Dr. Doug Powell has posted a report on his Barfblog internet
site this week documenting how researchers examined Listeria monocytogenes
deaths and hospitalizations eventually linked to chocolate milk in Ontario.
There were two waves between November, 2015, and June, 2016,
and the source was difficult to track down, first because there was a Listeria
outbreak linked to leafy greens about the same time, second because there were
some other false leads.
Eventually investigators found stale milk in a refrigerator
of one of the patients and identified the exact strain of Listeria involved in
the other cases.
But the wrapping on the four-litre pouch pack was missing,
so it took more sleuthing to trace it to the supermarket chain, which was not
named in the scientific journal report, from which all the patients and victims
bought chocolate milk.
Eventually it was traced to the Neilson plant in Georgetown.
The scientific report says this situation illustrates how
difficult it can be to track down the source of an outbreak of food poisoning.
Dr. Powell says the lack of information for the public is unfortunately
typical for the Public Health Agency of Canada.
