a negative correlation was found between the MIR and SDI for TB, including DS-TB, MDR-TB and XDR-TB. Notably, central sub-Saharan Africa had the highest MIR, which indicated a higher-than-expected burden given its level of sociodemographic development.

CONCLUSION

This study provides comprehensive insights into the global burden and temporal trends of TB incidence and mortality, as well as the relationship between MIR and SDI. These findings contribute to our understanding of TB epidemiology and can inform public health strategies for prevention and management.

Risk of mortality and clinical outcomes associated with healthcare delay among patients with tuberculosis

BACKGROUND

To eliminate tuberculosis (TB), World Health Organization (WHO) initiated "The End TB Strategy" with the goal of a 95% reduction in deaths. While many resources are contributed to eradicating TB, a substantial number of TB patients are still unlikely to receive timely treatment. Thus, we aimed to measure healthcare delay and its association with clinical outcomes from 2013 to 2018.

METHODS

We conducted a retrospective cohort study using linked data of the National Tuberculosis Surveillance Registry and the health insurance claims data of South Korea. We included incident TB patients, and healthcare delay was defined as the period between the first medical visit with TB-related symptoms and the initiation of an anti-TB regimen. We described the distribution of healthcare delay, and the study population was classified into two groups with mean as a cutoff. The association between healthcare delay and clinical outcomes (all-cause mortality, pneumonia, progression to multi/extensively drug-resistant, intensive care unit admission, and mechanical ventilation use) was evaluated using the Cox proportional hazard model. Several stratified and sensitivity analyses were also conducted.

RESULTS

Among 39,747 patients with pulmonary TB, mean healthcare delay was 42.3 days and delayed and non-delayed groups, classified by mean (or average), were 10,680 (26.9%) and 29,067 (73.1%), respectively. Healthcare delay was associated with an increased risk of all-cause mortality (HR 1.10, 95% CI 1.03-1.17), pneumonia (HR 1.13, 95% CI 1.09-1.18), and mechanical ventilation use (HR 1.15, 95% CI 1.01-1.32). We also observed the duration-response of healthcare delay. Stratified analyses showed patients with respiratory diseases were at higher risk, and consistent results were observed in sensitivity analyses.

CONCLUSIONS

We observed a substantial number of patients experiencing healthcare delays, and it was associated with the deterioration of clinical outcomes. Our findings suggest that attention from authorities and healthcare professionals is needed to attenuate the preventable burden caused by TB through timely treatment.

Gender differences in tuberculosis patients with comorbidity: A cross-sectional study using national surveillance data and national health insurance claims data in South Korea

The coexistence of tuberculosis and other chronic diseases complicates disease management. Particularly, the lack of information on the difference in the prevalence of chronic diseases in tuberculosis based on age and gender can hinder the establishment of appropriate public health strategies. This study aimed to identify age- and gender-based differences in the prevalence of chronic diseases as comorbidities in patients with tuberculosis. An anonymized data source was established by linking the national health insurance claims data to the Korean national tuberculosis surveillance data from 2014 to 2018. The prevalence of chronic diseases was stratified by gender and age (age groups: ≤64, 65-74, and ≥75 years), and the differences in the prevalence of chronic diseases were analyzed by multinomial logistic regression and classified using the Charlson Comorbidity Index. A total of 148,055 patients with tuberculosis (61,199 women and 86,856 men) were included in this study. Among the patients aged ≥65 years, 48.2% were female and 38.1% were male. In this age group, the probability of chronic disease comorbidity was higher in female patients than in male patients. The prevalence of congestive heart failure and dementia as comorbidities in patients with tuberculosis increased more drastically with age in women than in men. Thus, the present study confirmed gender and age differences in the distribution of comorbidities among patients with tuberculosis. A more comprehensive gender-responsive approach for patients with tuberculosis and chronic diseases is required to alleviate the double burden of infectious diseases and non-communicable diseases in an aging society.

Sex and Gender Differences in Tuberculosis Pathogenesis and Treatment Outcomes

Tuberculosis remains a daunting public health concern in many countries of the world. A consistent observation in the global epidemiology of tuberculosis is an excess of cases of active pulmonary tuberculosis among males compared with females. Data from both humans and animals also suggest that males are more susceptible than females to develop active pulmonary disease. Similarly, male sex has been associated with poor treatment outcomes. Despite this growing body of evidence, little is known about the mechanisms driving sex bias in tuberculosis disease. Two dominant hypotheses have been proposed to explain the predominance of active pulmonary tuberculosis among males. The first is based on the contribution of biological factors, such as sex hormones and genetic factors, on host immunity during tuberculosis. The second is focused on non-biological factors such as smoking, professional exposure, and health-seeking behaviors, known to be influenced by gender. In this chapter, we review the literature regarding these two prevailing hypotheses by presenting human but also experimental animal studies. In addition, we presented studies aiming at examining the impact of sex and gender on other clinical forms of tuberculosis such as latent tuberculosis infection and extrapulmonary tuberculosis, which both appear to have their own specificities in relation to sex. We also highlighted potential intersections between sex and gender in the context of tuberculosis and shared future directions that could guide in elucidating mechanisms of sex-based differences in tuberculosis pathogenesis and treatment outcomes.

Mycobacterium tuberculosis Transmission in High-Incidence Settings-New Paradigms and Insights

Tuberculosis has affected humankind for thousands of years, but a deeper understanding of its cause and transmission only arose after Robert Koch discovered Mycobacterium tuberculosis in 1882. Valuable insight has been gained since, but the accumulation of knowledge has been frustratingly slow and incomplete for a pathogen that remains the number one infectious disease killer on the planet. Contrast that to the rapid progress that has been made in our understanding SARS-CoV-2 (the cause of COVID-19) aerobiology and transmission. In this Review, we discuss important historical and contemporary insights into M. tuberculosis transmission. Historical insights describing the principles of aerosol transmission, as well as relevant pathogen, host and environment factors are described. Furthermore, novel insights into asymptomatic and subclinical tuberculosis, and the potential role this may play in population-level transmission is discussed. Progress towards understanding the full spectrum of M. tuberculosis transmission in high-burden settings has been hampered by sub-optimal diagnostic tools, limited basic science exploration and inadequate study designs. We propose that, as a tuberculosis field, we must learn from and capitalize on the novel insights and methods that have been developed to investigate SARS-CoV-2 transmission to limit ongoing tuberculosis transmission, which sustains the global pandemic.

Male Sex Is Associated With Worse Microbiological and Clinical Outcomes Following Tuberculosis Treatment: A Retrospective Cohort Study, a Systematic Review of the Literature, and Meta-analysis

BACKGROUND

Although the incidence of tuberculosis is higher in men than in women, the relationship of sex with tuberculosis treatment outcomes has not been adequately studied.

METHODS

We performed a retrospective cohort study and a systematic review and meta-analysis of observational studies during the last 10 years to assess sex differences in clinical and microbiological outcomes in tuberculosis.

RESULTS

In our cohort of 2894 Taiwanese patients with drug-susceptible pulmonary tuberculosis (1975 male and 919 female), male patients had higher adjusted hazards of 9-month mortality due to all causes (hazard ratio, 1.43 [95% confidence interval (CI), 1.03-1.98]) and infections (1.70 [1.09-2.64]) and higher adjusted odds of 2-month sputum culture positivity (odds ratio [OR], 1.56 [95% CI, 1.05-2.33]) compared with female patients. Smear positivity at 2 months did not differ significantly (OR, 1.27 [95% CI, .71-2.27]) between the sexes. Among 7896 articles retrieved, 398 were included in our systematic review describing a total of 3 957 216 patients. The odds of all-cause mortality were higher in men than in women in the pooled unadjusted (OR, 1.26 [95% CI, 1.19-1.34]) and adjusted (1.31 [1.18-1.45]) analyses. Men had higher pooled odds of sputum culture (OR, 1.44 [95% CI, 1.14-1.81]) and sputum smear (1.58 [1.41-1.77]) positivity, both at the end of the intensive phase and on completion of treatment.

CONCLUSIONS

Our retrospective cohort showed that male patients with tuberculosis have higher 9-month all-cause and infection-related mortality, with higher 2-month sputum culture positivity after adjustment for confounding factors. In our meta-analysis, male patients showed higher all-cause and tuberculosis-related mortality and higher sputum culture and smear positivity rates during and after tuberculosis treatment.

Combined assessment of tuberculosis case notification rate and infection control at health facilities of Dale districts, Sidama Zone, Southern Ethiopia

Background

Mycobacterium tuberculosis (TB) is the deadliest disease that claims millions of deaths globally. Ethiopia is among the countries heavily hit by the disaster. Despite the effective directly observed treatment and TB infection control (TBIC) measures provided by the world health organization (WHO), the rate of new cases increased daily throughout the country. Healthcare workers (HCWs) are at highest risk serving without having the necessary facility in place while overcrowding of patients exacerbated TB transmission. The study aimed to assess TBIC implementation and analyze case notification rate (CNR) of smear-positive pulmonary TB in the selected health facilities at Dale district, Sidama Zone, Southern Ethiopia.

