A new virus has been associated with respiratory illness and resulting death in a common dolphin (Delphinus delphis), according to researchers at Columbia University’s Mailman School of Public Health. The study, published July 10, 2013 in the journal PLOS ONE, identifies the virus as a new strain of polyomavirus.
Polyomaviruses are small, DNA-based viruses that are known to cause acute and severe illness in birds, but are generally mild in mammals. Six polyomaviruses are known to infect humans; some are actually quite common but cause no disease. In fact, polyomaviruses are generally latent (meaning not currently active, but with the potential to become so) in hosts with healthy immune systems but can cause illness in immunosuppressed individuals (such as those infected by HIV). Antivirals have been used to treat illnesses caused by these viruses, but current management primarily involves reducing immunosuppression (or improving immune system health) in order for the host’s immune system to combat the virus on its own. This family of viruses has never before been found in dolphins, and has only been discovered once in another marine mammal (a California sea lion).
The infected dolphin was found dead in October 2010 on a beach in San Diego, Calif. The cause of death, tracheal bronchitis (a respiratory illness), was of suspected viral origin, and researchers Anthony et al. identified it as a polyomavirus. Further research will seek to identify instances of this virus in other dolphins.
Although the mystery of this dolphin’s death has been solved, many questions remain. Did this particular strain of polyomavirus originate in dolphins, or did it come from another species? How prevalent is it in dolphins and other marine mammals? Do many dolphins carry the virus without falling ill? And of course, from a more anthropocentric perspective, does this discovery pose any new threats to humans?
Many viruses that spread among human populations are believed to have originated in other animals. Some of these are serious, such as HIV, which supposedly originated in monkeys and apes. Another is SARS (severe acute respiratory syndrome), which scientists believe originated in bats. While not all viruses jump from animals to humans (and vice versa) it does occur and can occasionally be serious.
Lead author Dr. Anthony notes, “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.” Regardless of whether or not this new polyomavirus can be transmitted to humans or other animals, it is important to monitor new diseases for the sake of both animal and human health.
Discovery of a New Human Polyomavirus Associated withTrichodysplasia Spinulosa in an Immunocompromized Patient. http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1001024
HIV ‘may have an ancient origin’. http://www.bbc.co.uk/news/science-environment-21189141
Identification of a Novel Cetacean Polyomavirus from a Common Dolphin (Delphinus delphis) with Tracheobronchitis. http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068239 - pone.0068239-Colegrove1
New Virus Discovered in Stranded Dolphin. http://www.mailman.columbia.edu/news/new-virus-discovered-stranded-dolphin
Polyomaviruses and human diseases. http://www.ncbi.nlm.nih.gov/pubmed/16626024
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