Repeat infections multiply risk of health problems, study warns

Beware of repeated infections. People who have had Covid-19 more than once are more likely to have a series of serious health problems than those who have had it only once, the first major study on the subject. Repeat infections increased as the virus mutated, but the long-term health effects of these reinfections remained unclear until then.

A new study published Thursday in the journal NatureMedicine examines for the first time how reinfection increases the risk of health problems and long Covid. The US researchers analyzed the anonymous medical records of 5.8 million people in the US Department of Veterans Affairs National Health Care Database.

“All kinds of unwanted health problems”

More than 443,000 people tested positive for Covid at least once between March 1, 2020 and April 2022. Of these, 41,000 had Covid more than once. In detail, more than 93% had a total of two infections, while 6% had three and almost 1% had four. The remaining 5.3 million have never contracted Covid. When the researchers compared the health outcomes of the different groups, they found that “people who were reinfected had an increased risk of all kinds of unwanted health problems,” epidemiologist Ziyad Al-Aly told AFP. at Washington University in St Louis and lead author of the study.

Heart and lung problems, for example, were more than three times more common among people who had been reinfected. Reinfection also promoted brain disease, kidney disease and diabetes, according to the study. The authors, however, acknowledged some biases in their study, including the fact that it mostly involved white, older men.