The Texas Department of State Health Services is warning people not to eat Rocky Ford cantaloupes from Colorado because they may be contaminated with Listeria monocytogenes, a bacterium that can cause severe illness.

The cantaloupes were grown in the Rocky Ford region of Colorado and may carry a Rocky Ford label. People who have cantaloupes in their homes can check the label or check with the grocery store to determine if the fruit came from the Rocky Ford region.

Texas-grown cantaloupes are not included in the warning and have not been linked to the illnesses.

Rocky Ford cantaloupes were distributed from Colorado to various grocery stores in Texas and other states.

At least 15 people, including two from Texas, have become ill after consuming Rocky Ford cantaloupe. Both Texas cases – one in North Texas and one in Southeast Texas – were hospitalized.

DSHS is collaborating with the Centers for Disease Control and Prevention, the Food and Drug Administration and health officials in other states to investigate.

People should wash their hands before and after handling melon. The surface of melons should be washed and dried with a clean cloth or paper towel before cutting. Cut melon should be promptly refrigerated at less than 41 F / 5 C.

Symptoms of listeriosis can include fever, muscle aches, diarrhea and vomiting. People with these symptoms should consult a physician. Symptoms typically occur three to 70 days after exposure. The disease affects primarily older people, pregnant women, newborns and people with weakened immune systems.

Texas averages about 44 listeriosis cases per year. In 2010 there were 53 reported cases of listeriosis. There have been 20 reported cases so far in 2011.