Related Experiment Videos
Morbilliviruses and morbillivirus diseases of marine mammals
R L de Swart1, T C Harder, P S Ross
1Seal Rehabilitation and Research Center, Pieterburen, The Netherlands.
Abstract:
In recent years, serious disease outbreaks among seals and dolphins were attributed to infection with established or newly recognized morbilliviruses. The first identification of a morbillivirus as causative agent of mass mortality among marine mammals was in 1988, when the previously unrecognized phocine distemper virus (PDV) caused the death of 20,000 harbor seals (Phoca vitulina) in northwestern Europe. A similar epizootic among Baikal seals (Phoca sibirica) in Siberia in 1987 was later attributed to infection with canine distemper virus (CDV). A morbillivirus isolated from stranded harbor porpoises (Phocoena phocoena) between 1988 and 1990 proved to be yet another new member of the genus Morbillivirus, distinct from PDV and CDV and more closely related to rinderpest virus and peste-des-petits-ruminants virus: porpoise morbillivirus. A similar virus, dolphin morbillivirus, was the primary cause of mass mortality among striped dolphins (Stenella coeruleoalba) in the Mediterranean from 1990 to 1992. In this review, current knowledge of the genetic and antigenic relationships of these viruses is presented, and the origin and epizootiological aspects of the newly discovered morbilliviruses are discussed. In addition, the possible contributory role of environmental contaminant-related immunosuppression in the severity and extent of the different disease outbreaks is discussed.
Insights
New morbilliviruses, including phocine distemper virus (PDV) and dolphin morbillivirus, have caused significant marine mammal deaths. This review examines their genetic relationships, origins, and the potential role of environmental contaminants in disease outbreaks.
Area of Science:
- Veterinary Virology
- Marine Mammal Health
- Ecology
Background:
- Marine mammals like seals and dolphins are susceptible to morbillivirus infections.
- Recent years have seen severe disease outbreaks causing mass mortality in these populations.
- Established and newly identified morbilliviruses are implicated in these epizootics.
Purpose of the Study:
- To review current knowledge on genetic and antigenic relationships of newly discovered morbilliviruses.
- To discuss the origin and epizootiological aspects of these marine mammal morbilliviruses.
- To explore the potential role of environmental contaminants in disease severity.
Main Methods:
- Literature review of morbillivirus outbreaks in marine mammals.
- Analysis of genetic and antigenic data of identified viruses.
- Discussion of epizootiological factors and potential environmental influences.
Main Results:
- Phocine distemper virus (PDV) caused significant mortality in harbor seals.
- Canine distemper virus (CDV) was linked to Baikal seal deaths.
- Distinct porpoise and dolphin morbilliviruses were identified, causing mass mortality events.
- Genetic and antigenic distinctness of these viruses from known morbilliviruses confirmed.
Conclusions:
- Newly identified morbilliviruses pose a significant threat to marine mammal populations.
- Understanding viral relationships and origins is crucial for disease management.
- Environmental contaminants may exacerbate morbillivirus outbreaks, warranting further investigation.