BMJ authoritative release: Most coronavirus sequelae disappear within a year of mild infection

A large study from Israel published in the British Medical Journal found that most symptoms or conditions that appear after a mild Covid-19 infection last for several months but return to normal
within a year.

In general, vaccinated people have a lower risk of breathing difficulties, which is the most common symptom
after mild infection, compared to unvaccinated people.

The findings suggest that despite the fear and discussion about the long crown phenomenon since the beginning of the pandemic, the vast majority of mild cases do not develop serious or chronic long-term illness
, the researchers said.

Long crown is defined as persistent symptoms or new symptoms
for more than 4 weeks after the first infection.
In March 2022, an estimated 1.
5 million people (2.
4% of the population) in the UK reported prolonged Covid symptoms, mainly fatigue, shortness of breath, loss of smell, taste and difficulty concentrating
.

However, the clinical impact of long crowns one year after mild infection and its relationship to age, sex, COVID-19 variants, and vaccination status are unclear
.

To address this, the latest study compared
the health of uninfected people with those who recovered from mild Covid-19 within a year of infection.

They used electronic records from a large public healthcare facility in Israel that tested nearly 2 million members for COVID-19 between March 1, 2020 and October 1
, 2021.
In a group of infected and matched uninfected members (mean age 25 years; 51% women).

They compared unvaccinated people in the early (30-180 days) and late (180-360 days) post-infection period, including those infected with and without COVID-19, and controlled for age, gender, and COVID-19 variants
.
During the same period, vaccinated and unvaccinated COVID-19 patients were also compared
.

To ensure that only minor illnesses were assessed, they excluded hospitalized patients
with more severe disease.
Other potential contributing factors such as alcohol intake, smoking status, socioeconomic level and a range of pre-existing chronic conditions are also taken into account
.

Covid-19 infection is significantly associated with an increased risk of several diseases in the early and late stages, including loss of smell and taste, attention and memory impairment, dyspnea, weakness, palpitations, streptococcal tonsillitis, and dizziness, while alopecia, chest pain, cough, muscle pain, and breathing disorders are relieved
in advanced stages.

For example, the risk of loss of smell and taste in the early stages of mild COVID-19 infection is 4.
5 times higher (20 more per 10,000 people) and almost 3 times higher in the later stages (11 more per 10,000 people)
compared to uninfected people.

The highest overall burden after infection during the 12-month study period was frailty (136 per 10,000) and dyspnea (107 per 10,000).

Dyspnea was the most common when assessed by age, occurring in 5 of the 6 age groups, but persisted in the first year after infection in the 19-40 years, 41-60 years and over 60 age groups
.

Frailty occurred in four out of six age groups, and only the 19-40 and 41-60 age groups experienced frailty symptoms that persisted into the later stages
.

There is little difference between male and female patients, and in the early stages of COVID-19, children have fewer symptoms than adults, and most resolve in the late stages
.
The results of studies for the wild-type, alpha-type and Delta COVID-19 variants were similar
.

Compared with unvaccinated infected people, vaccinated infected people have a lower risk of breathing difficulties and a similar
risk of developing other diseases.

The researchers point to some limitations, such as incomplete measurements in medical records, so the data may not fully reflect the diagnosis and reported results
.
They cannot rule out the possibility that COVID-19 patients may use medical services more frequently, leading to higher reporting and more screening
of potential COVID-19-related outcomes for these patients.

Nevertheless, this is a large-scale detailed analysis of the health records of different populations and is one of
the longest follow-up studies to date in patients with mild COVID-19.
These findings should apply to similar Western populations
worldwide.

"Our study shows that patients with mild COVID-19 are at risk for a small number of health outcomes, most of which resolve
within a year of diagnosis," the researchers said.

"Importantly, vaccinated patients with breakthrough infections had a reduced risk of persistent dyspnea compared to unvaccinated people, while the risk of all other outcomes was comparable
," they added.