Oregon Norovirus Outbreak Linked to Reusable Grocery Bags
Cloth, reusable grocery bags are an excellent way to cut back on the amount of waste we produce, but like our clothes, we must remember that these need to be washed on a regular basis to prevent bacteria from accumulating to levels that can cause illness. A recent norovirus outbreak among Oregon soccer players reminds us of how serious this can be.
In October 2010, Kimberly K. Repp PhD MPH, now an epidemiologist with the Washington County Department of Health and Human Services, was asked to help pinpoint how a team of 13- and 14-year-old soccer players and their chaperones became ill on a weekend trip for a tournament. Nine people became ill with symptoms that included vomiting and diarrhea.
Experts determined through interviews that most of those who became ill had eaten packaged cookies at a Sunday lunch. The cookies were included among other snacks that were in a reusable grocery bag left in an empty hotel room that had been occupied by the first girl who had become ill. She had been in the bathroom and spread an “aerosol of norovirus” that landed everywhere, including the bag. The scientists tested the bag and it was positive for the virus, even two weeks later.
Noroviruses are the leading cause of endemic diarrheal disease across all age groups, the leading cause of foodborne disease, and the cause of half of all gastroenteritis outbreaks worldwide. The extremely contagious virus is responsible for about 21 million cases of gastrointestinal illness each year, including 70,000 hospitalizations and 800 deaths. It is a “tough bug” in that it can live for prolonged periods on objects and surfaces, says Dr. William Schaffner, chairman of the department of preventive medicine at Vanderbilt University Medical Center.
While most often, the virus is transmitted person to person in public areas such as cruise ships and airplanes, this incident is one of the first to determine that norovirus can also be transmitted without direct personal contact. (The original girl was presumably infected prior to the soccer trip, and had no contact with the other girls after her symptoms began.)
The most common symptoms after contracting norovirus include diarrhea, nausea and vomiting, and stomach pain. Fever, headache and body aches may also be present. Thankfully, most people with norovirus illness get better within 1 to 3 days.
The Oregon incident reminds us to consider the cleanliness of our reusable shopping bags before transporting food or anything else that might contribute to illness. Although overall the risk of contracting illness from a cloth bag is low, “We wash our clothes when they’re dirty; we should wash our bags, too,” says Repp.
A previous study conducted by researchers at the University of Arizona and Loma Linda University found that large numbers of bacterias reside on reusable grocery bags. In the study, 12% were found to be contaminated with E.coli, another bug linked to foodborne illness. Plus, keep in mind that many of us keep empty bags in our cars, where the warm temperature can cause the number of bacteria to multiply 10-fold.
Washing the reusable bags regularly can decrease contamination by 99.9 percent. “You could (even) just wipe it down with Lysol or Clorox,” said Repp.
The CDC offers the following tips for preventing norovirus infection:
• Practice proper hygiene, washing hands carefully with soap and water, especially after using the bathroom and changing diapers.
• Wash hands before handling, preparing or eating food. Carefully wash all fruits and vegetables before eating. Ensure foods are cooked to the appropriate temperature to kill bacteria and viruses. (Note that norovirus can survive temperatures as high as 140 degrees.)
• After vomiting or having diarrhea, immediately clean and disinfect contaminated surfaces using a chlorine bleach solution with a concentration of 1000-5000 ppm – 5 to 25 tablespoons of household bleach per gallon of water. Remember to also wash clothing and bedding as well.
Kimberly K. Repp and William E. Keene. A Point-Source Norovirus Outbreak Caused by Exposure to Fomites J Infect Dis. first published online May 8, 2012 doi:10.1093/infdis/jis250
Aron J. Hall. EDITORIAL COMMENTARY: Noroviruses: The Perfect Human Pathogens?J Infect Dis. first published online May 8, 2012 doi:10.1093/infdis/jis251
Centers for Disease Control and Prevention