Disease Control Journal

A study of the outcomes of a model development for HIV self-test kit accessibility

2025-05-21T10:27:51+07:00

This study aimed to investigate the outcomes of developing an access model for HIV self-test kits at Lerdsin Hospital between October 1, 2021, and September 30, 2024. This information was crucial for service planning and strategic activity planning. The goal was to promote access for targeted groups, who were hesitant to seek testing services at the hospital and did not disclose their HIV status, and to enable them to undertake HIV testing and to know their HIV status. Data collection involved creating a data collection table to record information from individuals interested in receiving HIV test kits through outreach campaigns and peer referrals. Data were retrieved from dashboard reports at www.prepthai.net/sns/home; then analyzed with descriptive statistics, including frequency distribution, counting, and percentages. The study found that a total of 116 individuals requested HIV self-test kits. The majority were male (73.25%) and belonged to the general population (59.90%), who were accessing registration through outreach campaigns (70.69%) and peer referrals (29.31%). Notably, a portion of these individuals were not acquainted with their peer referrers (39.53%). HIV self-test kits were primarily distributed via home delivery (55.17%), and a significant proportion of recipients had never been tested for HIV (56.90%). The operational recommendations suggested a development of a referral system for confirmatory diagnostic testing and follow-up on referrals. Furthermore, the study's model should be adapted for future work to reach targeted groups who were hard to reach and reluctant to disclose their HIV status.

The Epidemiological Characteristics of Mushroom Poisoning Outbreaks in Thailand,2013 and 2023

2025-05-26T12:07:45+07:00

This study is a cross-sectional study that retrospectively collected secondary data from the Outbreak Investigation Reporting System of the Department of Disease Control. The objective was to describe the magnitude of the problem, distribution and types of mushrooms associated with the severity of death from mushroom poisoning in Thailand from 2013 to 2023. Descriptive statistics, including frequency, percentage, median, maximum, and minimum values and Inferential statistics were applied using univariate logistic regression analysis to present odds ratios. The study identified 214 outbreak events, involving 931 patients and 81 deaths (case-fatality rate of 8.73%). The median number of patients per outbreak was 3 (range: 1-30). The proportion of male and female patients was nearly equal. The most common symptoms were gastrointestinal-related (66.10%). The highest number of outbreaks occurred between May and July, with a median of 2 outbreaks (range: 0-14), while the lowest occurred between January and April, with a median of 0 outbreaks (range: 0-1). The highest number of outbreaks was reported in Health Region 1 (57 events), followed by Health Region 10 (51 events) and Health Region 12 (20 events). Regarding the identification of mushrooms causing outbreaks, 159 events (74.30%) involved mushrooms definitively identified as poisonous. There were 89 events (41.59%) where the species of mushroom was either unspecified or unknown, and 21 events (9.81%) where mushrooms were identified as edible or with unclear classification. Analysis of symptoms by mushroom poison groups revealed that gastrointestinal symptoms were the most commonly reported events across all mushroom types. Secondary symptoms, particularly in cases involving mushrooms with unclear or erroneous classification, included neurological symptoms (13.33%). The study identified specific mushroom species that were significantly associated with the severity of mortality. These included Amanita hemibapha (OR=9.00, 95% CI=1.38-58.44), Astraeus odoratus (OR =10.00, 95% CI=1.44-69.26), Gyrodon spp. (OR=17.50, 95% CI=1.96-155.59), and Termitomyces spp. (OR=10.00, 95% CI=1.02-97.50). The quality of data in outbreak investigation reports is critical for comprehensive analysis. Therefore, improving data management, including complete and accurate tracking of poisonous mushroom species, is essential for planning and implementing effective surveillance and control measures at the local level.

Factors Associated with Self-Care Behaviors among Older Adults in Disaster-Prone Areas of Eight Upper Northern Provinces

