Asymptomatic people also responsible for virus spread

The transcript discusses a study by the CDC on COVID-19 cases in Singapore from January 23 to March 16. Researchers identified 7 clusters with possible pre-symptomatic transmission, with 10 cases confirmed. A detailed examination of two clusters, E and B, highlights instances of transmission before symptoms appeared. In Cluster E, a man traveled to Japan and infected his housemate before showing symptoms. In Cluster B, patient B1 likely contracted the virus at an event and later transmitted it to patient B2 during a singing class.

What was the primary focus of the study conducted by the Centers for Disease Control and Prevention in Singapore?

• The effectiveness of vaccines

• Pre-symptomatic transmission of COVID-19

• The role of masks in preventing infection

• The impact of lockdown measures

How many clusters of cases were identified in the study that showed possible pre-symptomatic transmission?

• 12 clusters

• 5 clusters

• 7 clusters

• 10 clusters

In the study, how many cases were determined to be due to pre-symptomatic transmission?

• 7 cases

• 5 cases

• 10 cases

• 15 cases

Where did the man in cluster E travel to, where he may have been infected?

• Thailand

• South Korea

• China

• Japan

What activity did patient B1 participate in that likely led to the transmission of the virus to patient B2?

• Attending a concert

• Going to a restaurant

• Participating in singing classes

• Visiting a shopping mall