Figure 2. Development and transmission of severe acute respiratory syndrome coronavirus 2 among asymptomatic contacts, Thailand, March–April 2020. Clusters indicate coronavirus disease (COVID-19) contacts from nightclubs (A); boxing stadiums (B), and the state enterprise office (C). Black nodes represent primary index patients, red dots cases (contacts of primary index patients who had COVID-19), green dots noninfected controls, and orange dots patients with confirmed COVID-19 who could not be contacted by the study team. Black lines represent household contacts, purple lines contacts at workplaces, and gray lines contacts at other locations.