Wild and farmed tilapia are the targets for a new virus, researchers confirmed in a paper for the journal mBio.
The bug comes from a family of influenza viruses, and kills tilapia by causing brain swelling and liver disease. Dubbed tilapia lake virus (TiLV), the pathogen seems to predominantly affect tilapia – the world’s second most-farmed fish.
A group of scientists lead by a research core at Columbia University's Mailman School of Public Health and Tel Aviv University convened to research the reason behind a steady decline of tilapia — as much as 85 percent declining yields annually — observed in Israel starting in 2009. Similar die-offs were also recognized in Ecuador and Colombia. High-throughput sequencing and mass spectroscopy was used by the scientists to determine the genetic code of the virus, which was lifted from tissue taken from diseased fish in Israel and Ecuador.
Not much is yet known about the virus, however, scientists were able to hypothesize certain characteristics of the pathogen during the initial stages of investigation.
"It appears to be most closely related to a family of influenza viruses called orthomyxoviruses; however, we still don't understand much about its biology," adds Nischay Mishra, associate research scientist at the Center for Infection and Immunity at Columbia's Mailman School.
"We are shifting our focus now to implementing diagnostic tests for containment of infection and to developing vaccines to prevent disease," said Avi Eldar, a researcher at the Kimron Veterinary Institute in Bet Dagan, Israel.
Five institutions across four countries joined in on the investigation: the Center for Infection and Immunity and the New York Genome Center in the U.S.; Tel Aviv University and Kimron Veterinary Institute in Israel; the University of Edinburgh, Scotland; and St. George's University, Grenada, West Indies. Perhaps best known for its work identifying human diseases, back in 2010 the Center for Infection and Immunity was integral in pinpointing a virus responsible for plaguing European salmon farms; the institution has also been involved in identifying diseases in seals, sea lions and Great Apes.
"Resolution of this mystery was only possible through the concerted efforts of this talented group of international collaborators," concluded Ian Lipkin, a senior author of the paper and director of the Center for Infection and Immunity and John Snow Professor of Epidemiology at the Mailman School.