Methods

Seven health care facilities have been visited in the study area and smear-positive pulmonary TB notification rate was determined retrospectively during the years 2012 to 2014. Data on smear positive test results and demographic characteristics were collected from the TB unit registries. A structured questionnaire, facility survey, and observation checklists were used to assess the presence of TBIC plans at the health care facilities.

Results

The overall case notification rate of smear-positive pulmonary tuberculosis was 5.3% among all 7696 TB suspected patients. The odds of being diagnosed with smear-positive TB were 24% more in males than in females (adj OR = 1.24, 95% CI: (1.22, 1.55). Moreover, in the study area, only 28% of the facilities have been practiced TB infection control and 71% of the facilities assigned a focal person for the TBIC plan. The implementation of environmental control measures in the facilities was ranged between 16–83%. N95 particulate respirators were found only in 14% of the facilities.

Conclusion

TB CNR in Dale district was low. Moreover, implementations of TBIC in Dale district health facilities were poor when the survey was done. Hence, urgent measures should be taken to reverse the burden of TB.

Determining the Prevalence of Rifampicin Resistant Tuberculosis in A Tertiary Care Centre of North India by using Rapid Culture Method and Gene Xpert

The objective of the present study is to find the prevalence of Mycobacterium tuberculosis from respiratory samples like sputum, BAL and pleural fluid, compare conventional LJ culture with rapid culture method i.e Mycobacterium growth indicator tube (MGIT) and to determine the pattern of drug resistance by automated methods i.e Gene Xpert. Respiratory samples were collected in sterile, wide-mouth, disposable, leak proof containers without any preservatives. Specimens were inoculated into MGIT for primary isolation of Mycobacteria. The specimen was processed according to the SOP manual provided by Becton Dickinson Company. The tubes were read for increasing fluorescence by MGIT reader. Reported results only when a MGIT tube was positive by the MGIT reader and smear made from the positive broth is also positive for AFB. For further identification, TBcID card test was put from MGIT positive tube and the result was given accordingly as mentioned in the procedure for TBcID kit insert. Polymerase chain reaction (PCR) was done in all 17 positive cases. The drug sensitivity test (CB-NAAT) was done at State Intermediate Reference Laboratory, Chandan Nagar, Dehradun, Uttrakhand as per RNTCP laboratory operational guidelines. In our study total number of samples received from the clinically suspected cases of pulmonary tuberculosis were 156, out of which 11% were positive and 89% were negative. The predominant age group involved was 51-60 years 24%, followed by 61-70 years 22%. In young children and adolescent age group very less number of samples were received i.e. 0-5%. Out of 17 positive samples, 94.11% (16/17) were detected as sensitive for Rifampicin and 5.89% (1/17) were resistant. On the statistical analysis of our data for MGIT, Positive Predictive Value (PPV) was 29% against Negative Predictive Value (NPV) of 100%. The specificity of MGIT was 92% against a sensitivity of 100%. Culture is still needed for species identification, confirmation and drug susceptibility testing. The diagnostic superiority of MGIT, both in terms of sensitivity and specificity has been proven better as compared to LJ in previous other studies and supported by our study as well. In our study, the diagnostic efficacy of MGIT culture was found to be superior as compared to the conventional LJ culture. The positivity rate was 10.89% (17/156) in MGIT & 3.2% (5/156) in LJ culture.

Self-reported gender differentials in the knowledge of tuberculosis transmission and curative possibility using national representative data in Ghana

Background

Health-seeking behaviour, stigma, and discrimination towards people affected by tuberculosis (TB) are influenced by awareness of the disease. Gender differentials in the diagnosis and treatment of TB have been reported in other settings of the world. However, little is known about the gender differences in the knowledge of TB transmission and curative possibility in Ghana.

Methods

The analysed data were a weighted sample of 9,396 women aged 15–49 years and 4,388 men aged 15–59 years, obtained from the 2014 Ghana Demographic and Health Survey. The dependent variable, correct knowledge regarding TB transmission and cure was derived from questions on the transmission of the disease and the possibility of a cure. A design-based multivariate logistic regression model in Stata 13.0/SE was used to identify the correlates of reporting correct knowledge.

Results

Overall, the mean knowledge score was 6.1±0.9 (maximum = 7). Of the 13,784 respondents, 45.7% (95% CI: 44.0–47.3) reported correct knowledge regarding TB transmission and cure. Men had significantly higher knowledge than women (50.9% versus 43.2%). Misconceptions, including TB transmitted through sharing utensils (13.3%), food (6.9%), touching a person with TB (4.5%), sexual contact (4.1%), and mosquito bites (0.4%) were noted. About 30% (33% women and 25% men) of the total sample would keep the information secret when a household member is affected with TB. In the adjusted analysis, age, gender, education, region, place of residence, wealth quintile, frequency of reading newspaper/magazine, listening to the radio, and watching television were significantly associated with reporting correct knowledge.

Conclusions

There was low knowledge regarding TB transmission and cure. Misconceptions regarding the transmission of TB prevailed among the participants. Gender differential in knowledge was observed. Comparatively, females were less likely to be aware of TB and report correct knowledge regarding TB transmission but were more likely to conceal information when a household member was affected by the disease.

Genetic diversity and primary drug resistance transmission in Mycobacterium tuberculosis in southern Mexico

Tuberculosis is a global human health threat, especially in developing countries. The present study aimed to describe the genetic diversity of Mycobacterium tuberculosis and to measure the transmission rates of primary and acquired resistance. A total of 755 M. tuberculosis isolates from a cohort study of patients with culture-confirmed pulmonary tuberculosis in Orizaba, Veracruz, performed between 1995 and 2010 were genotyped by the 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) method. Drug susceptibility was determined. Logistic regression models were constructed to identify the variables associated with resistance and clusters. The recent transmission index (RTI), the Hunter-Gaston discrimination index (HGDI) for the MIRU-VNTR test and allelic diversity (h) were calculated. The Haarlem and LAM lineages were the most common in the population. A total of 519 isolates were grouped into 128 clusters. The overall drug resistance rate was 19%, isoniazid monoresistance (10%) was the most common, and 3.4% of the isolates were multidrug resistant. Among the 116 isolates resistant to at least one drug, the primary and acquired resistance rates were 81.9% and 18.1%, respectively. Primary resistance was associated with belonging to a cluster (aOR 4.05, 95% CI 1.5-11.2, p = 0.007). Previous treatment history (aOR 9.05, 95% CI 3.6-22.5, p < 0.001) and LAM lineage (aOR 4.25, 95% CI 1.4-12.7, p = 0.010) were associated with multidrug-resistant tuberculosis (MDR-TB). The RTI was 51.7%, and the 24-locus MIRU-VNTR HGDI was 0.98. The alleles with the greatest diversity were 4056-QUB26 (h = 0.84), 2163b-QUB11b (h = 0.79), and 424-Mtub04 (h = 0.72). Primary resistance transmission, high LAM lineage prevalence and its association with MDR-TB represent public health problems. The implementation of molecular tools is needed to improve the existing control surveillance tuberculosis program.

Predictors of mortality in patients with drug-resistant tuberculosis: A systematic review and meta-analysis

BACKGROUND

Even though the lives of millions have been saved in the past decades, the mortality rate in patients with drug-resistant tuberculosis is still high. Different factors are associated with this mortality. However, there is no comprehensive global report addressing these risk factors. This study aimed to determine the predictors of mortality using data generated at the global level.

METHODS

We systematically searched five electronic major databases (PubMed/Medline, CINAHL, EMBASE, Scopus, Web of Science), and other sources (Google Scholar, Google). We used the Joanna Briggs Institute Critical Appraisal tools to assess the quality of included articles. Heterogeneity assessment was conducted using the forest plot and I2 heterogeneity test. Data were analyzed using STATA Version 15. The pooled hazard ratio, risk ratio, and odd's ratio were estimated along with their 95% CIs.

RESULT

After reviewing 640 articles, 49 studies met the inclusion criteria and were included in the final analysis. The predictors of mortality were; being male (HR = 1.25,95%CI;1.08,1.41,I2;30.5%), older age (HR = 2.13, 95%CI;1.64,2.62,I2;59.0%,RR = 1.40,95%CI; 1.26, 1.53, I2; 48.4%) including a 1 year increase in age (HR = 1.01, 95%CI;1.00,1.03,I2;73.0%), undernutrition (HR = 1.62,95%CI;1.28,1.97,I2;87.2%, RR = 3.13, 95% CI; 2.17,4.09, I2;0.0%), presence of any type of co-morbidity (HR = 1.92,95%CI;1.50-2.33,I2;61.4%, RR = 1.61, 95%CI;1.29, 1.93,I2;0.0%), having diabetes (HR = 1.74, 95%CI; 1.24,2.24, I2;37.3%, RR = 1.60, 95%CI;1.13,2.07, I2;0.0%), HIV co-infection (HR = 2.15, 95%CI;1.69,2.61, I2; 48.2%, RR = 1.49, 95%CI;1.27,1.72, I2;19.5%), TB history (HR = 1.30,95%CI;1.06,1.54, I2;64.6%), previous second-line anti-TB treatment (HR = 2.52, 95% CI;2.15,2.88, I2;0.0%), being smear positive at the baseline (HR = 1.45, 95%CI;1.14,1.76, I2;49.2%, RR = 1.58,95%CI;1.46,1.69, I2;48.7%), having XDR-TB (HR = 2.01, 95%CI;1.50,2.52, I2;60.8%, RR = 2.44, 95%CI;2.16,2.73,I2;46.1%), and any type of clinical complication (HR = 2.98, 95%CI; 2.32, 3.64, I2; 69.9%). There are differences and overlaps of predictors of mortality across different drug-resistance categories. The common predictors of mortality among different drug-resistance categories include; older age, presence of any type of co-morbidity, and undernutrition.

