Chiang Dao is one of the districts in Chiang Mai, Thailand facing high level of seasonal air pollution every year, the exposure of community dwellers to outdoor air pollutants 24 hours a day during seasonal smog period because of their open-air housing style, and agricultural occupational hazard. In addition, Chiang Dao hospital is the only available hospital serving the community with open-air wards; therefore we could certainly to identify the association between air pollution and mortality of hospitalized patients. Thus, the aim of this study was to determine the association between daily average seasonal air pollutants and daily mortality of hospitalized patients and community dwellers as well as emergency and hospitalization visits for serious respiratory, cardiovascular, and cerebrovascular diseases. This time series study was conducted between 1 March 2016 and 31 March 2017. The association of various air pollutant concentrations including particulate matter diameter less than 10 and 2.5 microns (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3) and daily mortality of hospitalized patients and community dwellers as well as relationship with frequencies of serious respiratory, cardiovascular, and cerebrovascular diseases were analyzed using a general linear model with Poisson distribution. Only PM2.5 was found to be associated with increased daily mortality of hospitalized patients (lag day 6, adjusted RR =1.153, 95% CI: 1.001-1.329), whereas PM10, PM2.5, NO2, and O3 were associated with increased daily non-accidental mortality of community dwellers (lag day 0-7, adjusted RR =1.006-1.040, 95% CI: 1.000-1.074). For acute serious respiratory events; PM10 and PM2.5 were associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), while SO2, CO, and O3 were associated with emergency visits for community-acquired pneumonia (CAP). O3 was associated with emergency visits for heart failure (HF), NO2 with emergency visits for myocardial infarction (MI), and SO2 with hospitalized visits for cerebrovascular accident (CVA). Seasonal air pollutants were found to be associated with higher mortality among hospitalized patients and community dwellers with varying effects on severe acute respiratory, cardiovascular, and cerebrovascular diseases.

Background: Poor inhalation techniques are associated with decreased medication delivery and poor disease control in chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate techniques for using inhaler devices in COPD patients. Methods: A prospective cross-sectional study was conducted to assess patient compliance with correct techniques for using inhaler devices across four regimens, ie, the pressurized metered-dose inhaler (pMDI), the pMDI with a spacer, the Accuhaler^®, and the Handihaler^®. The percentage of compliance with essential steps of correct device usage for each regimen was recorded without prior notification when COPD patients presented for a routine visit, and 1 month after receiving face-to-face training. We compared the percentage of compliance between the devices and risk factors related to incorrect techniques using logistic regression analysis. Percentage of patient compliance with correct techniques was compared between the two visits using the chi-square test. Statistical significance was set at P<0.05. Results: A total of 103 COPD patients (mean age 71.2±9.2 years, males 64.1%, low education level 82.5%, and percent predicted forced expiratory volume in 1 second 51.9±22.5) were evaluated. Seventy-seven patients (74.8%) performed at least one step incorrectly. Patients using the Handihaler had the lowest compliance failure (42.5%), and the odds ratio for failure with the other devices compared with the Handihaler were 4.6 (95% confidence interval [CI] 1.8–11.8) for the pMDI, 3.1 (95% CI 1.2–8.2) for the pMDI with a spacer, and 2.4 (95% CI 1.1–5.2) for the Accuhaler. Low education level was the single most important factor related to incorrect technique (adjusted odds ratio 4.1, 95% CI 1.2–13.4, P=0.022). Formal training resulted in a statistically significant decrease in percentage of incorrect techniques for all devices and for the pMDI (59.4% vs 48.6%, P<0.001; 72.4% vs 48.3%, P=0.039, respectively). Conclusion: Inhalation technique in COPD patients without face-to-face training was mostly unsatisfactory, especially in patients with low education levels. The Handihaler was the inhaler device associated with the lowest technique failure. Face-to-face inhalation technique training significantly increased technique compliance for the pMDI.

