What we know about the long Covid so far

Among the many confusing aspects of the coronavirus is the spectrum of possible symptoms, as well as their severity and duration. Some people develop mild Covid-19 and recover quickly, with no lasting effects. But some studies estimate that 10% to 30% of people report lingering medical problems or new months after their initial coronavirus infections — a series of symptoms known as long-term Covid.

People who suffer from mild or moderate illnesses, as well as those without any underlying medical conditions, may experience some long-term debilitating symptoms, such as fatigue, shortness of breath, irregular heart rate, headache, dizziness, depression, and problems with sleep. memory and concentration.

These persistent medical problems are so varied that a study by a patient-led research group looked at 203 symptoms that can fluctuate or even appear out of nowhere after people seem to have recovered.

As Dr. Ziyad Al-Aly, head of research and development at the VA St. Louis and a clinical public health researcher at Washington University in St. Louis, each case of Covid long is different from the other.

How do doctors currently diagnose long Covid?

There is little consensus on the exact definition of long-term Covid, also known by the medical term PASC, an acronym for “post-acute sequela of Covid-19”. While the World Health Organization (WHO) says long Covid begins three months after the original outbreak of the disease or the positive test result, the Centers for Disease Control and Prevention (CDC) defines the initial period as soon after a month. .

Some researchers and health professionals use other timeframes, making attempts to study and quantify the disease difficult, said Al-Aly, who has conducted many studies of long-term problems after Covid.

When patients with persistent symptoms go to the doctor, tests such as electrocardiograms, chest X-rays, CT scans and blood tests don’t always identify physiological problems, Al-Aly said. Researchers are working to identify certain biological factors, called biomarkers, that are linked to persistent symptoms of Covid. These can include signs of inflammation or certain molecules produced by the immune system that can be measured in blood tests, for example.

For now, clinicians need to trust their patients’ description of symptoms and rule out alternative explanations or causes. Some post-Covid clinics have multidisciplinary teams of specialists who evaluate patients to define the best treatment options.

What causes long Covid?

It’s unclear what exactly produces the long Covid, but research has begun to offer some clues. Some experts theorize that the immune response that kicks in when a person first gets sick can cause inflammation and damage throughout the body, which could result in long-term Covid symptoms, said Dr. Michael Peluso, an infectious disease physician at the University of California at San Francisco.

“We know that during acute Covid-19, some people have a really accelerated immune response and some people have a reduced immune response, and that response can determine the trajectory of how the person will do,” he said.

Another explanation, experts say, could be that your immune system doesn’t shut down completely after the initial infection.

Who is at risk?

The research offers some insight into which patients may face a higher risk of lasting symptoms. In a study of 209 patients published in January, researchers found four factors that could be identified early in the coronavirus infection that appeared to be related to an increased risk of a person having ongoing symptoms two to three months later.

One factor was the level of coronavirus RNA in the blood at the start of the infection, an indicator of viral load. Another was the presence of autoantibodies — antibodies that mistakenly attack the body’s own tissues, as in diseases like lupus and rheumatoid arthritis. A third factor was the reactivation of the Epstein-Barr virus, which can cause mononucleosis and infect most people, often when they are young, and then usually go dormant.

The fourth factor was having type 2 diabetes, although experts say that in studies involving larger numbers of patients, diabetes may be just one of several medical conditions that increase the risk of long-term Covid.

Post-Covid clinic studies have also found other preexisting medical conditions that can put people at risk for lasting Covid. In a report on the first 100 patients treated for neurological and cognitive symptoms at a post-Covid clinic at Northwestern Memorial Hospital in Chicago, 42% reported that they had previously had depression or anxiety, although these patients might simply feel more comfortable seeking neurological treatment, the doctors said. Other preexisting conditions included autoimmune diseases and headache.

