Frequent hand washing is an excellent way to prevent illness. The Centers for Disease Control and Prevention notes that you should always wash your hands in the following instances: before, during, and after preparing food; before eating food; before and after caring for someone who is sick; after using the bathroom, changing diapers, or cleaning up a child who has used the bathroom; after blowing your nose, sneezing, or coughing; after touching an animal, their cage, or their food or handling animal waste; after handling garbage; and if you have dirty hands.

Centers for Disease Control and Prevention, November 2018