An association between PM2.5 components and respiratory infectious diseases: A China's mainland-based study.

The particulate matter with diameter of less than 2.5 µm (PM2.5) is an important risk factor for respiratory infectious diseases, such as scarlet fever, tuberculosis, and similar diseases. However, it is not clear which component of PM2.5 is more important for respiratory infectious diseases. Based on data from 31 provinces in mainland China obtained between 2013 and 2019, this study investigated the effects of different PM2.5 components, i.e., sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and organic matter (OM), and black carbon (BC), on respiratory infectious diseases incidence [pulmonary tuberculosis (PTB), scarlet fever (SF), influenza, hand, foot, and mouth disease (HFMD), and mumps]. Geographical probes and the Bayesian kernel machine regression (BKMR) model were used to investigate correlations, single-component effects, joint effects, and interactions between components, and subgroup analysis was used to assess regional and temporal heterogeneity. The results of geographical probes showed that the chemical components of PM2.5 were associated with the incidence of respiratory infectious diseases. BKMR results showed that the five components of PM2.5 were the main factors affecting the incidence of respiratory infectious diseases (PIP>0.5). The joint effect of influenza and mumps by co-exposure to the components showed a significant positive correlation, and the exposure-response curve for a single component was approximately linear. And single-component modelling revealed that OM and BC may be the most important factors influencing the incidence of respiratory infections. Moreover, respiratory infectious diseases in southern and southwestern China may be less affected by the PM2.5 component. This study is the first to explore the relationship between different components of PM2.5 and the incidence of five common respiratory infectious diseases in 31 provinces of mainland China, which provides a certain theoretical basis for future research.

Immediate and long-term changes in infectious diseases in China at the "First-level-response", "Normalized-control" and "Dynamic-COVID-zero" stages from 2020 to 2022: a multistage interrupted-time-series-analysis.

BACKGROUND: From January 2020 to December 2022, China implemented "First-level-response", "Normalized-control" and "Dynamic-COVID-zero" to block the COVID-19 epidemic; however, the immediate and long-term impact of three strategies on other infectious diseases and the difference in their impact is currently unknown. We aim to provide a more comprehensive understanding of the impact of non-pharmacological interventions (NPIs) on infectious diseases in China. METHODS: We collected data on the monthly case count of infectious diseases in China from January 2015 to July 2022. After considering long-term trends using the Cox-Stuart test, we performed the two ratio Z tests to preliminary analyze the impact of three strategies on infectious diseases. Next, we used a multistage interrupted-time-series analysis fitted by the Poisson regression to evaluate and compare the immediate and long-term impact of three strategies on infectious diseases in China. RESULTS: Compared to before COVID-19, the incidence of almost all infectious diseases decreased immediately at stages 1, 2, and 3; meanwhile, the slope in the incidence of many infectious diseases also decreased at the three stages. However, the slope in the incidence of all sexually transmitted diseases increased at stage 1, the slope in the incidence of all gastrointestinal infectious diseases increased at stage 2, and the slope in the incidence of some diseases such as pertussis, influenza, and brucellosis increased at stage 3. The immediate and long-term limiting effects of "Normalized-control" on respiratory-transmitted diseases were weaker than "First-level-response" and the long-term limiting effects of "Dynamic-COVID-zero" on pertussis, influenza, and hydatid disease were weaker than "Normalized-control". CONCLUSIONS: Three COVID-19 control strategies in China have immediate and long-term limiting effects on many infectious diseases, but there are differences in their limiting effects. Evidence from this study shows that pertussis, influenza, brucellosis, and hydatid disease began to recover at stage 3, and relaxation of NPIs may lead to the resurgence of respiratory-transmitted diseases and vector-borne diseases.

Immediate and long-term changes in the epidemiology, infection spectrum, and clinical characteristics of viral and bacterial respiratory infections in Western China after the COVID-19 outbreak: a modeling study.

BACKGROUND: The impact of COVID-19 on the epidemiology, clinical characteristics, and infection spectrum of viral and bacterial respiratory infections in Western China is unknown. METHODS: We conducted an interrupted time series analysis based on surveillance of acute respiratory infections (ARI) in Western China to supplement the available data. RESULTS: The positive rates of influenza virus, Streptococcus pneumoniae, and viral and bacterial coinfections decreased, but parainfluenza virus, respiratory syncytial virus, human adenovirus, human rhinovirus, human bocavirus, non-typeable Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydia pneumoniae infections increased after the onset of the COVID-19 epidemic. The positive rate for viral infection in outpatients and children aged <5 years increased, but the positive rates of bacterial infection and viral and bacterial coinfections decreased, and the proportion patients with clinical symptoms of ARI decreased after the onset of the COVID-19 epidemic. Non-pharmacological interventions reduced the positive rates of viral and bacterial infections in the short term but did not have a long-term limiting effect. Moreover, the proportion of ARI patients with severe clinical symptoms (dyspnea and pleural effusion) increased in the short term after COVID-19, but in the long-term, it decreased. CONCLUSIONS: The epidemiology, clinical characteristics, and infection spectrum of viral and bacterial infections in Western China have changed, and children will be a high-risk group for ARI after the COVID-19 epidemic. In addition, the reluctance of ARI patients with mild clinical symptoms to seek medical care after COVID-19 should be considered. In the post-COVID-19 era, we need to strengthen the surveillance of respiratory pathogens.

