[Translated from French]

Long COVID, often attributed to a psychosomatic mechanism, has biological causes, a study reveals. Months after the infection, the virus was still active, at low levels, in the brainstem of hamsters.

“We hope to bring relief to the patients who may have heard that they are not sick, that it is ‘in their heads.’ What we are showing in the laboratory is that long COVID has a biological cause!,” says Guilherme Dias de Melo, a veterinarian and researcher in infectious diseases and neuropathologies at the Institut Pasteur. Eighty days after the initial infection, the COVID-19 virus was found, still infectious, in the brainstems of hamsters affected by symptoms similar to those of long COVID, according to the work that he has directed and published in the journal Nature Communications.

Anxiety, depression and memory disorders

Anxiety, depression and memory disorders

“Animals infected 80 days earlier showed the virus still infectious in the brain, where several metabolic pathways were deregulated, showing that the virus was responsible for the symptoms,” explains Guilherme Dias de Melo. These symptoms, exhibited only by hamsters infected with SARS-CoV-2 (the virus responsible for COVID-19), included anxiety, depression and memory problems, just like patients suffering from long COVID. The study confirms in passing that the hamster, which unlike the mouse has the same ACE2 receptors as humans serving as an entry point for the virus, is one of the first reliable animal models of long COVID.