Published Date: 2011-09-25 16:52:17
Subject: PRO/AH/EDR> Epizootic ulcerative synd., fish - Australia: (QL)
Archive Number: 20110925.2908
EPIZOOTIC ULCERATIVE SYNDROME, FISH - AUSTRALIA: (QUEENSLAND)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Fri 23 Sep 2011
Source: Nine News [edited]
A fungal disease and a parasite are to blame for the sickness
afflicting fish in Gladstone Harbour, Queensland biosecurity
Commercial and recreational fishing in the central Queensland waterway
has been banned for 3 weeks [September-October 2011] after fish were
found with sores and cloudy eyes.
Initial test results identified 2 conditions, red-spot disease [also
known as epizootic ulcerative syndrome] and a parasite, said Fisheries
Queensland general manager of habitat and assessment John Robertson.
"Red-spot disease starts with a red spot, hence the name, but can
develop into burn-like marks, or ulcers with red centres," Dr
Robertson said. He said red-spot disease is endemic in Queensland and
usually happens in winter, when the immunity of fish is lower, or
after the 1st heavy rainfall of the wet season. "It is caused by a
fungus and often occurs in fish when they are under stress."
Dr Robertson said more research was needed into the parasite, which
affected the eye of the fish. "We now know that this parasite is what
has been causing the cloudy eyes in some barramundi in the area," he
said. "We still have more to learn about this condition and how it is
affecting fish within the area." Additional testing is being conducted
on fish, prawns, and mud crabs from Gladstone Harbour.
Queensland Seafood Industry Association president Michael Gardner said
identifying the disease was just the 1st step. "It is critical that
not only [microbiological] and pathology testing be conducted but a
full suite of toxicology testing also be conducted to identify any
residues that may be present in these fish," he said in a statement.
He said further testing is required "if industry is to have any
confidence in being able to return to work."
Fishermen are also running out of patience for the time it has taken
to complete the tests, Mr Gardiner said. "They are facing severe
financial difficulties associated with the fishing lock-out and no
certainty when and if they will be able to return to work," he said.
"Fishermen have worked well with government but are increasingly
desperate for real answers as to what has decimated their fishery and
the harbour environment."
He called for affected businesses to be compensated while they waited
for payments to be set up by the coordinator-general.
[Red spot disease is quite a serious ulcerative disease of many (more
than 100) species of freshwater and estuarine fish. In Australia, the
disease is more common in the Northern Territory, but it also occurs
in New South Wales, Queensland, and Western Australia.
Cloudiness of the cornea is sometimes observed in some fish species,
especially barramundi, with this condition (Humphrey and Pearce,
Fishnote no. 1, October 2004). The causative agent of red spot disease
is a fungus, _Aphanomyces invadans_.
There is no mention on the finding of a parasite in cases of eye
cloudiness. This sign might be part of the red spot disease syndrome,
but cloudy eyes can also be caused by digeneans [parasitic flatworms]
or coccidians [parasitic protozoans].
The overall impact of red spot disease on wild stocks of fish is
uncertain, although high losses in juvenile stocks are known to occur.
If _A. invadans_ invades aquaculture farms it may cause unsightly
injuries in fish, market rejection, and fish mortality.
The fungus is not known to cause disease in humans. However, advanced
lesions in fish sometimes contain bacteria which potentially cause
disease in humans. Therefore, people should not eat diseased fish.
Portions of this comment were extracted from
http://www.nt.gov.au/d/Content/File/p/Fishnote/FN01.pdf. - Mod.PMB]
[A HealthMap/ProMED-mail interactive map of Australia can be seen at
http://healthmap.org/r/1hix. - Sr.Tech.Ed.MJ]