Prolonged Covid symptoms may emerge months after infection: Study

NEW YORK. Long COVID can persist for at least a year after the end of acute illness, or appear months later, according to the most comprehensive look ever at how symptoms appear over a year. Long COVID involves a range of symptoms that persist or develop for about a month after the initial infection. These symptoms are associated with significant morbidity or reduced quality of life. About 16 percent of Covid-positive people have symptoms for at least a year, but in others these symptoms come and go. The study appears in the latest Morbidity and Mortality Weekly Report (MMWR) from the US Centers for Disease Control and Prevention (CDC). “It is common for symptoms to regress and re-emerge months later,” said lead author Juan Carlos Montoy, associate professor in the Department of Emergency Medicine at the University of California, Berkeley. “A lot of prior research has focused on symptoms at one or two points in time, but we were able to describe symptom trajectories with greater clarity and granularity. This suggests that measurements at a single point in time may be more realistic can underestimate or misreport the burden of disease,” Montoy said. Symptoms were assessed every three months in the study, which helped researchers distinguish between symptoms that improve and those that emerge months after the initial infection. It included 1,741 participants – two-thirds of whom were women. . Three-quarters of people tested positive for Covid, but even those who tested negative may have had some sort of infection because they were experiencing symptoms. These include fatigue, runny nose, headache, sore throat, shortness of breath, chest pain, diarrhea, forgetfulness, and difficulty thinking or concentrating. COVID-positive participants were more likely to have symptoms in each symptom category at baseline, but by the end of the year, there was no difference between COVID-positive and negative people. “We were surprised to see how similar the patterns were between the Covid positive and Covid negative groups,” Montoy said. “This suggests that the burden may be higher after Covid, but it may also be higher for other non-Covid diseases. We have a lot to learn about post-illness processes for Covid and other conditions. “