In 2017, more than half of the global burden of incident tuberculosis (TB) came from the Western Pacific region. In Lao People’s Democratic Republic (PDR), the high rates of tobacco use and use of polluting biomass fuels for cooking (e.g., wood, charcoal, crop waste, dung) represent significant risk factors for TB. The purpose of this study was to determine the association between self-reported (1) smoking and TB; and (2) exposure to air pollution (from both cooking fires and environmental tobacco smoke) and TB among adults in Lao PDR. We analyzed data from the 2012 National Adult Tobacco Survey (NATSL) of Lao PDR—a multi-stage stratified cluster sample of 9706 subjects from 2822 households located in all 17 provinces. Utilizing a nationally representative sample and inferential, multivariable methods, we observed a significant increase in odds of self-reported TB among those who smoked tobacco (OR = 1.73, 95% CI = (1.00 to 2.98)). Larger multivariable models identified independent contributions from exposure to tobacco pipes (OR = 21.51, 95% CI = (6.34 to 72.89)) and communal outdoor fires (OR = 2.27, 95% CI = (1.15 to 4.49)). An index measuring combined exposure to smoked tobacco, environmental tobacco smoke in enclosed workspace, indoor cooking fire, trash fires, and other outdoor communal fires also showed a positive association (OR per added exposure = 1.47, 95% CI = (1.14 to 1.89)). The findings of this study underscore the need for multi-sectoral collaboration between tobacco control, environmental health, TB prevention and treatment programs, national authorities, policy makers, civil groups, and the private sector to address the convergence of potential risk factors impacting respiratory health in Lao PDR.

Background The use of the Asian tobacco waterpipe (TWP) in the Lao People's Democratic Republic represents a potential communal source of infectious disease. This practice of smoking can lead to weakened defences of a smoker's respiratory epithelium, making the smoker vulnerable to respiratory diseases such as coronavirus disease 2019, tuberculosis and others. Methods This study evaluated the water quality and hygiene factors among 43 smokers of five villages in rural Luang Namtha Province. Water samples were collected from participant's TWPs and assessed for the presence of Escherichia coli, coliforms and aerobic plate count (APC) bacteria using the 3M Petrifilm. Results The microbial indicator testing results were 95% positive for the APC, 38% positive for coliforms and 17% positive for the E. coli indicator. The concentrations were highest for the APC, with an average of 106 colony forming units (cfu)/ml, followed by coliforms with <100 cfu/ml and lowest for E. coli with <10 cfu/ml. Most TWPs were infrequently cleaned, heavily used and contained a warm, brown-coloured water. Conclusions The warm, dark and moist internal water container may facilitate microbial survival and growth. The use of a TWP adds several unstudied modes of transmission to a complex and common biobehavioural and environmental pathogen exposure. Future TWP cessation activities should be tailored to consider risks of infectious disease transmission.

In Southeast Asia, household air pollution (HAP) from solid fuel use is the leading cause of disability-adjusted life years (DALYs), a risk which is compounded by exposure to other sources of indoor and outdoor air pollution including secondhand tobacco smoke (SHS). The purpose of this study was to measure the individual and combined prevalence of exposure to household and community sources of air pollution in a national sample of adults in Lao PDR. We analyzed data from the 2012 National Adult Tobacco Survey (NATSL) of Lao PDR—a multi-stage stratified cluster sample of 9706 subjects from 2822 households located in all 17 provinces. Our findings indicate a high prevalence of exposure to household air pollution from cooking fires (78%) and SHS exposure in the home (74.5%). More than a third (32.8%) reported exposure to both inside the home. Exposure to outdoor sources of smoke from cooking, trash, and crop fires was substantial (30.1% to 56.0%). The aggregation of exposures from multiple sources of household air pollution raises the need for initiatives that establish programmatic linkages in the health, environmental, and agricultural sectors to provide a comprehensive strategy to reduce risk factors for respiratory disease in Lao PDR and the region.