Archive Number 20070813.2637
Published Date 13-AUG-2007
Subject PRO/AH/EDR> Vibrio parahaemolyticus, oysters - USA (WA): int'l alert
VIBRIO PARAHAEMOLYTICUS, OYSTERS - USA (WASHINGTON): INTERNATIONAL ALERT
************************************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Fri 10 Aug 2007
Source: FDA (US Food and Drug Administration) News, press release [edited]
<http://www.fda.gov/bbs/topics/NEWS/2007/NEW01680.html>
The FDA is warning consumers not to eat raw oysters harvested from an
area of the southern tip of Hood Canal [Mason County] in Washington
[state] after an outbreak of illness caused by _Vibrio
parahaemolyticus_.
Symptoms of the illness, called vibriosis, include watery diarrhea,
often with abdominal cramping, nausea, vomiting, fever, and chills.
Usually these symptoms occur within 24 hours of ingestion and last no
more than 3 days. Severe disease is rare and occurs most commonly in
people with weakened immune systems. Those who believe they have
experienced these symptoms after consuming raw oysters should consult
their health care provider and contact their local health department.
Raw oysters harvested from "growing area 6" in Hood Canal from 3 Jul
2007 and after, have caused at least 6 people to become ill in
California and Washington. Additional reports of illness are being
investigated by the states. To date, records indicate that raw
oysters from the area were distributed to California, Florida,
Hawaii, Idaho, New York, Oregon, Washington, British Columbia
(Canada), Hong Kong, Malaysia, and Singapore.
The Washington State Department of Health has closed the growing area
associated with the illness and has asked commercial oyster
harvesters and dealers who obtained oysters from this area to recall
them. Consumers who have recently purchased oysters should check with
the place of purchase and ask if they were harvested from the
affected growing area.
Those with weakened immune systems, including people affected by
AIDS, chronic alcohol abuse, liver, stomach, or blood disorders,
cancer, diabetes, or kidney disease should avoid eating raw oysters,
regardless of where they are harvested.
FDA advises that consumers can continue to enjoy oysters in many
cooked preparations by doing the following:
At Restaurants and other Foodservice Establishments:
- order oysters fully cooked.
In the Shell:
- purchase oysters with the shells closed.
- throw away any oysters with shells already opened.
- never allow raw seafood to come into contact with cooked food.
- boil oysters until the shells open. Once shells open, boil for an
additional 3 to 5 minutes.
- to steam, add oysters to water that is already steaming and cook
live oysters until the shells open, once open steam for another 4 to
9 minutes.
- use smaller pots to boil or steam oysters. Using larger pots, or
cooking too many oysters at a time, may cause uneven heat
distribution, which may cause the oysters in the middle to be
under-cooked.
- discard any oysters that do not open during cooking.
Shucked Oysters:
- never allow raw seafood to come into contact with cooked food.
- boil or simmer shucked oysters for at least 3 minutes or until the
edges curl.
- fry at 375 deg F (190 deg C) for at least 3 minutes.
- broil 3 inches (8 cm) from heat for 3 minutes.
- bake at 450 deg F (230 deg F) for 10 minutes.
For more information: "Shellfish growing areas close due to vibriosis
outbreak" at
<http://www.doh.wa.gov/Publicat/2007_news/07-131.htm> (the affected
area can be found at this URL. - Mod.LL]
--
Communicated by:
ProMED-mail Rapporteur Brent Barrett
[It is important to stress that _Vibrio parahaemolyticus_ is
naturally present in marine waters and does not imply sewage
contamination, as would be the case with _Salmonella_ sp. or _E.
coli_. It is most common in warmer waters such as those of the
American Gulf Coast, but warmer waters in more northern climates can
also be associated with oyster-associated _V. parahaemolyticus_.
In 2005, a New England Journal of Medicine report highlighted this
infection linked to even Alaskan oysters:
McLaughlin, JB, DePaola A, Bopp CA, et al: Outbreak of _Vibrio
parahaemolyticus_ Gastroenteritis Associated with Alaskan Oysters. N
Engl J Med 2005; 353: 1463-70.