Studies also suggest that the risk of developing long-term Covid peaks in middle age, Peluso said. The median age of patients in the Northwestern study was 43 years. An analysis of 78,252 private health insurance claims across the United States revealed that people between the ages of 36 and 64 accounted for about two-thirds of patients with long-term Covid. (But that study did not include the majority of Medicare beneficiaries, so it involved relatively few older patients.)

Women can be affected in greater proportion: 60% of patients are female, according to some studies. A similar pattern has emerged in other long-term conditions, such as ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome), which has several symptoms similar to long-term Covid.

Because the pandemic has had a significant effect on black and Latino communities across the United States, and these groups have more limited access to medical care, they may also have a high number of long-term Covid cases, Peluso said.

Can vaccines protect against long-term Covid?

The picture is still fuzzy, but several studies suggest that getting a Covid vaccine can reduce — but not eliminate — the risk of long-term symptoms.

The UK Health Safety Agency carried out an analysis of eight studies on vaccines and the long-term Covid before mid-January. Six of them found that vaccinated people who were infected with the coronavirus were less likely than unvaccinated patients to develop symptoms of long-term Covid. The remaining two studies found that vaccination did not appear to conclusively reduce the chances of developing long-term Covid.

In that analysis, a study, which was not peer-reviewed, of about 240,000 patients in the United States found that those who received even one dose of the vaccine before Covid infection were 7 to 10 times less likely than patients who did not. vaccinated reporting long-term Covid symptoms 12 to 20 weeks later.

But another large study of electronic patient records at the U.S. Veterans Health Administration, also not yet peer-reviewed, found that those who were vaccinated had only a 13% lower risk than unvaccinated patients of showing symptoms six months later. . Vaccinated patients benefited primarily because they were less likely to develop lung problems and blood clotting difficulties, said Al-Aly, one of the study’s authors.

“Reliance on vaccination as the only mitigation strategy is totally inadequate,” said Al-Aly. “It’s like fighting with a shield that only partially works.”

Seeking medical care

If you are concerned about any persistent symptoms following a confirmed or suspected coronavirus infection, don’t be afraid to ask for help. Checking with your primary care provider is a good first step. More doctors are becoming aware of Covid’s lasting symptoms and may recommend tests that can at least rule out other causes of your symptoms.

“Even if we say long Covid is when symptoms last a month or three months after infection, you don’t have to wait that long to get help,” Al-Aly said. “People should really take their symptoms seriously.”

If you are not seeing a doctor, you can seek out a post-Covid treatment clinic, although Al-Aly acknowledges that “this is easier said than done”. # Access to post-Covid clinics can be difficult for people without adequate medical insurance. And in some states, people may have to travel hundreds of miles to get to the nearest one. # You can search for post-Covid clinics near your home in the Survivor Corps database.

Take your medical exams if you are visiting a new provider and make a list of your symptoms, especially if you have cognitive problems as you will likely forget about some health issues when you go to the appointment.

Some long-term Covid problems can be treated with medications or existing treatments for symptoms like headache or gastrointestinal problems. Physical therapy and “cognitive rehabilitation,” which includes approaches used for patients who have had a stroke or brain injury, can also be helpful over time. Some people improve with personalized physical and mental health rehabilitation services and breathing exercises, which can help slowly regain strength and endurance for physical activity.

Other possible tools against long-term Covid, including antiviral treatments, are just beginning to be studied. The US National Institutes of Health is investing more than $1 billion in a major research effort called the Initiative Recover, but progress has been slow. Lawmakers are pushing for better funding for long-term Covid research and medical care.

Several civic groups such as Body Politic, Long Covid Alliance and Survivor Corps offer psychological support as well as resources to seek treatment, disability benefits and patient legal advocacy.

People with long-term Covid can also participate in research studies, Peluso said. You can find ongoing clinical studies at universities and academic centers near you or apply to be part of the Recover Initiative.

“Participating in research can be very empowering,” said Peluso.

_{Translated by Luiz Roberto M. Gonçalves}