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On Friday,
January 26, 2007, the Interstate Shellfish Sanitation Conference (ISSC)
with assistance from the U.S. Food and Drug Administration (FDA)
sponsored a meeting in Ocean City, MD, to discuss the current situation
surrounding Vibrio parahaemolyticus (Vp) and raw oyster
consumption. The meeting was advertised as an opportunity to learn more
about the Vp situation and to provide input to the ISSC/FDA on
harvesting/handling procedures. The meeting was directed strictly to
oysters and not directly at other shellfish, although they were
mentioned through out the meeting. Unfortunately, there were more
bureaucrats and academics in attendance than there were industry
members. I’ll have more to say about this aspect later when I have a
suggestion to make. First some background information.
Virginia, as are all shellfish producing states, is a member
state of the ISSC and must meet the requirements of the National
Shellfish Sanitation Program (NSSP). The Division of Shellfish
Sanitation within the Virginia Department of Health is our shellfish
control agency. Within the NSSP, Vp has always been recognized as a
potential illness causing organism, but really didn’t receive much
attention. Most ISSC/NSSP attention had been focused on Vibrio
vulnificus (Vv). This is because Vv is a life-threatening pathogen,
while Vp under most circumstances is not a life-threatening pathogen.
Outbreaks of Vp have been recorded in the past. A particularly large
outbreak in the Pacific Northwest and Texas during 1997 and 1998,
resulted in the ISSC adopting an interim control plan addressing Vp. In
2006, there was a significant Vp outbreak in the Pacific Northwest which
resulted in “hundreds” of people getting sick and causing a great deal
of harm to the oyster industry. To the FDA, this indicated that the
interim control guidelines were not adequate to deal with the situation.
Despite Vp not generally being a life-threatening pathogen, it
still can cause food borne illness, which raises red-flags with FDA. In
2005, the FDA submitted a proposal to ISSC addressing illnesses
associated with Vp. ISSC delegates adopted a recommendation for
education of licensed harvesters and shellstock dealers concerning the
public health issues surrounding Vp. In 2006, the Executive Board of
ISSC directed the executive office to hold regional Vp workshops for the
purpose of developing a Vp educational program. This was expanded to
include discussion of potential harvest controls to reduce Vp levels in
shellfish. The Ocean City meeting was the last of 4 regional meetings.
Information was provided regarding the known basic biology for
Vp. Vp is a naturally occurring marine pathogen. Unlike other Vibrio’s,
everyone is susceptible to Vp, not just health compromised individuals.
Fortunately, Vp normally is not life-threatening, causing varying
degrees of gastroenteritis (e.g. diarrhea and stomach distress).
Symptoms generally do not occur until 2 or 3 days after consumption.
This makes tracing the cause of the illness somewhat difficult. Vp is a
fast grower, with a minimum temperature for growth of ~50 F and growth
increasing with increasing temperature. At temperatures over ~120F Vp
will die. Temperature is the single most important factor in Vp growth.
If you are familiar with “ISSC-speak” this is generally referred to as
“time-temperature” factors and plays into handling regulations.
Perhaps the most “disturbing” portion of the meeting was the
information provided by the FDA and their position and options. This was
presented by Don Kramer. He emphasized that FDA views control of Vp as a
significant challenge and that effective controls are not in place. This
was apparent from the fact that the interim control plan, which was
being followed, did not prevent the 2006 outbreak. According to FDA
data, Vp outbreaks are “predictable and preventable” and as such must be
dealt with. The FDA position is that the past outbreaks only represent
the “tip of the iceberg” and must be addressed. Perhaps the most
distressing parts of his presentation were the data he showed regarding
documented Vp cases. While there were clearly patterns for the Pacific
Northwest and the Gulf of Mexico, there were no such identifiable
patterns for the Atlantic Coast. At this point a question from the
audience asked specifically about Chesapeake Bay. He was unable to
answer this question.
A great deal of discussion occurred regarding assigning
“responsibility” for an outbreak. Industry argued that they could do
everything in accordance with the guidelines for maintaining temperature
and proper handling, only to have their due diligence destroyed by
abuses during the transport, wholesale, retail, or consume handling.
However, if someone got sick, it would still be the harvester who would
be singled out as the “cause” of the problem. This is a serious
disconnect that needs to be addressed. Of all the discussions, this is
probably the biggest concern for harvesters.
The FDA presented their options, should the ISSC fail to enact
adequate control measures for Vp. While the FDA representative went to
great lengths to state that these options were not a “threat” it was
very obvious that they are at the very least “a very big stick” that
they will wield if they don’t get their way. You decide whether that’s a
threat or not.
Two options were presented. The first was to enforce the action
level, number of Vp present, at the retail level. This is impractical
given the number of retail outlets and FDA agents available. The second
option, and the most likely to be implemented, is for FDA to issue
public advisories publicizing the “patterns” of Vp outbreaks and to
advise the public not to consume raw shellfish during a certain period
of time (summer). Such an advisory would be extremely harmful to
anyone in the shellfish business.
An underlying theme regarding the potential for post-harvesting
processing kept surfacing through out the discussions. Essentially this
would be a diversion from a raw, untreated product, to alleviate the Vp
potential. In this same vein, the possibility of closed harvesting
seasons (e.g. summer) or “for shucking only” restrictions were also
mentioned.
So, what can the oyster culture/harvesting industry do? First,
educate yourselves on the ISSC/NSSP, by going to their web site (
www.issc.org) and reading as much as you can about Vp and Vv. More
importantly, however, is to contact your ISSC representatives/members
(also listed on web site) and express your concern on this issue. In
particular, I would stress how a “one size fits all” approach for the
control of Vp is inappropriate given the past history of events along
the Atlantic coast. The other issue of accountability must also be
addressed. It is unfair that a harvester be held responsible for the
“sins” of others. The ISSC must address the inequity of assigning
responsibility to a harvester who has complied with all requirements and
has taken due diligence to ensure the wholesomeness of his product, only
to be condemned for something outside of his control. Shellfish
growers/businesses must become involved in the regulation of their
industry by making sure that their concerns are known. Only by
communicating with your representatives and regulatory agency can this
happen. You must remember that their first concern is for human health
issues. We are fortunate in Virginia to have a shellfish control agency
which is very sympathetic towards industry, will listen to you and
welcomes you input. My guess is that other shellfish control agencies
will also welcome industry involvement.
Mike Oesterling
Michael J. Oesterling
Fisheries/Aquaculture Specialist
Virginia Institute of Marine Science
P.O. Box 1346
Gloucester Point, VA 23062
Tel 804-684-7165
Fax 804-684-7161 |