Pathogenicity and transmissibility of Mpox virus in African dormice

The global spread of monkeypox virus (MPXV) clade IIb has highlighted the urgent need for reliable animal models to investigate its biological characteristics. This study established an African dormouse (Graphiurus spp.) model and systematically characterized the pathogenicity and transmissibility of a clade IIb strain (hMPXV/China/GZ8H-01/2023). Intranasal inoculation induced significant weight loss, lethal infections, and multi-organ pathology, with robust viral replication in the respiratory and liver tissues. Direct contact transmission was efficient: 1/3 of contact-exposed dormice shed infectious virus, while 2/3 showed seropositivity. Although airborne exposure resulted in 1/3 seropositivity, no infectious virus was detected, thereby indicating limited airborne transmission. Infected dormice emitted abundant virus-laden aerosols, peaking at 3.78 ± 1.01×10⁶ copies/dormouse/hour at 12 days post-infection (dpi). These findings establish African dormice as effective models for studying MPXV infection, pathogenicity, and transmission. Enhanced surveillance of wild dormouse populations is critical due to their potential role in MPXV transmission chains.