Study: Contact Tracing Effective in Controlling Spread of Coronavirus

A recent study by professors at College of Science and the Schar School of Policy and Government indicates coronavirus is transmitted in densely populated venues—such as music concerts—and travels great distances, infecting new populations as it spreads from its location of origin. The study was published this month in the journal of the International Society of Travel Medicine.

Researchers, including Schar School Director of Research and Associate Professor Naoru Koizumi and College of Science Interim Dean Ali Andalibi, spent two months beginning in mid-February following developments from a series of live house concerts in Osaka, Japan. The researchers, which included Schar School public policy PhD student Abu Bakkar Siddique, examined the virus’ spread through the concerts in a two-month period.

“The study points to the importance of social distancing and other precautionary measures, given that close contact, as well the significant number of asymptomatic carriers both appear to contribute to the spread of the disease,” said Andalibi, who is a molecular biologist and geneticist.

“We identified the ‘seed’ person who subsequently infected over 100 people in 13 prefectures—including primary, secondary and tertiary transmissions,” said Koizumi. “The virus quickly spread to 100-plus people after the concert, but the effective contact tracing managed to stop the transmissions from this cluster completely within less than two months.”

Contact tracing is the practice of finding and monitoring individuals who may have had contact with an infectious person.

The study, Siddique suggested, points to the importance of contact tracing in the presence of asymptomatic patients.

“I was surprised that asymptomatic people can infect other people as effectively as symptomatic people,” he said, noting that more than a quarter of the infected concert goers were asymptomatic. “The active contact-tracing measures—called ‘cluster countermeasures’—implemented by the government of Japan have helped the nation to reduce the potential impact of the virus.

“Contact-tracing is an effective strategy to minimize infections, so the U.S. should emphasize more on developing and executing contact-tracing method to reduce the spread of the virus.”

The takeaway from the study for Siddique?

“Family is a big source of infections where close contact is inevitable. Individuals need to behave responsibly not only for themselves but also for their loved ones with whom they live with.”