Although some people will no longer be comforted, the symptoms of covid-19, when the mild infection has been suffered, end up disappearing. According to a large study published today by “The BMJ”, most symptoms or conditions after a mild Covid-19, despite persisting for several months, disappear after a year.
And this is especially the case in those vaccinated, who have a lower risk of respiratory difficulties – the most common effect that develops after a mild infection – compared to those who are not vaccinated.
These results suggest that although the phenomenon of persistent coronavirus has been feared and discussed since the beginning of the pandemic, the vast majority of cases of mild illness do not suffer from severe or chronic long-term illness, the researchers say. Symptoms or conditions that develop after a mild infection by Covid-19 persist for several months, but return to normal after a year, according to a large Israeli study published today in “The BMJ”.
Persistent covid-19 is defined as the maintenance of symptoms or the appearance of new symptoms more than four weeks after the initial infection. In March 2022, it is estimated that 1.5 million people in the UK (2.4% of the population) reported symptoms of prolonged coronavirus, mainly fatigue, shortness of breath, loss of smell, loss of taste, and difficulty concentrating.
But the clinical effects of persistent covid one year after a mild infection and its association with age, sex, covid-19 variants and vaccination status are still unclear.
To address this question, the researchers compared the health of uninfected individuals with that of those who had recovered from mild Covid-19 one year after infection.
They used the electronic records of a large public health organization in Israel, where almost 2 million members were tested for Covid-19 between March 1, 2020 and October 1, 2021. More than 70 persistent Covid conditions were tested in a group of matched infected and uninfected members (mean age 25 years; 51% female).
Conditions were compared in unvaccinated people, with and without Covid-19 infection, controlling for age, sex, and Covid-19 variants, during early (30-180 days) and late (180-360 days) time periods. ) after infection. Too conditions were compared in vaccinated and unvaccinated people with Covid-19 during the same time periods.
To ensure that only mild disease was assessed, they excluded patients admitted to hospital with more severe disease. Other potentially influential factors such as alcohol intake, smoking habit, socioeconomic status, and a number of pre-existing chronic conditions were also taken into account.
Covid-19 infection was significantly associated with increased risk of several conditions, including loss of smell and taste, concentration and memory problems, breathing difficulties, weakness, palpitations, strep throat, and dizziness, both in periods early and late, while hair loss, chest pain, cough, muscle pain, and respiratory disorders resolved in the late period.
For example, compared to uninfected people, mild Covid-19 infection was associated with increased risk. 4.5 times greater loss of smell and taste (20 more people per 10,000) in the early period and a risk almost 3 times higher (11 per 10,000 people) in the late period.
Vaccinated people who became infected had a lower risk of breathing difficulties
The global burden of conditions after infection in the study period of 12 months was higher for weakness (136 more people per 10,000) and respiratory difficulties (107 per 10,000).
When conditions were assessed by age, respiratory distress was the most common, appearing in five of the six age groups but persisting through the first year after infection in the 19-40, 41-60, and older groups. 60 years old.
The weakness appeared in four of the six age groups and remained persistent in the late phase only in the 19-40 and 41-60 age groups.
Male and female patients showed minor differences, and children had fewer outcomes than adults during the early phase of Covid-19, which mostly resolved in the late period. The results were similar in the Alpha and Delta type Covid-19 variants.
Vaccinated people who became infected were at lower risk of respiratory difficulties and a similar risk of other conditions compared with unvaccinated infected patients.
The researchers point to some limitations, such as incomplete measurement in medical records, so the data may not fully reflect the reported diagnoses and results. In addition, they cannot rule out the possibility that patients infected with the Covid-19 virus will seek more frequent health services, which would lead to a higher number of reports and increased screening for possible outcomes related to the Covid virus in these patients.
Nonetheless, this is a large, detailed analysis of the medical histories of a diverse population, representing one of the longest follow-up studies conducted to date in patients with mild Covid-19. And the findings should apply to similar Western populations around the world.
“Our study suggests that patients with mild Covid-19 are at risk of a small number of health problems, most of which resolve.” within one year of diagnosis», the authors state.