Pimples in the genital and anal area, inflammation of the glands and rectum, tonsillitis… Monkeypox is a disease that manifests itself in most cases in a benign way, but often painful. Four out of 10 patients require medical treatment to manage the complications described, according to a Spanish study published this Tuesday in the journal the Lancet, which also confirms the hypothesis Direct contact with the skin as the main route of transmission of the disease.
The observational study reinforces the knowledge that existed on the manifestations of monkeypox and brings a nuance that had not yet appeared, thanks to its large sample: 181 confirmed cases. “There is a much greater clinical impact than expected,” explains Oriol Mitzo, coordinator of the study. Beyond the pain that the pustules themselves can cause, studies have shown that rectal inflammation caused by receptive anal sex can cause a lot of pain when defecating. Tonsillitis caused by oral sex, major swallowing problems. “So much so that one of the hospitalized patients had to be admitted because he couldn’t eat,” says Mitzo, an infectious disease specialist at Germany’s Trias Hospital.
However, there are no hospitalizations in this monkeypox epidemic, which adds to the total of 4,942 people affected in Spain, according to the latest figures from the Ministry of Health. under investigation the Lancet, which brought together the CHU 12 d’Octubre, the German CHU Trias, the Foundation for the Fight against Infection and the CHU Val d’Hébron, counted three admissions. According to Health, about 3% of all infected people require hospital care. At present, two people have died from this disease in Spain.
The PCR data of the patients studied indicate that the viral load is higher in the lesions than in the samples taken from the pharynx. This suggests that the respiratory tract is less relevant for contagion than direct contact, which explains why sexual intercourse is the main route of transmission: 80% of cases according to ministry statistics.
In previous monkeypox outbreaks, Mitzo explains, saliva droplets were thought to be the most common form of contagion, which has also been observed in animal models. “The new data leads us to believe that transmission through the respiratory tract is very rare. There is now a local vaccine and of course local replication as well. [en los alrededores de la zona que entra en contacto con el virus]“, explains the researcher.
The low viral load in the respiratory tract prompts the study authors to suggest further research to determine the possibility of transmission through this medium. “Such prolonged isolation at home may not be necessary,” says Eloy Tarin, one of the authors of the research carried out with patients from Madrid and Barcelona, who accumulate the majority of cases in Spain.
Check for viral mutations
What has changed in the virus that it now changes the way it spreads? On the one hand, explains Tarin, it will be necessary to study whether the pathogen has a mutation that facilitates the mechanism of direct exposure during respiration. “You can find a new population location” [los hombres que practican sexo con hombres, que suman el 98% de los casos en el mundo y más del 80% en España] and a new form of sexual transmission,” he says.
One of the data confirmed in this study is the incubation period of the virus, which is around seven days and not between 15 and 22 in previous outbreaks of monkeypox in the Dominican Republic. Democratic Congo. According to the researchers, a week is too short a time for a post-exposure vaccine to be effective in exposure to confirmed cases. At the moment, it is still one of the groups currently vaccinated in Spain, which the researchers consider unnecessary with their data. “It makes more sense to focus on pre-exposure vaccination of risk groups” [algo que ya se hace en paralelo a los anteriores]“says Tarin.
The truth is that the doses entering Spain are still insufficient to vaccinate the risk groups, that is, men who have several male sexual partners. At present, there are 5,300 vaccines in Spain, which have been distributed between communities, especially between Catalonia and Madrid. Health said another 7,000 would arrive last week, but they have not yet been received. This makes it very difficult to book appointments for vaccinations. And this for the first dose, the effectiveness of which is estimated at around 30%. To reach approximately 80% of these injections, a second puncture must be obtained a few weeks later.