Use of high hydrostatic pressure to inactivate Hepatitis A virus in oysters studied

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08 Jun 2005

Use of high hydrostatic pressure to inactivate Hepatitis A virus in oysters

studied

NOAA/Virginia Sea Grant has awarded Virginia Tech $119,000 to study whether

high hydrostatic pressure will inactivate Hepatitis A virus in both shucked

and unshucked oysters.

The project, led by Holliman, an M.D. with the High Pressure

Processing Laboratory, and , lab manager, will identify one or

more effective high pressure processing schedules. The laboratory is a

facility of the Department of Food Science and Technology at Virginia Tech,

devoted to improving food safety and food processing.

Hepatitis A virus (HAV) is one of the more serious illnesses transmissible

by shellfish. Worldwide, HAV is responsible for more than 1.5 million cases

of the disease each year, with 260,000 cases and more than 100 deaths in the

United States. Hepatitis A infection is characterized by fatigue, malaise,

fever, loss of appetite, nausea, vomiting, joint and muscle aches, and

abdominal pain, coupled with the onset of jaundice, a yellowing of the

whites of the eyes, and dark urine. The disease generally runs its course in

two months, but can linger as long as six. While survival rates for

Hepatitis A are above 99 percent, the disease can be very dangerous for

infants, the elderly, immunosuppressed people, and those with existing liver

disease.

Bivalve shellfish, such as oysters, have been demonstrated to concentrate

pathogenic organisms from their environment. In some cases, sewage

contamination of harvesting areas, either from coastal runoff or ship

discharges, has been shown to result in HAV contamination of oysters.

Several studies have demonstrated remarkable concentration and persistence

of HAV in shellfish exposed to the virus through their surrounding seawater.

Even with depuration, HAV may persist in oysters for several weeks after

exposure. The virus also is fairly resistant to heating and may remain

viable in shellfish after up to five minutes of steaming.

For these reasons, high hydrostatic pressure treatment of raw oysters is

especially appealing to oyster processors and distributors, as well as

public health officials. HPP makes it possible to eradicate or inactivate

pathogens while still delivering a 'raw' product to the consumer.

The study will benefit processors and distributors by mitigating their food

safety liability, but most importantly, also will help protect consumers

from foodborne infectious disease.

Virginia Sea Grant is part of a 30-state National Sea Grant Program

established by Congress in 1966 as part of the National Oceanic and

Atmospheric Administration. Sea-grant colleges research new ideas and

technologies to help use, manage, and understand ocean and coastal

resources. Virginia Sea Grant funds marine science research in aquaculture,

seafood safety and quality, marine resources, coastal ecosystems through a

competitive, peer-reviewed grant proposal process. In addition to its core

programs, Virginia Sea Grant coordinates research in oyster disease and

toxics in the Chesapeake Bay.

Contact: Correa

acorrea@...

540-231-2075

Virginia Tech

http://www.vtnews.vt.edu

http://www.medicalnewstoday.com/medicalnews.php?newsid=25816 & #38;nfid=rssfeeds