Clinical presentation of human monkeypox virus infection during the 2022 outbreak: descriptive case series from a large italian Research Hospital

BACKGROUND: In May 2022, a new case of Monkeypox Virus (MPX) was reported in a non-endemic area, the United Kingdom, and since then, the number of confirmed cases in Europe has been increasing until WHO, on May 10 2023, declared that MPOX is no longer a public health emergency of international concern. We aimed to describe the clinical and microbiological characteristics of sixteen patients with a confirmed diagnosis of MPX followed by a single Italian clinical centre, the Fondazione Policlinico Universitario Agostino Gemelli, between May 20 and August 30. MATERIALS AND METHODS: A prospective observational study has been conducted, collecting microbiological samples during the time of the infection, as well as epidemiological and clinical data of the patients. All patients provided written informed consent. RESULTS: During clinical practice, 16 individuals presenting with consistent symptoms tested positive for MPX on a polymerase chain reaction. All patients were men having sex with men (MSM). The most frequent clinical presentation was a vesicular erythematous cutaneous rash, mainly distributed on the genital and perianal area, but also regarding limbs, face, neck, chest and back in some of the patients. Systemic symptoms, such as fever or lymphadenopathy, involved eight patients. The symptom most frequently reported by patients was pruritus in the area of the vesicles. Thirteen patients also reported pain. Nine patients were HIV-1 coinfected, but no significant differences have been observed compared to other cohort patients. The median time between the onset of symptoms and the healing was 19.5 days (IQR 14.0–20.3). CONCLUSIONS: Our cohort of patients presented a mild manifestation of the disease with no complications and no need for antiviral therapy nor hospitalization. This population seems different from the ones reported in the literature during the previous outbreaks in endemic areas in epidemiological data and clinical manifestations but also from a cohort of patients described in the literature from the 2022 outbreak, suggesting the importance for healthcare workers to keep in mind the possibility of an MPX infection in the differential diagnosis of patients presenting with consistent symptoms, even in non-endemic areas, to ensure efficient isolation of the patient for infection control purposes and effective management of the infection preventing the development of MPOX-related complications.