In a recent commentary, Anna Devon-Sand makes the case that "germs are necessary for healthy immune function" and argued that the "five-second rule" is a reasonable approach to dealing with food that falls on the floor ("How clean is too clean?" June 17).
However, proper food handling and hand-washing are nothing to sneeze at. Food-borne illness remains a serious issue that can sicken even healthy people with strong immune systems.
While there is evidence that exposure to some microbes in infancy and throughout life helps stimulate the immune system, Ms. Devon-Sand's argument fails to recognize the critical difference between harmless microbes and pathogenic, disease-causing microbes that can pose a grave risk to health.
Our modern approach to hygiene, including appropriate hand-washing and food-handling, has made us healthier. It has contributed to a dramatic decrease in infectious disease and infant mortality and an increase in average life expectancy.
These advances should not be taken lightly since, even though we know a lot more about germs, there continue to be outbreaks of serious, life-threatening diseases.
Recently there were reports of outbreaks of highly contagious diseases on college campuses, including meningitis at Rutgers University and mumps at Sacred Heart and Harvard universities.
The recent outbreak of norovirus in the Chipotle chain is only one example of food poisoning associated with restaurants. The Centers for Disease Control estimates that one in six Americans are victims of foodborne illnesses every year. Of those cases, more than 100,000 are hospitalized and an estimated 3,000 die.
In "The Hand Book: Surviving in a Germ-Filled World," I explain how to reduce your risk of infectious disease through proper hand hygiene and food-handling. Regarding the so-called "five-second rule," if food falls on the floor, it may or may not be safe to eat if it is recovered within a few seconds.
Some surfaces, such as a sidewalk that has been baking in the mid-day sun, may be relatively germ-free. But others, like bathroom and kitchen floors or public spaces, may be teeming with bacteria and viruses from human waste or contaminated food. Depending on the type of food and where it is dropped, food can pick up disease-causing germs immediately.
Would you want the "five-second rule" to be applied to the restaurant worker who dropped your pizza, burger or tuna sandwich on the floor? Clearly it is not a good idea to permit this practice in public food establishments, and it is likewise risky at home.
When it comes to hand hygiene and food safety there is a great deal of ignorance regarding proper policy and practices. Even people who know better are failing to wash hands properly, putting themselves and others at risk.
Proper hygiene is like wearing a seat-belt. Most of the time you do not need it, but when your car careens into a ditch you are lucky to have it on.
In everyday life most of the time we are not exposed to disease-causing germs. But when you do encounter the flu virus or E. coli bacteria — or are exposed to meningitis or the mumps — you will be safer if you practice good hand-washing and food handling.
You may never know that you saved yourself from a serious illness or even death because germs are invisible and being exposed to an infection is not as dramatic as a car crash.
So buckle up in the car, and practice good hygiene. You may never find out you avoided a bout of food poisoning but. believe me, that's a lot better than the alternative.
Miryam Z. Wahrman, Wayne, N.J.
The writer is a professor of biology at William Paterson University