At least 51 patients in South Korea are confirmed to be positive again for coronavirus after leaving quarantine, said health officials this week. According to the Korea Centers for Disease Control and Prevention, the patients were already given a clean bill of health following an earlier diagnosis for COVID-19, with the agency sending them home in batches between March 26 to April 1.In a report carried by the Yonhap News Agency, KCDC Director-General Jeong Eun-kyeong said that the unusual results may have been due to the reactivation of the virus. The patients, she added, tested positive again for COVID-19 a “relatively short time” after they were first cleared of the disease. The agency has since sent epidemiological investigators to Daegu and the North Gyeongsang region to investigate the results further.
“We’re viewing these as examples of reactivation, not reinfection,” added Jeong. “We have yet to confirm any cases of second-generation transmission occurring from patients who’ve been released from quarantine, but we’ll consider the extent to which we should tighten surveillance [of people released from quarantine] after seeing the results of the epidemiological survey.”
Can reinfections trigger new outbreaks?
As the world grapples with the coronavirus, which has infected over 1.6 million people and caused over 95,000 deaths across the globe as of writing, researchers are also still learning more about this deadly virus. In particular, it’s still unclear if people who recover from the disease will be immune to reinfection.
“We don’t know very much,” explains Matt Frieman, a microbiologist and coronavirus researcher at the University of Maryland School of Medicine.
What Frieman and other experts do know is that SARS-CoV-2, the virus responsible for the global pandemic, is related to the four seasonal coronaviruses that cause up to 30 percent of common colds. But if the way that these viruses behave is any indication, that means people who have recovered are still prone to reinfection.
“I think there’s a very likely scenario where the virus comes through this year, and everyone gets some level of immunity to it, and if it comes back again, we will be protected from it – either completely or if you do get reinfected later, a year from now, then you have much less disease,” he added.
In the case of the coronavirus, experts are also worried that reinfections could mean that the virus may lie dormant in the body before reaching the lungs to wreak havoc to the system. The varicella-zoster virus, which causes chickenpox, works similarly. After an initial bout with chickenpox, the virus can reactivate several times and cause shingles in adults.
“Once you have the infection, it could remain dormant with minimal symptoms,” explains Philip Tierno, Jr., a pathology professor at New York University. “And then you can get an exacerbation if it finds its way into the lungs.”
The lingering question of whether a person can get reinfected with coronavirus is a cause for concern in countries like South Korea, where a scenario like this could present a vector for community-based transmissions. (Related: Second wave of coronavirus lockdowns return to China, shattering narrative that Beijing “has it all under control.”)
“The period of time after COVID-19 patients are [released from quarantine] and discharged from the hospital could be a chink in the armor of our efforts to combat the disease,” explained Kim Woo-ju, and infectious disease expert at Korea University Guro Hospital.
In Japan, a person tested positive for the disease again in February after showing signs of recovery, while in China, where the outbreak originated, around 14 percent of patients in the Guangdong province also tested positive again for the disease after they were released from quarantine.
Learn more about the ongoing COVID-19 pandemic at Pandemic.news.