Now when the Peru’s officials are almost certain that it was morbillivirus infection that caused the Unusual Mortality Event, our readers might be interested to know about one piece of information that the media, NGOs and other parties involved are not telling you.
Research showed that dolphins can be infected with morbillivirus but it does not necessarily mean that they cannot survive it. Nor does it mean that all infected by morbillivirus cetaceans die off in huge numbers and strand. Please read it again. This is very important. It means that the presence of morbillivirus infections does not necessarily mean that it was the reason for Peruvian unusual mortality event. Now everybody needs to watch very closely what exactly will be found in Peru testing.
Below are two very important studies on the topic:
Study #1. Tested bottlenose dolphins in Florida and North Carolina. “Positive morbillivirus titers were found on initial capture in 12 of 122 (9.8%) IRL dolphins in the absence of an epizootic (die off).” The study also made interesting suggestion how dolphins can deal with morbillivirus without dying. “Based on the canine model, dolphins may respond similarly with production of a humoral immune response, neutralizing antibody titers and the development of subclinical infection”
Reference: Bossart, G. D., Reif, J. S., Schaefer, A. M., Goldstein, J., Fair, P. A., & Saliki, J. T. (2010). Morbillivirus infection in free-ranging Atlantic bottlenose dolphins (Tursiops truncatus) from the Southeastern United States: Seroepidemiologic and pathologic evidence of subclinical infection. Veterinary Microbiology, 143(2-4), 160-166.
Study #2. Tested 18 stranded dolphins in California for morbillivirus. Six dolphins tested positive for a virus. But then it got interesting. One dolphin actually recovered and was released. The study conclusion: “One recovered and the other five did not have postmortem lesions characteristic of morbilhiviral disease such as syncytia and inclusion bodies although one had mild meningoencephalitis and cerebral toxoplasmosis. These findings indicate that morbillivirus infection occurs in common dolphins of the Pacific Ocean, that infected common dolphins may not have characteristic pathologic features of morbilliviral disease and that recovery is possible. “
Reference: Reidarson, T.H. et al., (1998), MORBILLIVIRUS INFECTION IN STRANDED COMMON DOLPHINS FROM THE PACIFIC OCEAN, Journal of Wildlife Diseases, 34(4), 771-776.
So what does this all mean? It means that the presence of morbillivirus should not by any means get the oil company off the hook. Dolphins might have virus in the wild and still live normal life. Just like humans with herpes virus can live a normal life. It would be absurd to test some plane crash victims and conclude that because they had herpes, it was the likely cause of death. But this is exactly what Peruvian authorities are trying to do with these dolphins. Please keep the conversation going and realize how easy it is to twist things when the public is not given all available information.