The symptoms of the novel coronavirus usually take five days to show in an infected person, a new study has found.
The study, published on Monday in the journal Annals of Internal Medicine, looked at 181 cases of COVID-19 in China and other countries in order to estimate the length of the virus’s incubation period.
Researchers from Johns Hopkins Bloomberg School of Public Health said the average incubation time was 5.5 days.
The study said, though, that the incubation period could differ for milder cases.
The new coronavirus was first detected in China late last year. Since then, it has spread around the globe, infecting more than 118,000 people and claiming more than 4,000 lives as of Tuesday afternoon.
Researchers conducted the study early in the COVID-19 outbreak, when community transmission was limited to Wuhan, China — the city believed to be the epicentre.
This allowed them to track when an individual was exposed to the virus. They were able to use this data to estimate the virus’s incubation period.
“We have sort of a narrow window at the beginning of the epidemic to really tease out what’s going on,” the study’s senior author Justin Lessler, an associate professor in the Bloomberg school’s department of epidemiology told CNN. “If it’s everywhere, you don’t know where people got infected.”
The study suggests that the current recommended 14-day quarantine period for COVID-19 patients is “reasonable,” because in 97.5 per cent of cases studied, patients experienced symptoms within 11.5 days.
“Based on our analysis of publicly available data, the current recommendation of 14 days for active monitoring or quarantine is reasonable, although with that period some cases would be missed over the long-term,” Lessler said in a press release.
The study said, though, that in extreme cases, a longer quarantine period might be justified, with 101 out of every 10,000 infected individuals developing symptoms after the 14-day period.
Stanley Perlman, a coronavirus expert at the University of Iowa, who was not a part of the study, told Global News knowing a virus’s incubation period not only allows health officials to “hone down” on an appropriate incubation period, and also helps to determine the risk.[ad_2]