2025-05-26T16:50:12+07:00

This cross-sectional descriptive study aimed to examine self-care behaviors and factors associated with the self-care behaviors among older adults in disaster-prone areas across eight provinces in upper northern Thailand. A total of 600 participants were sampled from the list of individuals aged 60 years and older residing in sprawling villages with a history of public health emergencies related to diseases and health hazards, including floods, earthquakes, haze, and acute respiratory infectious diseases. The study created a structured questionnaire to elicit information comprising general characteristics and self-care behaviors by an interview. The questionnaire had been assessed for content validity and attained the index of item-objective congruence (IOC) value between 0.67-1.00, and thereafter, a test of reliability by Cronbach’s alpha yielded a coefficient value of 0.68. The analyses were carried out using descriptive statistics, which include
percentages, means, and standard deviations. Inferential statistics, including chi-square tests and multivariable logistic regression analysis identified association of the factors. Statistical significance set out at a p-value level less than 0.05. The results revealed that 91.33% (95% CI=88.70-93.50) of older adults exhibited a good level of self-care behavior. Factors significantly associated with self-care behaviors included gender; family caregiving support, advocacy of government officials, and information received from the media (p <0.05). After controlling for these four factors, the multiple logistic regression analysis showed that female gender (AOR=2.47, 95% CI=1.35-4.51), family caregiving support (AOR=2.63, 95% CI=1.17-5.90), and advocacy of government officials (AOR=5.30, 95% CI=2.48-11.33) were significantly associated with self-care behaviors. Therefore, to ensure that older adults are fully prepared to cope with disasters, it is essential to promote self-care behaviors, particularly among older males. Additionally, fostering support from both family members and government officials can strengthen these self-care practices. Effective self-care behaviors contribute to reducing loss of life and property damage, as well as facilitating a quicker recovery to normalcy. This approach is a critical component of efficient public health emergency management.

Electronic health literacy and factors related to self-care behaviors among hypertensive patients in Nonthaburi Province

2025-05-26T11:17:48+07:00

Electronic health literacy is a significant determinant in enabling patients to adopt appropriate self-care behaviors to prevent complications that may lead to various diseases resulting from uncontrolled hypertension. This cross-sectional study aimed to examine electronic health literacy and the factors associated with self-care behaviors among patients with hypertension in Nonthaburi Province. The sample consisted of 267 hypertensive patients. Data was collected using interview questionnaires and analyzed using descriptive and inferential statistics, including the point-biserial correlation coefficient (rpb) and Eta coefficient. The results showed that 41.05% (95% CI=35.2-46.9) of the samples had a moderate level of electronic health literacy. Factors significantly related to self-care behaviors among hypertensive patients (p<0.05) were occupation, education level, comorbidity, and electronic health literacy. Consequently, public health organizations and relevant stakeholders should implement interventions to enhance electronic health information literacy, focusing on improving patients' knowledge and comprehension regarding online health information retrieval and their capacity to make decisions from online health information for their self-care practices.

Research and development of innovative underwater cover to eliminate mosquito pupae at Phra Achan Fan Arjaro Hospital in Phanna Nikhom District, Sakon Nakhon Province

2025-06-04T16:37:53+07:00

This research aims to study the mortality rates of mosquito pupae, create innovations to eliminate mosquito pupae, and to compare the average mortality rates of pupae. Sample pupae were collected from Village Group Number 8, Ban Khok Chumphon, Panna Subdistrict, Phanna Nikhom District, Sakon Nakhon Province. Experimental research was carried out from October 2024-January 2025 in investigational group and control group, each using 25 pupae and 10 replications tested. All mosquito pupae were classified into Aedes (Aedes aegypti + Aedes albopictus) and Culex pupae. During the study a trial disc, clear acrylic sheet, and product sheet were used as underwater cover inside the containers. The number of pupae deaths was recorded every 6 hours. Results: Mortality rates of Aedes and Culex pupae from a bottle with a lid were 92.00% and 93.20%, respectively. Development results: a trial disc used with a water glass indicated the mortality rates of Aedes and Culex pupae were 98.00% and 95.20%, respectively; while the mortality rates of Aedes and Culex pupae in clear acrylic sheet test unit were 85.60% and 90.80%; and product sheet test units were 85.60% and 90.80%. All experimental units detected the highest mortality rate in the first 6 hours. Results from independent samples t Test on the mean number of deaths of Aedes and Culex pupae in the experimental and control groups of the four pairs compared were significantly different (p<0.05). Aedes pupae: Bottle with/without a lid (MD=22.90; 95%CI=22.52-23.28) Glass with/without trial disc closed under water (MD=24.40; 95%CI=23.98-24.81) tank container with/without clear acrylic sheet closed under water (MD=21.30; 95%CI=20.68-21.92) tank container with/without product sheet closed under water (MD=21.30; 95%CI=20.68-21.92). Culex pupae: Bottle with/without a lid (MD=23.20; 95%CI=22.69-23.71) Glass with/without trial disc closed under water (MD=23.70; 95%CI=22.95-24.46) tank container with/without clear acrylic sheet closed under water (MD=22.60; 95%CI=21.90-23.30) tank container with/without product sheet closed under water (MD= 22.60; 95%CI=21.90-23.30). Innovation from this study are a clear acrylic sheet and product sheet which did not allow mosquito pupae to breathe at the water surface, resulting in its death. Underwater covers made from trial disc, clear acrylic sheet, and product sheet can effectively eliminate mosquito pupae with mortality rate of more than 85.60%. This innovative method maybe applied by a private sector and communities for the prevention and control of mosquito borne diseases.

