Pre-Clade IIb Mpox Virus Exposure in Ghana: A Retrospective Serological Analysis

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Monkeypox virus (MPXV), an Orthopox virus endemic to Africa, causes mpox disease.
• Ghana had no confirmed human mpox cases before 2022, but a 2003 U.S. outbreak was linked to Ghanaian rodents, suggesting potential prior exposure.
• Previous assumptions indicated Ghana was unaffected by human mpox prior to 2022.

Purpose of the Study:

• To assess mpox (MPXV) exposure in Ghana before the 2022 emergence of Clade IIb in humans.
• To investigate the prevalence and demographic associations of MPXV seropositivity in the Ghanaian population.

Main Methods:

• Tested 457 serum samples from 14 Ghanaian regions using a commercial anti-MPXV IgG ELISA.
• Samples included archived sera from 2021 SARS-CoV-2 surveillance and from suspected mpox cases in 2022.
• Employed multivariable logistic regression to analyze associations between MPXV seropositivity and demographic factors.

Main Results:

• Overall MPXV seroprevalence was 6.6%.
• Participants from the Western Region showed significantly increased odds of seropositivity (aOR = 6.70, p = 0.005).
• Participants from Greater Accra had decreased odds of seropositivity (aOR = 0.28, p = 0.033).

Conclusions:

• Findings suggest localized MPXV circulation or repeated, undetected zoonotic spillover events in Ghana prior to 2022.
• Challenges the assumption of Ghana being unaffected by human mpox before 2022.
• Underscores the critical importance of strengthening disease surveillance and preparedness in Ghana for zoonotic diseases like mpox.