Hand is the "diplomatic organ" of human body, which plays a leading role in all people's "foreign affairs activities", such as doing all kinds of work, taking out garbage, brushing spittoon, washing feet, wearing shoes and cleaning stools. Therefore, hands are easily infected with many pathogenic microorganisms. Scientists have made such a survey that an unwashed hand contains at least 40,000 to 400,000 bacteria. Nail seam is a good place for bacteria to hide. One nail seam can hide as many as 3.8 billion bacteria. In addition, someone did an experiment. Patients with acute dysentery use 5~8 layers of toilet paper, and Shigella can penetrate into their hands. Shigella can survive for 3 days in their hands. The flu virus can survive for 7 days on wet and warm hands. So, my hands are dirty. Moreover, when traveling, visiting and studying, and performing tasks, hands often touch some items and get dirty. In particular, patients with infectious diseases and people who look healthy but actually have viruses in their bodies often spread pathogenic microorganisms to various articles and appliances. When a healthy person touches his hand, pathogenic microorganisms will come to his hand. If you don't wash your hands before and after meals, you will bring bacteria into your mouth and eat them in your stomach. This is what people often say: "Bacteria come from hands and diseases come from mouth." So you should get into the habit of cutting your nails frequently and washing your hands after meals and work.

Washing hands can remove bacteria and eggs attached to hands. Washing your hands with running water can remove 80% bacteria from your hands. If you wash your hands with soap first and then with running water, you can wash 99% of the bacteria off your hands. When washing hands, be careful that several people should not use the same basin of water to avoid cross-infection and spread diseases to each other for more than 15 seconds.