according to findings of a large study.
Anuradhaa Subramanian, PhD, with the Institute of Applied Health Research at the University of Birmingham (England), led the research published online in Nature Medicine.
The team analyzed 486,149 electronic health records from adult patients with confirmed COVID in the United Kingdom, compared with 1.9 million people with no history of COVID, from January 2020 to April 2021. Researchers matched both groups closely in terms of demographic, social, and clinical traits.
New symptoms
The team identified 62 symptoms, including the well-known indicators of long COVID, such as fatigue, loss of sense of smell, shortness of breath, and brain fog, but also hair loss, sexual dysfunction, chest pain, fever, loss of control of bowel movements, and limb swelling.
“These differences in symptoms reported between the infected and uninfected groups remained even after we accounted for age, sex, ethnic group, socioeconomic status, body mass index, smoking status, the presence of more than 80 health conditions, and past reporting of the same symptom,” Dr. Subramanian and coresearcher Shamil Haroon, PhD, wrote in a summary of their research in The Conversation.
They pointed out that only 20 of the symptoms they found are included in the World Health Organization’s clinical case definition for long COVID.
They also found that people more likely to have persistent symptoms 3 months after COVID infection were also more likely to be young, female, smokers, to belong to certain minority ethnic groups, and to have lower socioeconomic status. They were also more likely to be obese and have a wide range of health conditions.
Dr. Haroon, an associate clinical professor at the University of Birmingham, said that one reason it appeared that younger people were more likely to get symptoms of long COVID may be that older adults with COVID were more likely to be hospitalized and weren’t included in this study.
“Since we only considered nonhospitalized adults, the older adults we included in our study may have been relatively healthier and thus had a lower symptom burden,” he said.
Dr. Subramania noted that older patients were more likely to report lasting COVID-related symptoms in the study, but when researchers accounted for a wide range of other conditions that patients had before infection (which generally more commonly happen in older adults), they found younger age as a risk factor for long-term COVID-related symptoms.
In the study period, most patients were unvaccinated, and results came before the widespread Delta and Omicron variants.
More than half (56.6%) of the patients infected with the virus that causes COVID had been diagnosed in 2020, and 43.4% in 2021. Less than 5% (4.5%) of the patients infected with the virus and 4.7% of the patients with no recorded evidence of a COVID infection had received at least a single dose of a COVID vaccine before the study started.
Eric Topol, MD, founder and director of the Scripps Research Translational Institute in La Jolla, Calif., and editor-in-chief of Medscape, said more studies need to be done to see whether results would be different with vaccination status and evolving variants.
But he noted that this study has several strengths: “The hair loss, libido loss, and ejaculation difficulty are all new symptoms,” and the study – large and carefully controlled – shows these issues were among those more likely to occur.
A loss of sense of smell – which is not a new observation – was still the most likely risk shown in the study, followed by hair loss, sneezing, ejaculation difficulty, and reduced sex drive; followed by shortness of breath, fatigue, chest pain associated with breathing difficulties, hoarseness, and fever.