'Superspreaders' Driving the COVID-19 Pandemic, Contact-Tracing Study Shows

Ralph Ellis

October 02, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

A small number of infected people are the main cause ofthe coronavirus's spread, according to a massive contact tracing study conducted in two Indian states.

The study published in Science found that 8% of infected individuals were responsible for 60% of new infections. Meanwhile, 71% of infected individuals did not infect anybody.

"Superspreading events are the rule rather than the exception when one is looking at the spread of COVID-19, both in India and likely in all affected places," said lead researcher Ramanan Laxminarayan, a senior research scholar at the Princeton Environmental Institute (PEI), according to a news release from Princeton.

The release said this was the largest contract tracing study of any disease in the world.

Researchers from the PEI, Johns Hopkins University, and the University of California, Berkeley, coordinated with public health officials in the Indian states of Tamil Nadu and Andhra Pradesh. They studied 575,071 people who had been exposed to 84,965 confirmed cases of COVID-19, the release said.

The study confirmed that children and young adults were the key demographics in spreading the virus and that they're most likely to spread the virus to somebody their own age.

The role of children has been in question since the pandemic began. Young adults make up about a third of COVID-19 cases, the news release said.

"Kids are very efficient transmitters in this setting, which is something that hasn't been firmly established in previous studies," Laxminarayan said. "We found that reported cases and deaths have been more concentrated in younger cohorts than we expected based on observations in higher-income countries."

The releasesaid COVID-19 deaths in India occurred, on average, six days after hospitalization, compared to 13 days in the United States. Deaths in India have been concentrated in ages 50-64, compared to the 60-plus demographic in the United States.

India has the second-most COVID cases in the world with 6.3 million, according to Johns Hopkins University. The United States has 7.2 million. India has a much bigger population ― 1.3 billion people compared to around 329 million in the U.S.

Sources

Science. "Epidemiology and transmission dynamics of COVID-19 in two Indian states"

https://science.sciencemag.org/content/early/2020/09/29/science.abd7672

"Superspreading events are the rule rather than the exception when one is looking at the spread of COVID-19, both in India and likely in all affected places," said lead researcher Ramanan Laxminarayan, a senior research scholar at the Princeton Environmental Institute (PEI), according to a news release from Princeton.

https://environment.princeton.edu/people/ramanan-laxminarayan/

Princeton University. "Largest COVID-19 contact tracing study to date finds children key to spread, evidence of superspreaders."

https://www.princeton.edu/news/2020/09/30/largest-covid-19-contact-tracing-study-date-finds-children-key-spread-evidence

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....