COLLIER COUNTY, Fla.- A new health warning about a stomach bug spreading around the country. The CDC just sent out an alert about shigellosis. Doctors say some strains can’t be cured by medication. The super bug can be lurking on a door knob or any surface. There have been three cases of the bacteria, also known as shigella, in Collier County this year. “We get sporadic cases of shigella throughout the year. We have had a few cases in the last few months,” said epidemiologist Terri Harder. “It takes a very small amount of the bacteria to make someone ill, so it is highly contagious.” You can catch shigellosis through contaminated food or water, or through skin contact with the bacteria. Symptoms last five to seven days and include an irritated stomach and bowel or diarrhea. The CDC says most people pick up shigella when traveling. Health officials say the best way to fight off bacteria is to make sure to use soap when washing your hands. Doctors recommend rubbing your hands together for about 20 seconds because the heat and friction will help kill germs.