Most people who get the coronavirus will fully recover and go back to their lives. But the latest research suggests that at least 10 percent have long-term symptoms, even after their body has apparently removed the virus.
The condition, known as ‘long covid’, emerged as a narrow feature of the pandemic – a reminder that millions of people will continue to suffer from infections as hospitalizations and deaths decline.
And, as it turns out, ‘it’s not unique to Covid,’ Akiko Iwasaki, an immunologist at the Yale School of Medicine, told Vox.
Instead, Covid-19 appears to be one of the many infections, from Ebola to sore throats, which can lead to persistent symptoms in an unhappy group of patients. “This is more typical than that a viral infection in some fractions leads to prolonged symptoms,” Iwasaki said.
The difference now is that long-term guards with 137 million Covid-19 cases worldwide are more visible: their suffering occurs in unprecedented numbers. It is also possible that the coronavirus causes even more long-term symptoms than other infections.
In this week’s episode of Unexplained, we go into what we know about long covid and what other viruses can teach us about the condition, including the main hypotheses for the symptoms that can cause the covid long-term drivers.
We also look at what we can learn from patients who have been struggling with medically unexplained symptoms for years – the kind that do not match problematic diagnostic test results or imaging – before the pandemic struck. Here’s an overview of what scientists think may explain the mysterious symptoms, and why even the vaccine may not help.
1) The virus and ‘viral ghosts’ did not actually leave the body
:format(webp):no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/22440780/1231882875.jpg)
The first explanation for what can cause persistent symptoms in people infected with Covid-19 is the simplest: the virus or its ingredients are still lurking somewhere in the body, long after someone has started testing negatively.
We have learned from other long-term viral diseases that pathogens in some cases do not cleanse the body. “It’s out of the blood, but gets into tissue at a low level – the gut, maybe even the brain in some people who are really sick – and you have a reservoir of the virus left over,” said Amy Proal, microbiologist. of PolyBio Research Foundation, told Vox. . “And it causes a lot of inflammation and symptoms.”
These viral reservoirs have been documented following infections with many other pathogens. During the 2014-2016 Ebola epidemic, studies have emerged showing that the Ebola virus can linger in the eye and semen. There were similar findings during the 2015-2016 Zika epidemic when health officials warned about the possibility that Zika could be sexually transmitted. (Viral reservoirs are also the reason why the moniker ‘post-viral’ can be problematic, Proal added.)
A related explanation for what can happen to long-covid patients is what Iwasaki calls ‘viral ghosts’. While the intact virus may have left the body, “there may be RNA and proteins from the virus that continue to stimulate the immune system,” Iwasaki said. “It’s almost like having a chronic viral infection – it still stimulates the immune system because the virus or viral components are still there and the body does not know how to shut it down.”
Recent studies in Earth and The Lancet documented coronavirus RNA and proteins in a variety of body systems, including the digestive tract and the brain.
In autopsies of people with chronic fatigue syndrome, researchers also found enterovirus RNA and proteins in patients’ brains, including in one case in the brainstem area. The brain stem controls sleep cycles, autonomic functions (the largely unconscious system that drives bodily functions such as digestion, blood pressure and heart rate) and the flu-like symptoms we develop in response to inflammation and injury.
‘If the area of brain signaling is not regulated [by viruses], “Proal said,”[that] can lead to sets of symptoms that meet a diagnostic criterion for [chronic fatigue syndrome], or even for long Covid. ”
2) Other pathogens lurking in the body wake up again
Other pathogens already hiding in the body before a coronavirus infection can also aggravate the symptoms. For example, viruses in the herpes family – such as Epstein-Barr (the cause of mono) or varicella zoster (the cause of chickenpox and shingles) – remain dormant in the body forever. Under normal conditions, the immune system can keep them in check.
“So, for example, 90 percent of the people in the world already have herpes viruses,” Proal said. ‘But in those patients, the immune system keeps them in a place where they cannot repeat, where they cannot express proteins. They are kind of controlled. ”
But then Covid-19 comes along, and suddenly these other viruses get the chance to gain a foothold again. Since the immune system is trapped against Covid-19, the other viruses can wake up again. And it does not cause symptoms – not the coronavirus.
3) The immune system activates the body
Another important hypothesis: Long-Covid patients developed an autoimmune disorder. The virus disrupts normal immune function, causing it to flare up incorrectly, allowing molecules that normally target foreign invaders, such as viruses, to enter the body.
These ‘rogue antibodies’, known as motor antibodies, ‘attack elements of the body’s immune defenses or specific proteins in organs such as the heart’, according to Earth. The assault is suspected to be different from cytokine storm, an acute immune system disorder that appeared early in the pandemic as a possible threat.
