Epidemiological and Clinical Characteristics of Patients Admitted to a Secondary Hospital with Suspected MPOX Virus Infection: Is HIV Playing a Role?

MPOX (monkeypox) is a zoonotic viral disease, endemic in some Central and West African countries. However, in May 2022, cases began to be reported in non-endemic countries, demonstrating community transmission. Since the beginning of the outbreak, different epidemiological and clinical behaviors have been observed. We conducted an observational study at a secondary hospital in Madrid to characterize suspected and confirmed cases of MPOX epidemiologically and clinically. Besides the general descriptive analysis, we compared data between HIV-positive and HIV-negative subjects; 133 patients were evaluated with suspected MPOX, of which 100 were confirmed. Regarding positive cases, 71.0% were HIV positive, and 99.0% were men with a mean age of 33. In the previous year, 97.6% reported having sex with men, 53.6% used apps for sexual encounters, 22.9% practiced chemsex, and 16.7% went to saunas. Inguinal adenopathies were significantly higher in MPOX cases (54.0% vs. 12.1%, p < 0.001), as the involvement of genital and perianal area (57.0% vs. 27.3% and 17.0% vs. 1.0%, p = 0.006 and p = 0.082 respectively). Pustules were the most common skin lesion (45.0%). In HIV-positive cases, only 6.9% had a detectable viral load, and the mean CD4 count was 607.0/mm3. No significant differences were observed in the disease course, except for a greater tendency towards the appearance of perianal lesions. In conclusion, the MPOX 2022 outbreak in our area has been related to sexual intercourse among MSM, with no severe clinical cases nor apparent differences in HIV and non-HIV patients.