CONCLUSION

Different patient-related demographic (male sex, older age), and clinical factors (undernutrition, HIV co-infection, co-morbidity, diabetes, clinical complications, TB history, previous second-line anti-TB treatment, smear-positive TB, and XDR-TB) were the predictors of mortality in patients with drug-resistant tuberculosis. The findings would be an important input to the global community to take important measures.

Assortative social mixing and sex disparities in tuberculosis burden

Globally, men have higher tuberculosis (TB) burden but the mechanisms underlying this sex disparity are not fully understood. Recent surveys of social mixing patterns have established moderate preferential within-sex mixing in many settings. This assortative mixing could amplify differences from other causes. We explored the impact of assortative mixing and factors differentially affecting disease progression and detection using a sex-stratified deterministic TB transmission model. We explored the influence of assortativity at disease-free and endemic equilibria, finding stronger effects during invasion and on increasing male:female prevalence (M:F) ratios than overall prevalence. Variance-based sensitivity analysis of endemic equilibria identified differential progression as the most important driver of M:F ratio uncertainty. We fitted our model to prevalence and notification data in exemplar settings within a fully Bayesian framework. For our high M:F setting, random mixing reduced equilibrium M:F ratios by 12% (95% CrI 0-30%). Equalizing male case detection there led to a 20% (95% CrI 11-31%) reduction in M:F ratio over 10 years-insufficient to eliminate sex disparities. However, this potentially achievable improvement was associated with a meaningful 8% (95% CrI 4-14%) reduction in total TB prevalence over this time frame.

Sex-related differences in smear-positive pulmonary tuberculosis patients in Kuala Lumpur, Malaysia: Prevalence and associated factors

Smear-positive pulmonary tuberculosis (PTB) is more infectious compared to smear-negative PTB and have great significance for epidemiology and infection control. The prevalence of smear-positive PTB rarely affects males and females equally. Hence, we aimed to identify the sex-related differences in the prevalence of smear-positive PTB and its associated factors in Kuala Lumpur, Malaysia. A cross-sectional study was conducted using data from the National Tuberculosis Information System (TBIS) from 1 January, 2015, to 31 December, 2019. The study population was selected using simple random sampling from the list of registered PTB patients in TBIS. The criteria for inclusion were all Malaysian adults aged ≥18 years residing in Kuala Lumpur and registered as PTB in TBIS. Factors associated with smear-positive PTB in male and female patients were determined using multiple logistic regression analysis. Overall prevalence of smear-positive PTB was 68.6%, and male patients predominated (71%). The male:female prevalence ratio of smear-positive PTB was 2.4:1. Male patients who worked as machine operators and elementary workers (adjusted odds ratio (aOR) 2.23, 95% confidence interval (CI) 1.24-4.02, p = 0.007), were self-employed (aOR 2.58, 95% CI 1.46-4.56, p = 0.001), lived in a residence categorized as 'other' (aOR 2.49, 95% CI 1.28-4.86, p = 0.007) and were smokers (aOR 1.37, 95% CI 1.01-1.87, p = 0.045) had higher odds for smear-positive PTB. Meanwhile, female patients with diabetes mellitus had higher odds for smear-positive PTB (aOR 1.92, 95% CI 1.05-3.54, p = 0.035), while female patients who were healthcare workers had lower odds (aOR 0.33, 95% CI 0.12, 0.94, p = 0.039). The prevalence of smear-positive PTB is higher in males compared to females. The factors associated with smear-positive PTB differed based on sex. The current TB control program, especially on smear-positive PTB, should likely be strategized and stratified by sex.

Gender difference in mortality among pulmonary tuberculosis HIV co-infected adults aged 15-49 years in Kenya

Setting

Kenya, 2012–2015

Objective

To explore whether there is a gender difference in all-cause mortality among smear positive pulmonary tuberculosis (PTB)/ HIV co-infected patients treated for tuberculosis (TB) between 2012 and 2015 in Kenya.

Design

Retrospective cohort of 9,026 smear-positive patients aged 15–49 years. All-cause mortality during TB treatment was the outcome of interest. Time to start of antiretroviral therapy (ART) initiation was considered as a proxy for CD4 cell count. Those who took long to start of ART were assumed to have high CD4 cell count.

Results

Of the 9,026 observations analysed, 4,567(51%) and 4,459(49%) were women and men, respectively. Overall, out of the 9,026 patients, 8,154 (90%) had their treatment outcome as cured, the mean age in years (SD) was 33.3(7.5) and the mean body mass index (SD) was 18.2(3.4). Men were older (30% men’ vs 17% women in those ≥40 years, p = <0.001) and had a lower BMI <18.5 (55.3% men vs 50.6% women, p = <0.001). Men tested later for HIV: 29% (1,317/4,567) of women HIV tested more than 3 months prior to TB treatment, as compared to 20% (912/4,459) men (p<0.001). Mortality was higher in men 11% (471/4,459) compared to women 9% (401/4,567, p = 0.004). There was a 17% reduction in the risk of death among women (adjusted HR 0.83; 95% CI 0.72–0.96; p = 0.013). Survival varied by age-groups, with women having significantly better survival than men, in the age-groups 40 years and over (log-rank p = 0.006).

Conclusion

Women with sputum positive PTB/HIV co-infection have a significantly lower risk of all-cause mortality during TB treatment compared to men. Men were older, had lower BMI and tested later for HIV than women.

Prevalence and incidence rate of tuberculosis among HIV-infected patients enrolled in HIV care, treatment, and support program in mainland Tanzania

BACKGROUND

Despite improvements in access to antiretroviral therapy (ART), mortality in people living with human immunodeficiency virus (PLHIV) is still high and primarily attributed to tuberculosis (TB) infection. In Sub-Saharan Africa, approximately 80% of HIV-related mortality cases are associated with TB. Relatively little is known about the incidence of TB among PLHIV in Tanzania and the determinant factors. We report the prevalence and incidence rate of confirmed TB and determine association with selected demographic and program-related factors based on data in the national HIV care and treatment program from 2011 to 2014.

METHODS

We used the Tanzania National AIDS Control Programme database to obtain information on all HIV clients enrolled in the HIV care and treatment program between January 2011 and December 2014. We analyzed retrospective cohort data to assess the prevalence and TB incidence rate per 1000 person-years. A multivariable Cox proportional hazards regression model was used to estimate hazard ratios and 95% confidence intervals for putatively associated factors.

RESULTS

Over 4 years, there were 22,071 confirmed cases of pulmonary TB in 1,323,600 person-years. The overall TB incidence was around 16.7 (95% CI 16.4-16.9) cases per 1000 person-years. The annual incidence rate decreased by 12.4 % from 17.0 (95% CI 16.5-17.4) in 2011 to 14.9 (95% CI 14.5-15.4) in 2014. The TB incidence rate was higher in persons not using ART and in males than in females. The incidence of TB was higher in patients with advanced HIV disease and decreased with increasing age. The overall prevalence of TB was 2.2%, with a peak prevalence of 2.5% in 2013 and was higher among children < 15 years (3.2%) in the same year.

CONCLUSION

The study found an overall decrease in the incidence of TB in PLHIV. Our results emphasize the need for early initiation of ART and the provision of TB preventive therapy for those PLHIV without active TB after intensified TB case-finding.

Nutritional Status of Patients with Tuberculosis and Associated Factors in the Health Centre Region of Burkina Faso

Extreme hunger and poverty remain a significant barrier to maintaining a normal and healthy life, and increase the burden of tuberculosis (TB) in sub-Saharan African countries. The purpose of this study was to assess the prevalence and factors associated with undernutrition among adult patients with TB in Burkina Faso. In the Health Centre Region of Burkina Faso, we conducted a cross-sectional survey with face-to-face interviews of patients aged 15 years and older with TB (n = 302), from March to April 2019. Undernutrition was defined as a body mass index of <18.5 kg/m². Multiple logistic regression analyses were performed to determine the correlates of undernutrition. The prevalence of undernutrition was 35.8%, in which severe, moderate, and mild thinness were 7.7%, 8.9%, and 19.5%, respectively. Low food frequency per day (adjusted odds ratio [aOR] = 3.28, confidence interval [CI]: 1.42–7.55, p = 0.005), human immunodeficiency virus infection (aOR = 6.18, CI: 2.26–16.88, p < 0.001), and diabetes mellitus (aOR = 17.52, 95% CI: 1.88–162.97, p = 0.012) and young age (45–54 years vs. 65 years and older, aOR = 2.93, 95% CI: 1.11–7.70, p = 0.029) were associated with increased odds of undernutrition. We concluded that the assessment of comorbidity and nutritional status should be part of the treatment for adult TB patients.

