Sometimes I take it for granted that I occupy a part of the world in which there are more Purell dispensers than people.
In fact, at times I wonder if I’ve developed some odd transdermal addiction. I find myself seeing out this glorious gelled delight in settings other than the lab or the hospital. After walking through grocery stores, filling the tank at the gas station, or before sitting down to dinner in a restaurant, I crave that faintly perfumed peace-of-mind.
Suffice it to say, as a result I rarely get sick. In fact, for the third time in a year, I’ve played doctor to Mrs. Blog, MD, who has contracted several nasty colds. She says that it is because I’ve been around so many sick children that I’ve become sufficiently immune. I say it’s because of my fastidious hand hygiene.
Whatever the case may be, I feel confident that I’ll not be affected by the current wave of viral gastroenteritis. I started to see cases of it several weeks ago at the hospital where I moonlight. Today, according to the Boston Globe, it appears to be a full-fledged outbreak, enough to warrant the attention of the Centers for Disease Control and, of course, a story in the paper. It appears that there have been over 3700 gastro-related ED visits in Boston in the past 6 weeks, as well as a surge (pun intended) of visits on Christmas Day.
The current outbreak appears to be due to a member of the norovirus family. Noroviruses (genus Norovirus, family Caliciviridae) are a group of related, single-stranded RNA, nonenveloped viruses that cause acute gastroenteritis in humans. Norovirus was recently approved as the official genus name for the group of viruses provisionally described as “Norwalk-like viruses” (NLV). The prototype of this family, Norwalk virus, was named for the town of Norwalk, Ohio where, in November 1968, an outbreak of acute gastroenteritis occurred among children at an elementary school. In 1972, immune electron microscopy on saved stool samples identified the virus, which was called subsequently called Norwalk virus. Those of you who, like me, enjoy the history of medical discovery, might be interested in reading a terrific historical perspective paper by Albert Kapikian, who identified Norwalk virus (note: links to .pdf file).
Norwalk virus received a lot of press several years ago when it caused several outbreaks of diarrhea on cruise ships. These outbreaks were so bad that several ships had to return to port, emptied of their passengers, and then cleaned from (ahem) stem to stern. It appears that noroviruses are making quite a … um … splash, this year. Wikipedia has a very detailed list of outbreaks for 2006. I counted 12 major outbreaks in December alone.
Of course, as a pediatrician, whenever I think viral gastro, I usually think of rotavirus, but the timing of this outbreak makes rotavirus an unlikely suspect. Rotavirus is also a fascinating bug, first isolated by electron microscopy from cow diarrhea, and was subsequently identified in humans by electron microscopy of bowel biopsy samples. My hat is off (and my mask is on) for the scientists who wrote that paper. What is so interesting about rotavirus is that it follows a regular spatial and temporal pattern. Rotavirus season typically begins in the late fall (November) with the greatest number of cases in the southwestern United States. As the year progresses, the disease marches northeast, arriving in our neck of the woods by April:
You can track the ebb and flow of rotavirus through the CDC’s National Respiratory and Enteric Viruses Surveillance System:
As you can see, the rotavirus peak is just starting to form. Incidentally, it also looks like we’re finally hitting the peak for this year’s RSV (respiratory syncytial virus) season:
In any case, my point was not necessarily to give a full lecture on the epidemiology of these common ailments. Rather, it was to impress the need for meticulous, regular and damn-near universal handwashing. It’s not hard to do. There are videos available on-line for those who really need help. When you consider that, at least for rotavirus, there are 10^12 viral particles (colony-forming units) in each millileter of liquid poop (that’s 30,000,000,000,000 infectious particles in each ounce of poop for those not SI-inclined), you have to realize that it is hard to keep all of those viruses coralled. They’re inclined to stick to hands, and then to other flat surfaces. Shake hands with someone shedding virus, or who has a child at home who is sick, or touch a doorknob after someone else wasn’t so good about handwashing, and presto! You’re primed to infect yourself as soon as you put hand to mouth.
So please, please, please … for yourself, for your kids, for those like me fielding admissions from the pediatric ED in the middle of the night, for the Fleas who have to take phone calls in the middle of the night, and for the interns who have to trudge down from their call rooms to the ED to admit you … please wash your hands (or at least stock up on the good stuff).