# 3809
There are certainly times, and circumstances, where it makes a lot of sense to disinfect surfaces to try to limit the spread of the H1N1 virus.
When I was at my local Walgreens a couple of weeks ago to get my seasonal flu shot, one of the employees at the Rx window sprayed down the pickup counter with alcohol. It was an area where hundreds of people stood each day, placing their hands on the surface, and probably coughing and sneezing as well.
Coming out every 30 minutes or so and giving it a disinfecting wipe down probably makes some sense. I know I was glad to see them taking this flu virus seriously.
This sort of real-time cleaning and disinfecting, while patrons are continually coming and going, could be argued as being a good hygienic practice.
But of late I’m reading more and more about schools (and sometimes businesses) that are shutting down, often for days, in order to give them time to perform a `deep disinfecting cleaning’ of the premises - and here the science and logic isn’t quite so clear.
A couple of examples from today’s news, then some discussion.
Arizona school closes with flu outbreak
(AP)
HUACHUCA CITY, Ariz. — Health officials suspect an outbreak of swine flu has caused an Arizona school to shut down after more than a third of the students called in sick.
Huachuca City Elementary will closed, the rest of the week followed by the regular fall break. Crews will disinfect everything that children put their hands on, from door knobs and desks to restrooms, and the cafeteria.
25 teachers call in sick Monday; students resume Oct. 19 after fall break
By Samantha Swindler / Managing Editor
Corbin schools will be closed the rest of this week due to illness, and class won’t be back in session until Oct. 19, following fall break.
<Snip>
“Twenty-five teachers were out also and we didn’t have enough subs to go into six classrooms,” McNeel said.
Corbin Intermediate School had the lowest attendance rate at 84 percent. That’s down from the normal 94-95 percent attendance.
Over the break, McNeel said custodial staff will be disinfecting walls, desks, door handles and other surfaces often touched.
This seems to be a common reaction. Close the school for a week, bring in the custodial staff, and maniacally disinfect all surfaces.
I’m sure it is very reassuring to the the students, their parents, and the general public. It shows the school is concerned, exercising due diligence, and that the health and safety of those in attendance is important.
But . . . does it make any sense?
From a scientific standpoint, that is.
According to the CDC’s guidance, it doesn’t appear to.
Questions & Answers
2009 H1N1 Flu (Swine Flu) and You
September 24, 2009 10:00 AM ET
How long can influenza virus remain viable on objects (such as books and doorknobs)?
Studies have shown that influenza virus can survive on environmental surfaces and can infect a person for 2 to 8 hours after being deposited on the surface.
In other words, if school lets out at 3 o’clock in the afternoon, by about midnight each night any viruses deposited on surfaces will have probably died.
Which means that closing a school for days, and bringing in a cleaning crew, is of dubious value at best.
Now . . . if the point is to reassure the public, and to show that the school is being`proactive’ and protective of the kids, I suppose it has some `public relations’ value.
But if the point is to protect the students and staff from infection, this would seem to be a less than cost-effective way to go about it.
Worse, it may instill in some people a false sense of security. A belief that since the school has been disinfected, there is no need to take other precautions.
The evidence strongly suggests that most influenza infections are acquired through a respiratory route, and the role of fomites (inanimate objects like books, door knobs, desks) is probably limited.
Those infections that do come from fomites almost certainly come from relatively `fresh deposits’ of viral material . . . minutes or hours old . . . not left over from yesterday or last week.
And last but not least, even the most thorough deep disinfecting of the school premises can be undone in the time it takes a returning student with the virus to sneeze.
All of which calls into question the disinfecting tactics being employed by schools around the country. The money being spent on deep cleaning of schools would be better spent on more hand sanitizer, paper towels in the bathrooms, and perhaps `real-time’ cleaning of surfaces during school hours.