"Bridging the Gap" Everything that Could Have Been Avoided If We Had Applied Gender Medicine, Pharmacogenetics and Personalized Medicine in the Gender-Omics and Sex-Omics Era

Gender medicine is the first step of personalized medicine and patient-centred care, an essential development to achieve the standard goal of a holistic approach to patients and diseases. By addressing the interrelation and integration of biological markers (i.e., sex) with indicators of psychological/cultural behaviour (i.e., gender), gender medicine represents the crucial assumption for achieving the personalized health-care required in the third millennium. However, ‘sex’ and ‘gender’ are often misused as synonyms, leading to frequent misunderstandings in those who are not deeply involved in the field. Overall, we have to face the evidence that biological, genetic, epigenetic, psycho-social, cultural, and environmental factors mutually interact in defining sex/gender differences, and at the same time in establishing potential unwanted sex/gender disparities. Prioritizing the role of sex/gender in physiological and pathological processes is crucial in terms of efficient prevention, clinical signs’ identification, prognosis definition, and therapy optimization. In this regard, the omics-approach has become a powerful tool to identify sex/gender-specific disease markers, with potential benefits also in terms of socio-psychological wellbeing for each individual, and cost-effectiveness for National Healthcare systems. “Being a male or being a female” is indeed important from a health point of view and it is no longer possible to avoid “sex and gender lens” when approaching patients. Accordingly, personalized healthcare must be based on evidence from targeted research studies aimed at understanding how sex and gender influence health across the entire life span. The rapid development of genetic tools in the molecular medicine approaches and their impact in healthcare is an example of highly specialized applications that have moved from specialists to primary care providers (e.g., pharmacogenetic and pharmacogenomic applications in routine medical practice). Gender medicine needs to follow the same path and become an established medical approach. To face the genetic, molecular and pharmacological bases of the existing sex/gender gap by means of omics approaches will pave the way to the discovery and identification of novel drug-targets/therapeutic protocols, personalized laboratory tests and diagnostic procedures (sex/gender-omics). In this scenario, the aim of the present review is not to simply resume the state-of-the-art in the field, rather an opportunity to gain insights into gender medicine, spanning from molecular up to social and psychological stances. The description and critical discussion of some key selected multidisciplinary topics considered as paradigmatic of sex/gender differences and sex/gender inequalities will allow to draft and design strategies useful to fill the existing gap and move forward.

Older age at first tuberculosis diagnosis is associated with tuberculosis recurrence in HIV-negative persons

SETTING

Tuberculosis (TB) clinic in Durban, South Africa.

OBJECTIVE

To assess the factors associated with TB recurrence among human immunodeficiency virus (HIV) negative adults and children.

DESIGN

We conducted a retrospective longitudinal study from January 2000 to December 2012. We defined recurrence as a TB episode occurring within the study period after treatment completion or cure of a previous episode. We used a multivariable Poisson regression model to assess the factors associated with the number of recurrences among HIV-negative patients.

RESULTS

Among 17 941 patients with known HIV status, 3653 (20%) were HIV-negative; of these, 235 (6%) had one recurrence, 21 (1%) had two recurrences and 4 (0.1%) had three recurrences. The median follow-up time from the end of treatment for the first episode was 3.0 years (interquartile range 1.9-4.2). Age at the first TB episode was significantly associated with the number of TB recurrences: younger patients had the lowest rate of recurrence, with a steady increase in rates until age 40 years, after which rates stabilized.

CONCLUSIONS

TB recurrence rates among HIV-negative patients were higher at increased age at the first TB episode. Further translational studies are needed to clarify the factors that drive multiple TB recurrences in older age, including impaired immunity, the results of which have implications for TB vaccine development.

Morbidity Trends and Risk of Tuberculosis: Mexico 2007-2017

Background

To know the current status of the epidemiological and geographic distribution of tuberculosis and its complication meningeal tuberculosis in Mexico, this work analyzes national surveillance data (ten years) issued by the General Directorate of Epidemiology (GDE).

Methods

An observational and retrospective analysis of monthly and annual reports of pulmonary and meningeal tuberculosis cases from January 2007 to December 2017 was performed on the annual reports issued by the GDE in Mexico. The number of cases and incidence were classified by year, state, age group, gender, and seasons.

Results

A national case distribution map of pulmonary and meningeal tuberculosis incidence was generated. During this period, a total of 184,003 and 3,388 cases were reported with a median of 16,727.5 and 308 cases per year for pulmonary and meningeal tuberculosis diseases, respectively. The number of cases and incidence of pulmonary and meningeal tuberculosis per year showed that male gender presented a continuous increase in both parameters. The geographic analysis of the distribution of cases of tuberculosis showed that states like Guerrero, Tabasco, and Veracruz presented higher means of tuberculosis cases during this period. Northern states had the highest number of cases in the country compared to other states. In Mexico, pulmonary tuberculosis and meningeal tuberculosis are seasonal. Interestingly, cases of meningeal tuberculosis show an increase during October and November (autumn).

Conclusions

In Mexico, during the years 2007-2017, there has been an increase in the proportion of male TB patients. It remains necessary to implement strategies to detect TB in the adult population, especially among men, because tuberculosis could be difficult to recognize in an early stage in the population, and the appearance of resistant strains can cause an increase in the incidence of the disease.

Models for Predicting Time to Sputum Conversion Among Multi-Drug Resistant Tuberculosis Patients in Lagos, South-West Nigeria

Background: Multi-drug resistant tuberculosis (MDR-TB) develops due to problems such as irregular drug supply, poor drug quality, inappropriate prescription, and poor adherence to treatment. These factors allow the development and subsequent transmission of resistant strains of the pathogen. However, due to the chronic nature of MDR-TB, cure models allow us to investigate the covariates that are associated with the long-term effects of time-to-sputum conversion among multi-drug resistant (MDR-TB) tuberculosis individuals. Therefore, this study was designed to develop suitable cure models that can predict time to sputum conversion among MDR-TB patients. Methods: A retrospective clinic-based cohort study was conducted on 413 records of patients who were diagnosed of MDR-TB and met inclusion criteria from April 2012 to October 2016 at the Infectious Disease Hospital, Lagos. The main outcome measure (time-to-sputum conversion) was the time from the date of MDR-TB treatment to the date of specimen collection for the first of two consecutive negative smear and culture taken 30 days apart. The predictor variables of interest include: demographic (age, gender and marital status) and clinical (registration group, number of drugs resistant to at treatment initiation, HIV status, diabetes status, and adherence with medication) characteristics. Kaplan-Meier estimates of a detailed survivorship pattern among the patients were examined using Cox regression models. Mixture Cox cure models were fitted to the main outcome variable using Log-normal, Log-logistic and Weibull models as alternatives to the violation of Proportional Hazard (PH) assumption. Akaike Information Criterion (AIC) was used for models comparison based on different distributions, while the effect of predictors of time to sputum conversion was reported as Hazard Ratio (HR) at α0.05. Results: Age was 36.8 ± 12.7 years, 60.8% were male and 67.6% were married. Majority of the patients (58.4%) converted to sputum negatives. Patients who were resistant to two drugs at treatment initiation had 39% rate of conversion than those resistant to at least three drugs [HR: 1.39; CI: 0.98, 1.98]. The likelihood of sputum conversion time was shorter among non-diabetic patients compared to diabetics [HR: 0.55; CI: 0.24, 0.85]. The overall median time for sputum conversion was 5.5 (IQR: 1.5-11.5). In the cure model, resistance to more drugs at the time of initiation was significantly associated with a longer time to sputum culture conversion for Log normal Cox mixture [2.06 (1.36-3.47)]; Log-logistic Cox mixture cure [2.56(1.85-4.09)]; and Weibull Cox mixture [2.81(1.94-4.19)]. Diabetic patients had a significantly higher sputum conversion rate compared to non-diabetics; Log-normal Cox mixture [2.03(1.17-3.58)]; Log-logistic Cox mixture cure [2.11(1.25-3.82)]; and Weibull Cox mixture [2.02(1.17-3.34)]. However, Log-normal PH model gave the best fit and provided the fitness statistics [(-2LogL: 519.84); (AIC: 1053.68); (BIC: 1078.04)]. The best fitting Log-normal PH model was Y = 1.00X1+2.06X2+0.98X3+2.03X4+ε where Y is time to sputum conversion and Xs are age, number of drugs, adherence, and diabetes status. Conclusion: The models confirmed the presence of some factors related with sputum conversion time in Nigeria. The quantum of drugs resistant at treatment initiation and diabetes status would aid the clinicians in predicting the rate of sputum conversion of patients.

