April 18 (UPI) — Some 163 South Koreans who recovered from COVID-19 have tested positive again for the virus, public health officials said as the global death toll surpassed 150,000 Saturday.
The Korea Center for Disease Control and Prevention said it’s trying to understand why the patients retested positive for COVID-19 despite previous negative tests.
Similarly, in China, some patients retested positive after they seemed to have recovered.
The issue raises the question of whether people are getting reinfected with the virus, there’s a possible a test error or the virus has been reactivated. For now, Korea CDC Deputy Director Kwon Joon-wook says the most likely explanation appears to be that the test is picking up remnants of the virus’ genetic information leftover in the body.
He added that remnants can be there without any live virus present. For example, scientists attempted to incubate the virus in individuals from the same family in which three retested positive after recovering. But they weren’t able to incubate it, which indicated no live virus was present.
Kwon also said that so far there has been no indication that patients who retest positive are contagious even with 44 percent showing mild symptoms.
“At the moment, we think there is no danger of further secondary or tertiary transmission,” Kwon said.
Still, he warned that scientists still don’t know much about naturally acquired immunity from the virus.
“COVID-19 is the most challenging pathogen we may have faced in recent decades,” Kwon said. “It is a very difficult and challenging enemy.”
South Korea has 10,653 cases and 232 deaths, the Johns Hopkins University global tracker reported Saturday
Globally, COVID-19 has sickened more than 2.2 million people and killed 154,789, the same tracker shows.
The United States has the leading number of cases at 706,779 and the most deaths at 37,079, followed by Spain, which has 191,726 cases and 20,043 deaths.
Italy has the third-highest number of cases at 172,434 and the second-highest number of deaths at 22,745. The number of patients in intensive care units has sharply dropped.
The number of intensive care patients dropped to 2,812 by Friday from more than 4,000 two weeks ago.
A nationwide lockdown has decreased the spread of the virus resulting in the decline, experts said.