|
A new, more toxic strain of a bacterium that contaminates
oysters has been found in oysters harvested from Galveston Bay, Texas.
The bacterium, Vibrio parahaemolyticus, causes diarrhea,
usually within 24 hours of eating infected seafood, along with abdominal
cramping, nausea, and headache
in most people, according to Dr. Nicholas A. Daniels and associates at
the University of California, San Francisco.
"Shellfish, particularly oysters since they
are filter-feeders, concentrate the bacteria in their tissues," Dr.
Daniels told Reuters Health. "Humans become infected when they eat
raw or undercooked shellfish. Each year in the United States, Vibrio cause
an estimated 8,000 infections and 50 deaths."
-
The authors investigated more than 400 cases of
Vibrio-associated diarrhea that occurred between May 31 and July 10,
1998.
-
The strain of Vibrio bacteria grown from 28 people
was type O3:K6, which has never been seen before in US shellfish.
-
Although oysters from the harvest sites were
found to contain well below the allowable limit of total bacteria
counts (10,000 per gram of oyster meat), half of the oysters contained
low levels of the dangerous Vibrio bacteria.
The researchers also theorize that the rising seawater
temperatures and salinity levels may have contributed to this large outbreak,
since both of these had gone up during the year of the outbreak.
The researchers advise consumers
to "thoroughly cook oysters and avoid eating raw or undercooked oysters,
particularly in the warmer months."
The Journal of the American
Medical Association 2000; 284: 1541-1545.
| 