Animal Models Used in Monkeypox Research

Abstract

Monkeypox is an emerging zoonotic disease with a growing prevalence outside of its endemic area, posing a significant threat to public health. Despite the epidemiological and field investigations of monkeypox, little is known about its maintenance in natural reservoirs, biological implications or disease management. African rodents are considered possible reservoirs, although many mammalian species have been naturally infected with the monkeypox virus (MPXV). The involvement of domestic livestock and pets in spillover events cannot be ruled out, which may facilitate secondary virus transmission to humans. Investigation of MPXV infection in putative reservoir species and non-human primates experimentally uncovered novel findings relevant to the course of pathogenesis, virulence factors and transmission of MPXV that provided valuable information for designing appropriate prevention measures and effective vaccines.

Keywords: animal models; emerging infectious diseases; monkeypox virus; reservoir; vaccine; zoonosis.

Figure 1

Confirmed cases of monkeypox in humans (orange and dark blue circles) and animals represented by countries. Countries that reported monkeypox infection in animals by PCR or viral isolation (bold italic species name) and serological method (italic species name) are marked with yellow. Dashed line indicates shipment of animals from Africa to the United States. The figure was based on continuously updated data available at the website of Centers for Disease Control and Prevention (data reported until 17 October, 2022) (https://www.cdc.gov/poxvirus/monkeypox/response/2022/world-map.html Accessed on 17 October 2022).

Figure 2

Potential transmission routes of monkeypox virus. Rodents have been suggested as natural hosts of MPXV that may transmit the virus to the human environment (green arrow). Close contact with the animals (green arrow) and with infected humans (purple arrow), consumption (blue arrow) and wild animal trade (yellow arrow) pose a risk to species spillover and zoonotic MPXV infection. Although non-human primates may be reservoirs of the virus, accidental infection of this group of animals is conceivable (orange arrow).

Figure 3

Schematic representation of cellular processes modulated by monkeypox virus proteins (green arrows, upregulation; red arrows, downregulation). Black arrows refer to experimentally verified result. Grey arrows show putative signaling concluded through mechanisms described for homologues of other orthopoxviruses.