Outbreak investigation of coronavirus disease 2019 (COVID-19) in prison, Narathiwat Province, 11–15 October 2021

Abstract

Background: On 10^th October 2021, the operation team of Department of Disease Control was notified by the Office of Disease Prevention and Control Region 12, Songkhla Province, that 185 patients were infected with Coronavirus Disease 2019 (COVID-19) in a prison in Narathiwat Province. We jointly conducted an investigation to confirm the diagnosis, describe the epidemiological characteristics of the outbreak, identify possible factors of COVID-19 infection, and provide prevention and disease control measures.

Methods: We started with reviewing the situation of COVID-19 in prison, conducted active case finding using the definitions of anyone who had at least one of the following symptoms: body temperature > 37.3 degrees Celsius, cough, runny nose, sore throat, parosmia, dysgeusia, watery diarrhea, red eyes, rashes, tachypnea, or dyspnea, from September 27 to October 14, 2021. We conducted laboratory studies using RT-PCR for SARS-CoV-2 detection. The environment in the prison was surveyed.

Results: All probable and confirmed cases were found, with an attack rate is 19.74% (405/2,052). 96.54% of cases were prisoners, 3.21% were assistant officers, and 0.25% were border guards. All cases were male with a median age of 33 years (19–54 years), and the highest attack rate was found in Prison Zone 6 (38.63%). More than half (57.96%) of the cases had not been vaccinated, and there were no deaths or severe cases. The most symptoms were fever (43.46%), runny nose (32.91%) and headache (29.54%). RT-PCR results were positive among the early 14 cases. Not wearing mask at all times was a possible factor in COVID-19 infection in the prison, accounting for 100% of cases, while close contact with assistant staff who had been diagnosed with COVID-19 and was another a possible risk factor, accounting for 18.18%. Delayed detection of the early cases was identified.

Conclusions: This COVID-19 outbreak had a high attack rate. Possible factors of the outbreak included sleeping and engaging in daily activities together without wearing masks at all times, and the movement of assistant staff might have led to the spread of disease to other areas. We recommended stopping the relocation prisoners and staff, and regularly monitoring new infections by rapid antigen tests (ATK) screening among newly admitted inmates to reduce risk of the future outbreak.