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

Norfazilah Ahmad,Mazni Baharom,Rohaya Ramli,Azimatun Noor Aizuddin,Seyed Ehtesham Hasnain

doi:10.1371/journal.pone.0245304

Abstract

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.

Highlights

Tuberculosis (TB) is an infectious disease caused by the tubercle bacilli called Mycobacterium tuberculosis (MTb)
Our study shows that female patients who are Healthcare Worker (HCW) had lower odds for smear-positive pulmonary TB (PTB), which is contrary to previous findings that indicated that HCW workers are at higher risk for TB [15]
Most of the discussion refers to previous studies focusing on PTB, we suggest that this could be the basis for the association with smear-positive PTB among the patients in the present study, where the mechanism warrants further studies

Summary

Introduction

Tuberculosis (TB) is an infectious disease caused by the tubercle bacilli called Mycobacterium tuberculosis (MTb). According to the World Health Organization (WHO), approximately a quarter (1.7 billion) of the world population are latently infected with MTb, where they have a 5–10% lifetime risk of becoming sick or infectious with TB [1]. In 2019, TB caused around 10 million new cases worldwide, with an estimated global incidence of 130 cases per 100 000 population. Malaysia is a moderate burden TB country with an incidence of 92 per 100 000 population [1]. The most common type of TB in Malaysia was PTB (82.2%), and 81.2% of new PTB cases in 2018 were smear-positive PTB [2]. The transmission risk is higher if the index case is sputum smear–positive, and is corresponds to the respiratory secretion bacillary density [3]

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