When 150 passengers and crew on a Hawaiian cruise ship came down with a stomach virus, a state health official’s advice for prevention was “wash hands, wash hands, wash hands.”

Public health experts agree: To stop the spread of stomach viruses, colds, flu or worse – like the antibiotic- resistant MRSA infection recently in the news – frequent and thorough hand washing is your first line of defense.

Plain soap and warm water are best, but alcohol-based sanitizers are just as good when water isn’t available. Antibacterial soap isn’t needed and can lead to more resistant germs that are harder to kill.

The right way to wash your hands

Wet them with clean, running water.

Apply soap.

Rub your hands together briskly to make lather.

Scrub all surfaces, including under your fingernails.

Continue scrubbing for 20 seconds, or the time it takes to sing “Happy Birthday” twice.

Rinse well.

Dry with a clean towel.

When using an alcohol-based sanitizer, apply half a teaspoon to the palm of your hand. Rub your hands together, covering all surfaces, until they are dry.