A study on the relationship between air pollution and pulmonary tuberculosis based on the general additive model in Wulumuqi, China.

OBJECTIVE: This study aimed to explore the impact of atmospheric pollutants on the incidence of tuberculosis (TB), and provide new ideas for the prevention and control of TB in the future. METHODS: It explored the relationship between air pollutants and meteorological factors, as well as between air pollutants and heating through Spearman correlation analysis and rank sum test. Additionally, it analyzed the relationship between air pollutants and TB incidence using the general additive model. Statistical analysis results at the p<0.05 level were considered significant. RESULTS: Three months after exposure to air pollutants (PM2.5, SO2, NO2, and CO) TB incidence increased. However, TB incidence increased 9 months after exposure to PM10. The single pollutant model showed when concentrations of PM2.5, PM10, SO2, NO2, CO, and O3 increased by 1µg/m3 (or 1mg/m3), the number of TB cases increased by 0.09%, 0.08%, 0.58%, 0.42%, 6.9%, and 0.57%, respectively. The optimal multi-pollutant model was a two-factor model (PM10+NO2). CONCLUSION: Air pollutants including PM2.5, PM10, SO2, NO2, CO, and O3 increased the risk of TB. Few studies have been conducted in this area of research, especially regarding the mechanism. The results of this study should contribute to the understanding of TB incidence and prompt additional research.

HIV-1 and hepatitis C virus selection bottleneck in Chinese people who inject drugs.

OBJECTIVES: For both HIV-1 and hepatitis C virus (HCV), assessing the stringency of the transmission process is a scientific priority. Enumerations of transmitted/founder (TF) viruses have shown a strict transmission bottleneck in sexual transmission of HIV-1 and a wide range in the multiplicity of infection in HCV. Here, we aim to determine the stringency of parenteral transmission for HIV-1 and HCV in people who inject drugs (PWID). DESIGN: We used molecular sequencing and several complementary analyses to enumerate the TF HIV-1 and HCV variants in a well described cohort of PWID in Xinjiang, China. METHODS: We performed single genome sequencing of HIV-1 env and 5' half HCV genomes, then applied phylogenetic analysis and validated models of early virus diversification to enumerate TF viruses in 60 PWID. We used multivariate analysis to determine correlates of multivariant transmission (MVT). RESULTS: We generated 1070 env region sequences from 33 HIV-1 early infected individuals and 773 5' half region sequences from 27 HCV early infected individuals. We found rates of MVT of 39 and 54%, respectively, for HIV-1 and HCV, with a limited range in the number of TF viruses in both infections. Behavioural characteristics suggested high-risk injection practices and lower risk sexual practices; we did not find an association between any specific behaviours and MVT. CONCLUSION: MVT is frequent in parenteral transmission of both HIV-1 and HCV in Xinjiang PWID, indicating a less stringent transmission process than sexual transmission.