Evaluation of the Acute Flaccid Paralysis Surveillance System in Health Region 8

2025-06-17T12:55:24+07:00

This surveillance system evaluation aimed to study the acute flaccid paralysis (AFP) surveillance process, assess both the quantitative and qualitative aspects of the system, and provide recommendations for AFP-related operations. It was a descriptive cross-sectional study that collected data from eight hospitals in four provinces within Health Region 8. Medical record reviews were conducted for patients under 15 years old diagnosed with relevant conditions (37 diseases) over the past two years (2023-2024), and for general diseases over the past year (2024). Interviews were also conducted with stakeholders at the hospital, provincial, and regional levels. The study found that hospitals had AFP surveillance guidelines in place and operated through multi-sectoral collaboration. Physicians and nurses served as the frontline in detecting and reporting cases to epidemiologists. A review of 2,605 medical records revealed a male-to-female ratio of 1.21:1, with a median age of 7 years (minimum 1 month, maximum 14 years). The 10-14 age group was the largest, accounting for 31.74%. Eleven cases met the AFP case definition, but only one case was reported, resulting in a low reporting sensitivity (9.09%), especially in large hospitals where report completeness was lower. The positive predictive value, representativeness, timeliness, and overall data quality were satisfactory. Stool samples were collected twice per patient, and case investigations and reports were conducted in a timely manner. However, follow-up on patient symptoms was incomplete, and active case finding was lacking. Interviews with stakeholders indicated recognition of the importance and benefits of the surveillance system. However, there was a lack of shared understanding and review of the surveillance guidelines within the organizations. Physicians and nurses often did not suspect AFP, resulting in underreporting and failure to meet surveillance standards. It is recommended that hospitals review and reinforce the knowledge and understanding of AFP definitions and surveillance guidelines among relevant personnel and implement active case finding measures to enhance case detection opportunities. Provincial and regional authorities should monitor, support, and expedite follow-up while seeking measures to strengthen the AFP surveillance system to ensure compliance with established standards.

Factors associated with treatment outcomes among patients with HIV receiving second-line antiretroviral drugs

2025-07-30T14:36:06+07:00

This study aims to assess the rate of virological suppression at 1 year and its associated factors among people living with HIV receiving second-line antiretroviral therapy (ART). We conducted a retrospective cross-sectional study of the medical records of second-line ART users with a HIV viral load > 1000 copies/ml. Data were analyzed using descriptive statistics and multiple logistic regression analysis. The results revealed that the proportion of virological suppression among people living with HIV receiving second-line ART at 1 year was 35.9% (95% CI=28.0%-43.8%). Factors significantly associated with viral load below 50 copies/ml were reported, including being aged 25-34 years (ORadj=12.1, 95%CI=1.4-103.4) and 35-49 years (ORadj=9.0, 95%CI=1.2-66.5), switching to second-line ART within less than 30 days (ORadj= 4.5, 95%CI=1.1-18.0), and having good adherence to second-line ART (ORadj=11.0, 95% CI=3.4-35.5). The study results indicate that the quality of health services for people living with HIV should be improved, especially timely switching to second-line ART after virological failure and promoting second-line ART adherence.

