The endless hangover of covid that affects millions: one in eight infected has prolonged symptoms

The covid pandemic has left behind a long and mysterious shadow that brings scientists upside down: persistent covid.

An amalgam of symptoms that last over time – there are more than 200 different ones identified – that some people experience after passing the covid infection.

The scientific community does not know for sure why certain sequelae persist, nor who will suffer them, nor for how long.

The World Health Organization (WHO) has already set a definition of persistent covid —"post-covid condition", it calls it— to refine the diagnosis and more or less improvised consultations spring up in hospitals to care for those affected.

But patients and health workers continue to swim in a sea of ​​​​uncertainty.

For not knowing, it is not known how many people are affected.

suggests that one in eight adults infected with coronavirus have persistent symptoms, but it also has its limitations.

Experts call for more research and care units for "an urgent health problem."

Vicky Béjar, 47, was caught by covid at the beginning of the pandemic, in March 2020. She started with digestive symptoms, fever, tiredness, headache, fatigue... Months went by and all that clinical picture continued, better days and worse days, but it was never the same.

The persistent covid accompanies her since then.

“I still have a fever above 38 degrees, tachycardia, bradycardia, fatigue and mild cognitive impairment: I am an accountant, I have a family business in which I handled administrative matters, and I cannot work.

Now I am relearning the multiplication table.

The numerical and organizational issue is difficult for me, I have a mental fog that does not allow me to concentrate, ”she says.

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The scars of covid

Experts differentiate the sequelae of serious illness, such as respiratory failure after having gone through intensive care with severe pneumonia - the damage can be seen in radiological tests - from those non-specific conditions that often persist in people who have slightly overcome covid.

In the latter, there are usually no physical signs or affected organs, which complicates the diagnosis.

In her case, Béjar, a resident of Montcada i Reixac, in Barcelona, ​​is "lucky", she says, to be under the scrutiny of the specialized unit of the Germans Trias i Pujol Hospital in Badalona, ​​which monitors her, but denounces the " institutional mistreatment” of the system: “They don't listen to us”.

Lorenzo Armenteros, spokesman for the Spanish Society of General Practitioners, regrets the suspicion of some colleagues who "still do not believe that this picture exists": "It is a social need and an important epidemiological problem.

You have to treat it ”, ditch.

The WHO definition already clarifies that these are symptoms that "last at least two months and cannot be explained by an alternative diagnosis."

The definition agreed upon by the Carlos III Health Institute (ISCIII) is also along the same lines, although it does not indicate a duration time.

"What is clear is that something is happening," says Antoni Serrano, a psychiatrist at the Parc Sanitari de Sant Joan de Déu and a researcher at the Center for Biomedical Research in the Public Health Network, who participated in the ISCIII study.

The dimensions of the phenomenon have danced throughout the pandemic in a wide range.

The WHO European Observatory of Health Systems and Policies pointed out in 2021 that a quarter of those infected continued to have symptoms up to a month after diagnosis and 10% were still affected 12 weeks later.

One study reduced this figure to 2.3% and another investigation raised the presence of at least one recurrent symptom in 73% of those infected.

A June survey by the US Centers for Disease Control (CDC) reported that one in five adults who had suffered from covid had persistent symptoms.

It is not so easy to measure the prevalence of a clinical condition with such a variable picture and sometimes non-specific symptoms.

The period of time that is measured, the population under study or the symptoms used to define the persistent covid condition influence this variability, points out Aranka Ballering, author of the article in

and researcher at the Department of Psychiatry at the University of Groningen (The Netherlands): “Many studies only evaluated whether people's symptoms were present at a certain time after their covid diagnosis.

However, some symptoms related to post-covid are very common (for example, headache, tiredness) and people experience them regularly, even if they are not sick.

Additionally, some symptoms may also be caused by seasonal changes — for example, a runny nose or sneezing may be caused by allergic rhinitis rather than covid.

This implies that we need adequate control populations if we want to estimate the prevalence of post-Covid well.”

In their research, they followed more than 76,000 people between March 2020 and August 2021 with routine questionnaires.

Of these, 4,231 participants became infected with COVID during the study and were matched with 8,462 people of similar age and gender, who were never diagnosed with COVID during that time.

“We included a control group of covid-negative people, which allowed us to take into account the effects of public health measures (such as confinement, home education…) on somatic symptoms, but also allowed us to take into account Account for symptoms due to seasonal changes.

Second, since our study is a general population cohort study, we collected information about people's health even before they were diagnosed with covid.

This allowed us to assess whether people had an increase in symptom severity after COVID diagnosis, compared to before diagnosis."

The participants, explains the researcher, functioned “as their own control”.

“It allowed us to see if the symptoms three to five months after their Covid-19 diagnosis were worse in severity than before or a continuation of pre-existing symptoms.”

The research concludes that one in eight adults who had covid (12.7%) in the general population experience long-term symptoms due to coronavirus infection.

The main symptoms reported were, above all, loss of smell and/or taste (anosmia and ageusia) and muscle pain, although chest pain, shortness of breath, tingling and tiredness were also frequent.

More questions than answers

For Pere Domingo, covid coordinator at the Sant Pau Hospital in Barcelona and who has not participated in the study, the research is “very solid”: “It has a control group without covid and that is useful to see the responsibility of the infection in these symptoms. ”.

But he cautions: “This study is done with old strains.

We do not know if it is applicable to the delta or the omicron.

Probably, there are differences because with omicron there was not so much anosmia”.

