Modeling Analysis Of The Impact Of Air Pollutants,Meteorological Factors And Different Transmission Modalities On The Incidence Of Pulmonary Tuberculosis In Xinjiang

Objective:To study the impact of multiple air pollutants and meteorological factors on the incidence of pulmonary tuberculosis（PTB）in Xinjiang,and find out the key parameters that affect the incidence of PTB,and provide scientific evidences for the prevention and control of PTB.Methods:（1）The incidence of PTB,air pollutants and meteorological factors data in Hotan from 2015 to 2018 were collected.The method of principal component analysis（PCA）was used to eliminate the collinearity among multiple air pollutants and a semi-parametric generalized additive model（SGAM）was established.The maximum likelihood method was used to estimate the parameter values for this model and then the relative risk（RR）was calculated to evaluate the effect of multiple air pollutants on PTB.（2）The incidence of PTB in Xinjiang from 2004 to 2019 and the meteorological data of the same period were collected.The correlation between meteorological factors and the incidence of PTB was analyzed by using the penalty distribution lag nonlinear model,and the impact of meteorological factors on the incidence of PTB was comprehensively evaluated by using apparent temperature（AT）.（3）According to the characteristics of PTB transmission in Xinjiang,a mathematical model with two transmission routes（direct and indirect）and different infected populations（smear positive and negative pulmonary tuberculosis,i.e.,SPPTB and SNPTB）was established to study the dynamic behaviors of the model,such as positive invariance and basic reproduction number（R₀）.Based on the data of SPPTB and SNPTB cases in Xinjiang from 2008 to 2017 and the Markov Monte Carlo（MCMC）method,unknown parameters and basic regeneration number were estimated.Some key parameters affecting the incidence of PTB in Xinjiang were find out by using sensitivity analysis.Results:（1）It was revealed that the risk of pulmonary tuberculosis separately increased by 5.4%（95%CI:3.8%～7.0%）and 5.0%（95%CI:3.4%～6.6%）when the concentrations of PM_2.5and PMβ₁₀in air pollutants increased by 10μg/m³,respectively.（2）When air temperature at the lowest value（-16.1°C）,relative humidity at 59.2%and wind speeds at 1.4 m/s could increase the risk of PTB incidence with the highest RR 1.63（95%CI:1.21～2.20）,1.49（95%CI:1.32～1.67）and 2.20（95%CI:1.95～2.51）.In particular,the lag effect of low AT on the incidence of PTB is a"V-type",and the lag effect of high AT on the incidence of PTB is a"N-type".（3）It demonstratesR₀=2.45（95%CI:1.20～3.84）,and the parameters that have a direct impact on theR₀ are:the coefficient of direct/indirect contact transmission rate,i.e.,β₁₀|PRCC|=0.8029)/β₂₀（|PRCC|=0.6917）,the mycobacterium tuberculosis（Mtb）shedding rate of SPPTB/SNPTB,i.e.,₁（|PRCC|=0.2972）/₂（|PRCC|=0.2357）and the clearance rate of Mtb in the environment(8（|PRCC|=0.2852）.Conclusions:（1）The incidence of PTB in Hotan is highly correlated with PM_2.5 and PMβ₁₀,thus,the particulate pollution matters are the main pollutant affecting the incidence of PTB in Hotan area.（2）It was indicated that the environment with low air temperature,suitable relative humidity and wind speed is more conducive to the transmission of PTB,and low AT is significantly associated with increased risk of PTB in Xinjiang.（3）The results suggest that screening,isolating and treating SPPTB/SNPTB patients,and increasing the clearance rate of Mtb in the environment are feasible measures for the prevention and control of PTB in Xinjiang.