Paris. An American was infected twice with Covid-19 in a month and a half of interval and the second infection was more serious than the first, according to a study released last Tuesday that details this case of reinfection, one of the five registered so far in the world.
“There is still great ignorance about SARS-CoV-2 infections and the immune system response, but our work shows that a previous infection would not necessarily protect against a future infection,” says Professor Mark Pandori, lead author of the study published in The Lancet Infectious Diseases medical journal.
This implies that “people who have tested positive for SARS-CoV-2 should continue to take precautions, such as physical distance, wear a mask and wash their hands,” because it is possible to become infected again, explains Pandori, quoted in a statement from the magazine.
According to this medical journal, five cases of reinfection have been confirmed so far: in Hong Kong (the first, announced on August 24), in Belgium, the Netherlands, Ecuador and in the North American state of Nevada (the subject of this new study).
“This does not mean that there are no more, since many cases of covid-19 are asymptomatic” and therefore difficult to detect, warns Pandori, an expert from the University of Nevada.
Video: What is tuberculosis, what are the symptoms and how is the treatment? (Dailymotion)
The five cases are different. In the case of Nevada and Ecuador, the second infection was more serious than the first, unlike what happened with the other three.
In the case of Nevada, a 25-year-old young man, no immune disorder or any other previous disease was detected.
On April 18, she tested positive for the first time, with some symptoms (sore throat and headache, cough, nausea and diarrhea). He isolated himself at home and his condition improved. Then it tested negative twice.
But 48 days later, on June 5, he tested positive again, after presenting more serious symptoms this time, such as breathing difficulties that required his admission to the emergency room and the administration of oxygen. You are now recovered.
A genetic analysis has shown that these two successive infections were caused by two different strains of coronavirus, an essential piece of information to be sure that it is a reinfection.
“More research is needed to understand how long immunity against SARS-CoV-2 lasts and why some of the second infections, although rare, are more serious,” Pandori wonders.