The Modified Self-Assessment (MSA) and Present Self-Assessment (PSA) forms are questionnaires used to prioritize the risk of infection of health workers exposed to tuberculosis (TB) in Srinagarind Hospital in Thailand. As MSA was developed from PSA, the validity and reliability of MSA need to be assessed. The research aim is to examine the content validity of MSA and to assess the respective reliability of MSA and PSA vis-à-vis expert opinion. Seven experts determined the content validity index (CVI) of MSA. MSA and PSA were used to prioritize the TB contact of 108 subjects, and we compared the result with the risk assessed by the experts. The respective Kappa agreements between MSA and PSA and the experts were used to assess reliability. The result of the content validity index revealed that MSA had I-CVI > 0.83 for all questions and an S-CVI/Ave above 0.90 for all factors. The Kappa agreement of contact priority between MSA and the experts was 0.80; it was 0.58 between PSA and the experts. MSA can, thus, be used to prioritize contact with tuberculosis in Srinagarind Hospital. MSA is a valid risk communication tool for aerosol-generating procedures. Further study should be conducted in other hospitals, and the number of participants should be increased in order to come to a concrete result.

OBJECTIVE To explore different strategies for achieving proper use of N95 respirators by hospital staff, including viewing the donning process in a mirror, receiving assistance from a Buddy during donning, and using a bouffant cap to cover the hair after donning an N95 respirator. This study evaluated the fit factor, the time required for donning a respirator, and the practical usability of each strategy. METHODS This quasi-experimental study involved 60 healthcare workers. Demographic and medical information were collected using Occupational Safety and Health Administration (OSHA) compliant questionnaires. Facial dimensions were measured and classified into three face-size groups according to the NIOSH bivariate panel. Participants practiced one of four different N95 respirator donning strategies after watching a training video: using a mirror, receiving Buddy assistance, and using a bouffant cap. A quantitative fit test (QNFT) was conducted before and after practicing each strategy following a modified OSHA protocol. After completing each of the strategies, participants indicated their preferred donning method. They were subsequently randomly divided into three groups to further practice one of the strategies, with repeated QNFTs to ensure consistency. RESULTS Post video training, participants had a higher fit factor (FFs) (median, IQR) (113.50 [48.50, 200]) and an increased passing rate (61.67%) on the fit test compared to no training which had an FF of 65.50 [18.50, 118.50]) and a passing rate of 25.00%. Practice with the Buddy and Mirror strategies resulted in significantly higher FFs for small, medium, and large face sizes. The Bouffant cap strategy showed significantly higher FF than post video training alone for small face sizes: (102 [50.5, 143]) and (50 [18, 108]), respectively. CONCLUSIONS The study found significant differences in FF for different facial sizes, with participants having medium and large face sizes achieving higher FFs compared to those with small face sizes. For individuals with small face sizes, FF improved significantly post video training using alternative strategies (Mirror, Buddy, and Bouffant cap) compared to no training. Using a mirror during donning allowed wearers to inspect the mask fit more effectively, while the Buddy strategy proved more efficient in identifying and addressing leaks compared to self-checking. KEYWORDS N95 respirator, Quantitative Fit Tests, face sizes, health care workers, strategies

Despite ongoing TB control efforts, health workers (HWs) in Thailand remain at risk for latent tuberculosis infection (LTBI), yet the burden of LTBI in Thai HWs is insufficiently characterized. This study aimed to determine LTBI proportions across preplacement, post-exposure, and annual screening approaches, and to identify factors associated with LTBI among HWs. This retrospective analysis (2016-2022) utilized secondary data from an LTBI surveillance program at a large Thai tertiary hospital. HWs underwent LTBI screening with interferon-gamma release assays (IGRAs) through three surveillance approaches: preplacement, post-exposure, and annual screening in high-risk units (2021-2022). LTBI was defined as IGRA-positive in the absence of active TB. Demographic and exposure characteristics were recorded; associations were analyzed using chi-square and Mann-Whitney U tests. An exploratory restricted analysis using multivariable logistic regression was also performed to assess between-cohort patterns. Between 2016 and 2020, LTBI was detected in 198 of 1,823 HWs (10.9%; 95% CI: 9.5-12.4). Preplacement screening identified LTBI in 96 of 1,230 HWs (7.8%; 95% CI: 6.5-9.5), while post-exposure surveillance detected LTBI in 102 of 706 HWs (14.4%; 95% CI: 12.1-17.2). Annual surveillance (2021-2022) yielded 47 cases among 626 HWs (7.5%; 95% CI: 5.7-9.8). Among HWs diagnosed with LTBI in the preplacement and post-exposure cohorts, 40.9% of LTBI cases initiated TB preventive treatment. In post-exposure surveillance, older age and higher exposure-priority categories were associated with LTBI, although estimates for priority categories were imprecise because of sparse data. LTBI remains an important occupational health concern among HWs, with the highest detection proportion observed during post-exposure surveillance. These findings highlight the ongoing need for targeted, risk-based monitoring and efforts to enhance TB preventive treatment uptake in healthcare settings.