Last Thanksgiving I made the unfortunate decision to visit my in-laws in Pennsylvania for the entire week. As if seven days trapped in a house full of frenemies weren’t bad enough, disaster struck the day we arrived. All three of my kids developed projectile vomiting and explosive diarrhea. They passed it to Aunt Betsy. Who gave it to Aunt Bonnie. By Vacation Day 3, most of my relatives were puking and defecating in whatever basin was closest. We put the household under voluntary quarantine and canceled Thanksgiving, knowing there was no treatment and the virus just had to run its course.
Comic relief arrived when I noticed my husband shuffling around the house wearing adult diapers. I laughed hysterically, until my own intestines started to rumble. Then I grabbed a pair. Ironically, I had just completed a Norovirus outbreak investigation in my role with the Santa Barbara County Public Health Department, and I knew a quick phone call to the local authorities would help us confirm the infectious agent. A friendly public health nurse would show up on our doorstep with a bag of stool-sample cups and we would each be asked to submit a fecal specimen. (“No problem. Let me just scrape some off the bathroom wall here …”) The specimens are then tested for Norovirus, as well as other potential enteric pathogens if necessary.
Norovirus is highly contagious and is spread by eating contaminated food or touching a contaminated surface. It is resistant to most antiseptic cleaners and only sterilized by a chlorine bleach/ water mixture. It spreads quickly in group settings such as schools, nursing homes, or uncomfortable family gatherings. Norovirus season traditionally stretches from November to April, and last year in Santa Barbara County, Public Health conducted 12 different investigations into Norovirus outbreaks involving over 300 people. The illness, which has no specific treatment other than hydration and rest, can be deadly in infants, the elderly, or those with underlying medical conditions.
But that was last year. What’s different about the virus in this 2012-2013 season involves one of my favorite topics: evolutionary genetics. Norovirus is a single-stranded RNA virus which can evolve rapidly by inserting small mutations into its genome. In March 2012, the virus mutated again, resulting in the GII.4 Sydney strain (named after its origin in Sydney, Australia). This mutant strain is spreading rapidly across the world and across California. Santa Barbara County is now sending all positive stool specimens to the California Department of Public Health (CDPH) for further subtyping to determine which strain we are dealing with. So far all of our positive specimens have been the new Sydney strain.
Why is Norovirus so hard to contain? To answer that question, government researchers constructed a human sized robot (“humanoid”) for the sole purpose of projectile vomiting. Researchers in the United Kingdom’s Health and Safety Laboratory have developed said robot, affectionately named Vomiting Larry, to study the actual distance infective virus particles fly during severe vomiting episodes. The robot’s stomach was filled with fake vomitus which included a fluorescent marker, enabling the researchers to identify even the smallest of specks under ultraviolet (UV) light. Simulated vomiting ensued, followed by UV light identification of a spew radius. Although the actual vomit projected only a few feet, the invisible droplets splattered a whopping ten feet. This is significant information for those assigned the unpleasant task of decontaminating a room after projectile vomiting. And it gives a whole new meaning to “gut strength.”
I can’t wait for the Larry 2.0 model, where Larry demonstrates explosive robot-diarrhea. Are you wondering why researchers would study the distance diarrhea particles travel, you ask, when one is sitting on the toilet and all such particles are contained therein? Ah, my friend, then you have never experienced Norovirus! Making it to the toilet is what I would call an “ideal situation,” and one that only happens approximately 64.9% of the time (a made-up statistic based on my personal experience.) Might I recommend adult diapers?
My nephew locked himself in his bedroom and didn’t emerge for the entire seven days. He is the only one who didn’t get sick. The other nine of us, despite extensive efforts to decontaminate all areas, fell victim to the virus.
My advice for Norovirus season this year is the same as always: Practice good hygiene, self-isolate if you are sick, and decontaminate affected areas with a mixture of water and bleach. And, for all you germaphobes toting antibacterial gel keychains, transmission of Norovirus is best prevented by washing your hands with good old soap and water, not alcohol disinfectants. If you are unlucky enough to catch the virus, seek advice from your medical provider. To report a potential outbreak, Disease Control and Prevention can be reached at (805) 681-5280. We are experts – sometimes unwittingly – in projectile vomiting and explosive diarrhea.
Charity Thoman, M.D., is a deputy health officer in Santa Barbara County's Public Health Department.