I believe that now everyone has heard of the sequelae of the new crown, also known as the long-term symptoms of the new crown, some people feel that this is the patent of seriously ill patients, some people feel that there are not many people who occur, and some people think that the long-term symptoms of the new crown have been abolished for a lifetime.
So what is the truth?
For COVID-19 sequelae, WHO gives the official definition of sequelae as symptoms that last more than two months and cannot be explained by having other diseases. And these symptoms plague many people who have recovered from COVID-19.
Long-term COVID-19 symptoms are not a patent for severely ill patients
As early as February 2021, the University of Washington in the United States released a survey result: it was found that mild diseases also have long-term symptoms.
Of the study's respondents, 11 (6.2%) were asymptomatic, 150 (84.7%) had mild illness, and 16 (9.0%) had moderate or severe illness requiring hospitalization. Few of them had health problems before infection, with only 13 percent of high blood pressure, 5 percent diabetes and 4.5 percent of active smokers.
But eventually about 30% of patients reported persistent symptoms (more than the proportion of moderately severe patients), and the proportion increased with age:
About 27% of patients aged 18 to 39 years reported persistent symptoms, compared with 30% among patients aged 40 to 64 years and 43% among patients aged 65 years and older.
The most common persistent symptoms were fatigue (13.6%) and loss of smell or taste (13.6%), with about 13% reporting other symptoms, including brain fog symptoms (2.3%).
PS: Brain fog refers to a collection of symptoms that include distressing cognitive symptoms such as amnesia, confusion, difficulty concentrating, dizziness, and forgetting everyday vocabulary.
A recent study by the University of Oxford also found that after excluding hospitalized COVID-19 patients, relative to people who are not infected, they can still find significant changes in the brain of mild patients for the difference between smell and cognition, as well as cognitive function decline, corresponding to the performance of olfactory regression /disappearance, memory/attention and other declines.
It can be seen that patients with mild disease also develop long-term symptoms, but there are also studies that have found that the proportion of patients with severe disease is higher (usually their age is also higher).
The proportion of long-term symptoms of COVID-19 is not determined
The results of current studies on the proportion of long-term symptoms of COVID-19 vary widely.
In a paper published by Italian researchers in August 2020, they followed up patients diagnosed from April 21 to May 29, 2020, and 60 days later, 87% of people still showed at least one symptom, the most common symptoms being fatigue (53.1%), dyspnea (43.4%), joint pain (27.3%) and chest pain (21.7%).
In a paper published in March 2021, researchers in the United Kingdom, the United States, and Sweden followed up patients diagnosed with COVID-19 from March 25 to June 30, 2020, and found that 13.3% had symptoms lasting ≥ 28 days, 4.5% had symptoms lasting ≥ 56 days, and 2.6% had symptoms lasting ≥ 84 days. The most common were fatigue and intermittent headaches, which accounted for 97.7% and 91.2% of "patients with symptoms lasting ≥ 28 days", respectively.
In February 2022, researchers in the UK conducted a meta-analysis of 18 papers published between January 1, 2021 and November 6, 2021, on "Results from follow-up of COVID-19 patients for at least 1 year", which were from China, Italy, Spain, germany, and finally found that the long-term symptoms with high prevalence after one year were:
Fatigue/weakness 28%, arthralgia 26%, depression 23%, anxiety 22%, memory loss/memory complaints/forgetfulness 19%, shortness of breath/dyspnea 18%, difficulty concentrating 18%, insomnia/difficulty sleeping 12%, joint pain 10%.
Most long-term symptoms still disappear over time, and a Danish study of long-term symptoms in children found that at least 54-75% of children disappear within 1-5 months.
The long-term symptoms of COVID-19 patients have many manifestations, although the proportion of occurrence in different studies has been high and low, but it can be determined that fatigue is the most common symptom, and the rest of the more common shortness of breath/dyspnea, pain, etc.
The onset of long-term symptoms after infection with the virus is not unique to COVID-19
I believe many people want to know, can long-term symptoms be seen in other infectious diseases?
The answer is yes.
For example, studies of Epstein-Barr virus, dengue virus, chikungunya virus, Ebola virus, Burgdorferi (a pathogen of Q fever), and Giardia, 10% to 35% of adolescents or adults have documented general complaints of post-infection fatigue lasting 6 months or more.
However, I have not found studies on the long-term symptoms of influenza, and most of the current studies are still supporting immune-normal young people who have the symptoms to disappear within 3-7 days after infection with influenza, and a small number of patients will last for 2 weeks or more.
The long-term symptoms of COVID-19 need to be properly understood
The reason why we need to pay attention to the long-term symptoms of new crown patients is because the number of people infected with new crown is large, and the proportion of long-term occurrence is not low, such a large number of people must be accompanied by medical appeals; some patients have been unable to return to work in the short term because of long-term symptoms.
And it's also a process of constantly getting to know the coronavirus, and understanding this helps to help people who have suffered from long-term symptoms recover, and it also helps us better defend against the new crown virus.
But we don't have to equate all long-term symptoms with permanent sequelae, nor do we have to exaggerate their effects, look at them properly, and address them.
For example, like olfactory and taste loss/disappearance, with the prolongation of the follow-up time, the prevalence is decreasing, indicating that it will gradually recover, in the British meta-analysis, when the follow-up time is 1 year, the prevalence of olfactory loss/disappearance is 6%; and if the follow-up time is limited to 3 months, in another study, after meta-analysis, the prevalence of olfactory loss/disappearance has reached 37%. Compared with the two, it has decreased by 84% after 1 year.
I hope we will defeat the epidemic as soon as possible.
The cover image is from Qiantu Network