Trends, patterns and causes of respiratory disease mortality among inpatients in Tanzania, 2006-2015

OBJECTIVE

To determine the causes, patterns and trends of respiratory diseases-related deaths in hospitals of Tanzania 2006-2015.

METHODS

Retrospective study involving 39 hospitals. Medical records of patients who died in hospital were retrieved, reviewed and analysed. Sources of data were hospital admission registers, death registers and International Classification of Diseases report forms. Information on demographic characteristics, date of death, the immediate underlying cause of death and co-morbid conditions was collected.

RESULTS

Of the 247 976 deaths reported during the 10-year period, respiratory diseases accounted for 12.92% (n = 32 042). The majority of the respiratory mortality was reported among males (55.9%). Overall median age at death was 31 years with an interquartile range (IQR) of 1-47. Median age at death was significantly higher among males (35 years) than females (28 years) (P < 0.0001). Most deaths (37.8%) occurred in eastern Tanzania. About one-third (31.3%) of all respiratory mortality was reported among under-five children, being among girls than boys (34.3% vs. 28.9%, χ²  = 10.3, P < 0.0001). Adolescent and young adult females (15-29 years) had higher age-standardised mortality rates per 100 000 due respiratory diseases than males. Pneumonia (n = 16 639; 51.9%) and pulmonary tuberculosis (n = 9687; 30.2%) accounted for the majority of deaths due to respiratory diseases. Significantly more females (n = 7665; 54.5%) than males died from pneumonia (n = 8878; 49.8%; χ²  = 8.5, P < 0.0001). By contrast, significantly more males (n = 6024; 34%) than females (n = 3596; 26%; χ²  = 15.5, P < 0.0001) died of tuberculosis. The proportion of death due to tuberculosis declined from 32.8% in 2006-2010 to 7.9% in 2011-2015. However, there was a significant increase in the proportion of death due to pneumonia from 49.6% in 2006-2010 to 53.4% in 2011-2015. Co-morbid conditions contributed to 9.1% (2871/31 628) of all deaths due to respiratory diseases. The most common co-morbid condition was HIV which accounted for 1735 (60.4%) deaths and was more common among males (60.8%; n = 957) than among females (59.7%; n = 764).

CONCLUSIONS

Respiratory diseases account for a substantial proportion of all causes of hospital death in Tanzania. Pneumonia and tuberculosis contribute to more than three quarters of all deaths due to respiratory diseases. Since most major respiratory illnesses are avoidable, it is important to strengthen the capacity of the health delivery system in managing cases of respiratory diseases.

Differential Susceptibility of Male Versus Female Laboratory Mice to Anaplasma phagocytophilum Infection

Human granulocytic anaplasmosis (HGA) is a debilitating, non-specific febrile illness caused by the granulocytotropic obligate intracellular bacterium called Anaplasma phagocytophilum. Surveillance studies indicate a higher prevalence of HGA in male versus female patients. Whether this discrepancy correlates with differential susceptibility of males and females to A. phagocytophilum infection is unknown. Laboratory mice have long been used to study granulocytic anaplasmosis. Yet, sex as a biological variable (SABV) in this model has not been evaluated. In this paper, groups of male and female C57Bl/6 mice that had been infected with A. phagocytophilum were assessed for the bacterial DNA load in the peripheral blood, the percentage of neutrophils harboring bacterial inclusions called morulae, and splenomegaly. Infected male mice exhibited as much as a 1.85-fold increase in the number of infected neutrophils, which is up to a 1.88-fold increase in the A. phagocytophilum DNA load, and a significant increase in spleen size when compared to infected female mice. The propensity of male mice to develop a higher level of A. phagocytophilum infection is relevant for studies utilizing the mouse model. This stresses the importance of including SABV and aligns with the observed higher incidence of infection in male versus female patients.

Sexual dimorphism in bacterial infections

Background

Sex differences are important epidemiological factors that impact in the frequency and severity of infectious diseases. A clear sexual dimorphism in bacterial infections has been reported in both humans and animal models. Nevertheless, the molecular mechanisms involved in this gender bias are just starting to be elucidated. In the present article, we aim to review the available data in the literature that report bacterial infections presenting a clear sexual dimorphism, without considering behavioral and social factors.

Main body

The sexual dimorphism in bacterial infections has been mainly attributed to the differential levels of sex hormones between males and females, as well as to genetic factors. In general, males are more susceptible to gastrointestinal and respiratory bacterial diseases and sepsis, while females are more susceptible to genitourinary tract bacterial infections. However, these incidences depend on the population evaluated, animal model and the bacterial species. Female protection against bacterial infections and the associated complications is assumed to be due to the pro-inflammatory effect of estradiol, while male susceptibility to those infections is associated with the testosterone-mediated immune suppression, probably via their specific receptors. Recent studies indicate that the protective effect of estradiol depends on the estrogen receptor subtype and the specific tissue compartment involved in the bacterial insult, suggesting that tissue-specific expression of particular sex steroid receptors contributes to the susceptibility to bacterial infections. Furthermore, this gender bias also depends on the effects of sex hormones on specific bacterial species. Finally, since a large number of genes related to immune functions are located on the X chromosome, X-linked mosaicism confers a highly polymorphic gene expression program that allows women to respond with a more expanded immune repertoire as compared with men.

Conclusion

Notwithstanding there is increasing evidence that confirms the sexual dimorphism in certain bacterial infections and the molecular mechanisms associated, further studies are required to clarify conflicting data and to determine the role of specific hormone receptors involved in the gender bias of bacterial infections, as well as their potential as therapeutic targets.

Immunoendocrine abnormalities in the male reproductive system during experimental pulmonary tuberculosis

INTRODUCTION

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that mainly affects the lungs. Along the course of pulmonary TB there are remarkable changes in the production of cytokines that cause endocrine changes. So far, it is not known the physiological and histological changes in the male reproductive system during pulmonary TB.

OBJECTIVE

To investigate whether pulmonary TB produces histological alterations of the BALB/c mice reproductive organs, as well as abnormalities in spermatogenesis, serum testosterone concentrations and expression of testicular cytokines.

METHODS

BALB/c mice were infected intratracheally with high dose Mtb strain H37Rv. Groups of six non infected and infected animals were euthanized on days 1, 3, 7, 14, 21, 28, 60, 90 and 120 post-infection. Bacillary loads were determined by counting colony forming units (CFUs) in lungs, testes, prostate and seminal vesicles. Histological sections were obtained from the same organs. Spermatozoids number and quality were assessed by spermatobioscopy. Serum testosterone concentrations were determined by radioimmunoanalysis (RIA) in control and infected mice in each time of sacrifice.

RESULTS

Mtb only grew in lung tissue. Serum androgens showed a trend to decrease in the infected mice compared to the healthy animals, the difference turn into statistically significance at post infection day 120. The weight of the testis was not modified throughout the study, and no histopathological changes were found. However, we detected a significant decrease in the weight of the seminal vesicles and prostate starting at 28 days post-infection. Atrophy of the seminal vesicles and prostate epithelia were significant, beginning after 60 days of infection. Spermatobioscopy revealed hypospermia in the later stages of the disease. We have observed in the testes a local significant disbalance on the cytokine profile (increase of IL-6 and decrease of IL-10 and TGF-b levels) together with a very significant reduction of the body weight during late pulmonary TB.

CONCLUSION

Pulmonary TB affects the histophysiology of the male reproductive system due to hormonal changes, an imbalance of pro-inflammatory cytokine profile, and a wasting syndrome during late disease.

Isoniazid Mono-Resistant Tuberculosis: Impact on Treatment Outcome and Survival of Pulmonary Tuberculosis Patients in Southern Mexico 1995-2010

Background

Isoniazid mono-resistance (IMR) is the most common form of mono-resistance; its world prevalence is estimated to range between 0.0 to 9.5% globally. There is no consensus on how these patients should be treated.

Objective

To describe the impact of IMR tuberculosis (TB) on treatment outcome and survival among pulmonary TB patients treated under programmatic conditions in Orizaba, Veracruz, Mexico.

Materials and Methods

We conducted a prospective cohort study of pulmonary TB patients in Southern Mexico. From 1995 to 2010 patients with acid-fast bacilli or culture proven Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and microbiological evaluation. We included patients who harbored isoniazid mono-resistant (IMR) strains and patients with strains susceptible to isoniazid, rifampicin, ethambutol and streptomycin. All patients were treated following Mexican TB Program guidelines. We performed annual follow-up to ascertain treatment outcome, recurrence, relapse and mortality.

