A new virus has been discovered in — and implicated in the death of — a short-beaked dolphin which was found stranded on a beach in San Diego back in 2010, according to researchers at the Center for Infection and Immunity at Columbia University’s Mailman School of Public Health. This is the first time that any virus from the polyomavirus family of viruses has been found in a dolphin.
Birds are typically thought to be the animals are most susceptible to polyomavirus — in mammals the effects of polyomavirus are typically mild. Lead author Simon Anthony, a researcher in the Center for Infection and Immunity at the Mailman School, explains: “It is therefore interesting that this particular polyomavirus appears to be what killed this dolphin. It’s no immediate cause for alarm, but it’s an important data point in understanding this family of viruses and the diseases they cause.”
The researchers think that the new findings may help in the solving of past unsolved cases. “There are many cases of disease in animals that we never have solved,” states Dr. Anthony. “When we make a new discovery like this, it allows us to ask, Have we seen it before? Will we see it again?”
Columbia University continues:
The dolphin, a female calf, was found dead in October 2010. Judy St. Leger, DVM, of SeaWorld in San Diego, a co-author of the study, conducted a necropsy that identified the cause of death as tracheal bronchitis with signs of an infection, which an electron microscope revealed to be of possible viral origin. To identify the culprit, she sent a biological sample to the Center for Infection and Immunity in New York, where Dr. Anthony used high throughput DNA sequencing and a number of other techniques to identify the novel polyomavirus.
Genetic analysis showed that the polyomavirus in the San Diego dolphin was distinct from other members of the virus family.
The researchers postulate that there may be other varieties of polyomaviruses in dolphins and other marine mammals, than just the one that has now been found. “It’s possible that many dolphins carry this virus or other polyomaviruses without significant problems. Or perhaps it’s like the common cold where they get sick for a short while and recover,” states Dr. St. Leger.
“We don’t even know if this is even a dolphin virus. It could also represent a spillover event from another species. Several important outbreaks in the past have resulted from viruses jumping into new hosts,” he explains, such as the previously documented case of bird flu in a seal population in New England.
“But for now, the significance of the discovery of a polyomavirus in a dolphin is that it appears to be the cause of death of this animal,” says Dr. Anthony. “One of our main goals is to protect the health of wildlife.”
The new research was recently published online in the journal PLOS ONE.