Nearly one-third of all catfish sold in America is imported from Vietnam and China, where fish farming environments are far less controlled according to the report and the incidence of contamination is much greater than in the US.
And eating contaminated imported fish could have serious long-term human health consequences, including longer-lasting illnesses due to antibiotic build-ups that leave people less responsive to antibiotic medications and an increase in drug-resistant pathogens that can be transmitted to humans via the food chain, the report warns.
Analysts also cited dangerous short-term health impacts, finding that imported catfish are twice as likely to be contaminated with salmonella as domestic fish.
The report stressed the importance of identifying risks and imposing appropriate controls before consumers contract illnesses that could frighten them from eating fish.
The report recommends that the USDA regulatory programme that includes evaluations and inspections of catfish production and processing provides stronger oversight and consumer safety than current government inspection programmes.
Congress approved a law shifting catfish oversight to USDA two years ago, but the law has not been implemented.
Consumers generally,says the report, are unable to distinguish one type of catfish from another, particularly once the fish is prepared for sale or consumption and in revising the food safety inspection programme to provide greater consumer protection, Exponent recommend that the broader biological classification of catfish be used to include all imported and domestic catfish species. The different species of catfish occupy the same product niche and frequently are interchanged in the US marketplace.
Key findings in the report include:
- Nearly one-third of all catfish sold in America is imported. Of those imports, 52 per cent are from Vietnam and about 30 percent are from China.
- FDA import inspections from 1998 to 2004 have shown consistently that fish and seafood products have one of the highest rates of import refusals due to food safety issues. The presence of harmful microorganisms and unapproved drugs is a frequent reason for refusals.
- Imported fish from Vietnam and China are produced in much less controlled environments with many more opportunities for microbiological and chemical contamination. Vietnamese farmers use water directly from the Mekong River with most farmers using no screen against contaminants.
- Fish are frequently transported to the processing plant by boats that have tanks or cages flushed with polluted river water.
- Antimicrobial residues in catfish and other foods is an emerging worldwide health concern.
- Prohibited antimicrobials detected in imported catfish include Malachite green and Gentian violet, the latter of which has been linked to human bladder cancer.
- The widespread prophylactic use of antibiotics, particularly fluoroquinolones, in Asian countries which are not approved for use in the US. These antibiotics, which usually are administered in feeds to prevent bacterial infections and promote animal growth, are receiving particular scrutiny.
- These drugs can cause harmful microorganisms to become resistant to the drugs. When drugresistant microorganisms infect humans who eat or handle the fish, illnesses can be more severe and more difficult to treat.
- The FDA this year has issued an import alert for catfish raised in China because of the presence of potentially dangerous drugs.
- A published study showed that imported catfish from Vietnam were twice as likely as domestic catfish to be contaminated by salmonella.