In previous centuries, the importance of hand washing was not understood, and led to the needless deaths of many millions of people. When performed properly, hand washing is by far the most effective way to reduce the spread of communicable diseases.
Up to 25% of women in the 19th century died in childbirth from childbed fever (peurperal sepsis), a disease subsequently found to be caused by the bacteria Streptococcus pyogenes, which was inadvertently transmitted to the mothers on the hands of the doctors attending them. When hand washing was instituted in the delivery room, the rate of death dropped to less than 1%.
Washing your hands after using the toilet or changing a diaper is of utmost importance, as the ingestion of even the smallest amount of fecal matter can cause serious illness from deadly pathogens such as E. coli, salmonella, giardiasis and hepatitis A, among others.
Viruses can also be spread via the hands when they come into contact with infectious respiratory secretions, such as after coughing, sneezing, shaking hands with someone or touching an object that has been in the proximity of someone who is ill, then touching the face, particularly the nose, eyes or mouth. This is one of the primary ways of transmitting the virus that causes the common cold.
Those who handle food should routinely wash their hands, not only after using the toilet, but also after touching raw meat, fish or poultry, as the microbes present on uncooked food can cause gastrointestinal infections that can range anywhere from mild to severe.
Other instances in which you should wash your hands are after handling garbage, handling animals or animal waste, visiting or caring for an ill person, or if the hands show visible dirt.
To wash your hands properly you need only two things: soap and clean, running water. If these two are not available, you can use an alcohol-based hand sanitizer that has a minimum 60% alcohol content.
Before washing your hands, remove all rings and other jewelry. Using warm, running water, wet your hands thoroughly, then apply enough soap to work up a nice lather. Keeping your hands out of the water, rub them together, being sure to scrub both the front and backs of your hands, including your wrists, and also washing between the fingers and under the nails. Do this for 20 seconds, then rinse completely under the running water. Turn off the taps with a paper towel and dry your hands thoroughly with a clean towel or air dryer.