(Bloomberg) -- One in eight people recovering from Covid-19 had lingering symptoms due to the illness at least three months later in a study that provides greater clarity on the ailments triggered by the pandemic disease.
Scientists used data from the Netherlands’ largest population-based cohort study to track long Covid problems, such as a loss of smell and chest pain. The proportion of participants who had one or more hallmark symptoms was 21% among those who caught Covid, compared with almost 9% in people who didn’t, leaving about 13% of patients with symptoms that can be attributed to the coronavirus, according to researchers at the University of Groningen.
The study, published Thursday in The Lancet medical journal, is the first comprehensive report on long Covid, also called post-Covid condition, that corrects for symptoms people had before they were infected and those occurring in the general population, the authors said. The research may help form a clearer definition of the enduring symptoms estimated to afflict as many as 5 million adults in the US alone.
“This finding shows that post-Covid-19 condition is an urgent problem with a mounting human toll,” Aranka Ballering and colleagues from University Medical Center Groningen wrote.
The data provide a unique and “very powerful” demonstration of Covid’s long-term health effects, said Rachel Evans, a clinical associate professor at the University of Leicester’s Institute for Lung Health, who wasn’t involved in the research.
Read More: What Experts Know About ‘Long Covid’ and Who Gets It
The study, conducted in the northern region of the Netherlands, used data collected from 76,422 participants from late March 2020 through early August 2021. Since then, the risks of long Covid have been reduced by the use of immunizations and newer drug treatments.
Still, the rapid spread of omicron variants means more people are being infected, adding to the long-Covid tally, Evans said in an interview. The World Health Organization counts more than 577 million Covid-19 cases globally since 2020, with daily infections topping 900,000.
“One in 20 people who are triple vaccinated and get Covid are still going to have symptoms three to four months later. That’s huge,” Evans said. “I’m seeing people infected in March 2020 in my clinic who are still very debilitated. The majority are on a trajectory of improvement, but it is very, very slow.”
Covid also substantially increases the risks of a number of rare but serious complications in children, a study from the US Centers for Disease Control and Prevention found Thursday.
Nearly all participants in the Dutch study were white and more than 60% were female. The pattern of post-Covid symptoms observed was similar to previous reports, with fatigue and breathlessness among the most common.
“What really surprised me was that there was such a clear pattern,” Ballering said in an interview. Fever and coughing were commonly reported in the acute phase of illness, but quickly abated, while chest pain and the loss of the senses of smell and taste endured in a large proportion of patients. “You really see a persistence of these symptoms three-to-five months after Covid.”
The study began within weeks of Covid cases being reported in the Netherlands and well before researchers recognized long Covid and its myriad symptoms, Ballering said. A blood-circulation disorder known as postural orthostatic tachycardia syndrome, or POTS, and post-exertional malaise were identified later as other important long-Covid effects, and are the subject of further research, she said.
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