Why Recovered COVID-19 Patients Are Testing Positive Again
Sat, April 10, 2021

Why Recovered COVID-19 Patients Are Testing Positive Again



The coronavirus is horrifying for many people, mainly because it is highly contagious and the death toll across the world continues to rise. But, despite these, the reality is that the vast majority of people who come down with COVID-19 have survived it. More than 1.7 million or 85% of all coronavirus cases are known to have recovered from the coronavirus.

"Eventually, if all goes well, your immune system will completely destroy all of the viruses in your system. A person who was infected with and survived a virus with no long-term health effects or disabilities has 'recovered’,” Tom Duszynski, director of epidemiology education at Indiana University–Purdue University Indianapolis, said. 

While this is good news for everyone, there are still many uncertainties that still have no answers: how the illness will affect the recovered patients in the long run or how long they will be immune. 



What Recovery is Like

Medical experts say that the recovery time of coronavirus patients will depend on how sick they become in the first place. For some, it might take weeks or months. Some people will shrug off the illness quickly, but for others, it could leave lasting problems. There are several risk factors that should also be taken into consideration such as age, gender, and other health issues. Dr. Shu-Yuan Xiao, a pathology professor at the University of Chicago School of Medicine, said that most people with mild cases of COVID-19 should recover "with no lasting effect."



However, it’s not the same for patients who develop a severe illness. Last March, Hong Kong’s Hospital Authority reported that two to three from a group of 12 recovered patients showed decreased lung capacity in follow-up visits with doctors. They reportedly gasped for air when they walked. Scans of nine patients' lungs also revealed signs of organ damage. According to Business Insider, a fast-growing business site with deep financial, media, tech, and other industry verticals, the disease may scar their lung tissue if they develop acute respiratory distress syndrome (ARDS). 

"It's the same general thing that you have with any type of phenomena that's severe enough to land you in the ICU," Dr. Amesh Adalja, an infectious-disease expert at the Johns Hopkins Center for Health Security, said. 

Dr. Bala Hota, a professor of infectious diseases and Associate Chief Medical Officer at Chicago's Rush University Medical Center, said that recovery doesn’t necessarily mean feeling all better. Even they are considered recovered and are no longer contagious, patients can still experience mild cough and feel tired. It can take a long time to fully get back to normal.

"It takes anything up to six weeks to recover from this disease. People who suffer very severe illness can take months to recover from the illness,” Dr. Mike Ryan, executive director of the World Health Organization's (WHO) Health Emergencies Program, said. 



Why Do Some People Test Positive Again?

Last April, officials from South Korea reported that 91 patients thought to have been cleared of COVID-19 had tested positive again. They experienced the same symptoms such as fever, cough, sore throat, and fatigue. “We are aware of these reports of individuals who have tested negative for Covid-19 using PCR (polymerase chain reaction) testing and then after some days testing positive again,” the WHO said. 

“We are closely liaising with our clinical experts and working hard to get more information on those individual cases. It is important to make sure that when samples are collected for testing on suspected patients, procedures are followed properly.”

Other countries also reported cases of reinfection. Health officials in Guangdong, China found out that 14% of patients retested positive for COVID-19, while at least one died five days after he was discharged and tested negative. According to Quartz, a business-focused English-language international news organization, the proportion of patients in Wuhan, China who tested positive after testing negative is between 5% and 10%. 



Jeong Eun-kyeong, the director of the Korea Centers for Disease Control and Prevention (KCDC), said that the virus may have been “reactivated” rather than the patients being re-infected. However, US health experts disagree, saying that they don’t think a reactivation of COVID-19 is likely since we’ve never observed viral reactivation in other coronaviruses. There’s a possibility that the patients were never fully cured of the disease and the virus never left their system. 

The most likely explanation to this, according to scientists, is that the test is picking up remnants of the virus. According to CNN, an American news-based pay television channel owned by AT&T's WarnerMedia, the reverse transcription-polymerase chain reaction (RT-PCR) test works by finding evidence of a virus's genetic information in a sample taken from the patient. KCDC deputy director Kwon Joon-wook said there’s a chance that the test may still be picking up parts of the RNA even after the person has recovered because the tests are so sensitive.

"That's one possible and very strong explanation," he said.

Another explanation is that the tests administered to these patients weren’t sensitive enough to distinguish between an active infection and one from which a patient has mostly recovered. “What many people don’t understand is that PCR tests simply for the virus’ genetic material and it is not an assay for an active virus,” Richard Condit, a molecular biologist and professor emeritus at the University of Florida College of Medicin, said. 

Unfortunately, the WHO said that they don’t have enough evidence to understand if and why some people may experience reactivation after recovery. According to Healthline, an American website and provider of health information, a lot of research is needed before they get to have a clear picture of the virus’s behavior. 

“The truth is that we don’t exactly understand the dynamics of how people who test negative after initial infection end up testing positive again. We need more studies to clarify this observed phenomenon,” Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City, said. 

South Korean health officials said that it’s still unclear what was behind the trend. The good news is that epidemiological investigations are underway. “As Covid-19 is a new disease, we need more epidemiological data to draw any conclusions,” the WHO said.