Humboldt County is first public agency to use molecular testing
1/23/12
Humboldt's vibrant oyster farming industry and bioterrorism funds have allowed the county's public health laboratory to deploy a cutting-edge process to test for shellfish contamination.
The laboratory is now the only public facility in California to utilize a molecular process -- known as polymerase chain reaction -- for oyster testing. The only other laboratory to perform this type of work is a private lab in San Diego.
Laboratory manager Jeremy Corrigan said the new process, which started last week, allows the county to perform bacteria testing for Humboldt's oyster farmers as well as operations in Oregon and Washington.
”This is an opportunity for us to get more business from not only our county but other places,” he said.
Corrigan worked with the U.S. Food and Drug Administration to get the molecular method in place at the lab. He said the agency recognized the county's established oyster testing program. The lab has been performing tests on and off since 1999, according to the public health department.
Corrigan adjusted the protocol to use the equipment required for oyster testing. The county purchased the equipment -- which can also be used to test for diseases such as whooping cough and influenza, or substances like anthrax --with bioterrorism funding.
For nearly 20 years, Coast Seafood Co. has contracted with the lab to run weekly tests on samples of Pacific and Kumamoto oysters for a type of bacteria that causes intestinal infection.
”It really aids in our ability to control the quality of our product and really monitor the quality of our product. We really have a high quality of seafood that comes out of Humboldt Bay,” Coast Seafood Co. Southwest Operations Manager Greg Dale said.
This bacteria, virbrio parahaemolyticus, is a naturally occurring organism commonly found in brackish saltwater along the coast in the United States and Canada where oysters are cultivated, according to the Centers for Disease Control and Prevention. Certain conditions can cause the bacteria to flourish in coastal waters, and shellfish can become contaminated.
According to public health, two cases of the intestinal infection caused by virbrio parahaemolyticus were reported in 2007, but it is unclear if they were linked to oyster consumption. No cases have been reported in the past four years.
Dale said the company has done quality control for oysters and water as a precaution. About 70 percent of California's oysters are grown in Humboldt Bay.
Although there has never been a positive result, a recent false positive illustrates the streamlined convenience of the new process, he said.
In the past, the lab performed a chemical test to see if the bacteria was present. If the test was positive, samples were sent to the San Diego lab to determine if pathogens that can make people sick were present. The entire process took about five to six days. According to public health, any contaminated oyster beds are shut down until the results are available.
