Suara.com – New research shows when patients are most infectious Covid-19. In this study, researchers stated that people are most infectious two days before and three days after they develop symptoms.
Launching from Medicinenet, these findings highlight the importance of rapid testing and quarantine if someone feels sick.
The researchers also found that infected people were more likely to be asymptomatic if they contracted the virus from a primary case who was also asymptomatic.
“In previous studies, viral load has been used as a measure of indirect transmission,” said study co-leader Dr. Leonardo Martinez, assistant professor of epidemiology at Boston University School of Public Health.
“We wanted to see if the results from previous studies showing that Covid-19 cases were most contagious a few days before and after the onset of symptoms could be confirmed by looking at secondary cases among close contacts.”
For the study, Martinez and his colleagues analyzed data from about 9,000 close contacts of primary cases in China’s Zhejiang province from January 2020 to August 2020. That was before the emergence of the even more contagious Delta variant.
Close contacts are people who live in the same household or who eat together, co-workers, people in the hospital environment and drivers in shared vehicles.
They are monitored for at least 90 days after their initial positive Covid-19 test result.
Of the primary cases, 89 percent had mild or moderate symptoms, 11 percent had no symptoms, and none had severe symptoms.
This research was published online August 23 at JAMA Internal Medicine.
Compared with mild and moderately symptomatic primary cases, those without symptoms were much less likely to infect close contacts. If infected, contacts are also likely to have visible symptoms.