Editor's Note: This story has been updated from the printed version.

Illnesses like COVID-19 spread when sick people sneeze or cough. This sprays droplets that contain disease-causing germs near them. People can get sick if they breathe in these droplets or touch an infected surface and then touch their eyes, nose, or mouth. 

Frequently washing your hands with soap and water can help prevent that. Oil on your skin contains dirt and germs. When you wash your hands, soap breaks up the oil into smaller drops. Rubbing your hands together creates friction that lifts the oil and germs off your skin. Water then carries the germs down the drain.

The water you use can be warm or cold. But you should rub the entire surface of your hands, including between your fingers and under your nails. Wash for at least 20 seconds—about the same time it takes to sing “Happy Birthday” twice!

Experts work to prevent diseases from spreading in many ways. Epidemiologists look for patterns in how diseases transfer among people. For instance, when a patient is found to have COVID-19, these scientists locate the people the patient was in contact with. These people can be kept away from others for a period of time to see if they show symptoms of the disease. Governments can also close schools or discourage travel to places with many cases.

Even though the news about the new virus can sound scary, experts say it’s important to stay calm. Most cases are mild. It’s also important that you and your family pay attention to the latest guidelines from health and local officials.

As of April 2020, officials are recommending that people wear cloth masks if they have to go outside. Masks covering your nose and mouth can help you keep from spreading a disease, even if you’re not feeling sick. Experts say the best thing you can do is stay home. “Keep up-to-date with what’s going on in your community,” says Amesh Adalja, a disease expert at the Johns Hopkins Center for Health Security. “You shouldn't panic.”