The Hunt for the Norovirus

A Oregon soccer team has been decimated by a nasty case of the norovirus. The state’s health officials have done a great job of detective work in tracking down the source. Strangely enough it was the reusable grocery bag that contained millions of the ‘perfect pathogen’ bacteria. It is another salutary lesson in hygiene, even in temporary containers such as grocery bags. Perhaps it is even an argument for the use of disposable plastic carriers despite their adverse effects on our ecology.

The lesson is of course that people need to sanitize even reusable bags. The case is published this week in the Journal of Infectious Diseases by the Washington County Department of Health and Human Services in Hillsboro, Oregon.

The soccer group and their minders were on a trip from Beaverton and Tigard Oregon, to Washington’s state for a two-day competition. By the end of the fateful weekend, nine people were struck low with horrible symptoms that included nausea, vomiting and diarrhea. So the hunt was on to find where they could have picked up the bug?

All of the young girl athletes were 13 or 14-year-old, and the first of them fell ill on Saturday night. She was immediately isolated in a room belonging to one of the adults in the group. Both the sufferer and the adult went home early next morning, without further contact within the group.

Within hours, seven other members of the party fell victim to the norovirus interviewing and collating of the actions of the whole group eventually turned up the key piece of evidence that all of the afflicted people had eaten prepackaged cookies at lunchtime on that fateful Sunday. But where had the cookies come from? This was the point in the investigation when the reusable bag was found, the cookies having been left in it, in the first victims hotel room, the bathroom, in fact. Light bulbs went on above the heads of the epidemiologists.

The original girl had been vomiting violently in that very hotel bathroom, launching an airborne cloud of the norovirus that settled on every available surface, including on the reusable grocery bag that was stored in the bathroom. Forensic analysis of the bag, even 14 days after the outbreak, found an extensive microbiological colony of the norovirus. The discovery proves beyond doubt the possibility of transmission of the virus without interpersonal physical contact.

This virus is the source of an estimated 20 million, at a minimum, cases of gastroenteritis each year in the US. More than 70,000 hospital admissions and even 800 plus fatalities. They are robust microbes that survive for long periods, invisibly, on the surfaces of everyday objects. While the chances of catching the norovirus from a reusable bag is very slight be aware that a 2010 study did find huge numbers of pathogenic bacteria in and on reusable grocery bags. Most notably twelve percent of them were found to harbor e-coli.

When the researcher’s simulated normal shopping behavior and kept bags in a car trunk for just two hours, the numbers of bacteria multiplied ten times.