Analysis of community-acquired COVID-19 cases in Taiwan

The demographic characteristics and transmission dynamics of the community-acquired coronavirus disease 2019 (COVID-19) cases in Taiwan were analyzed for more effective control and prevention of the community transmission of this novel disease.

Open-access data and press releases on COVID-19 in Taiwan were collected on the website of the Taiwan Centers for Disease Control. All 55 community-acquired cases of COVID-19 confirmed from January 28 to April 12, 2020, in Taiwan were included. Basic demographic characteristics, symptom presentation, infection source, route of identification, and transmission dynamics were analyzed.

Of the 55 cases, 52.7% were female and 74.5% were between 20-59 years of age. One-sixth (16.4%) of community-acquired cases were asymptomatic. More than half (58.2%) of the cases were identified via contact tracing. The median incubation period was 6 days (range 1-13 d) and the median serial interval was 4 days (range -3-24 d). Twenty-six cases (47.3%) were transmitted from presymptomatic cases, 11 cases (20%) from symptomatic cases, and 2 cases (3.6%) from an asymptomatic case. The contagious period of symptomatic cases was from 7 days before to 15 days after the onset of symptoms.

The high proportion of asymptomatic cases and the transmissibility in the presymptomatic and asymptomatic periods make control of COVID-19 challenging. Protective measures such as social distancing, wearing face masks, and hand washing are mandatory to prevent community transmission.