Influence and prediction of meteorological factors on brucellosis in a northwest region of China.

This paper aims to study the cumulative lag effect of meteorological factors on brucellosis incidence and the prediction performance based on Random Forest model. The monthly number of brucellosis cases and meteorological data from 2015 to 2019 in Yongchang of Gansu Province, northwest China, were used to build distributed lag nonlinear model (DLNM). The number of brucellosis cases of lag 1 month and meteorological data from 2015 to 2018 were used to build RF model to predict the brucellosis incidence in 2019. Meanwhile, SARIMA model was established to compare the prediction performance with RF model according to R2 and RMSE. The results indicated that the population had a high incidence risk at temperature between 5 and 13 °C and lag between 0 and 18 days, sunshine duration between 225 and 260 h and lag between 0 and 1 month, and atmosphere pressure between 789 and 793.5 hPa and lag between 0 and 18 days. The R2 and RMSE of train set and test set in RF model were 0.903, 1.609, 0.824, and 2.657, respectively, and the R2 and RMSE in SARIMA model were 0.530 and 7.008. This study found significant nonlinear and lag associations between meteorological factors and brucellosis incidence. The prediction performance of RF model was more accurate and practical compared with SARIMA model.

Effect of different vaccine strategies for the control of Japanese encephalitis in mainland China from 1961 to 2020: A quantitative analysis.

BACKGROUND: We aimed to quantify the impact of each vaccine strategy (including the P3-inactivated vaccine strategy [1968-1987], the SA 14-14-2 live-attenuated vaccine strategy [1988-2007], and the Expanded Program on Immunization [EPI, 2008-2020]) on the incidence of Japanese encephalitis (JE) in regions with different economic development levels. METHODS: The JE incidence in mainland China from 1961 to 2020 was summarized by year, then modeled and analyzed using an interrupted time series analysis. RESULTS: After the P3-inactivated vaccine was used, the JE incidence in Eastern China, Central China, Western China and Northeast China in 1968 decreased by 39.80 % (IRR = 0.602, P < 0.001), 7.80 % (IRR = 0.922, P < 0.001), 10.80 % (IRR = 0.892, P < 0.001) and 31.90 % (IRR = 0.681, P < 0.001); the slope/trend of the JE incidence from 1968 to 1987 decreased by 30.80 % (IRR = 0.692, P < 0.001), 29.30 % (IRR = 0.707, P < 0.001), 33.00 % (IRR = 0.670, P < 0.001) and 41.20 % (IRR = 0.588, P < 0.001). After the SA 14-14-2 live-attenuated vaccine was used, the JE incidence in Eastern China and Northeast China in 1988 decreased by 2.60 % (IRR = 0.974, P = 0.009) and 14.70 % (IRR = 0.853, P < 0.001); the slope/trend of the JE incidence in Eastern China and Central China from 1988 to 2007 decreased by 4.60 % (IRR = 0.954, P < 0.001) and 4.70 % (IRR = 0.953, P < 0.001). After the EPI was implemented, the JE incidence in Eastern China, Central China and Western China in 2008 decreased by 10.50 % (IRR = 0.895, P = 0.013), 18.00 % (IRR = 0.820, P < 0.001) and 24.20 % (IRR = 0.758, P < 0.001), the slope/trend of the JE incidence in Eastern China from 2008 to 2020 decreased by 17.80 % (IRR = 0.822, P < 0.001). CONCLUSIONS: Each vaccine strategy has different effects on the JE incidence in regions with different economic development. Additionally, some economically underdeveloped regions have gradually become the main areas of the JE outbreak. Therefore, mainland China should provide economic assistance to areas with low economic development and improve JE vaccination plans in the future to control the epidemic of JE.

Impact of the expanded program on immunization on the incidence of Japanese encephalitis in different regions of Mainland China: An interrupt time series analysis.

