A corona infection can significantly increase the risk of a pulmonary embolism or thrombosis up to months later.
According to a study, which will appear in the British Medical Journal (BMJ) on Thursday, a corona infection may cause a 33 times greater risk of a pulmonary embolism and five times greater risk of deep vein thrombosis (DVT).
It was already known that corona infections lead to a greater chance of blood clots, but details were lacking about the duration of the risk and the chance of it in people who hardly got sick. A Swedish study by Umeå University among more than one million corona patients offers new insights.
Scientists compared data from corona patients between February 2020 and May 2021 with a group of four million people who did not test positive for the coronavirus. The risk of a pulmonary embolism was found to be increased up to six months after an infection; for DVT, this applied up to three months.
The researchers report that people who hardly became ill from a corona infection and were not hospitalized were also at greater risk of blood clots. However, as the pandemic progressed, the likelihood of this declined, probably due to the effectiveness of vaccinations.
According to the scientists, the research shows that more attention should be paid to the treatment of blood clots in corona patients. Researchers from the University of Glasgow, who were not involved in the study, report that the results show “that even mild infections can lead to complications”.