Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus

Abstract

Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

Comparative morphometric analysis of lungs of the semifossorial giant pouched rat (Cricetomys gambianus) and the subterranean Nigerian mole rat (Cryptomys foxi)

“…Because of its highly developed sense of smell 104 , C. gambianus has been effectively trained for mine detection 105,106 , some human communities use it for food 107 and it is also kept as a pet 108 . The rodent has, however, earned the bad reputation of being a potential reservoir host for the zoonotic monkeypox virus 109,110 . C. foxi, is a subterranean rodent belonging to the family Bathyergidae and occupies tropical dry lowland grasslands, riverside Table 3.…”

Ophthalmic examination findings and intraocular pressures in wild‐caught African giant pouched rats (Cricetomys spp.)

“…African giant pouched rats are housed as pets in some regions of the world, although their possession in the United States for this purpose is currently forbidden. Giant pouched rats were initially implicated for the outbreak of human Monkeypox virus that occurred in 2003 in the Midwestern United States . It was later determined that the outbreak was started and spread by captive North America black‐tailed prairie dogs shipped from Ghana, West Africa .…”

“…Giant pouched rats were initially implicated for the outbreak of human Monkeypox virus that occurred in 2003 in the Midwestern United States . It was later determined that the outbreak was started and spread by captive North America black‐tailed prairie dogs shipped from Ghana, West Africa . Clinical reports of experimentally infected pouched rats with Monkeypox revealed ocular lesions of white–yellow corneal opacities and ocular discharge .…”

“…Ocular lesions were common, but only one eye had changes that precluded fundus [15][16][17] It was later determined that the outbreak was started and spread by captive North America black-tailed prairie dogs shipped from Ghana, West Africa. 16,17 Clinical reports of experimentally infected pouched rats with Monkeypox revealed ocular lesions of white-yellow corneal opacities and ocular discharge. 15,16 African giant pouched rats have also been identified with several other infectious diseases.…”

“…16,17 Clinical reports of experimentally infected pouched rats with Monkeypox revealed ocular lesions of white-yellow corneal opacities and ocular discharge. 15,16 African giant pouched rats have also been identified with several other infectious diseases. Leptospira interrogans serovar Kenya was identified in the urine of newly captured pouched rats, and they are suspected to be carriers of this zoonotic disease.…”