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

Abstract

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 NDVI_250-m and NDVI_500-m (from low to high: Q1, Q2, Q3, Q4) respectively. Six logistic regression models (NDVI, NDVI + PM_2.5/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 NDVI_250-m Q1 and NDVI_500-m Q1, other groups had lower rates of MDR-TB, PDR-TB, RFP-resistance, SM-resistance, RFP + SM resistance, INH + RFP + EMB + SM resistance. NDVI_500-m reduced the risk of multidrug resistant tuberculosis (MDR-TB) and the adjusted odds ratio (aOR, 95% confidence interval, CI) compared with NDVI_500-m Q1 were 0.736 (0.547-0.991) in NDVI + PM₁₀ model, 0.733 (0.544-0.986) in NDVI + PM_2.5 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. NDVI_500-m contributed to a decreased risk of streptomycin (SM)-resistance. The aOR of rifampicin (RFP) + SM resistance were 0.132 (NDVI_250-m, Q4 vs Q1, 95% CI: 0.03-0.578), 0.199 (NDVI_500-m, Q3 vs. Q1, 95% CI: 0.057-0.688) and 0.264 (NDVI_500-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 + PM_2.5 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.

Keywords: Air pollution; Drug resistance; Greenness exposure; Mediation effect; Tuberculosis.