- Yellowhead disease
Taxobox
name=Yellowhead virus
virus_group=iv
ordo= "Nidovirales "
familia= "Roniviridae "
genus= "Okavirus "
species= Yellowhead virusYellowhead disease (YHD) is a viral infection of
shrimp andprawn , in particular of the giant tiger prawn ("Penaeus monodon"), one of the two major species of farmed shrimp. The disease is highly lethal and contagious, killing shrimp quickly. Outbreaks of this disease have wiped out in a matter of days the entire populations of many shrimp farms that cultivated "P. monodon", i.e. particularlySoutheast Asia n farms. In Thai, the disease is called "Hua leung". [ Gulf States Marine Fisheries Commission: [http://nis.gsmfc.org/nis_factsheet.php?toc_id=119 "Non-Native Species Summaries: "Yellowhead Virus" (YHV)"] , 2003. Accessed June 30, 2005.]The disease is caused by the yellowhead virus (YHV), a positive-sense single-stranded
RNA virus related tocoronavirus es andarterivirus es. A closely related virus is thegill-associated virus (GAV), which is the type species of thegenus "Okavirus".The
cephalothorax of infected shrimp turns yellow after a period of unusually high feeding activity ending abruptly, and the then moribund shrimps congregate near the surface of their pond before dying. YHD leads to death of the animals within two to four days. [World Organization for Animal Health (OIE): "Aquatic Manual", 4th Ed., 2003. [http://www.oie.int/eng/normes/fmanual/A_00049.htm Section 4.1.3] . ISBN 92-9044-563-7.]YHD had been reported first from
Thailand in1990 , the closely related GAV has been discovered in1995 during a yellowhead-like disease inAustralia n shrimp farms.References
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