SARS-CoV-2 transmission appears to mainly be spread via droplets and close contact with infected symptomatic cases. In an analysis of 75,465 COVID-19 cases in China, 78-85% of clusters occurred within household settings, suggesting that transmission occurs during close and prolonged contact.
(6) A study of the first patients in the Republic of Korea showed that 9 of 13 secondary cases occurred among household contacts.
(70) Outside of the household setting, those who had close physical contact, shared meals, or were in enclosed spaces for approximately one hour or more with symptomatic cases, such as in places of worship, gyms, or the workplace, were also at increased risk of infection.
(7, 42, 71, 72) Other reports have supported this with similar findings of secondary transmission within families in other countries.
(73, 74)