Potentially harmful pathogens discovered at Pohnpei’s main fish markets

by Dr. Kevin Rhodes, MarAlliance

In collaboration with state and national government agencies, Dr. Kevin Rhodes of MarAlliance conducted sampling at five of Kolonia’s fish markets in November to test for harmful bacteria, viruses and temperature. The testing found coliform bacteria at all of the fish markets.

Five fish from each of the selected markets were tested by taking swabs of the fish and display tables and measured for temperature to see if fish were maintained at the state health code recommended 410 F temperature requirements. Fish temperatures at markets averaged between 560 F and 720 F, well above the 410 F requirement.

The virus Vibrio sp. was found at three of the five markets tested. E. coli was found at two of the five markets tested.

Testing at one of the most popular fish markets in Pohnpei found E. coli in 7 of 11 samples taken, while a second market had 6 of 11 samples positive for E. coli. At these same markets, 3 out of 11 and 5 of 11 samples tested positive for Vibrio sp.

Only two markets were free of Vibrio sp.  Coliform bacteria is often found in soil and groundwater, while the more harmful E. coli is present in warm-blooded animal feces, including rats, dogs, humans and cats, meaning that the fish had been exposed to at least one of these sources of contamination or that flies transferred fecal matter to fish being displayed.

In under-cooked meats, E. coli can cause diarrhea, vomiting and abdominal cramps, while some strains of Vibrio sp. can cause gastroenteritis. Illness can be most severe in infants and older adults. To prevent illness, consumers should thoroughly cook fish before eating.

Markets and fishers can reduce or eliminate these contaminants by cleaning coolers before and after use with a mild soap and bleach solution. The growth of these pathogens is also promoted by open display, inadequate pest control and not keeping fish on ice at all times.

Improvements in sanitation and safe handling are key to keeping consumers healthy and fish fresh. Regular inspection in Pohnpei is the responsibility of EPA, however the agency declined to participate in the current study.