New research shows that the likelihood of a COVID-19 patient to infect another person depends heavily on the circumstances and is mostly transmitted through superspreader events.
In the wake of the coronavirus pandemic, numerous epidemiologists found that superspreader events are responsible for more than half of the COVID-19 transmissions. Such occasions, according to disease experts, prompt the spread of coronavirus to a large number of people unevenly.
Recently, Hongkong-based researchers discovered that only 20% of coronavirus patients are the source of the virus and that the remaining 80% were contaminated due to superspreader events—mostly indoor gatherings like birthdays, office, and church activities.
70% of coronavirus patients did not infect another person
The coronavirus appears to behave differently from what experts previously thought. Based on the research article Clustering and Superspreading Potential of SARS-CoV-2 Infections in Hongkong, epidemiologists had also found that 70% of COVID-19 cases did not infect or transmit the virus to another person.
According to the study, it is said that the epidemiologists used contact tracing to identify the cause, in which they were able to examine several clusters of coronavirus cases.
They track down all individuals who interacted with a COVID-19 patient. Through the process, they learned that almost all situations lead to a single person as the source of the virus. Surprisingly, one person can infect six to eight persons.
“Superspreading events are happening more than we expected, more than what could be explained by chance. The frequency of superspreading is beyond what we could have imagined,” Ben Cowling, a co-author of the said research, shared with Business Insider.
The study also emphasized the while superspreader events account for most cases, the people who transmitted the virus are those with more contacts, particularly those who interact beyond their family members.
A study conducted in Israel also suggests the same result: 80% of coronavirus transmission was prompted by one to 10% of infected people. The researchers, however, used genome sequencing.
How superspreader events prompt virus transmission
Superspreader events, fortunately, share most of the same characteristics. Mainly, it involves indoor social gatherings filled with several individuals that came from different households and with poor ventilation.
A good example is one from South Korea. Months ago, the country had experienced an outbreak in Seoul, which took place in a call center. According to the report, out of 811 workers, 97 of them had contracted the virus. 94 of the employees sat on the same floor as well, while 79 of them were in the same section.
A churchgoer in Daegu, South Korea, had also prompted 43 infections, while a chorale singer in a Washington church transmitted the virus to 53 people while practicing. Studies show that restaurants have a high risk of spreading the coronavirus too.
On the other hand, Cowling explained that the outbreaks do not show how contagious a person is, but the type of activity and interaction involved.
At the same time, Cowling is hopeful that through these studies, it could help policymakers in creating rules as the world enters the “new normal.” “Now we know which measures might give you the most bang for your buck,” he said.