New virus detected in dolphin could trigger epidemic in marine mammals

Reading time: 2 min – Spotted on Gizmodo

Hawaiian biologists have detected a previously unknown strain of morbillivirus cetaceans, a pathogen that can cause fatal infections in marine mammals around the world. The virus was discovered in a Fraser’s dolphin, a very social species, raising fears the disease could spread and claim lives beyond the Pacific Ocean, reports Gizmodo.

When this young dolphin ran aground off the coast of Maui in 2018, scientists investigated its condition for two years. Her body was fairly healthy, but her organs were showing signs of illness. A genetic analysis of his cells revealed the reason: “New very divergent strain of morbillivirus”, says Kristi West, a researcher at the Institute of Marine Biology at the University of Hawaii, in a press release. Details of the study were published in Nature Scientific Reports.

Only a handful of strains of the morbillivirus are known, but these don’t bode well: these viruses can lead to deadly epidemics among marine mammals, including dolphins, whales and other cetaceans. Other morbillivirus species, for example, cause measles in humans.

200 dolphins died in Brazil from morbillivirus in 2017

Fraser’s dolphins are very social and friendly animals, and are known to mix with other dolphins, and even with whales. Hence, they could spread this highly contagious virus to other parts of the world. People working in contact with marine fauna and conservationists must therefore be on their guard.

“This is all the more important for us in Hawaii because we have many other species of dolphins and whales here that could also be vulnerable to an outbreak of this virus., adds Kristi West. This is for example the case of false killer whales, of which it is estimated that only 167 individuals remain. If the morbillivirus spread among these animals, it would not only create a major obstacle to the recovery of the population, but it would also pose a threat of extinction. “

The question is very serious. Two previous outbreaks involving strains of the morbillivirus have resulted in high mortality rates in dolphins off Brazil and on the west coast of Australia. In Brazil, more than 200 dolphins in Guyana are said to have died from the disease between November and December 2017.

Scientists behind the study say more research is needed to test the immunity of Pacific dolphins and whales, and to establish the rates of previous infections from outbreaks as well as the extent of the one that is at risk. to crack down. Controlling this disease will not be easy, however. The Health and Stranding Lab at the University of Hawaii manages to recover less than 5% of cetaceans that die in the waters of the archipelago. But a vaccination campaign is not ruled out: the National Oceanic and Atmospheric Administration has been working on a morbillivirus vaccine for a group of Hawaiian monk seals.

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