“Under the scenario, we’re talking about molecular imitation,” Proal said. “In fact, the virus creates proteins that look like human proteins or tissues, and the kind of tricks of the immune system.” Here, the immune system tries to target the virus, which ‘if it has a similar size and shape to a human tissue or protein, it also fires at the human tissue or protein’, she added.
4) The microbiome is eliminated
It is also possible that the coronavirus can deplete important microorganisms in the gut microbiome – the billions of bacteria, viruses and fungi that live in and on the body.
In one study, researchers detected blood and stool samples from 100 patients hospitalized with SARS-CoV-2 infection, and it was tested up to 30 days after removing the virus. (They also collected samples from a control group for comparison.) And they found that Covid-19 infection was linked to a ‘dysbiotic gut microbiome’, even after the respiratory tract was cleared; they also suggested that it may contribute to the persistent health problems experienced by some patients.
‘Under health conditions, the communities are in balance. It’s like a forest, like different organisms do different things, but it’s in a harmonious state, ” Proal said. But Covid-19 can lead to an imbalance in the microbiome. ‘And a large number of symptoms are related to dysbiosis of microbiomes. Irritable bowel syndrome or even neuro-inflammatory symptoms can be driven by these ecosystems if they are also out of balance. ”
5) The body is injured
:format(webp):no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/22440784/1289176732.jpg)
The virus may have cleansed the body, but left injuries in the aftermath – for example, lesions in the lungs or damage to the heart – and these injuries can cause symptoms.
According to a recent preliminary press release involving 201 patients, 70 percent had disabilities in one or more organs four months after their initial Covid-19 symptoms occurred. In other unpublished research, radiologists at the University of Southern California have detected scans recovering patients’ lung recovery using CT scans. They found that a third more than a month later caused lesions through the tissue. Other patients may have brain damage that causes neurological symptoms.
There is also increasing evidence of widespread heart injury, even in patients not admitted to hospital. In a JAMA Cardiology study, researchers performed cardiac MRIs on 100 patients in Germany who had recovered from Covid-19 in the past two to three months. A staggering 78 percent still had heart disorders.
For coronavirus patients who had to be admitted to intensive care units, there is a related explanation: long before the pandemic, the intensive care unit created a term for the persistent symptoms that people often experience as a result of a stay in an ICU, of cancer to tuberculosis. . These symptoms include muscle weakness, brain fog, sleep disorders and depression – the aftermath of a body lying in a hospital bed for days on end and injuries or side effects from treatments patients have received, including intubation.
The term “post-intensive care syndrome” was “Created to raise awareness and education because so many of our ICU survivors go to their primary care physician and say they are tired,” said Dale Needham, who treated Covid-19 patients at the Johns Hopkins ICU. . “They had trouble remembering, and they were weak. Their primary care physician did some lab tests and said, “Oh, there’s nothing wrong with you.” The patient may walk away and feel as if the doctor is saying, ‘This is all in your head. You make it up. ‘”
The Covid-inspired medical revolution
What, then, can help alleviate the nagging symptoms of Covid long shepherds? One idea that has spread is the Covid-19 vaccine: some long-distance guards report that their symptoms improve after being vaccinated. But others reported feeling worse – and others, not others. Researchers are therefore rushing to understand the effects of vaccination on long Covid, but it does not yet look like a silver bullet.
Proal had a simpler solution that could be implemented today: “It’s time for medicine to be rooted in the patient’s faith.”
Even with a growing awareness of long-term Covid, patients with the condition – and other chronic “medically unexplained” symptoms – are still too often minimized and discharged by health care professionals.
People “want diseases to kill you, or them to return to amazing good health,” said Jaime Seltzer, director of scientific and medical outreach at the ME Action advocacy group for chronic fatigue syndrome. “If you stay sick, compassion can fade. And it’s not just friends and family. These are also your clinicians; they want to fix someone. ”
But long-term people of any chronic condition can exist for years in a space between illness and health, sometimes without a diagnosis. Their unexplained symptoms can arouse immediate skepticism among health professionals trained to treat patients as the “lowest form of evidence on [the evidence hierarchy], even under research on mice, ”said Proal.
The situation can be even more challenging for patients who have never had a positive PCR test that confirmed their Covid-19 diagnosis. Of the dozens of medical appointments that one long-term Covid-19, Hannah Davis, had for her persistent symptoms – which included memory loss, muscle and joint pain, and headaches a year after her initial illness – was one of the best experiences. who simply said, “I do not know.”
“The doctor [told me]’We see hundreds of people like you with neurological symptoms. Unfortunately, we still do not know how to treat it. We do not even understand what is going on. But just know that you are not alone, ” she says. ‘And that’s the kind of conversation that needs to take place. Because we can wait, but we can not let the anxiety of the doctor stand out on us as patients. ”