No one knows why these Covid-19 patients’ symptoms keep relapsing

“When am I going to be free from this?”: the mystery of coronavirus relapse.

On April 11, more than a month after she first fell ill with Covid-19, Melanie Montano spritzed perfume around her bedroom to test her senses. She couldn’t smell anything.

The next morning, Montano woke up and noticed a “faintly fragrant” scent; her symptoms were finally subsiding. She had more energy for household chores, phone calls with friends, and remote work.

“I felt a massive wave of encouragement zap me back to life,” said Montano, 32, who lives in New Jersey. Then, five days later, fever, shortness of breath, and crippling gastrointestinal issues suddenly returned. “This has been the pattern, on-and-off, ever since.” Now, over two months after she first fell ill, Montano still has symptoms.

In May, the World Health Organization announced that Covid-19 recoveries were taking longer than expected, and that some patients were experiencing what appeared to be a “relapse” of symptoms. This contradicted an earlier WHO report, which stated that recovery for non-severe Covid-19 cases should only take two weeks. That guidance has been questioned, as more stories of long recoveries and lingering symptoms emerge.

It’s too early to really know what is causing symptom relapse, according to several physicians I spoke to, but almost all of them reported treating or hearing about patients who had cycling symptoms. Doctors and research scientists aren’t sure whether potential relapses mean patients are still infectious — and if the recurrent symptoms are from other infections, viral reactivation, chronic post-viral conditions, or the virus simply taking its normal course.

For patients who think they’ve recovered from Covid-19, symptom relapses can be emotionally, physically, and financially devastating. For researchers looking for answers, the relapses remain one of the ongoing mysteries of Covid-19.

When it just keeps coming back

In researching symptom relapse, I spoke with over a dozen patients who believed they’d experienced the return of symptoms at least once during their lengthy recoveries from Covid-19. Almost all first became sick in March, tested positive for Covid-19 within the following month, and are still experiencing symptoms today. Most sought medical care during their perceived symptom relapse(s), but few were satisfied with the advice they got.

Susan Nagle, 54, of Massachusetts, first experienced symptoms in late March, and tested positive in April. A month into her illness, her symptoms began to disappear. She was finally fever-free, and her fatigue, chest pain, and shortness of breath improved significantly.

“I was starting to be able to get projects done around the house … and I realized I wasn’t walking around with my pulse oximeter,” Nagle said. Then, on May 9, Nagle’s fever returned, spiking at 101 degrees Fahrenheit. Eventually her chest pain and breathlessness came back, as well. Today, Nagle is battling symptoms that she says are “worse than they were at the start.”

Courtesy of Susan Nagle

Cara Schiavo, 31, of New Jersey, experienced a similar episode. She tested positive for COVID-19 on March 10, and was sick with fever, shortness of breath, and chest pain.

On week four, her symptoms started to subside. “I felt like I was getting back to my old self,” Schiavo said. “I started walking, exercising and even told family and friends [I’d] recovered.” A week later, her symptoms returned, along with new dermatological and GI issues. “Relapse to me is a scary word,” Schiavo said.

Until the WHO’s recent announcement, it was mostly just Covid-19 survivors and patients using the word “relapse.” Montano, said until she joined an online support group where others were discussing it, the concept of “relapse” felt like a “feverish supposition.”

Nagle said she doesn’t think of her experiences as relapses. “I think this is [just] what it means to have COVID-19,” she explained.

Not knowing if they’re infectious, relapsed patients are staying home from work and fear their illness will get worse

Many of the patients I spoke with have not been able to return to work, even remotely, because they still feel sick, and some fear that excess activity triggers their symptom relapses. None have received confirmation from doctors about whether they’re still infectious.

Montano and Schiavo sought medical care when their symptoms returned, but neither was satisfied with the answers they received. “My [primary care doctor] was less than helpful,” Montano told me. Schiavo says her doctor dismissed her symptoms as anxiety.

After three months of isolating at home, Montano relapsed again in late May, and her doctor suggested she be retested for Covid-19. She went to a drive-through testing center, where she had to self-administer a nasal swab, and received a negative result. The test result confused Montano, given her recurrent fever and other symptoms, but she has continued to isolate at home in case she is still infectious.

Daniel Kuritzkes, the Chief of the Division of Infectious Diseases at Brigham and Women’s Hospital in Boston, says that patients returning to work face “a real challenge,” given the lack of information on contagiousness. When asked whether patients like Montano should be concerned about returning to work due to their lingering symptoms, Kuritzkes said, “we don’t have a good answer for that at the moment.” The question of when to return to work is especially confusing for healthcare workers and others who employers sometimes require to test negative before they can resume their jobs, he added.

