British researchers estimate that monkeypox is transmitted in half of cases before the first symptoms and can occur up to four days before symptoms.
- As of May 2022, there have been more than 70,000 people infected with monkeypox worldwide, according to the WHO.
- The disease has claimed 36 lives, according to the WHO dashboard.
- The WHO decided to maintain the maximum health alert last Tuesday, in particular because of new infections in certain countries.
The peak of monkey pox contamination has passed but there are still new cases in Francewhich casts doubt on the future face of the epidemic.
Monkey pox: we know more about the mode of transmission
In the meantime, researchers have made a discovery that could play a decisive role in managing the crisis. It would seem that the monkeypox virus is often transmitted before the appearance of the first symptoms.
The authors of the study, published Wednesday, November 2 in the British Medical Journal (BMJ) looked at data from almost 3,000 UK patients, mostly men who had had gay sex. Their goal was to understand the risk of transmission”silent“, that is to say during the incubation period, before the patient is struck by the first symptoms. The incubation period corresponds in fact to the time during which the future patient carries the virus without knowing it.
The second temporality that interested scientists was the time that elapsed from the appearance of symptoms in a given patient, until their appearance in the one to whom he transmitted the disease.
Caution even in the absence of symptoms of monkeypox!
Thanks to their work, they concluded that this second delay tends to be shorter than the first, which goes in the direction of transmission before the first symptoms.
British researchers estimate that this pre-symptomatic transmission represents more than half of cases, and can occur up to four days before symptoms. The results still need to be refined but other studies also suggested pre-symptomatic transmission.
Indeed, anal swabs taken from 213 asymptomatic men who have sex with other men had been retrospectively screened for monkeypox virus. Thirteen had tested positive and two men had subsequently developed symptoms of monkeypox.