Open burnings, agricultural and forest fires, are the major sources of particulate matters (PM) in Chiang Mai during dry season. We aim to determine the association of an increased daily PM (PM₁₀, PM_2.5) and daily non-accidental mortality and causes of death in Chiang Mai. The association between PM and daily non-accidental mortality including causes of death were analyzed using a generalized linear model with Poisson distribution. The results showed that PM₁₀ and PM_2.5 were associated with daily non-accidental mortality on different lag days (adjusted RR range from 1.009–1.018 and 1.016 for each 10 µg/m³ increment of PM₁₀ and PM_2.5, respectively). The causes of death associated with PM₁₀, PM_2.5 found on different lag days were chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), and sepsis. We concluded that PM₁₀ and PM_2.5 are associated with daily non-accidental mortality and causes of death were COPD, CAD, and sepsis.

Various vaccines have been developed to control the COVID-19 pandemic, but the available vaccines were developed using ancestral SARS-CoV-2 wild-type (WT) strains. Commercial anti-SARS-CoV-2 receptor binding domain (RBD) antibody assays have been established and employed for validation of vaccine efficacy. However, these assays were developed before the SARS-CoV-2 variants of concern (VOCs) emerged. It is unclear whether anti-RBD IgG levels can predict immunity against VOCs. In this study, we determined the correlations between the levels of anti-RBD IgG and neutralizing antibodies (NAbs) against SARS-CoV-2 variants in vaccinated subjects. After vaccination, 100% of subjects showed an anti-RBD IgG response, whereas 82, 79, 30, 75, and 2% showed NAb responses against WT, Alpha, Beta, Delta, and Omicron variants, respectively. A high correlation was observed between anti-RBD IgG and NAbs against WT, Alpha, Beta, and Delta, but not so for the Omicron NAbs. Among subjects with high levels of anti-RBD IgG, 93, 93, 71, 93, and 0% of them had NAbs against WT, Alpha, Beta, Delta, and Omicron variants, respectively. These results indicate that anti-RBD IgG levels cannot be used as a predictor for the presence of NAbs against the globally dominant SARS-CoV-2 Omicron variant.

The impact of outdoor air pollution on the quality of life (QoL) of chronic obstructive pulmonary disease (COPD) patients, as measured by the COPD assessment test (CAT) questionnaire, is limited. The aim of this study was to determine the impact of a short-term increase in outdoor particulate matter in which the particles are less than 10 microns in diameter (PM₁₀) during a seasonal smog period on QoL, symptoms, and lung function in COPD patients. This prospective observational study was conducted at Chiang Dao Hospital, Chiang Mai, Thailand between March and August 2016. Measurement of QoL, severity of dyspnea, forced vital capacity (FVC), and forced expiratory volume in the first second (FEV₁) were performed at both high and low PM₁₀ periods. Fifty-nine patients met the inclusion criteria for enrollment into the study, with the mean age being 71.5 ± 8.0 years. Total CAT score, but not mMRC score, was statistically higher during the high PM₁₀ period. The two lung function parameters, FVC and FEV₁, were significantly lower at the high PM₁₀ compared to the low PM₁₀ period. We concluded that exposure to PM₁₀ during the seasonal smog period resulted in short-term negative impact on the quality of life and lung function in COPD patients.

Background: COPD prevalence and consequent burden are expected to rapidly increase worldwide. Until now, there has been no community-based study of COPD in Thailand. Purpose: We aimed to compare the prevalence, clinical characteristics, disease severity, previous diagnosis, and management of COPD between urban and rural communities. Materials and methods: A population-based cross-sectional study was designed to compare COPD prevalence and burden in rural and urban communities in Chiang Mai Province, Thailand. The COPD subjects were diagnosed and severity categories assigned using Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The prevalence between the groups was compared using risk regression analysis. Unpaired t-test and chi-square were used to compare differences between the groups. Results: There were 574 and 293 enrolled subjects with acceptable spirometry, in rural and urban communities respectively. The prevalence of COPD in general and COPD in females was higher in the rural group (6.8% vs 3.7% and 4.4% vs 0.9%, respectively) across all independent variables. However, after adjustment for age, sex, and smoking status, no significant differences were demonstrated. Although the pulmonary function and disease severity between the two groups were not significantly different, the tendency was more pronounced in the rural group (COPD stage III-IV: 65.0% vs 33.3%). Most of the COPD patients in both groups were underdiagnosed (80.0% vs 77.2%) and undertreated (85.0% vs 81.9%). None of the patients in the study had participated in exercise training programs. Conclusion: The prevalence of COPD in general and particularly COPD in females tended to be higher, with more severe disease in the rural community. However, both groups were similarly underdiagnosed and undertreated.