"Abstract: Background: _Vibrio parahaemolyticus_, the leading cause
of seafood-associated gastroenteritis in the USA, typically is
associated with the consumption of raw oysters gathered from warm
water estuaries. We describe a recognized outbreak of _V.
parahaemolyticus_ infection associated with the consumption of
seafood from Alaska.
Methods: After we received reports of the occurrence of
gastroenteritis on a cruise ship, we conducted a retrospective cohort
study among passengers, as well as active surveillance throughout
Alaska to identify additional cases, and an environmental study to
identify sources of _V. parahaemolyticus_ and contributors to the
outbreak.
Results: Of 189 passengers, 132 (70 percent) were interviewed; 22 of
the interviewees (17 percent) met our case definition of
gastroenteritis. In our multiple logistic-regression analysis,
consumption of raw oysters was the only significant predictor of
illness; the attack rate among people who consumed oysters was 29
percent. Active surveillance identified a total of 62 patients with
gastroenteritis. _V. parahaemolyticus_ serotype O6:K18 was isolated
from the majority of patients tested and from environmental samples
of oysters. Patterns on pulsed-field gel electrophoresis were highly
related across clinical and oyster isolates. All oysters associated
with the outbreak were harvested when mean daily water temperatures
exceeded 15.0 deg C/59 deg F (the theorized threshold for the risk of
_V. parahaemolyticus_ illness from the consumption of raw oysters).
Since 1997, mean water temperatures in July and August at the
implicated oyster farm increased 0.21 deg C per year (P less than
0.001 by linear regression); 2004 was the only year during which mean
daily temperatures in July and August 2004 at the shellfish farm did
not drop below 15.0 deg C/59 deg F.
Conclusions: This investigation extends by 1000 km (621 mi) the
northernmost documented source of oysters that caused illness due to
_V. parahaemolyticus_. Rising temperatures of ocean water seem to
have contributed to one of the largest known outbreaks of _V.
parahaemolyticus_ in the USA."
The wide range of distribution of oysters from this bed, both across
the North American continent and across the Pacific Ocean, once again
speaks to the global marketplace of foodborne illness. - Mod.LL]
Published Date 13-AUG-2007
Subject PRO/AH/EDR> Vibrio parahaemolyticus, oysters - USA (WA): int'l alert
VIBRIO PARAHAEMOLYTICUS, OYSTERS - USA (WASHINGTON): INTERNATIONAL ALERT
************************************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Fri 10 Aug 2007
Source: FDA (US Food and Drug Administration) News, press release [edited]
<http://www.fda.gov/bbs/topics/NEWS/2007/NEW01680.html>
The FDA is warning consumers not to eat raw oysters harvested from an
area of the southern tip of Hood Canal [Mason County] in Washington
[state] after an outbreak of illness caused by _Vibrio
parahaemolyticus_.
Symptoms of the illness, called vibriosis, include watery diarrhea,
often with abdominal cramping, nausea, vomiting, fever, and chills.
Usually these symptoms occur within 24 hours of ingestion and last no
more than 3 days. Severe disease is rare and occurs most commonly in
people with weakened immune systems. Those who believe they have
experienced these symptoms after consuming raw oysters should consult
their health care provider and contact their local health department.
Raw oysters harvested from "growing area 6" in Hood Canal from 3 Jul
2007 and after, have caused at least 6 people to become ill in
California and Washington. Additional reports of illness are being
investigated by the states. To date, records indicate that raw
oysters from the area were distributed to California, Florida,
Hawaii, Idaho, New York, Oregon, Washington, British Columbia
(Canada), Hong Kong, Malaysia, and Singapore.
The Washington State Department of Health has closed the growing area
associated with the illness and has asked commercial oyster
harvesters and dealers who obtained oysters from this area to recall
them. Consumers who have recently purchased oysters should check with
the place of purchase and ask if they were harvested from the
affected growing area.
Those with weakened immune systems, including people affected by
AIDS, chronic alcohol abuse, liver, stomach, or blood disorders,
cancer, diabetes, or kidney disease should avoid eating raw oysters,
regardless of where they are harvested.
FDA advises that consumers can continue to enjoy oysters in many
cooked preparations by doing the following:
At Restaurants and other Foodservice Establishments:
- order oysters fully cooked.
