On 400 BCE - Thucydides has a breakthrough moment: The ancient Greek historian Thucydides is the first to suggest that disease can spread from one person to another.
On 1546 - Germ theory begins. Italian scholar and poet Girolamo Fracastoro suggests that epidemics are caused by small particles or "spores" that can be transmitted from one person to another.
On 1807 - Microorganisms are found: Italian entomologist Agostino Bassi discovers that microorganisms can cause disease.
On 1818 - Ignaz Philipp Semmelweis is born: Ignaz Philipp Semmelweis, a pioneer in and advocate for antiseptic procedures, is born in Hungary.
On 1860 - A breakthrough safety process begins: Frenchman Louis Pasteur begins researching causes and prevention of disease, leading to his breakthroughs in vaccination and what came to be known as pasteurization.
Experts recommend washing your hands with soap and clean water for at least 20 seconds. Be sure to get a good lather going and clean the back of the hands, between the fingers and under the nails. Dry them using a clean towel. There is a lot of science behind these recommendations, so be sure to follow them each time you wash your hands.
The Centers for Disease Control and Prevention calls hand washing "a do-it-yourself vaccine" and suggests remembering five easy steps: Wet, lather, scrub, rinse, dry.
Endorsed by the American Medical Association and American Academy of Family Physicians, the four principles are: 1) Wash your hands when they are dirty and before eating; 2) Do not cough into hands; 3) Do not sneeze into hands; and 4) Don't put your fingers in your eyes, nose or mouth.
According to the Centers for Disease Control and Prevention, handwashing can prevent 1 in 3 diarrhea-related illnesses and 1 in 5 infections, including the flu.
About 1.4 million children under age 5 die from diarrheal diseases and pneumonia — the two most deadly afflictions for children worldwide.
The CDC also reports that only 31 percent of men and 65 percent of women washed their hands after using a public restroom.
Using antibiotics creates antibiotic resistance. Handwashing prevents many sicknesses, so people need less antibiotics. Therefore, less antibiotic resistance.
A typical human sneeze exits the body at about 200 miles per hour and emits around 40,000 droplets into the air.
Think of how many different things we touch during the course of an average day. Now imagine how many of those things were touched by other people's hands. Yuck! Wash your hands to prevent the spread of dangerous microbes.