title: Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia.
abstract: Tilapia are an important global food source due to their omnivorous diet, tolerance for high-density aquaculture, and relative disease resistance. Since 2009, tilapia aquaculture has been threatened by mass die-offs in farmed fish in Israel and Ecuador. Here we report evidence implicating a novel orthomyxo-like virus in these outbreaks. The tilapia lake virus (TiLV) has a 10-segment, negative-sense RNA genome. The largest segment, segment 1, contains an open reading frame with weak sequence homology to the influenza C virus PB1 subunit. The other nine segments showed no homology to other viruses but have conserved, complementary sequences at their 5' and 3' termini, consistent with the genome organization found in other orthomyxoviruses. In situ hybridization indicates TiLV replication and transcription at sites of pathology in the liver and central nervous system of tilapia with disease.
  
  
  OBJECTIVE
  The economic impact of worldwide trade in tilapia is estimated at $7.5 billion U.S. dollars (USD) annually. The infectious agent implicated in mass tilapia die-offs in two continents poses a threat to the global tilapia industry, which not only provides inexpensive dietary protein but also is a major employer in the developing world. Here we report characterization of the causative agent as a novel orthomyxo-like virus, tilapia lake virus (TiLV). We also describe complete genomic and protein sequences that will facilitate TiLV detection and containment and enable vaccine development.
authors.affiliation: Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Bacharach
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Nischay
authors.initials: N
authors.lastname: Mishra
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Briese
authors.affiliation: New York Genome Center, New York, New York, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Zody
authors.affiliation: Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Japhette Esther
authors.initials: JE
authors.lastname: Kembou Tsofack
authors.affiliation: Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Zamostiano
authors.affiliation: Department of Poultry and Fish Diseases, The Kimron Veterinary Institute, Bet Dagan, Israel.
authors.forename: Asaf
authors.initials: A
authors.lastname: Berkowitz
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ng
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Nitido
authors.affiliation: New York Genome Center, New York, New York, USA.
authors.forename: André
authors.initials: A
authors.lastname: Corvelo
authors.affiliation: New York Genome Center, New York, New York, USA.
authors.forename: Nora C
authors.initials: NC
authors.lastname: Toussaint
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Sandra Cathrine
authors.initials: SC
authors.lastname: Abel Nielsen
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Mady
authors.initials: M
authors.lastname: Hornig
authors.affiliation: Easter Bush Pathology, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, Scotland.
authors.forename: Jorge
authors.initials: J
authors.lastname: Del Pozo
authors.affiliation: New York Genome Center, New York, New York, USA.
authors.forename: Toby
authors.initials: T
authors.lastname: Bloom
authors.affiliation: Marine Medicine Program, Pathobiology, School of Veterinary Medicine, St. George's University, Grenada, West Indies.
authors.forename: Hugh
authors.initials: H
authors.lastname: Ferguson
authors.affiliation: Department of Poultry and Fish Diseases, The Kimron Veterinary Institute, Bet Dagan, Israel eldar@int.gov.il wil2001@cumc.columbia.edu.
authors.forename: Avi
authors.initials: A
authors.lastname: Eldar
authors.affiliation: Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, USA eldar@int.gov.il wil2001@cumc.columbia.edu.
authors.forename: W Ian
authors.initials: WI
authors.lastname: Lipkin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004484:Ecuador / Q000453:epidemiology; D005393:Fish Diseases / Q000453:epidemiology / Q000401:mortality* / Q000821:virology*; D007557:Israel / Q000453:epidemiology; D016366:Open Reading Frames; D009975:Orthomyxoviridae / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary* / Q000821:virology; D016415:Sequence Alignment; D017210:Tilapia / Q000821:virology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D014764:Viral Proteins