Vaccination, which began with this study already underway, could also have influenced to modulate the impact of persistent covid, weighs the Sant Pau doctor.

Serrano agrees, in fact, that "the perception is that the frequency of appearance of this condition was much more frequent before [in the first waves] than now."

Gema Lledó, assistant to the autoimmune and systemic diseases service at the Clínic responsible for the post-covid consultation, also focuses on the limitations of the research, which the authors themselves mention: the prevalence of covid may be underestimated because there are asymptomatic cases that can pass unnoticed and, adds Lledó, mistakenly considered as controls when both groups are compared.

“The diagnosis of covid is not clear.

It was left to the discretion of the doctor and is a reasonable limitation.

It is true that this situation is contemplated in the WHO definition, but we should make an effort to confirm the infection if we want to know the real prevalence of postcovid.

We would need better designed studies.

If we want to know the prevalence,

let's do it at the time when all patients are being tested or let's use a technique that allows us to confirm if they have had covid ”, exposes the doctor.

Lledó considers it essential to confirm the infection: "The most difficult thing is to get a proper diagnosis because we live with other infections or diseases with similar symptoms, but which have different approaches."

Beyond the volume of those affected, the phenomenon of persistent covid remains unknown to experts.

"There are more questions than answers," admits Domingo.

Starting with its origin.

“One hypothesis is that there may be pieces of the virus that persist in the body and generate a pathological and immunological response.

It seems plausible”, maintains the doctor.

Joan B. Soriano, epidemiologist at Hospital La Princesa in Madrid and WHO consultant in the working group that defined persistent covid, assures that there are up to seven different mechanisms under study: “Persistent inflammation, immune dysregulation, disorders of the coagulation, viral persistence, autonomic dysfunction, endocrine or metabolic mechanisms, and poor adaptation of the ACE2 pathway [the receptor through which the virus enters cells].”

The expert points out that

Domingo points out that the symptoms that most affect are neurocognitive disorders: "That kind of brain fog, difficulty concentrating, the dissolution of retentive memory...".

And also respiratory problems: "We saw in a study with a group of patients who have air trapping: the smallest airways remain inflamed and it is as if the patients had asthma."

Béjar assures that the most disabling is neurological deterioration and fatigue: “There are days when the body doesn't pull, I can't leave the house”.

Without finding its origin, however, getting the treatment right is also complicated.

Specialists bet on gymnastics: mental to overcome neurocognitive problems, physical exercise for motor damage and also train the sense of smell, for example, to recover odors.

But the impact on the quality of life of patients, the experts consulted agree, is high.

It has “many social and personal implications”, explains Armenteros: “Some patients recover, but not 100% and they feel anguish because their time off work is over and there are no alternatives for adapting to the job or gradual incorporation”.

Others have not yet managed to recover.

There are also no certainties about the profiles that predispose to persistent covid.

At the consultation and in the studies reviewed, such as that of Ballering, a greater affectation is seen in women, but the scientist warns: "We need additional research to assess whether the female sex is a risk factor."

The researchers do not know how long that process will take.

It is variable.

The Dutch study only looks up to five months after the infection and Domingo points out that the only way to know is “let time pass”: “The important thing about this film is the impact on the quality of life of the subjects, which seems to it has it, and if it is 13% of the millions of infected, this acquires stratospheric dimensions”.

Soriano agrees: if the affectation is 13% of those infected - the epidemiologist assures that the Dutch investigation is "elegant and with sophisticated statistics" -, it is "an enormous frequency" and, in Spain, he warns, given the levels of infection in the population, this health problem "can further saturate Primary Care services."

Health impact

The health system, already pressured by the workforce adjustments prior to the pandemic and the management of the covid crisis afterwards, is looking with concern at the impact of this phenomenon.

Some hospitals have made progress in creating multidisciplinary units to respond to this new demand, but patients complain about the lack of circuits and the pilgrimage they have to make for different queries in search of answers.

The Long Covid Act collective calls for "homogeneous protocols to guarantee care equity".

With the resources that exist, Domingo assumes, “what can be done”: “The ideal would be disciplinary units to deal with the different problems of the patient.

This is not being done to the desired extent."

Armenteros assures that patients transmit “desperation” to them after wandering from doctor to doctor without an answer: “Neither primary care nor hospitals are prepared.

The system is already at its limit and anything saturates it.

And this, without a suitable circuit, too.

We are shooting blind."

Resources for research and patient care are urgently needed, Domingo warns: “What suits us is to know the natural history of this complication: if it is self-limited, the impact will be bearable;

if it persists over time, it requires other, higher levels of investigation and attention”.

Experts point out that, in most cases, the symptoms tend to subside or, at least, fade.

In the case of anosmia (loss of smell) and

ageusia (taste dysfunctions), a study published in the journal

shows, after studying 168 people with olfactory or taste dysfunction after covid, that 88% are completely recovered after two years.

“In a significant number, symptoms are reduced over time, but others need external support.

They don't heal on their own.

Others recover and relapse again”, regrets Armenteros.

What the experts agree on, however, is their concern about the uncertainty and impact surrounding this whole phenomenon.

Ballering warns that it is "an urgent health problem, with a growing number of human victims."

In an article published in the magazine

, Rachel Levine, Undersecretary of Health of the Public Health Service of the United States Government, echoes the "enormous potential of the problem for medical care and public health systems" that symptoms can pose. persistent: “It is important to direct much-needed attention to persistent covid.

Caring for affected patients presents challenges given incomplete research, lack of diagnostic support, and widespread problems with access to services."