Herring egg harvest has re-opened, after a small group of people contracted Vibrio cholerae infections last March, said to be associated with consumption of herring eggs harvested in the French Creek and Qualicum Bay areas.
According to a press release from Island Health, the same type of Vibrio cholerae bacteria that was confirmed by lab testing in the group of people was also found in herring egg and marine water samples.
Herring eggs are an important traditional seafood for many First Nations in B.C., providing cultural, nutritional, and economic benefits. They are an important source of protein, vitamin D, vitamin A, iron, zinc and several other nutrients.
Island Health states the illnesses were caused by non-toxigenic Vibrio cholerae non-01/non-0139 bacteria, which was found both in ill persons and in herring eggs collected from French Creek and Qualicum Bay.
This bacteria does not produce cholerae toxin which is responsible for the well-known severe form of Vibrio cholerae illness. It is a natural inhabitant of the marine and estuarine environment and is not an indicator of poor sanitation or sewage contamination.
The release states that infections are relatively rare, but when they occur, include such symptoms as diarrhea, abdominal cramps, fever, vomiting, nausea, blood and mucus of the stool and until 2018, there have been no reported outbreaks associated with this bacteria following the consumption of seafood.
The two factors that contribute most to the growth of the bacteria are water temperature above 10 C and low salinity seawater.
At the time of the March 2018 harvest, although water temperatures were below 10 C, a relatively high rainfall could have affected different environmental factors, including lowering salinity and increasing nutrient availability.
Unlike other shellfish monitoring programs that have early warning indicators, there is currently not a single signal or combination of environmental signals that could be monitored to reliably predict the abundance of the bacteria in water.
Island Health advises anyone who becomes ill with any of the following symptoms: diarrhea, abdominal cramps, fever, vomiting, nausea, or blood in the stool after eating herring eggs, to visit your health care provider.
— NEWS Staff, submitted