Results

Between 1995 and 2010 1,243 patients with pulmonary TB were recruited; 902/1,243 (72.57%) had drug susceptibility testing; 716 (79.38%) harbored pan-susceptible and 88 (9.75%) IMR strains. Having any contact with a person with TB (adjusted odds ratio (aOR)) 1.85, 95% Confidence interval (CI) 1.15–2.96) and homelessness (adjusted odds ratio (aOR) 2.76, 95% CI 1.08–6.99) were associated with IMR. IMR patients had a higher probability of failure (adjusted hazard ratio (HR) 12.35, 95% CI 3.38–45.15) and death due to TB among HIV negative patients (aHR 3.30. 95% CI 1.00–10.84). All the models were adjusted for socio-demographic and clinical variables.

Conclusions

The results from our study provide evidence that the standardized treatment schedule with first line drugs in new and previously treated cases with pulmonary TB and IMR produces a high frequency of treatment failure and death due to tuberculosis. We recommend re-evaluating the optimal schedule for patients harboring IMR. It is necessary to strengthen scientific research for the evaluation of alternative treatment schedules in similar settings.

The evolution of sex-specific virulence in infectious diseases

Fatality rates of infectious diseases are often higher in men than women. Although this difference is often attributed to a stronger immune response in women, we show that differences in the transmission routes that the sexes provide can result in evolution favouring pathogens with sex-specific virulence. Because women can transmit pathogens during pregnancy, birth or breast-feeding, pathogens adapt, evolving lower virulence in women. This can resolve the long-standing puzzle on progression from Human T-cell Lymphotropic Virus Type 1 (HTLV-1) infection to lethal Adult T-cell Leukaemia (ATL); a progression that is more likely in Japanese men than women, while it is equally likely in Caribbean women and men. We argue that breastfeeding, being more prolonged in Japan than in the Caribbean, may have driven the difference in virulence between the two populations. Our finding signifies the importance of investigating the differences in genetic expression profile of pathogens in males and females.

Many infectious diseases are more likely to progress to serious illness or death in men than in women, which has been attributed to a stronger immune response in women. Here, the authors propose that pathogen transmission from mother to child favours the evolution of lower virulence in women, and argue that the higher risk of HTLV-1 infection progressing to leukaemia in Japanese men is due to prolonged breastfeeding in Japan.

Pulmonary tuberculosis among tribals in India: A systematic review & meta-analysis

Background & objectives:

There has been limited investigation on the prevalence of tuberculosis (TB) in tribal communities in India, a vulnerable section of Indian society. The lack of a population-based estimate prompted us to conduct a meta-analysis of existing studies to provide a single, population-based estimate of the TB prevalence for tribals.

Methods:

Literature search was conducted in PubMed using the keywords - “tuberculosis”, “tribals”, “India”, “prevalence”, and “survey”. References cited in the articles retrieved were also reviewed, and those found relevant were selected. TB prevalence rates estimated by the studies were used for our calculation of a pooled-estimate.

Results:

The pooled estimate, based on the random effects model, was 703 per 100,000 population with a 95 % CI of 386-1011. The associated heterogeneity measures in terms of Cochran's Q was significant (P=0 0.08 <0.1) and I² was moderate at 48 per cent.

Interpretation & conclusions:

The meta-analysis demonstrated a large variability in pulmonary TB prevalence estimates among the different studies with poor representation of the various tribal groups. The moderate level of heterogeneity found across the studies suggests that the pooled-estimate needs to be treated with caution. Our findings also highlight the need to assess the pulmonary TB burden in India.

A 20-year retrospective cohort study of TB infection among the Hill-tribe HIV/AIDS populations, Thailand

Background

A retrospective cohort study was conducted to determine the situation, trend, and factors associated with TB infection, and factors related to the life status among the HIV/AIDS Hill-tribe in Northern Thailand. Hill-tribe people have been migrating to and formed settlements along the Thai border areas for many decades. There are now having 1.6 million people of 6 different groups–Akha, Lahu, Lisu, Hmong, Yao and Keren–each with a specific culture, language and lifestyle. The Hill-tribe becomes a new vulnerable of HIV and TB infections in Thailand.

Methods

A systematic data-reviewing approach was used to identify the information from the rosters of ARV clinics, OPD cards, and laboratory reports from 16 hospitals in Chiang Rai Province, Thailand. The data were collected from the first reported HIV/AIDS case of the Hill-tribe to the end of 2010. A chi-square test and logistic regression models were used to identify associations at the significance level of alpha = 0.05.

Results

A total of 3,130 cases were included in the study. The majority of patients were Akha (46.0 %) followed by Lahu (19.7 %), 54.6 % were males, 44.6 % were 26–35 years old. The major risk factor of HIV infection was sexual intercourse (93.1 %); 23.9 % were still alive at the date of data collection, 30.7 % were diagnosed with pulmonary TB. The Akha Hill-tribe HIV/AIDS individuals had a greater chance of TB infection than did Yao individuals with OR_adj = 1.50 (95 % CI = 1.01-1.92). Females had a greater chance of TB infection than males with OR_adj = 1.33 (95 % CI = 1.11-1.59); being classified as HIV and AIDS groups had a greater chance of TB infection than those asymptomatic group with OR_adj = 11.59 (95 % CI = 7.19-18.71), and OR_adj = 1.71 (95 % CI = 1.03-2.87); and not having received the ARV group had a greater chance of TB infection than those who having received the ARV group with OR_adj = 2.59 (95 % CI = 2.09-3.22). The patients who had been diagnosed with HIV infection during 1990–1995 and 1996–2000 had less chance of TB infection than those who were diagnosed from 2006–2010, with OR_adj = 0.04 (95 % CI = 0.01-0.14) and 0.11 (95 % CI = 0.07-0.17), respectively. Regarding life status; females had a better chance of being still alive at the date of data collection than being males with OR_adj = 1.41 (95 % CI = 1.19-1.66). Those who had a defined route of transmission in the category of “mother-to-child” and “IDU” had a better chance of being still alive compared to those who contracted HIV from “sexual intercourse,” with OR_adj = 2.05 (95 % CI = 1.56-2.18), and OR_adj = 8.45 (95 % CI = 1.55-46.13), respectively.

Conclusions

Thailand needs to create a TB and HIV/AIDS surveillance system for Hill-tribe populations to determine the situation and trend and to develop an appropriate model for providing care at the earlier stage of HIV/AIDS infection to prevent later TB infection.

Association of Pulmonary Tuberculosis and Diabetes in Mexico: Analysis of the National Tuberculosis Registry 2000-2012

BACKGROUND

Tuberculosis (TB) remains a public health problem in Mexico while the incidence of diabetes mellitus type 2 (DM) has increased rapidly in recent years.

OBJECTIVE

To describe the trends of incidence rates of pulmonary TB associated with DM and not associated with DM and to compare the results of treatment outcomes in patients with and without DM.

MATERIALS AND METHODS

We analysed the National Tuberculosis Registry from 2000 to 2012 including patients with pulmonary TB among individuals older than 20 years of age. The association between DM and treatment failure was analysed using logistic regression, accounting for clustering due to regional distribution.

RESULTS

In Mexico from 2000 to 2012, the incidence rates of pulmonary TB associated to DM increased by 82.64%, (p<0.001) in contrast to rates of pulmonary TB rate without DM, which decreased by 26.77%, (p<0.001). Patients with a prior diagnosis of DM had a greater likelihood of failing treatment (adjusted odds ratio, 1.34 (1.11-1.61) p<0.002) compared with patients who did not have DM. There was statistical evidence of interaction between DM and sex. The odds of treatment failure were increased in both sexes.

CONCLUSION

Our data suggest that the growing DM epidemic has an impact on the rates of pulmonary TB. In addition, patients who suffer from both diseases have a greater probability of treatment failure.

Gender-dependent differences in plasma matrix metalloproteinase-8 elevated in pulmonary tuberculosis

Tuberculosis (TB) remains a global health pandemic and greater understanding of underlying pathogenesis is required to develop novel therapeutic and diagnostic approaches. Matrix metalloproteinases (MMPs) are emerging as key effectors of tissue destruction in TB but have not been comprehensively studied in plasma, nor have gender differences been investigated. We measured the plasma concentrations of MMPs in a carefully characterised, prospectively recruited clinical cohort of 380 individuals. The collagenases, MMP-1 and MMP-8, were elevated in plasma of patients with pulmonary TB relative to healthy controls, and MMP-7 (matrilysin) and MMP-9 (gelatinase B) were also increased. MMP-8 was TB-specific (p<0.001), not being elevated in symptomatic controls (symptoms suspicious of TB but active disease excluded). Plasma MMP-8 concentrations inversely correlated with body mass index. Plasma MMP-8 concentration was 1.51-fold higher in males than females with TB (p<0.05) and this difference was not due to greater disease severity in men. Gender-specific analysis of MMPs demonstrated consistent increase in MMP-1 and -8 in TB, but MMP-8 was a better discriminator for TB in men. Plasma collagenases are elevated in pulmonary TB and differ between men and women. Gender must be considered in investigation of TB immunopathology and development of novel diagnostic markers.