A pilot project to increase access to antiviral drug for treating chronic hepatitis C in 2022-2023

2025-06-30T14:53:28+07:00

Chronic hepatitis C is a major cause of liver cirrhosis and liver cancer. In previous implementations, access to screening services has remained limited due to the exclusion of such services from the national benefit package. Furthermore, notable barriers persist that hinder patients’ ability to access appropriate treatment, the Division of AIDS and STIs (DAS) initiated a pilot project to increase access to antiviral drug for treating chronic hepatitis C in 2022. The objective of this initiative is to improve access to hepatitis C virus (HCV) screening and treatment within pilot provincial settings. The project implemented a service delivery model in which trained general practitioners provide both diagnosis and immediate treatment across 3 pilot provinces. DAS provided reagents for hepatitis C viral load testing and antiviral drugs for those with a positive Anti-HCV result. Patients underwent confirmatory testing with HCV Viral Load. Those without complications received antiviral treatment for 12 weeks at community hospitals and monitored their treatment outcomes, administered by trained general practitioners. Local staff collected data from report forms and recorded treatment information in a reporting program and analyzed the data using descriptive statistics. The project results showed that 19,708 individuals in the target population underwent anti-HCV screening, with 2.2 % (425 individuals) testing positive for Anti-HCV. Among these, 96.2% underwent HCV viral load testing, with 87.5 % (358 individuals) testing positive. Of these, 98.6% (353 individuals) patients received treatment at community hospitals (CPH). Five individuals did not receive antiviral therapy: two patients with cirrhosis were referred to medical specialists, while three patients declined treatment due to work-related relocation. A total of 292 patients (82.7%) completed the 12-week antiviral treatment and follow-up, where 278 patients (95.2%) achieved a sustained virological response (SVR), indicating a complete cure. The implementation demonstrated that the target population had access to screening and received immediate and accurate treatment from trained general practitioners. In community hospitals, these physicians were able to manage and prescribe medications for patients without complications, thereby improving the timeliness and accessibility of care. Therefore, this operational model should be expanded to cover all provinces by providing training for doctors in community hospitals and establishing a consultation system with gastroenterologists in referral hospitals. Additionally, the system for recording screening and treatment data should be developed to link data with service units. Laboratory testing for hepatitis C should be integrated into the regular testing system to reduce referral costs from local service units. Finally, guidelines for managing hepatitis C should be developed to enhance understanding and efficiency among provincial staff.

The Relationship Between Health Literacy, Health Awareness, Health Behavior and Obesity among Staffs in Chonburi Hospital

2025-08-22T14:23:44+07:00

This study is a cross-sectional analytical study. The objectives were to examine the relationships between health literacy, health awareness, health behaviors, and obesity among hospital personnel, including the levels of these factors and the prevalence of obesity. The study was conducted among 815 personnel at Chonburi Hospital. Data were collected using a questionnaire that was validated for content validity by experts. Data analysis employed descriptive statistics including percentages, means, and standard deviations, as well as parameter estimation (means or percentages) at 95% confidence interval and Chi-squared test statistics. The findings revealed that the levels of health literacy, health awareness, and health behaviors among hospital personnel were at a moderate level, while exercise skills were rated as poor. The prevalence of obesity in hospital personnel was 38.4% (95% CI 35.1-41.8). Health awareness, health behaviors, and dietary habits were statistically significant associated with obesity (95%CI OR=1.22-2.52, 1.16-3.01, and 1.29-3.75, respectively). Therefore, it is recommended to promote health awareness and change health behaviors, particularly dietary habits, to prevent and reduce obesity. Additionally, organizing activities or programs aimed at enhancing health literacy, health awareness, and health behaviors to a higher standard is essential.

Factors relating COVID-19 vaccines procurement of Thailand Ministry of Public Health during pandemic situation

2025-06-24T10:20:33+07:00

This qualitative research aimed to study factors related COVID-19 vaccines procurement of Thailand Ministry of Public Health during pandemic situation. Data were collected through document analysis and in-depth interviews with 22 key informants from the Division of Communicable Diseases, the Institute of Urban Disease Control and Prevention, and 12 regional offices of the Department of Disease Control (Office of Disease Prevention and Control: ODPC). The results indicated that clear government policies were essential to support vaccine procurement during health emergencies. Notification of Ministry of Public Health specifying roles and responsibilities, along with the acceleration of COVID-19 vaccine registration, enabled timely vaccine distribution to risk groups. However, the existing procurement process, governed by the Public Procurement and Supplies Administration Act B.E. 2560 (2017), was not suitable for health emergency situation. This law created limitations in budget allocation for advance vaccine reservations that required the reliance on further special measures, including emergency decrees and Notification of Ministry of Public Health. The study highlighted the inadequacy of existing laws and the need to enhance government bargaining power to avoid unilateral terms from suppliers. Thailand’s inability to produce vaccines domestically hindered price negotiations and increased financial burdens. Therefore, vaccine security policies should promote technology transfer for upstream vaccine production. Furthermore, changing pandemic dynamics and viral mutations significantly influenced procurement decisions. A flexible, adaptive procurement strategy and strengthened international collaboration were recommended to improve accessibility and cost-efficiency. Transitioning from a centralized procurement system to a more diversified and collaborative model might also enhance timely vaccine access. In conclusion, policy direction, procurement procedures, legal frameworks, budgetary flexibility, and international coordination were important factors that influenced COVID-19 vaccine procurement during pandemic emergency situation.

