As of February 14, Public Health Agency of Canada (PHAC) reported an additional 19 cases of the gastrointestinal illness, bringing the total to 221 cases under investigation.
CBC Canada reports that Mark Samadhin, director of PHAC’s outbreak management division said, “We knew in November-December that there were cases popping up in B.C., but it wasn’t until the middle of January or so … that we started seeing or hearing about other cases in Ontario and Alberta.”
PHAC has taken the lead in the investigation and is collaborating with provincial public health officials, the Department of Fisheries and Oceans (DFO) and the Canadian Food Inspection Agency (CFIA) to investigate the gastrointestinal illnesses that have been linked to raw or undercooked oysters. Public health officials in the three provinces have linked the illnesses to B.C. oysters.
Although not all cases of illness have been tested, testing of several cases has confirmed the presence of norovirus infection, and it is assumed that the untested cases are also linked to B.C. oysters. PHAC says the investigation is ongoing and Canadians will continue to be updated on the outbreak.
Read More – How to keep safe from norovirus
Summary of investigation
As of February 14, a total of 221 clinical cases of gastrointestinal illness linked to oysters have been reported in three provinces: British Columbia (159), Alberta (36), and Ontario (26). No deaths have been reported. Individuals became sick between December 2016 and February 2017. All individuals who became ill reported having eaten oysters.
80 percent of all the human strains of noroviruses can be found in oysters
The shellfish industry is saying there is no great danger from eating raw shellfish, and the possibility of noroviruses in shellfish is not a new revelation. While this may be true to some extent, the fact is, the increase in the number of cases of norovirus worldwide linked to eating raw oysters is becoming of great concern to health officials.
However, it is humans who are responsible for norovirus contamination of coastal waters, due to waste-water, raw sewage and the like. This results in oysters picking up norovirus, where it persists for weeks in their tissues.