In the Shell:
- purchase oysters with the shells closed.
- throw away any oysters with shells already opened.
- never allow raw seafood to come into contact with cooked food.
- boil oysters until the shells open. Once shells open, boil for an
additional 3 to 5 minutes.
- to steam, add oysters to water that is already steaming and cook
live oysters until the shells open, once open steam for another 4 to
9 minutes.
- use smaller pots to boil or steam oysters. Using larger pots, or
cooking too many oysters at a time, may cause uneven heat
distribution, which may cause the oysters in the middle to be
under-cooked.
- discard any oysters that do not open during cooking.
Shucked Oysters:
- never allow raw seafood to come into contact with cooked food.
- boil or simmer shucked oysters for at least 3 minutes or until the
edges curl.
- fry at 375 deg F (190 deg C) for at least 3 minutes.
- broil 3 inches (8 cm) from heat for 3 minutes.
- bake at 450 deg F (230 deg F) for 10 minutes.
For more information: "Shellfish growing areas close due to vibriosis
outbreak" at
<http://www.doh.wa.gov/Publicat/2007_news/07-131.htm> (the affected
area can be found at this URL. - Mod.LL]
--
Communicated by:
ProMED-mail Rapporteur Brent Barrett
[It is important to stress that _Vibrio parahaemolyticus_ is
naturally present in marine waters and does not imply sewage
contamination, as would be the case with _Salmonella_ sp. or _E.
coli_. It is most common in warmer waters such as those of the
American Gulf Coast, but warmer waters in more northern climates can
also be associated with oyster-associated _V. parahaemolyticus_.
In 2005, a New England Journal of Medicine report highlighted this
infection linked to even Alaskan oysters:
McLaughlin, JB, DePaola A, Bopp CA, et al: Outbreak of _Vibrio
parahaemolyticus_ Gastroenteritis Associated with Alaskan Oysters. N
Engl J Med 2005; 353: 1463-70.
"Abstract: Background: _Vibrio parahaemolyticus_, the leading cause
of seafood-associated gastroenteritis in the USA, typically is
associated with the consumption of raw oysters gathered from warm
water estuaries. We describe a recognized outbreak of _V.
parahaemolyticus_ infection associated with the consumption of
seafood from Alaska.
Methods: After we received reports of the occurrence of
gastroenteritis on a cruise ship, we conducted a retrospective cohort
study among passengers, as well as active surveillance throughout
Alaska to identify additional cases, and an environmental study to
identify sources of _V. parahaemolyticus_ and contributors to the
outbreak.
Results: Of 189 passengers, 132 (70 percent) were interviewed; 22 of
the interviewees (17 percent) met our case definition of
gastroenteritis. In our multiple logistic-regression analysis,
consumption of raw oysters was the only significant predictor of
illness; the attack rate among people who consumed oysters was 29
percent. Active surveillance identified a total of 62 patients with
gastroenteritis. _V. parahaemolyticus_ serotype O6:K18 was isolated
from the majority of patients tested and from environmental samples
of oysters. Patterns on pulsed-field gel electrophoresis were highly
related across clinical and oyster isolates. All oysters associated
with the outbreak were harvested when mean daily water temperatures
exceeded 15.0 deg C/59 deg F (the theorized threshold for the risk of
_V. parahaemolyticus_ illness from the consumption of raw oysters).
Since 1997, mean water temperatures in July and August at the
implicated oyster farm increased 0.21 deg C per year (P less than
0.001 by linear regression); 2004 was the only year during which mean
daily temperatures in July and August 2004 at the shellfish farm did
not drop below 15.0 deg C/59 deg F.
Conclusions: This investigation extends by 1000 km (621 mi) the
northernmost documented source of oysters that caused illness due to
_V. parahaemolyticus_. Rising temperatures of ocean water seem to
have contributed to one of the largest known outbreaks of _V.
parahaemolyticus_ in the USA."
The wide range of distribution of oysters from this bed, both across
the North American continent and across the Pacific Ocean, once again
speaks to the global marketplace of foodborne illness. - Mod.LL]