The relationship between health literacy and health promotion behaviors among workers at Mae Fah Luang Chiang Rai International Airport

2025-07-09T15:20:57+07:00

This study aimed to examine the level of health literacy and health-promoting behaviors, to investigate the relationship between personal factors and health literacy, and to explore the relationship between health literacy and health-promoting behaviors among employees at Mae Fah Luang-Chiang Rai International Airport. Data were collected from December 2023 to August 2024. The sample consisted of 198 participants, selected through simple random sampling. The research instrument was adapted from the “Health Literacy and Health Behavior Assessment (3E.2S. - eating, exercise, emotion, stop smoking, stop drinking)” developed by the Health Education Division, Department of Health Service Support, Ministry of Public Health, for people aged 15 years and above. The questionnaire was revised to suit the study population without affecting the scoring of health literacy and health behaviors. Data were analyzed using frequency, percentage, mean, standard deviation, and multiple logistic regression. The findings revealed that most employees at Mae Fah Luang-Chiang Rai International Airport had poor health literacy while their health-promoting behaviors were at a fair level. Health literacy in the domains of self-management and media and information literacy was significantly associated with health-promoting behaviors. Employees with adequate self-management literacy were 2.71 times (95% CI=1.25-5.85) more likely to engage in appropriate health behaviors compared to those with inadequate literacy. Similarly, those with adequate media and information literacy were 2.58 times (95% CI=1.36-4.91) more likely to have appropriate health behaviors than those with inadequate literacy. After controlling for confounding factors, media and information literacy remained significantly associated with health-promoting behaviors (adjusted odds ratio=2.58; 95% CI=1.36-4.91). These results provide useful baseline information to support the development of appropriate health promotion strategies for Mae Fah Luang-Chiang Rai International Airport employees.

Prevalence and Factors Associated with Motorcycle Road Traffic Accidents among Undergraduate Students at a Higher Education Institution in Trang Province, Thailand

2025-08-22T14:26:05+07:00

This cross-sectional descriptive study aimed to examine the prevalence and factors associated with motorcycle accidents among undergraduate students in a higher education institution in Trang Province. The study included 299 participants. Data were collected in January 2025 using an online questionnaire distributed through Google Forms. The questionnaire covered personal factors, motorcycle information, riding environment, knowledge, attitudes, and behaviors related to accident prevention, as well as data on motorcycle accidents. Descriptive statistics and binary logistic regression analysis were applied at a significance level of 0.05. The results showed that 22.41% (95% CI=17.70-27.10) of the participants had experienced at least one motorcycle-related accident. The highest occurrence of accidents was observed in the evening (4 p.m.-6 p.m.). Environmental factors, such as rainfall and slippery road conditions, played a significant role in causing accidents. Factors significantly associated with motorcycle accidents among the participants included gender (COR=2.50, 95% CI=1.23-5.10), age (COR=1.96, 95% CI=1.13-3.40), and the experience of family members who had previously been involved in motorcycle accidents (COR=3.15, 95% CI=1.72-5.79). Male students, those aged over 20, and those with a family history of motorcycle accidents were more likely to experience accidents than other groups. Based on these findings, it is recommended to develop programs that promote safe driving among youth, enhance the enforcement of helmet use regulations, and provide training on driving in adverse weather conditions. These measures aim to enhance safety and sustainably reduce motorcycle accidents among students.

Factors influencing the performance of tuberculosis control roles among village health volunteers in Takhli District, Nakhon Sawan Province

2025-09-18T14:02:25+07:00

This cross-sectional study aimed to examine factors influencing the performance of tuberculosis control roles among village health volunteers (VHVs) in Takhli District, Nakhon Sawan Province. Data were collected using questionnaires administered to 193 (VHVs) who were responsible for the care of tuberculosis patients in the study area. Data analysis was conducted using multiple linear regression with the Enter method. The results showed that village health volunteers had good performance in tuberculosis control roles, accounting for 48.7%. of VHVs having demonstrated a good level of role performance in tuberculosis control. Factors positively associated with their performance included primary education (Beta=0.334), lower secondary education (Beta=0.308), work motivation based on motivator factors (Beta=0.280), and social support (Beta=0.678). Together, these factors significantly explained 56.1% of the variance in tuberculosis control role performance (p<0.05). These findings suggest that public health authorities should continuously promote activities that enhance both motivation and social support for VHVs. Additionally, knowledge and skill development through training programs tailored specifically to volunteers’ educational levels should be implemented to improve the efficiency and sustainability of tuberculosis control efforts.