Angela Aston, 49, is a registered nurse in Texas who contracted Covid-19 in late March while treating a patient. She hasn’t returned to work since April 23, when she thought she had recovered from the virus, after being fever-free for 72-hours. But at the end of her shift that day, Aston noticed she was feeling “shaky and weak,” and by the following afternoon, her fever and shortness of breath had returned. “I was confused [and] anxious,” Aston told me. “I had a meltdown in the staff lounge.”

Courtesy of Angela Aston

While Aston is eager to return to work, none of her doctors know if she’s actively infectious, and she says her workplace has “no idea” when it would be safe for her to return. “The [CDC’s] return to work guidelines say three days no fever, but those guidelines are not appropriate for me,” Aston said. “People freak out if a person with recent Covid-19 has an elevated temperature and wants to be around them. Even if it has been ten days with no fever.” Aston has been re-tested three times — one negative result, followed by two positives.

Since return to work guidelines vary and retesting can be unreliable, many relapsed patients face confusion and financial distress.

Zackary Berger, a primary care doctor and associate professor at Johns Hopkins School of Medicine, thinks retesting relapsed patients isn’t helpful because the test results aren’t always reliable. Some researchers estimate the rate of false negatives to be around 30 percent, due in part to discrepancies in how tests are administered, and the variety of types of tests that are being used.

A recent study from South Korea suggests that patients may test positive even after they have fully recovered and are no longer infectious. Because the 285 survivors did not appear to have infected any of their 790 close contacts, and the virus in their samples did appear to be alive, researchers now believe tests may be picking up small remnants of the virus that remain in the body even after recovery.

Berger says he sees many patients who need documentation that they’re virus-free to return to work, but his institution does not recommend re-testing, given the concerns about current testing methods.

The Centers for Disease Control and Prevention recommend guidelines for healthcare workers returning to work after being sick, which are dependent on test availability and follow either a test-based strategy (fever and respiratory symptoms have improved, and the worker has tested negative) or a symptom based strategy (the worker has been fever-free for 72-hours, and 10 days have passed since symptoms first appeared). The CDC currently does not require that any employee in the US test negative before returning to work.

Aston wants to go back to work, and is frustrated by the duration of her illness. “When am I going to be free from this?” she asked. “For another ten days? Twenty days? Because my fever always comes back.”

Montano feels similarly alone. “I felt anxious, I felt confused, and I felt the need to slap on a facade that aligned with the speedy, two-week recovery period depicted in the news,” she said.

Aston knows she’s lucky to still be earning wages, even though she can’t return to work. On May 4, almost two months into her illness, Montano lost her job as a post-graduate academic writing instructor, when the position was made redundant. Now, Montano’s struggling to find a new source of income, while managing her recurring symptoms.

“The job-hunting process is already work in itself, and it’s been exhausting having to push myself harder than my body is able to,” Montano said. “My first inclination is to tackle the job search with full-force, but the stark reality is my debilitating fatigue continues to impede any successful attempts to be proactive.”

Aston has found her fever often returns after she gets out of bed and moves around. One doctor she consulted suggested she stay in bed to avoid future relapses. She found this advice unrealistic. “Not a single healthcare provider has offered any solid, tangible guidelines on what to do next to address my issues,” she said.

For patients like Montano, Nagle, and Aston, who say they can’t see an end in sight, long-term impacts may be physical, mental, and financial. Gary Phelan, an employment lawyer in Connecticut, told me the Equal Employment Opportunity Commission has not yet decided whether Covid-19 will be recognized as a disability under the Americans with Disabilities Act, because the virus is so new.

Phelan, who has represented Covid-19 patients, says “until the EEOC takes that position it will lead to more uncertainty and, as a result … more COVID-19 victims losing their jobs or not being accommodated.”

We don’t know why people are relapsing. Here are some early guesses.

Based on the limited understanding of Covid-19, there are four possible explanations for patients who seem to experience symptom relapse. All are currently theoretical; the physicians I spoke to warned that science and medicine are still struggling to catch up with the novel virus. We don’t yet have hard evidence that any of these explanations are the true culprit, and other infections may explain symptom relapse, too.

1) The virus might be reactivating

The word “relapse” implies a resurgence of something previously dormant or non-existent, and many patients I spoke to assumed they’re experiencing some kind of viral reactivation. According to Bernard P. Chang, an emergency physician and psychologist at Columbia University in New York City, “viral reactivation is the concept that a latent or ‘not active’ virus that is already within your system ‘awakens’ or switches to an active phase and begins causing symptoms in patients.”

Viral reactivation is well-known in other illnesses, such as herpes, which remains dormant in between outbreaks. But it’s not a proven (or disproven) aspect of the new coronavirus. Kuritzkes thinks it is unlikely that SARS-CoV-2 can reactivate, because the virus infects and spreads differently than ones that do so. Right now, this is a possibility, but we don’t yet have scientific data either way.

