This week, the journal The Lancet published the results of a study showing that 40% of patients infected with monkeypox suffer complications that require medical treatment. Involved in this study were the Vall d’Hebron Research Institute (VHIR) Infectious Diseases and Microbiology Research Groups and the Vall d’Hebron University Hospital Infectious Diseases and Microbiology Departments, together with the Germans Trias University Hospital, the Lluita contra les Infeccions Foundation and the 12 Octubre University Hospital.

The study analysed lesions in 181 patients diagnosed with monkeypox in Barcelona and Madrid. All of them had skin lesions, 141 of which (78%) were in the anogenital region and 78 (43%) in the mouth region. The average age of the people affected was 37. 175 patients were male, and 166 of them identified as men that have sex with men. The average incubation period for the disease was seven days.

Out of these patients, 70 (39%) had complications that required medical treatment, mainly to ease pain. The reasons for treating the patients were the following complications: proctitis (45 patients, 25%), tonsillitis (19, 10%), penile oedema (15, 8%), abscesses (6, 3%) and exanthem (8, 4%). Three patients were also admitted to hospital. The large sample size and systemic analysis of the lesions helped identify previously unreported complications.

The publication also states that direct skin contact is the most frequent route of transmission for the virus, rather than airways. Indeed, the viral load is higher in skin lesions and lower in samples obtained from patients’ pharynx. This has implications for approaching the disease and rethinking the need to isolate infected individuals to avoid its spread.

The study authors state that, based on the results, the presence of atypical manifestations in many patients suggests healthcare professionals should strongly suspect the disease, especially in potentially exposed individuals and ones living in areas with high transmission rates. Furthermore, based on the short incubation period, they recommend pre-exposure vaccination among high-risk groups, which can be more effective than post-exposure vaccination.