Search

During 2012–2017, a total of 1,144 highly pathogenic avian influenza (HPAI) H5 outbreaks were reported in Taiwan. We conjectured the current 3‐km radius of the post‐outbreak containment policy could fail to effectively alleviate the current ongoing epidemics of HPAI H5 in Taiwan. The high intensity of localized transmission of HPAI H5 at certain focal hotspots was identified to follow the spatial distribution of poultry‐raising locations through our hotspot analyses on the HPAI H5 outbreak locations from 2015 to 2017. We then applied 3‐, 5‐ and 7‐km circular buffer zones to 15,444 registered poultry‐raising locations to inspect the characteristics of the poultry‐raising neighbourhood. Three spatial regression models using Bayesian inference were established to infer the risks attributable to poultry‐raising characteristics in the corresponding buffer areas. The different buffer radii were treated as a sensitivity analysis of the influential range of neighbouring farms on the HPAI H5 outbreak occurrence, so as to evaluate the effective radius for post‐outbreak containment. Evidence showed that the risks of outbreak occurrence were associated with increasing numbers of poultry‐raising locations in both 3‐km (relative risk [RR] 1.005, 95% confidence interval [CI] 1.002–1.008) and 5‐km buffer areas (RR 1.005, 95% CI 1.004–1.007), whereas in the 7‐km buffer model, no association between densely populated locations and increasing risks of outbreaks was observed (RR 1.000, 95% CI 0.999–1.001). Therefore, an extension to a 7‐km radius for the post‐outbreak containment policy (rather than a 3‐km radius as in the current policy) is recommended to effectively mitigate further spreading of HPAI H5 outbreaks among neighbouring farms. Overall, we demonstrated that the densely populated locations with multiple poultry species raised in proximity as defined with 3‐, 5‐ and 7‐km buffer areas facilitated H5 HPAI outbreak diffusion and shaped the scale of HPAI H5 epidemics in Taiwan. [ABSTRACT FROM AUTHOR]

To the Editor: Global climatic changes have resulted in more natural disasters worldwide. These natural disasters can then cause outbreaks of emerging infectious diseases, including leptospirosis and melioidosis (1-7). In [...]

Abstract Background Smoking is known to aggravate tuberculosis (TB), but such information has been ignored in clinical practice, as it was not thought to be relevant. The aim of this study is to assess the benefits of smoking cessation on TB mortality reduction. Methods The study attempts to quantify smokers' risks on subsequent TB mortality and the change in such risks after smokers quit smoking. In this prospective cohort study, the TB mortality risks of smokers, never smokers and former smokers were compared, by using the Cox proportional model to estimate the hazard ratio (HR) of TB. The cohort, consisting of 486,341 adults, participated in standard medical screening programs since 1994, including 5,036 with self-reported TB history. Of 15,268 deaths identified as of 2007, 77 were coded as TB. Results Smokers with self-reported TB history (1.2%) had very high TB mortality (HR = 44.02). Among those without self-reported TB history, smoking increased TB mortality by nine-fold (HR = 8.56), but when they quit smoking, the risk was reduced by more than half (65%), to a level not different from those who had never smoked. The overwhelming majority of TB deaths (83%) occurred among those without self-reported TB history. Given the high smoking prevalence and the high HR, smoking accounted for more than one-third (37.7%) of TB mortality in Taiwan. Smokers reported less TB history but died more from TB than those who had never smoked. Conclusions Smokers had very high TB mortality, as much as nine times those who had never smoked, but once they quit, the risk reduced substantially and was similar to those who never smoked. Smoking cessation has benefits to the smokers far beyond reducing TB risk, but successful tobacco control could favorably impact the TB mortality rate and reduce this public health burden, which has long haunted the Taiwanese population. Smoking cessation could reduce nearly one-third of tuberculosis deaths.

Abstract Background Buffer analyses have shown that air pollution is associated with an increased incidence of asthma, but little is known about how air pollutants affect health outside a defined buffer. The aim of this study was to better understand how air pollutants affect asthma patient visits in a metropolitan area. The study used an integrated spatial and temporal approach that included the Kriging method and the Generalized Additive Model (GAM). Results We analyzed daily outpatient and emergency visit data from the Taiwan Bureau of National Health Insurance and air pollution data from the Taiwan Environmental Protection Administration during 2000–2002. In general, children (aged 0–15 years) had the highest number of total asthma visits. Seasonal changes of PM10, NO2, O3 and SO2 were evident. However, SO2 showed a positive correlation with the dew point (r = 0.17, p < 0.01) and temperature (r = 0.22, p < 0.01). Among the four pollutants studied, the elevation of NO2 concentration had the highest impact on asthma outpatient visits on the day that a 10% increase of concentration caused the asthma outpatient visit rate to increase by 0.30% (95% CI: 0.16%~0.45%) in the four pollutant model. For emergency visits, the elevation of PM10 concentration, which occurred two days before the visits, had the most significant influence on this type of patient visit with an increase of 0.14% (95% CI: 0.01%~0.28%) in the four pollutants model. The impact on the emergency visit rate was non-significant two days following exposure to the other three air pollutants. Conclusion This preliminary study demonstrates the feasibility of an integrated spatial and temporal approach to assess the impact of air pollution on asthma patient visits. The results of this study provide a better understanding of the correlation of air pollution with asthma patient visits and demonstrate that NO2 and PM10 might have a positive impact on outpatient and emergency settings respectively. Future research is required to validate robust spatiotemporal patterns and trends.

Background: Physical activity (PA) increases a person's inhalation of air pollutants due to greater ventilation, possibly leading to larger adverse health effects. This study aims to investigate the combined effects of long-term exposure to fine particulate matter (PM2.5) and habitual PA on lung function in adults.Methods: This was a longitudinal cohort study that included 278,065 Taiwan residents with an age of 20 years old or above who joined a standard medical screening programme between 2001 and 2014. Each participant received at least one medical examination (including spirometric, blood, and urinary tests and a standard self-administered questionnaire survey) during the study period. We estimated the 2-year average PM2.5 concentrations at each participant's address using a new physical model based on observational data. Information on the participants' PA was collected using the standard self-administrated questionnaire. Generalised linear mixed models were used to investigate the combined effects of PM2.5 and PA on pulmonary function. We also performed stratified analyses by different levels of PM2.5 exposure and habitual PA.Results: Each 10 MET-h increase in PA was associated with a higher level of 0.20%, 0.16%, and 0.19% in forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and maximum mid-expiratory flow (MMEF), respectively, after adjusting for PM2.5 exposure and a wide range of covariates including age, sex education, body mass index, lifestyles, and health conditions. Each 10 μg/m3 increase in PM2.5 was associated with a lower FVC, FEV1, and MMEF (2.43%, 2.78% and 3.10%, respectively). Negative interactions were observed, and PM2.5 exposure was associated with a greater reduction in lung function among the participants with higher PA levels.Conclusions: We found significant negative interaction effects between long-term exposure to PM2.5 and habitual PA, suggesting that the increased intake of PM2.5 due to PA may attenuate the benefits of habitual PA on lung function. However, the PA benefits generally remained stable at different stratum of PM2.5 in the stratified analyses, and habitual PA may still be recommended to people residing in relatively polluted regions. [ABSTRACT FROM AUTHOR]