2) People might be getting reinfected

Can someone get the coronavirus, completely clear it from their system, and then catch it all over again? The answer would depend on whether people can develop immunity to the coronavirus (and if so, for how long).

Scientists and researchers are urgently trying to answer this question, as governments all over the world pin hopes on a wave of immune survivors who can travel freely and revive the economy.

Recent studies on immunity bode well for the possibility, but the WHO warns there’s no guarantee. One such experiment found that rhesus macaques monkeys that were infected once were not able to be reinfected.But that’s just one study, and a lot of research remains to be done. In order to determine if humans can become immune, scientists will need to further study B cells and T cells (which help to create antibodies), improve the accuracy of antibody tests, and determine what level of antibodies confirm some level of immunity.

3) It might be the normal course of Covid-19

Jeremy Faust, an ER doctor and colleague of Kuritzkes at Brigham Women’s Hospital in Boston, told me that mild viral symptoms often “return or get a little worse after initially recovering,” citing the common cold as one example. “Some may simply have coronavirus symptoms that come and go, but slowly improve over time, like a pendulum running out of energy,” he explained. “I can’t think of any illness that doesn’t ebb and flow in terms of symptom resolution, to some extent. So in that regard, coronavirus may be no different.”

4) Relapses might be chronic post-viral syndromes

Many of the patients I spoke with were concerned their condition might be chronic, because of how long their symptoms had lasted, and how regular their relapses were. “My fear is that ‘relapses’ are my new normal and this has done permanent damage,” Nagle told me. “I have yet to hear a story of someone who has had the same symptoms for the same length of time and are now back to whatever they called normal before they were infected.”

Despite some patients’ fears that their symptoms will never end, Kuritzkes is optimistic. He urges people facing non-linear recoveries to “not get discouraged” though they should speak to a healthcare provider if they experience high fevers, joint swelling, or persistent fatigue. “Based on what we know about coronaviruses generally, it is very likely that all of these individuals will completely recover,” he said.

Kuritzkes, Chang, and Berger all mentioned post-viral syndromes as a possible explanation for symptom relapse — although Kuritzkes doesn’t think such post-viral syndromes are likely to be common — and many patients I spoke with had received similar information from their doctors.

Neil Stone, a specialist in tropical and infectious diseases at University College London Hospitals, recently tweeted that he’d seen an uptick in hospitalizations of patients recovering from COVID-19, and theorized that the “wide array of covid phenomena which we don’t yet understand … may one day come to be known as Post Covid Syndrome.”

According to Kuritzes, post-viral fatigue syndrome, for instance, is sometimes found in patients who’ve had mononucleosis, among other infections. “I’ve heard anecdotally of some [Covid-19] patients who seem to be experiencing something akin to that,” Kuritzkes explained. “Since we’ve only got three to four months of experience in the United States, it’s very hard to say what proportion would go on to develop … some form of post viral fatigue syndrome.”

Some researchers are also concerned that Covid-19 might trigger ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome), after noticing that some patients with pre-existing ME/CFS experienced an exacerbation of those symptoms after contracting COVID-19. The Open Medicine Foundation, an organization dedicated to ME/CFS research, recently announced a study which will examine the prevalence of potential chronic conditions like ME/CFS in patients with Covid-19.

Another possibility Kuritzkes suggests is that patients with relapsing symptoms may be experiencing an inflammatory syndrome similar to Kawasaki disease, which has recently been linked to cases of COVID-19 in children and young adults and causes an inflammation of blood vessels that can lead to severe cardiac complications. However, we don’t yet know if this syndrome can develop in people of all ages.

Like many other aspects of the current pandemic, the question of relapse remains unanswered, and the stakes are increasingly high. Almost 2 million people have been diagnosed with Covid-19 in the US alone, and experts believe infection rates may peak again in the fall. Stories of relapsed patients indicate that those who fall ill and survive may still face devastating consequences of the disease.

Fiona Lowenstein is the founder of Body Politic, a queer feminist wellness collective, events series, and media company aimed at creating content and events on accessible wellness for marginalized populations. Her last piece for Vox was about the Covid-19 survivor support group she founded.

Support Vox’s explanatory journalism

Every day at Vox, we aim to answer your most important questions and provide you, and our audience around the world, with information that has the power to save lives. Our mission has never been more vital than it is in this moment: to empower you through understanding. Vox’s work is reaching more people than ever, but our distinctive brand of explanatory journalism takes resources — particularly during a pandemic and an economic downturn. Your financial contribution will not constitute a donation, but it will enable our staff to continue to offer free articles, videos, and podcasts at the quality and volume that this moment requires. Please consider making a contribution to Vox today.