Gender disparities in latent tuberculosis infection in high-risk individuals: a cross-sectional study

Male predominance in active tuberculosis (TB) is widely-reported globally. Gender inequalities in socio-cultural status are frequently regarded as contributing factors for disparities in sex in active TB. The disparities of sex in the prevalence of latent TB infection (LTBI) are less frequently investigated and deserve clarification. In this cross-sectional study conducted in a TB endemic area, we enrolled patients at high-risk for LTBI and progression from LTBI to active TB from 2011 to 2012. Diagnosis of LTBI was made by QuantiFERON-TB Gold In-Tube (QFT-GIT). Differences in sex in terms of prevalence of LTBI and clinical predictors for LTBI were investigated. Associations among age, smoking status, and sex disparities in LTBI were also analyzed. A total of 1018 high-risk individuals with definite QFT-GIT results were included for analysis, including 534 males and 484 females. The proportion of LTBI was significantly higher in males than in females (32.6% vs. 25.2%, p = 0.010). Differences in the proportion of LTBI between sexes were most prominent in older patients (age ≥ 55 years). In multivariate analysis, independent clinical factors associated with LTBI were age (p = 0.014), smoking (p = 0.048), and fibro-calcified lesions on chest radiogram (p = 0.009). Male sex was not an independent factor for LTBI (p = 0.88). When stratifying patients according to the smoking status, the proportion of LTBI remained comparable between sexes among smokers and non-smokers. In conclusion, although the proportion of LTBI is higher in men, there is no significant disparity in terms of sex in LTBI among high-risk individuals after adjusting for age, smoking status, and other clinical factors.

Investigating gender disparities in the profile and treatment outcomes of tuberculosis in Ebonyi state, Nigeria

SUMMARY Globally, twice as many men as women are being diagnosed with tuberculosis (TB) annually. Little is known about gender differentials in TB in Africa. A retrospective cohort analysis of routine data was conducted on adult TB patients treated between 2011 and 2012 in two large healthcare facilities in Nigeria. Gender differences in their demographic characteristics and treatment outcomes were analysed accordingly. Of 1668 TB patients enrolled, the male:female ratio was 1.4:1. The mean ages of males and females were 40.2 ± 14.7 and 36.1 ± 14.6 years, respectively (t test 6.62, P < 0.001). Male gender was associated with a higher failure to smear convert after 2 months (21.8% vs. 17.5%, P = 0.06) and 5 months (4.3% vs. 1.5%, P = 0.02) of treatment for smear-positive TB patients. Moreover, men were more likely than women to fail treatment (2.2% vs. 0.7%, P = 0.01). No significant differences exist in the treatment success rates between women and men (78.2% vs. 74.5%, P = 0.08). Adjusted analyses showed significant association between being an urban male and a HIV-infected female with unsuccessful outcome adjusted by socio-demographic and clinical factors. We found that gender disparities exist in TB profile and treatment outcomes in Nigeria and gender-specific strategies are needed to optimize TB management.

Mortality trends and risk of dying from pulmonary tuberculosis in the 7 socioeconomic regions and the 32 States of Mexico, 2000-2009

INTRODUCTION

Tuberculosis (TB) is a world public health problem that still has a high morbidity and mortality rate mainly in countries with significant wealth gaps. Poverty, malnutrition, HIV infection, drug resistance, diabetes and addictions (mainly alcoholism) have been seen to contribute to the persistence of TB as an important health problem in Mexico.

METHODS

Death certificates associated with pulmonary tuberculosis (PTB) for 2000-2009 were obtained from the National Information System of the Secretariat of Health. Rates of mortality nationwide, by state, and by socioeconomic region were calculated. The strength of association between states where individuals resided, socioeconomic regions, and education with mortality from PTB was determined.

RESULTS

Age-adjusted mortality rates per 100,000 inhabitants who died from PTB decreased from 4.1 to 2 between 2000 and 2009. Men (67.7%) presented higher mortality than women (32.3%). Individuals failing to complete elementary education presented a higher risk of dying from PTB (RR 1.08 [95%CI: 1.05-1.12]). The socioeconomic region and the entities with the strongest association were region 1, 5, Chiapas and Baja California. Region 1 in 2007 presented RR 7.34 (95%CI: 5.32-10.13), and region 5 in 2009 had RR 10.08 (95%CI: 6.83-14.88).

CONCLUSIONS

In Mexico, the annual mortality rate from PTB decreased. Men presented higher mortality than women. Individuals failing to complete elementary education showed a higher risk of dying from PTB. The states and regions of Mexico that presented a stronger association with mortality from PTB were Chiapas and Baja California, region 1 and 5.

Barriers and delays in tuberculosis diagnosis and treatment services: does gender matter?

Background. Tuberculosis (TB) remains a global public health problem with known gender-related disparities. We reviewed the quantitative evidence for gender-related differences in accessing TB services from symptom onset to treatment initiation. Methods. Following a systematic review process, we: searched 12 electronic databases; included quantitative studies assessing gender differences in accessing TB diagnostic and treatment services; abstracted data; and assessed study validity. We defined barriers and delays at the individual and provider/system levels using a conceptual framework of the TB care continuum and examined gender-related differences. Results. Among 13,448 articles, 137 were included: many assessed individual-level barriers (52%) and delays (42%), 76% surveyed persons presenting for care with diagnosed or suspected TB, 24% surveyed community members, and two-thirds were from African and Asian regions. Many studies reported no gender differences. Among studies reporting disparities, women faced greater barriers (financial: 64% versus 36%; physical: 100% versus 0%; stigma: 85% versus 15%; health literacy: 67% versus 33%; and provider-/system-level: 100% versus 0%) and longer delays (presentation to diagnosis: 45% versus 0%) than men. Conclusions. Many studies found no quantitative gender-related differences in barriers and delays limiting access to TB services. When differences were identified, women experienced greater barriers and longer delays than men.

The influence of sex steroid hormones in the immunopathology of experimental pulmonary tuberculosis

The relation between men and women suffering pulmonary tuberculosis is 7/3 in favor to males. Sex hormones could be a significant factor for this difference, considering that testosterone impairs macrophage activation and pro-inflammatory cytokines production, while estrogens are proinflammatory mediator’s inducer. The aim of this work was to compare the evolution of tuberculosis in male and female mice using a model of progressive disease. BALB/c mice, male and female were randomized into two groups: castrated or sham-operated, and infected by the intratracheal route with a high dose of Mycobacterium tuberculosis strain H37Rv. Mice were euthanized at different time points and in their lungs were determined bacilli loads, inflammation, cytokines expression, survival and testosterone levels in serum. Non-castrated male mice showed significant higher mortality and bacilli burdens during late disease than female and castrated male animals. Compared to males, females and castrated males exhibited significant higher inflammation in all lung compartments, earlier formation of granulomas and pneumonia, while between castrated and non-castrated females there were not significant differences. Females and castrated males expressed significant higher TNF-α, IFN γ, IL12, iNOS and IL17 than non-castrated males during the first month of infection. Serum Testosterone of males showed higher concentration during late infection. Orchidectomy at day 60 post-infection produced a significant decrease of bacilli burdens in coexistence with higher expression of TNFα, IL-12 and IFNγ. Thus, male mice are more susceptible to tuberculosis than females and this was prevented by castration suggesting that testosterone could be a tuberculosis susceptibility factor.

What patient factors predict physicians' decision not to treat latent tuberculosis infection in tuberculosis contacts?

Objective

The study aimed to determine factors that are associated with physicians’ decision to offer treatment for latent tuberculosis infection (LTBI) in contacts of patients with tuberculosis.

Methods

We performed a nested case-control study in a cohort of contacts of patients with pulmonary tuberculosis who had a tuberculin skin test (TST) ≥ 10 mm. Cases were those who were offered treatment for LTBI. Controls were randomly selected from those who were not offered treatment for LTBI by the reviewing physician. Odds ratios were estimated by multivariate logistic regression.

Results

There were 195 cases and 279 controls. The following factors were significantly (positively or negatively) associated with being offered LTBI treatment in the multivariate analysis: female gender (OR 2.9; 95% CI 1.6–5.5), TST conversion (OR 3.9; 2.0–7.9), TST > 20 mm (OR 4.1; 1.8–9.1, for TST of 21–30 mm and OR 7.9; 2.6–23.8, for TST >30 mm), sputum smear positive index case (OR 12.7; 4.5–36.1), being overseas-born and immigration more than 2 years ago (OR 0.1; 0.06–0.3), being a health care worker (OR 0.2; 0.1–0.6), being a non-household contact of the TB index case (OR 0.3; 0.2–0.6) and age >35 years (OR 0.2; 0.1–0.5 for age 35 to 54.9 years and OR 0.04; 0.01–0.2 for age ≥55 years). Previous BCG vaccine and chest x-ray findings were not significantly associated with physicians’ decision to offer treatment for LTBI.

Conclusions

Most factors that influenced physicians’ decisions on treatment for LTBI were based on evidence of an association with risk of developing TB or risk of having an adverse reaction to treatment for LTBI. However, the decreased likelihood of offering treatment for LTBI to people born overseas, men and health care workers, was apparently not based on any evidence of risk. Efforts should be made to ensure that these groups are given access to treatment for LTBI.

