Cross-species transmission of canine distemper virus—an update

Abstract

Canine distemper virus (CDV) is a pantropic morbillivirus with a worldwide distribution, which causes fatal disease in dogs. Affected animals develop dyspnea, diarrhea, neurological signs and profound immunosuppression. Systemic CDV infection, resembling distemper in domestic dogs, can be found also in wild canids (e.g. wolves, foxes), procyonids (e.g. raccoons, kinkajous), ailurids (e.g. red pandas), ursids (e.g. black bears, giant pandas), mustelids (e.g. ferrets, minks), viverrids (e.g. civets, genets), hyaenids (e.g. spotted hyenas), and large felids (e.g. lions, tigers). Furthermore, besides infection with the closely related phocine distemper virus, seals can become infected by CDV. In some CDV outbreaks including the mass mortalities among Baikal and Caspian seals and large felids in the Serengeti Park, terrestrial carnivores including dogs and wolves have been suspected as vectors for the infectious agent. In addition, lethal infections have been described in non-carnivore species such as peccaries and non-human primates demonstrating the remarkable ability of the pathogen to cross species barriers. Mutations affecting the CDV H protein required for virus attachment to host-cell receptors are associated with virulence and disease emergence in novel host species. The broad and expanding host range of CDV and its maintenance within wildlife reservoir hosts considerably hampers disease eradication.

Rapid changes in Atlantic grey seal milk from birth to desertion

“…The rapid change in protein profile is particularly impressive, but so too is the persistence of IgG with time after birth. This is unusual and could indicate a particular need to provision a rapidly growing offspring with a sufficient supply of antibody to maintain its defence against pathogens in circulation in breeding colonies, the phocine and other morbilliviruses being obvious examples [93,94]. A question therefore is whether this prolonged delivery of IgG is only for protection of the gut, or instead results in a systemically protective build-up of this immunoglobulin in the blood of the pups before desertion.…”

Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

“…Further support for this suggestion comes from CDV's presence in other South American animals, including ocelots (Leopardus pardalis) and Pampas foxes (Pseudalopex gymnocercus) in Bolivia (Fiorello et al 2007) and pumas, jaguars (Panthera onca), kinkajous (Potos flavus), and Geoffroy's cat (Leopardus geoffroyi) elsewhere (Beineke et al 2015). Although some seroepidemiological surveys have not detected CDV among wild canids (Courtenay et al 2001;Curi et al 2010), Megid et al (2009) report naturally occurring instances of infection in hoary foxes and crab-eating foxes in the south of Brazil.…”

“…A profound suppression of the immune system and generalised depletion of the lymphoid organs marks the acute phase of the disease and there is a high frequency of accompanying neurological complications. The length of the disease's incubation period and its duration and severity vary according to an animal's age and its immune status, as well as the virulence of the particular viral strain involved (Beineke et al 2015). While anywhere between 50% and 70% of infected dogs may remain asymptomatic (Greene and Appel 1990) and survivors retain immunity that is prolonged, or even lifelong (Rosado 2009), distemper's fatality rate is second only to that of rabies (Deem et al 2000, p. 441).…”

Advances in canine distemper virus pathogenesis research: a wildlife perspective

“…Host range and prevalence Although CDV was initially described as an infectious disease of domestic dogs, it has increasingly become known as a worldwide multi-host pathogen, infecting a wide range of carnivores [10]. Its ability to infect multiple species has led to mass mortalities in a range of carnivore species from wild canids to felids, hyaenids, procyonids, ailurids, ursids, mustelids and viverrids.…”

“…This highly contagious pathogen is the cause of canine distemper (CD), a severe systemic disease affecting carnivores worldwide. Initially diagnosed as a life-threatening disease in domestic dogs (Canis familiaris), it has subsequently been recognized in a wide range of hosts including some non-human primates, posing a conservation risk to several free-ranging and captive non-domestic carnivores [10,11]. The ability of CDV to switch hosts has raised concerns about the extinction threat it poses to several endangered wildlife species [12][13][14].…”