Indoor Air Pollution and Susceptibility to Tuberculosis Infection in Urban Vietnamese Children

Associations of residential greenness exposure and ambient air pollutants with newly-diagnosed drug-resistant tuberculosis cases

Growing evidence has found the health protective effects of greenness exposure on tuberculosis (TB) and the impact of ambient air pollutants on TB drug-resistance. However, it remains unclear whether residential greenness is also beneficial to reduce TB drug-resistance, and whether air pollution modify the greenness-TB resistance relationship. We enrolled 5006 newly-diagnosed TB patients from Shandong, China, during 2014 to 2021. Normalized Difference Vegetation Index (NDVI) in 250 m and 500 m buffer around individuals' residential zone was used to assess greenness exposure. All patients were divided by quartiles of NDVI250-m and NDVI500-m (from low to high: Q1, Q2, Q3, Q4) respectively. Six logistic regression models (NDVI, NDVI + PM2.5/PM10/SO2/NO2/O3) were used to estimate the association of NDVI and TB drug-resistance when adjusting different air pollutants or not. All models were adjusted for age, gender, body mass index, complications, smoking, drinking, population density, nighttime light index, road density. Compared with participants in NDVI250-m Q1 and NDVI500-m Q1, other groups had lower rates of MDR-TB, PDR-TB, RFP-resistance, SM-resistance, RFP + SM resistance, INH + RFP + EMB + SM resistance. NDVI500-m reduced the risk of multidrug resistant tuberculosis (MDR-TB) and the adjusted odds ratio (aOR, 95% confidence interval, CI) compared with NDVI500-m Q1 were 0.736 (0.547-0.991) in NDVI + PM10 model, 0.733 (0.544-0.986) in NDVI + PM2.5 model, 0.735(0.546-0.99) in NDVI + SO2 model, 0.736 (0.546-0.991) in NDVI + NO2 model, respectively, P < 0.05. NDVI500-m contributed to a decreased risk of streptomycin (SM)-resistance. The aOR of rifampicin (RFP) + SM resistance were 0.132 (NDVI250-m, Q4 vs Q1, 95% CI: 0.03-0.578), 0.199 (NDVI500-m, Q3 vs. Q1, 95% CI: 0.057-0.688) and 0.264 (NDVI500-m, Q4 vs. Q1, 95% CI: 0.087-0.799). The adjusted ORs (Q2 vs. Q1, 95% CI) of isoniazid (INH) + RFP + ethambutol (EMB) + SM resistance in 500 m buffer were 0.276 (0.119-0.639) in NDVI model, 0.279 (0.11-0.705) in NDVI + PM10 model, 0.281 (0.111-0.713) in NDVI + PM2.5 model, 0.279 (0.11-0.709) in NDVI + SO2 model, 0.296 (0.117-0.754) in NDVI + NO2 model, 0.294 (0.116-0.748) in NDVI + O3 model, respectively. The study showed, for the first time, that residential greenness exposure in 500 m buffer is beneficial for reducing newly-diagnosed DR-TB (including PDR-RB, MDR-TB, MR-TB), and ambient air pollutants may partially mediate this association.

Smoking Exposure and the Risk of Latent Tuberculosis Infection: Results from NHANES 2011-2012

The association between smoking exposure and latent tuberculosis infection (LTBI) has been investigated in a few studies; however, further investigation is needed. In this study, the 2011-2012 NHANES population was used to evaluate smoking exposure and LTBI risk. A total of 7042 participants with available LTBI results and without active tuberculosis were included for analysis. Smoking was defined as participants who smoked at least 100 cigarettes in their life. Both univariable and multivariable analysis were adopted to evaluate smoking exposure, as well as related factors on the risk of LTBI. LTBI rates among current smokers (12.1%) and former smokers (9.9%) were higher than non-smokers (5.9%). However, current smokers and former smokers were not significantly associated with LTBI risk when compared to non-smokers after adjusting by age and sex in the multivariable analysis. Meanwhile, we found that passive smoking was not associated with LTBI (adjusted odds ratio (AOR), 0.85; 95%CI, 0.66-1.09). In multivariable analysis, current smoking was associated with LTBI (OR, 1.67; 95%CI, 1.28-2.19), while former smokers had an increased OR of LTBI, but the OR did not reach statistical significance (OR, 1.15; 95%CI, 0.90-1.48). Household tuberculosis (TB) contact was also related to LTBI (OR, 1.93; 95%CI, 1.25-2.99). However, BMI and diabetes were not found to be associated with LTBI. Smoking, especially current smoking, was significantly associated with LTBI. LTBI screening should be recommended for active smokers. Former smoking and passive smoking exposure were not found to have a significant relationship with LTBI risk. However, the high LTBI rate among quitters indicated we should pay more attention to former smokers with LTBI.

