Investigating seroprevalence of IgG antibodies against Monkeypox Virus (MPXV) in a cohort of people living with HIV (PLWH) in Rome, during the 2022 outbreak: Moving beyond traditional at-risk populations

Abstract

Background: High incidence mpox rates suggest asymptomatic individuals may contribute to virus transmission. We undertook this study to assess the seroprevalence of IgG anti-MPXV in a cohort of asymptomatic PLWH, to analyze the size of the phenomenon of asymptomatic infections.

Materials and methods: From October 2022 to March 2023 we serially collected serum samples from PLWH attending our Clinic. IgG against MPXV have been assessed on stored cryopreserved samples with an ELISA. Only people with no previous reported vaccine against smallpox or mpox nor previous clinical manifestations consistent with a mpox diagnosis were included.

Results: 285 PLWH were included. Twenty-one participants tested positive for IgG anti MPXV (7.37 %, 95 % CI 4.62-11.0). Seropositivity was predominant in male (15/285, 71.4) with a small fraction of female (6/285,28.6 %) and PWID (1/285,4.8 %).

Conclusions: Our findings suggest the possibility of an asymptomatic course of the mpox infection even in populations beyond traditional high-risk groups.