A news story reports the outbreak of abalone viral ganglioneuritis in Tasmania. This is the first report of the disease in Tasmanian fisheries. In fact, the disease appears to be quite newly emergent since, according to the Department of Primary Industries for the State of Victoria, the virus was previously not described in Australia prior to 2005. Since 2005, it has been devastating abalone fisheries in Victoria. Now it’s in Tasmania. One theory for the emergence of this herpes-like virus is that it is actually endemic in abalone populations and usually harmless. Environmental stress (e.g., via warming or polluted water) could induce increased virulence, leading to the high observed mortality rates. This is an outbreak to keep an eye on. The PROMED-mail moderator writes this about the virus:
Ganglioneuritis is an interesting condition causing inflammation in the nervous tissue, which swells. The result is curling of the abalone foot and swelling of the mouth. Thus, the organism cannot eat and looses its grip on the rocks it so depends on.
Abalone viral ganglioneuritis (AVG) is a highly virulent herpes-like virus, undescribed in Australia before 2005, and still not well characterized. The virus affects the nervous tissue of abalone and rapidly causes death. The virus can be spread through direct contact, through the water column without contact, and in mucus that infected abalone produce before dying. The virus is thought to survive only a short time when out of a moist environment.