Household air pollution and risk of pulmonary tuberculosis in HIV-Infected adults

BACKGROUND

In low- and middle-income countries countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection.

METHODS

We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB.

RESULTS

We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/week were more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm].

CONCLUSION

Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

Tobacco smoke exposure recruits inflammatory airspace monocytes that establish permissive lung niches for Mycobacterium tuberculosis

Tobacco smoking doubles the risk of active tuberculosis (TB) and accounts for up to 20% of all active TB cases globally. How smoking promotes lung microenvironments permissive to Mycobacterium tuberculosis (Mtb) growth remains incompletely understood. We investigated primary bronchoalveolar lavage cells from current and never smokers by performing single-cell RNA sequencing (scRNA-seq), flow cytometry, and functional assays. We observed the enrichment of immature inflammatory monocytes in the lungs of smokers compared with nonsmokers. These monocytes exhibited phenotypes consistent with recent recruitment from blood, ongoing differentiation, increased activation, and states similar to those with chronic obstructive pulmonary disease. Using integrative scRNA-seq and flow cytometry, we identified CD93 as a marker for a subset of these newly recruited smoking-associated lung monocytes and further provided evidence that the recruitment of monocytes into the lung was mediated by CCR2-binding chemokines, including CCL11. We also show that these cells exhibit elevated inflammatory responses upon exposure to Mtb and accelerated intracellular growth of Mtb compared with mature macrophages. This elevated Mtb growth could be inhibited by anti-inflammatory small molecules, providing a connection between smoking-induced pro-inflammatory states and permissiveness to Mtb growth. Our findings suggest a model in which smoking leads to the recruitment of immature inflammatory monocytes from the periphery to the lung, which results in the accumulation of these Mtb-permissive cells in the airway. This work defines how smoking may lead to increased susceptibility to Mtb and identifies host-directed therapies to reduce the burden of TB among those who smoke.

Household Air Pollution and Risk of Pulmonary Tuberculosis in HIV-Infected Adults

Background

In developing countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection.

Methods

We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB.

Results

We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/weekwere more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm].

Conclusion

Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

Post-birth exposure contrasts for children during the Household Air Pollution Intervention Network randomized controlled trial

Exposure to household air pollution is a leading cause of ill-health globally. The Household Air Pollution Intervention Network (HAPIN) randomized controlled trial evaluated the impact of a free liquefied petroleum gas stove and fuel intervention on birth outcomes and maternal and child health. As part of HAPIN, an extensive exposure assessment was conducted. Here, we report on PM 2.5 and CO exposures of young children (≤ 15 months old) reconstructed using a Bluetooth-beacon based time-activity monitoring system coupled with microenvironmental pollutant monitors. Median (IQR) exposures to PM 2.5 were 65.1 (33 - 128.2) µg/m 3 in the control group and 22.9 (17.2 - 35.3) µg/m3 in the intervention group; for CO, median (IQR) exposures were 1.1 (0.3 - 2.9) ppm and 0.2 (0 - 0.7) ppm for control and intervention group, respectively. Exposure reductions were stable over time and consistent with previous findings for the children's mothers. In the intervention group, 75% of children's reconstructed exposures were below the WHO interim target guideline value of 35 µg/m 3 , while 26% were below the standard in the control group. Our findings suggest that an LPG fuel and stove intervention can substantially reduce children's exposure to household air pollution.