The effects of a carbohydrate counting program on self-management behaviors to hemoglobin A1C (HbA1c) remission control in patients with type 2 diabetes

2025-09-17T13:54:52+07:00

This quasi-experimental study employed a two-group pretest-posttest design to examine behavioral scores for hemoglobin A1C (HbA1c) control among patients with type 2 diabetes mellitus (T2DM) and the achievement of diabetes remission after receiving a 14-week carbohydrate counting program. The study sample consisted of 88 T2DM patients with HbA1c levels between 6.5% and 10.0% from a community hospital in Roi Et Province. Participants were divided into an experimental group (n=44) and a control group (n=44). The intervention tools included a carbohydrate counting program (content validity index=1.00) and a behavior assessment tool for HbA1c control (content validity index=0.89; reliability=0.81). Data were analyzed using paired sample t-test, independent t-test, Wilcoxon Signed Ranks Test, Mann-Whitney U test, and McNemar Test. The results were as follows: (1) the experimental group had significantly higher post-intervention behavioral scores than their pre-intervention scores (p<0.05, 95% CI=-19.01-16.85) and the control group (p<0.05, 95% CI=9.13-11.65); (2) the experimental group demonstrated significantly lower post-intervention HbA1c levels than both their pre-intervention levels and the control group (p<0.05); and (3) a significantly greater proportion of participants in the experimental group achieved diabetes remission (HbA1c<6.5%) after the intervention (p<0.001), accounting for 72.73% of the group. These findings suggest that the carbohydrate counting program is an effective intervention for improving self-management behaviors and achieving diabetes remission in patients with T2DM without the need for pharmacological treatment.

Investigation of Health Effects from Exposure to Airborne Benzyl Chloride: Case of an Explosion of Uninterruptible Power Supply in a Hospital

2025-06-30T15:39:31+07:00

The Office of Disease Control and Prevention, Region 4 Saraburi Province (ODPC 4) was notified by the Lopburi Provincial Public Health Office (LPPHO) regarding an accident involving the explosion of an uninterruptible power supply (UPS) within a hospital, on 28 December 2024. Following the explosion, executives and staff concerned about their health effects due to the presence of residual chemical odor. ODPC 4 and related organizations conducted 4 onsite investigations on 6, 13, 15, and 16 January 2025, respectively. The objectives were to confirm the diagnosis, describe the incident, survey a potentially dangerous environment, and propose health measures to prevent chemical exposure. A descriptive epidemiological study was conducted by interview and chemical vapor was measured by the portable gas analyzers. Descriptive statistics were used to analyze data. The investigation found 129 people exposed to chemicals. Of those, 79 people presented symptoms of respiratory irritation followed by no symptom (48 people) and eye burning/tear flowing (36 people). Health surveillance of 55 people from high-risk groups, including blood lead levels, complete blood counts, blood nitrogen estimates, blood values indicating kidney function, and stress assessments, found that all high-risk groups maintain normal results. Benzyl chloride content was measured in averaged value of 3.61, 2.70, 3.22, and 1.21 ppm, respectively (Average standard value over the entire working period less than 1 ppm). Benzyl chloride vapor was deduced from considerable electrical insulation burning which contained polyvinyl chloride (PVC) and spread to different hospital areas. Due to the molecular mass of benzyl chloride is about four times heavier than the atmospheric air, it will acquire negative pressure after the air is aspirated from a room and the benzyl chloride will recur if not replaced by the fresh air. Therefore, residual benzyl chloride vapor was identified after air extraction in some rooms. Benzyl chloride half-life in air is four days. However, in the fourth measurement, the evaporation value of benzyl chloride decreased from the initial value in all areas, which is expected to be due to the aforementioned improvement measure. These findings suggest preventive measures should include studying chemical information before managing ventilation, as well as providing knowledge and protective equipment for staff properly in the area.