An investigation of COVID-19 outbreak in a community hospital, Chiangrai Province, Thailand, May 13-16, 2023

Abstract

Background: According to the weekly report on the COVID-19 situation from the Department of Disease Control, the Ministry of Public Health, for week 19 of the year 2023 (May 7-13, 2023), a total of 2,356 new cases were admitted to hospitals. This represents an average of 334 cases per day. There is a trend of 8.7-fold increase in new cases compared to the previous week. On May 12, 2023, the Disease Control Unit of a community hospital in Chiangrai province was notified by the operating room staff that 8 operating room staff had tested positive for COVID-19 using ATK tests. The disease control staff therefore conducted a disease investigation.

Objectives: To confirm the diagnosis and outbreak of the disease, identify contacts, sources of infection, and factors affecting the infection, describe the epidemiological characteristics, and find ways to control the disease.

Methods: A descriptive epidemiological study was conducted. The case definition was as follows: A suspected case was a person with any of the following symptoms: fever of 37.50°C or higher, cough, sore throat, loss of smell, loss of taste, and a positive Antigen test kit (ATK) for SARS-CoV-2. A confirmed case was a person with the above symptoms and a laboratory test positive for SARS-CoV-2 genetic material. The study included hospital staff and contacts from April 22 to June 21, 2023. The environment was also studied for its relationship to the outbreak. Results: There were 13 suspected cases and 3 confirmed cases. The male-to-female ratio was 1:3. The median age was 34.50 years. The attack rate among operating room staff was 91.67%, 75.00% in females, 68.42% in the age group 20-59 years, 78.95% had received 3 or more doses of COVID-19 vaccine, and 65.22% had received the last dose more than 6 months ago. No patients had severe symptoms or died. The most common symptom was cough (100.00%). The outbreak was a propagated source outbreak. The environmental study found that before the outbreak, the operating room staff had close contact without wearing masks and ate together. There were patients who had contact with the same household as the staff and the structure of the operating room did not meet the standards set by the Ministry of Public Health. Most of the patients who met the definition were medical personnel in the operating room. The exact start of the outbreak was unclear. Factors associated with the outbreak were eating together among operating room staff, close contact without wearing masks, especially in enclosed spaces, and being a household contact.

Conclusion and Recommendations: This outbreak was an outbreak of COVID-19 in a community hospital, Chiangrai province. Infection prevention measures in staff and the operating room structure should be improved and developed further.