Genome-wide association study of ancestry-specific TB risk in the South African Coloured population

The worldwide burden of tuberculosis (TB) remains an enormous problem, and is particularly severe in the admixed South African Coloured (SAC) population residing in the Western Cape. Despite evidence from twin studies suggesting a strong genetic component to TB resistance, only a few loci have been identified to date. In this work, we conduct a genome-wide association study (GWAS), meta-analysis and trans-ethnic fine mapping to attempt the replication of previously identified TB susceptibility loci. Our GWAS results confirm the WT1 chr11 susceptibility locus (rs2057178: odds ratio = 0.62, P = 2.71e(-06)) previously identified by Thye et al., but fail to replicate previously identified polymorphisms in the TLR8 gene and locus 18q11.2. Our study demonstrates that the genetic contribution to TB risk varies between continental populations, and illustrates the value of including admixed populations in studies of TB risk and other complex phenotypes. Our evaluation of local ancestry based on the real and simulated data demonstrates that case-only admixture mapping is currently impractical in multi-way admixed populations, such as the SAC, due to spurious deviations in average local ancestry generated by current local ancestry inference methods. This study provides insights into identifying disease genes and ancestry-specific disease risk in multi-way admixed populations.

Tuberculin skin test and boosted reactions among newly employed healthcare workers: an observational study

Objective

To evaluate the prevalence of and factors associated with latent tuberculosis infection (LTBI) based on the tuberculin skin test (TST) and to estimate the boosted reaction rate among newly employed healthcare workers (HCWs).

Design

Newly employed HCWs between January 2010 and July 2012 at Severance Hospital in South Korea were enrolled in this study. A one-step TST was conducted before October 2011, and a two-step TST after October 2011.

Results

Of 2132 participants, 778 (36.5%) had positive TST results. Being older (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.06–1.13, P<0.001), male (OR 1.78, 95% CI 1.21–2.62, P = 0.003), rejoining the hospital workforce (OR 1.58, 95% CI 1.04–2.40, P = 0.032), and having a previous history of tuberculosis (TB) (OR 18.21, 95% CI 2.15–154.10, P = 0.008) during the one-step period, and being older (OR 1.15, 95% CI 1.10–1.21, P<0.001) during the two-step period were significantly associated with a positive TST. A two-step TST was performed in 556 HCWs, and a boosted reaction was observed in 79 (14.2%). The induration size on the first TST (5–9-mm group) was the only factor associated with a boosted reaction on the second TST.

Conclusions

The prevalence of LTBI based on the TST among newly employed HCWs was high. The boosted reaction rate on two-step TST was not low; therefore, the use of two-step TST may be necessary for regular monitoring in countries with an intermediate TB burden and a high rate of Bacillus Calmette-Guérin vaccination.

Impact of cigarette smoking on rates and clinical prognosis of pulmonary tuberculosis in Southern Mexico

OBJECTIVES

To examine the relationship between cigarette smoking and incidence and mortality rates of pulmonary tuberculosis (TB) and treatment outcomes.

MATERIALS

From 1995 to 2010, we analyzed data from 1062 patients with TB and from 2001 to 2004, 2951 contacts in Southern Mexico. Patients with acid-fast bacilli or Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and mycobacteriological evaluation and received treatment by the local DOTS program.

RESULTS

Consumers of 1-10 (LS) or 11 or more (HS) cigarettes per day incidence (1.75 and 11.79) and mortality (HS, 17.74) smoker-non-smoker rate ratios were significantly higher for smokers. Smoker population was more likely to experience unfavorable treatment outcomes (HS, adjusted OR 2.36) and retreatment (LS and HS, adjusted hazard ratio (HR) 2.14 and 2.37). Contacts that smoked had a higher probability of developing active TB (HR 2.38) during follow up.

CONCLUSIONS

Results indicate the need of incorporating smoking prevention and cessation, especially among men, into international TB control strategies.

Gender differences in notification rates, clinical forms and treatment outcome of tuberculosis patients under the RNTCP

Introduction:

An increased notification rate of tuberculosis (TB) in men is seen in the SAARC region. In India, the Revised National Tuberculosis Control Programme (RNTCP) detects nearly three times more male than female TB patients. Gender differences have also been reported in the clinical forms of tuberculous disease and in treatment adherence and cure rates in patients undergoing treatment for tuberculosis. The present study was undertaken to find out the sex differences in the notification rates and treatment outcomes of TB patients registered under the RNTCP in a rural tuberculosis unit (TU) in West Bengal.

Materials and Methods:

A retrospective record-based study was carried out among a total of 3605 cases registered under the RNTCP between January 1999 and June 2005. Notification rates of TB, clinical forms of TB and disease treatment outcomes recorded in the registers were analyzed based on genders. Outcomes were defined in accordance with the standard RNTCP definitions. The Z-test for proportion (for comparing differences in proportions), Student t-test (for comparing mean), and χ² test (to see association) were performed for statistical analysis.

Results:

Among the total of 3605 patients, 2498 (69.3%) were male and 1107 (30.7%) were female with a male female ratio of 2.25:1. In patients less than 20 years of age, the notification rates among males and females were similar. In the other age groups, males were more likely to be notified compared to females and the difference was statistically significant. While new smear positive and retreatment cases were significantly more than in males, among females, new smear negative and new extrapulmonary cases were significantly higher. Among the new smear positive patients 89.4% of females were cured compared to 85.8% of males which was again significant statistically (Z=1.70, P<0.05). Male patients outnumbered females in all the unfavorable outcomes like death, failure, and default although none of the differences were statistically significant (P>0.05).

Conclusion:

The present study demonstrates a gender difference in the notification rates, clinical presentations and treatment outcomes of patients with tuberculosis. Integrated research is necessary to find the reasons for these differences. Such studies will be helpful in improving the efficacy of the RNTCP.

Tuberculosis in ageing: high rates, complex diagnosis and poor clinical outcomes

BACKGROUND

worldwide, the frequency of tuberculosis among older people almost triples that observed among young adults.

OBJECTIVE

to describe clinical and epidemiological consequences of pulmonary tuberculosis among older people.

METHODS

we screened persons with a cough lasting more than 2 weeks in Southern Mexico from March 1995 to February 2007. We collected clinical and mycobacteriological information (isolation, identification, drug-susceptibility testing and IS6110-based genotyping and spoligotyping) from individuals with bacteriologically confirmed pulmonary tuberculosis. Patients were treated in accordance with official norms and followed to ascertain treatment outcomes, retreatment, and vital status.

RESULTS

eight hundred ninety-three tuberculosis patients were older than 15 years of age; of these, 147 (16.5%) were 65 years of age or older. Individuals ≥ 65 years had significantly higher rates of recently transmitted and reactivated tuberculosis. Older age was associated with treatment failure (OR=5.37; 95% CI: 1.06-27.23; P=0.042), and death due to tuberculosis (HR=3.52; 95% CI: 1.78-6.96; P<0.001) adjusting for sociodemographic and clinical variables.

CONCLUSIONS

community-dwelling older individuals participate in chains of transmission indicating that tuberculosis is not solely due to the reactivation of latent disease. Untimely and difficult diagnosis and a higher risk of poor outcomes even after treatment completion emphasise the need for specific strategies for this vulnerable group.

Gender differences in treatment outcomes of tuberculosis patients in Taiwan: a prospective observational study

Gender disparities in tuberculosis (TB) cases are reported worldwide, and socio-cultural factors have been proposed as possible causes. To date, gender differences in treatment outcomes of TB patients remain controversial. In this prospective observational study, newly diagnosed, culture-proven TB patients from six hospitals in Taiwan were enrolled for analysis. Gender differences in demographic characteristics and treatment outcomes, including sputum conversion and on-treatment mortality, were analysed accordingly. From January 2007 through to December 2009, a total of 1059 patients were enrolled, including 819 (77.3%) males and 240 (22.7%) females. The ratio of male gender was around 50 ~ 60% in TB patients below 35 years and >80% for those older than 65 years. When compared with the female patients, the male patients were older, more likely to have the habit of smoking, chronic obstructive pulmonary disorder, malignancy and liver cirrhosis, and more likely to present with haemoptysis, body weight loss and pleural effusion. Regarding treatment outcomes, male gender is associated with a lower 2-month sputum culture conversion rate (78.8% vs. 89.3%, p 0.002) and higher on-treatment mortality (21.1% vs. 12.1%, p 0.002). Kaplan-Meier survival analysis demonstrated significantly higher mortality in the men (p 0.005). In multivariate analysis, male gender was an independent risk factor for 2-month sputum culture un-conversion (OR, 1.96; 95% CI, 1.12-3.41). Our findings suggest that male gender is associated with older age, more co-morbidities and worse treatment outcomes. Gender-specific strategies, including active case finding in elderly women and smoking cessation in male patients, are warranted to optimize TB management.