ROCKY FORD, COLO. -- Health officials in southern Colorado think the recent listeria outbreak may be linked to cantaloupe from Rocky Ford, a rural southeastern Colorado town where the melons are grown and sold regularly.

As a result, health officials are issuing warnings, groceries stores are taking them off shelves and some schools are pulling them from their menus.

This puts Rocky Ford farmers in a tough position, as cantaloupe sales are a big part of their business.

Lusk Farms Manager and Grower Kent Lusk said cantaloupe sales make up about 40 percent of his produce business, and the listeria outbreak has hurt their wallets.

The cause of the listeria outbreak is still under investigation, as officials have been unable to prove definitively that the outbreak is linked to Rocky Ford melons. There haven't been any listeria cases in Otero or surrounding counties, so Lusk thinks his town's melons aren't to blame.

However, officials with El Paso County Public Health, representing the largest county in the state, issued a warning to high-risk people Tuesday not to eat Rocky Ford cantaloupe. 

"People who are 60 years and older, pregnant women, people who have weakened immune systems either from chronic medical conditions or from medications they are taking, those are the high risk groups to get Listeria infections," Bernadette Albanese, Medical Director with the El Paso County Health Department, said Tuesday.

The symptoms of Listeria include fever, body aches, headaches and diarrhea.

"If it starts involving the brain and starts an infection around the brain then you may have stiff neck, and you may have seizures," Albanese said. "You may have serious confusion and these are serious and progressive symptoms."

Albanese said if you have any of those symptoms, have recently eaten cantaloupe, and are in a high risk group you should contact your health care provider right away.

In Colorado, at least seven people have been sick from listeria, and two have died.