In 2008, Mainland China included the Japanese encephalitis (JE) vaccine in the Expanded Program on Immunization (EPI) to control the JE epidemic. However, Northwest China experienced the largest JE outbreak since 1994 in 2018, and the effects of the EPI in different regions are unclear. Therefore, we used an interrupted time series design to evaluate the effects of the EPI in different regions. In this study, ß1 and ß1+ß3 represented the slope or trend of the JE incidence before and after the EPI, respectively; ß2 was the level change of the JE incidence immediately after the EPI; ß3 represented the slope change of the JE incidence before and after the EPI. We found that the JE incidence in all regions showed a decreasing trend before the EPI (ß1<0.000, P<0.05). The JE incidence in Mainland China (ß2=-7.669, P<0.05), East China (ß2=-9.791, P<0.05), Central China (ß2=-10.695, P<0.05), South China (ß2=-6.551, P<0.05) and Southwest China (ß2=-2.216, P<0.05) decreased by 7.669/100,000, 9.791/100,000, 10.695/100,000, 6.551/100,000 and 2.216/100,000 immediately after the EPI, and the EPI had short-term effects on the JE incidence in these regions. The slope of the JE incidence in Mainland China (ß3=0.272, P<0.05), East China (ß3=0.337, P<0.05), Central China (ß3=0.381, P<0.05), South China (ß3=0.254, P<0.05) and Southwest China (ß3=0.081, P<0.05) increased by 0.272, 0.337, 0.381, 0.254 and 0.081 after the EPI, and the EPI had long-term effects on the JE incidence in these regions. The JE incidence in many regions (excluding North China) showed a decreasing trend after the EPI (ß1+ß3 <0.000). Northwest China (GDP from 2008 to 2020 ranked last in Mainland China) and Southwest China (GDP from 2008 to 2020 ranked fifth in Mainland China), with underdeveloped economy, used to be low-epidemic regions of JE, but they have become high-epidemic regions in recent years. Economic development may contribute to the geographic variations in the effects of the EPI. Therefore, it is significant for JE control in Mainland China to increase support for underdeveloped regions and adjust the vaccine strategy according to the new epidemic situation of JE.

A comparison of clinical manifestations of Japanese encephalitis between children and adults in Gansu Province, Northwest China (2005-2020).

Japanese encephalitis (JE), a mosquito-borne zoonotic disease, has emerged as a major public health concern around the world. Previous research has shown that JE has serious sequelae, and the recent shift in the population from children to adults presents a significant challenge for JE treatment and prevention. Therefore, we examined the differences in clinical manifestations (clinical symptoms, clinical signs, complications, and clinical typing) of JE between children and adults over the 15 years in Gansu Province to provide a theoretical basis for better response to JE treatment. Clinical typing was found to be statistically significant in the child versus adult groups and the groups with or without vaccination. Only the dysfunction of consciousness differed statistically between children with and without vaccination, whereas neurological symptoms such as vomiting (jet vomiting), irritability, drowsiness, convulsions, and hyperspasmia differed statistically between children and adults, and the rest of the symptoms did not differ statistically. Only pupil size changes were statistically different in clinical signs between the children with and without vaccination, while blood pressure changes, change in pupil size, positive meningeal stimulation signs, and positive pathological reflexes (increased muscle tone and Babinski's sign) were statistically different between adults and children. Bronchopneumonia was the most common complication, especially in adults. Therefore, the authors believe that children and adults differ in some clinical manifestations and propose that efforts should be directed toward developing individualized treatment plans for different age groups and employing more effective supportive treatment for various populations. In addition, we suggest expanding the coverage of the JE vaccine and increasing overall vaccination rates and adopting multiple measures in conjunction with JE prevention and control.

Association Between Air Pollutants and Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Time Stratified Case-Crossover Design With a Distributed Lag Nonlinear Model.

Acute exacerbation of chronic obstruction pulmonary disease (AECOPD) as a respiratory disease, is considered to be related to air pollution by more and more studies. However, the evidence on how air pollution affect the incidence of AECOPD and whether there are population differences is still insufficient. Therefore, we select PM10, PM2.5, SO2, NO2, CO, and O3 as representatives combined with daily AECOPD admission data from 1 January 2015 to 26 June 2016 in the rural areas of Qingyang, northwestern China to explore the associations of air pollution with AECOPD. Based on a time-stratified case-crossover design, we constructed a distributed lag nonlinear model to qualify the single and cumulative lagged effects of air pollution on AECOPD. Stratified related risks by sex and age were also reported. The cumulative exposure-response curves were approximately linear for PM2.5, "V"-shaped for PM10, "U"-shaped for NO2 and inverted-"V" for SO2, CO and O3. Exposure to high-PM2.5 (42 µg/m3), high-PM10 (91 µg/m3), high-SO2 (58 µg/m3), low-NO2 (12 µg/m3), and high-CO (1.55 mg/m3) increased the risk of AECOPD. Females aged 15-64 were more susceptible under extreme concentrations of PM2.5, SO2, CO, and low-PM10 than other subgroups. In addition, adults aged 15-64 were more sensitive to extreme concentrations of NO2 compared with the elderly ≥65 years old, while the latter were more sensitive to high-PM10. High-SO2, high-NO2, and extreme concentrations of PM2.5 had the greatest effects on the day of exposure, while low-SO2 and low-CO had lagged effects on AECOPD. Precautionary measures should be taken with a focus on vulnerable subgroups, to control hospitalization for AECOPD associated with air pollutants.