An Investigation of Coronavirus Disease (COVID-19) in a Chinese Tourist, January-February 2020: Surgical Mask Wearing in Pre-Physical Distancing Strategy

On 29 Jan 2020, the Operation team was notified by the Emergency Operation Center that there was a Chinese man infected with SARS-CoV-2 admitted in a private hospital in Bangkok. Division of Epidemiology, Office of Disease Prevention and Control 1, 11, and Institute for Urban Disease Control and Prevention jointly deployed to conduct an investigation. Descriptive study was conducted by interviewing the index case about his symptoms, travel history, and reviewing medical records. Contact tracing was done. Close contacts of the index case were classified to high-risk and low-risk contacts. Laboratory testing for SARS-CoV-2 was done among high-risk contacts and symptomatic low-risk contacts. The index case was a 30-year-old Chinese. He had worked in Guangxi province, China. He spent 2 days in Wuhan city and 2 days in Guangzhou city before traveling to Thailand. He developed fever, cough, and sore throat after being in Thailand for 3 days. According to the median incubation period of COVID-19, he could be infected from China.  Since he started traveling from China, he wore a surgical mask all the time. From contact tracing, the high-risk contacts that could be followed, none of them had laboratory test positive. Therefore, this strategy of wearing a face mask should be encouraged nationwide especially in case that physical distancing could not be done.