Comparison of the rate of certain trace metals accumulation in indoor plants for smoking and non-smoking areas

Tobacco smoke causes to release severe toxic metals into the environment. It is recognized as the most significant issue in indoor air quality. Pollution and toxic substances in smoke quickly spread and penetrate the indoor environment. Environmental tobacco smoke is responsible for lowering indoor air quality. There is much evidence that poor air quality occurs with inadequate ventilation conditions in indoor environments. The plants have been observed to absorb the smoke in the environment into their own body like a sponge. The plant species in this study can be used easily in almost every office, home, or other indoor areas. Using indoor plants is very beneficial in biomonitoring and absorbing these trace metals. Some indoor plants have shown successful performance as biomonitors for health-damaging pollutants. The study aims to determine the concentration of three trace metals (Cu, Co, and Ni) using five indoor ornamentals frequently used in smoking areas, namely D. amoena, D. marginata, F. elastica, S. wallisii, and Y. massengena. The Ni uptake and its accumulation in S. wallisii, and Y. massengena increased in correlation with smoke areas. However, the rate of accumulation of Co and Cu was found to be independent due to consideration of the environmental emissions. Consequently, our results suggest that F. elastica is more resistant to smoking, whereas S. wallisii would be a better choice as a biomonitoring plant of tobacco smoke.

Recent advances in the control of volatile organic compounds emissions from indoor wood-based panels: A comprehensive review

Wood-based panels provide efficient alternatives to materials such as plastics derived from traditional petroleum sources and thereby help to mitigate greenhouse gas emissions. Unfortunately, using indoor manufactured panel products also results in significant emissions of volatile organic compounds including olefins, aromatic and ester compounds, which negatively affect human health. This paper highlights recent developments and notable achievements in the field of indoor hazardous air treatment technologies to guide future research toward environmentally friendly and economically feasible directions that may have a significant impact on the improvement of human settlements. Summarizing and synthesizing the principles, advantages, and limitations of different technologies can assist policymakers and engineers in identifying the most appropriate technology for a particular air pollution control program based on criteria such as cost-effectiveness, efficiency, and environmental impact. In addition, insights into the development of indoor air pollution control technologies are provided and potential areas for innovation, improvement of existing technologies, and development of new technologies are identified. Finally, the authors also hope that this sub-paper will raise public awareness of indoor air pollution issues and promote a better understanding of the importance of indoor air pollution control technologies for public health, environmental protection, and sustainable development.

Interrelationships between tuberculosis and chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Our objective was to review the current literature regarding socioeconomic, environmental, clinical, and immunologic factors common to chronic obstructive pulmonary disease (COPD) and tuberculosis (TB).

RECENT FINDINGS

Recent studies suggest that TB patients might be at increased risk for developing COPD. Conversely, additional prospective cohort studies have determined that COPD patients are at increased risk for active TB: a risk that appears to be partially mediated through inhaled corticosteroid use. Tobacco smoking, poverty, air pollution, and malnutrition are associated with COPD and TB. Vitamin D has been shown to prevent COPD exacerbations, but its use for preventing TB infection remains unclear. Surfactant deficiency, elevated matrix metalloproteinases, and toll-like receptor 4 polymorphisms play key roles in the pathogenesis of both diseases.

SUMMARY

Recent studies have elucidated interrelationships between COPD and TB. Future research is needed to optimize clinical and public health approaches that could mitigate risk factors contributing to both diseases.

Tuberculosis Infection in Children and Adolescents

The burden of tuberculosis (TB) in children and adolescents remains very significant. Several million children and adolescents are infected with TB each year worldwide following exposure to an infectious TB case and the risk of progression from TB infection to tuberculosis disease is higher in this group compared to adults. This review describes the risk factors for TB infection in children and adolescents. Following TB exposure, the risk of TB infection is determined by a combination of index case characteristics, contact features, and environmental determinants. We also present the recently recommended approaches to diagnose and treat TB infection as well as novel tests for infection. The tests for TB infection have limitations and diagnosis still relies on an indirect immunological assessment of cellular immune response to Mycobacterium tuberculosis antigens using immunodiagnostic testing. It is recommended that TB exposed children and adolescents and those living with HIV receive TB preventive treatment (TPT) to reduce the risk of progression to TB disease. Several TPT regimens of similar effectiveness and safety are now available and recommended by the World Health Organisation.