Objectives: This study investigated the association between baseline exposures to particulate matter with a diameter < 2.5 microns (PM2.5) and subsequent temporal changes in PM2.5 exposure with the incidence of type 2 diabetes among Royal Thai Army personnel. Methods: A retrospective cohort study was conducted using nationwide health check-up data from 21 325 Thai Army personnel between 2018 and 2021. Multilevel mixed-effects parametric survival statistics were utilized to analyze the relationship between baseline (i.e., PM2.5-baseline) and subsequent changes (i.e., PM2.5-change) in PM2.5 exposure and the occurrence of type 2 diabetes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were employed to assess this association while considering covariates. Results: There was a significant association between both PM2.5 baseline and PM2.5-change and the incidence of type 2 diabetes in a dose-response manner. Compared to quartile 1, the HRs for quartiles 2 to 4 of PM2.5-baseline were 1.11 (95% CI, 0.74 to 1.65), 1.51 (95% CI, 1.00 to 2.28), and 1.77 (95% CI, 1.07 to 2.93), respectively. Similarly, the HRs for quartiles 2 to 4 of PM2.5-change were 1.41 (95% CI, 1.14 to 1.75), 1.43 (95% CI, 1.13 to 1.81) and 2.40 (95% CI, 1.84 to 3.14), respectively. Conclusions Our findings contribute to existing evidence regarding the association between short-term and long-term exposure to PM2.5 and the incidence of diabetes among personnel in the Royal Thai Army.

Objective: To investigate the incidence, spontaneous clearance, persistence and risk factors of Blastocystis infection in a rural community in Thailand. Methods: In February 2016, a cohort study was conducted in a rural community of Thailand. Baseline information of intestinal parasitic infections and follow-up visits were conducted. Blastocystis infection was detected in stool samples examined with short-term in vitro cultivation using Jones' medium supplemented with 10% horse serum. Participants were tested for Blastocystis infection at every study visit. Cox proportional hazard regression analysis was used to evaluate co-variates to determine the incidence of Blastocystis infection. Results: Of 733 enrolled participants, 57 (7.78%) were positive and 676 (92.22%) were negative for Blastocystis infection. All 676 participants were followed-up for Blastocystis infection between December 2016 and January 2018. In all, 52 of 482 cases (10.79%) comprised individual Blastocystis infection. The incidence density rates of Blastocystis infection, of spontaneous clearance of the disease and of persistent infection were 8.13, 63.14 and 38.70 per 1 000 person-months of follow-up, respectively. Our multivariate analysis revealed that opened defecation in fields or bushes (HR=4.8; 95% CI =2.1-10.4, P <0.001), raising cows (HR=2.8; 95% CI =1.1-7.1, P =0.032), not washing hands after animal contact (HR=2.1; 95% CI =1.0-4.2, P =0.044) and presenting symptoms of nausea or vomiting (HR=2.3; 95% C/=1.0-5.3, P =0.047) were predictive associated risks for the incidence of Blastocystis infection. Conclusions: Our study indicates that the best way to prevent Blastocystis infection can be by maintaining good personal hygiene, hand washing after animal contact and improving sanitary facilities.