Published Date: 2002-12-26 23:50:00
Subject: PRO/AH/EDR> Paralytic shellfish poisoning - Australia (VIC):alert
Archive Number: 20021226.6131
PARALYTIC SHELLFISH POISONING - AUSTRALIA (VICTORIA):ALERT
A ProMED-mail post
ProMED-mail, a program of the
International Society for Infectious Diseases
Date: 26 Dec 2002
From: ProMED-mail <email@example.com>
Source: The Age 24 Dec 2002 [edited]
Shellfish warning for Port Phillip Bay
Victorian health authorities have issued a warning that anyone eating
shellfish taken from the waters off inner city Melbourne could be fatally
The warning by Victoria's Chief Health Officer, Dr Robert Hall, was
prompted by the discovery of a toxic algal bloom in Hobson's Bay, which
consists of the northernmost reaches of Port Phillip Bay between
Williamstown and Elwood.
Dr Hall said shellfish gathered from the vicinity of the algal bloom could
be infected with dangerous levels of paralytic shellfish poisoning (PSP) toxin.
It was already illegal to gather shellfish like mussels, pipis, cockles, or
scallops in Hobson's Bay and the algal bloom was a timely reminder of the
dangers, Dr Hall said.
The bloom had occurred where large amounts of nutrient-rich fresh water
from the Maribyrnong and Yarra rivers mixed with the comparatively warm
seawater of Hobson's Bay.
Dr Hall said he was concerned that people visiting the area may not be
aware how dangerous it was to collect shellfish from the inter-tidal zone
and from piers in the area.
"The symptoms of PSP ranged from slight tingling and numbness about the
lips to, in the most severe cases, complete paralysis and death from
respiratory failure,'' Dr Hall said.
"People should note that cooking shellfish does not destroy the toxin,'' he
[Paralytic shellfish poisoning (PSP) is a significant problem in several
geographic areas, especially on both the east and west coasts of the U.S.
Caused by several closely related species in the genus _Alexandrium_, PSP
toxins are responsible for persistent problems due to their accumulation in
filter-feeding shellfish, but they also move through the food chain,
affecting zooplankton, fish larvae, adult fish, and even birds and marine
mammals. _Alexandrium_ blooms generally do not involve large-cell
accumulations that discolor the water and may be below the water surface
where they are not visible. Low-density populations can cause severe
problems due to the high potency of the toxins produced by these species.
Furthermore, _Alexandrium_ spp. can grow in relatively pristine waters,
and it is difficult to argue that anthropogenic nutrient inputs are
stimulating the blooms. These characteristics are important when
considering mitigation and control strategies.
Often PSP is associated with red tides or algal blooms. Red tide is caused
by an organism called _Karenia brevis_, which in high concentration can
make the water look red. The organism releases a toxin that paralyzes the
respiratory system of fish and other marine life.
Airborne toxins, water spray, and splashes in an outbreak have kept people
from beaches while leaving others with irritated eyes and throats. Red tide
irritates the skin of people exposed to it and can cause itchy eyes,
scratchy throats, and coughs.
Harvesting from affected areas for personal consumption is discouraged. Red
tide poisoning symptoms include nausea and dizziness and may last for
Previously red tide was known as _Gymnodinium breve_ and has been
reclassified in the taxonomy of dinoflagellates. Its new name is _Karenia
brevis_, or _K. brevis_. Karenia was chosen in honor of Dr. Karen
Steidinger, a prominent red tide scientist from the Florida Marine Research
Institute in St. Petersburg, FL.
<http://www.marinelab.sarasota.fl.us/~mhenry/rtupdate.phtml> - Mod.TG]