The first case of COVID-19 reinfection has reportedly occurred in Hong Kong. A 33-year-old man contracted the novel coronavirus this month after recovering from the coronavirus in April, according to multiple reports.

The man was returning to Hong Kong after a trip to Spain when researchers from the University of Hong Kong said he tested positive for the virus during a screening at the airport, according to the Japan Times.


The reported reinfection marks “the world’s first documentation of a patient who recovered from COVID-19, but got another episode of COVID-19 afterward,” the researchers told the Japan Times.

Using genomic sequence analysis, the researchers were reportedly able to detect that the patient was infected by two different strains of the coronavirus. The patient did not display symptoms from the second infection, which suggests that “subsequent infections may be milder," per the Japan Times.

“Before this report, many believe that recovered COVID-19 patients have immunity against reinfection, however, there is evidence that some patients have a waning antibody level after few months,” the researchers from the University of Hong Kong said in a statement to the outlet.

The novel coronavirus.  (iStock)

“Our results prove that his second infection is caused by a new virus that he acquired recently rather than prolonged viral shedding,” Dr. Kelvin Kai-Wang To, a clinical microbiologist at the university, told the New York Times.

The World Health Organization weighed in on the study, according to the Japanese Times, which noted the WHO’s technical lead Maria van Kerkhove told reporters that documenting cases like this one is important.

However, she cautioned “not jump to any conclusions," noting that larger studies of cases over time are needed to gain a better understanding of a patient’s antibody response to Sars- Cov-2, the novel coronavirus.

Infectious disease specialists told Fox News there been some reported anecdotal accounts of possible reinfection, but this is the first report involving a scientifically proven case.

Dr. Ravina Kullar, an infectious disease specialist in California, said the report is concerning.

“There have been prior reports of presumed reinfection, but none of those cases have been confirmed with rigorous testing," Kullar said.

Kullar, also a member of the Infectious Disease Society of America (IDSA), explained patients who recover from the novel coronavirus can shed viral fragments for weeks, giving some tests a positive result even though the virus is no longer live. But the 33-year-old man's case is a different scenario, Kullar noted.

“This report sequenced the virus from both rounds of infection and found differences in both sets of the virus, showing that the patient may have been infected a second time. This may support the finding that some patients [who] get infected with COVID-19 have diminishing antibody levels after just a few months," she said.


Dr. Aaron Glatt, an epidemiologist on Long Island, New York, made a similar statement, telling Fox News this case is significant since the reinfection of the virus was “a different strain of COVID-19, making it unlikely that it was just persistent dead virus from the first illness still being detected.”

Glatt, also a member of the IDSA, cautioned to keep the findings in perspective.

"While it clearly suggests what we suspected -- that COVID-19 immunity might not be lifelong -- it must be appreciated that this is the first case after 20,000,000 plus cases of COVID-19 worldwide. So while it is critically important to realize immunity may not last forever, at least in the short term, immunity is actually quite good," he said.