Massive Dolphin Die-Off: Measles-Kike Virus Suspected In Atlantic Bottlenose Dolphin Deaths

Atlantic dolphin deaths have been explained by a measles-like virus. The virus is suspected of killing hundreds of Atlantic bottlenose dolphins.

The dolphins have been dying in large numbers since July, officials say.

The measles-like virus, morbillivirus infects the lungs and the brain. It is similar to measles in humans and causes pneumonia and abnormal behavior, often proving fatal.

Since the beginning of the outbreak in July, 333 bottlenose dolphins in the mid-Atlantic region have died.

Thirty-two of 33 dolphins tested either confirmed positive or are suspected of dying from morbillivirus.

The measles-like morbillivirus outbreak may last for up to a year. Officials say it may be worse than the last major outbreak 25 years ago. That outbreak killed over 740 dolphins.

The measles-like disease can cause lesions on the dolphins' skin, mouth, joints and lungs.

"We are now calling this a morbillivirus outbreak," said Teri Rowles of the NOAA Fisheries Marine Mammal Health and Stranding Response Program.

And, she added, it may be worse than the last outbreak, which spread from New York to Florida.  "We are expecting that if indeed this plays out the way that die-off occurred, that we are looking at mortality being higher and morbillivirus spreading southward and likely continuing until spring of 2014," she told reporters.

Most dolphins that were victims of the outbreak were found dead on beaches, having washed up on the shore.

Scientists aren't sure what lead to this outbreak, but suspect a lack of immune response. They think some creatures are naturally immune to morbillivirus and some aren't. It's likely that a population of dolphins came in contact with an immune group, resulting in the current mass die-off.

Viruses in the same family can cause very similar diseases. They take the form of measles in humans, canine distemper in dogs and wolves and rinderpest in cattle.

"There is a tipping point in populations," said Stephanie Venn-Watson of the National Marine Mammal Foundation.

"The primary hypothesis is that East Coast dolphins simply don't have the immune response to effectively fight off this virus."

There is no way to stop the spread of the disease in the wild dolphins. However, they said that the illness is not likely to spread to humans.

"All morbilliviruses known to date infect a small number of closely related species," said Jerry Saliki, a virologist from the University of Georgia.

"So there is no indication that this virus could jump into humans given the species gap between marine mammals and humans."

488 bottlenose dolphins have been stranded so far this year along the coastline that stretches from New York to North Carolina. That's a huge jump compared to 167 last year.