Archive for December, 2008

We knew bleach works, now we know why

Thursday, December 25th, 2008

Throughout my book Germ Proof Your Kids – the Complete Guide to Protecting (without Overprotecting) Your Family from Infections (ASM Press, Washington, D.C., 2008) you’ll note that I tout the germ-proofing abilities of bleach.  Bleach is known to be the most effective disinfecting agent against both bacteria and viruses, the causes of most infections. As a household surface disinfectant for all solid surfaces in the kitchen, bathroom, playroom, child’s sick room, and laundry room, bleach-containing disinfectants have been shown to markedly reduce the numbers of potentially dangerous bacteria like E. coli, Salmonella, Campylobacter, Strep and Staph (including the resistant “superbugs”). Bleach disinfectants also work against the viruses that cause diarrheal illness, the viruses that cause colds and flu, and even the viruses that cause hepatitis and AIDS. In the laundry, bleach added to the usual wash cycles also dramatically improves germ-killing. For these reasons, bleach-containing disinfectants have also long been my preferred products for disinfecting schools and workplaces (see Chapter 9 in Germ Proof Your Kids – the Complete Guide to Protecting (without Overprotecting) Your Family from Infections).

But, although we have long known how effective bleach-containing disinfectants and laundry products are, it wasn’t until an elegant study published in the prestigious scientific journal Cell just last month (November 14, 2008) that we now understand how bleach actually works. One of the active ingredients of household bleach, hypochlorite, permanently unfolds and clumps the proteins of bacteria, killing those germs. You can picture this process as looking exactly like the effect of boiling a raw egg – the formerly fluid proteins of the egg permanently clump into a hard-boiled, solid egg. Although the new study only looked at bacteria, the impressive killing effect of bleach on viruses may also be due to the same unfolding and clumping process of virus proteins.

Another very cool aspect of the study by these investigators is that It turns out that our own immune systems also produce hypochlorite as part of our natural defenses against infection! That is, our bodies naturally produce hypochlorite (the active ingredient in household bleach) to kill invading germs.

So there you have it. We have effectively used bleach to disinfect our homes, schools, workplaces, and laundry for several decades now and, finally, we understand why it works so well. Live and learn!

Google Flu Trends – Welcome to the Future!

Monday, December 15th, 2008

If you have any doubts about the power of the internet and, in particular, the power of internet search engines, you need only read this blog entry to quell those qualms and quench those quandaries. 

To begin with, a few words about how the Centers for Disease Control and Prevention (CDC), our government’s primary public health agency, deals with influenza (and, for that matter, with other contagious diseases as well). The CDC tracks flu and other diseases by a system that combines laboratory and clinical reporting of diseases. Doctors and testing laboratories across the country are asked to send reports to their state health departments and/or the CDC when certain diseases, like influenza, are diagnosed. With flu, for example, when laboratories identify influenza viruses in the laboratory, those identifications are reported to the state health department which in turn reports them to the CDC. By this mechanism, the CDC is able to follow the progression of diseases during a particular season and in a particular part of the country. When the CDC begins to see “activity” of a disease like flu, for example, on the east coast, they issue alerts to hospitals and doctors in those regions to be on the outlook for additional cases. This is particularly helpful for diseases that tend to spread rapidly – recall the CDC warnings for other diseases like West Nile Virus, for example.

Well, now enter Google. The brilliant folks at the internet search engine company did a study in which they tracked the search terms “flu symptoms” and other flu-related queries. Turns out that the geographical patterns of searching predicted the outbreaks of flu by as much as 2 weeks ahead of the CDC’s own tracking system based on reporting by doctors and laboratories. Another study used the Yahoo search engine and found the same thing – when people start searching flu terms, flu has appeared in those areas.

The CDC, to their credit, has embraced these results. The New York Times quoted Dr. Lyn Finelli, lead for surveillance at the influenza division of the CDC,  “The earlier the warning, the earlier prevention and control measures can be put in place, and this could prevent cases of influenza.” It could turn out that Google will be the first clue to outbreaks of many serious diseases in the future, including, potentially, even pandemic Bird Flu should such a dreaded event ever occur.  It’s a brave new world, indeed.

For more about influenza, including the threats of pandemic, and all other contagious diseases, see: Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections (ASM Press, Washington, D.C., 2008).