(AP) -- Four people have died in an outbreak of listeria traced to Colorado cantaloupes, the Centers for Disease Control and Prevention said Monday.

One death occurred in Colorado, one in Oklahoma and two in New Mexico. The death count could soon rise to six. Chad Smelser of the New Mexico Department of Heath said the CDC is in the process of confirming two additional deaths linked to the outbreak in his state.

The CDC said that 35 people in 10 states have been sickened in the outbreak so far. The illnesses are in California, Colorado, Illinois, Indiana, Montana, Nebraska, New Mexico, Oklahoma, Texas and West Virginia. Colorado has the most illnesses with 12 sickened, followed by Oklahoma with six and New Mexico with five.

The illnesses have been traced to fruit from Jensen Farms in Holly, Colo. The FDA said Monday that it had found in samples of Jensen Farms' cantaloupe taken from a Denver-area store and on samples taken from equipment and cantaloupe at the farm's packing facility. Tests confirmed that the samples matched the strain of the disease found in those sickened.

Jensen Farms recalled its Rocky Ford-brand cantaloupes last week after the illnesses were linked to its fruit. The recalled cantaloupes were shipped from July 29 through Sept. 10 to Illinois, Wyoming, Tennessee, Utah, Texas, Colorado, Minnesota, Kansas, New Mexico, North Carolina, Missouri, Nebraska, Oklahoma, Arizona, New Jersey, New York and Pennsylvania. The FDA said it is possible the company distributed to other states as well.

Smelser of the New Mexico health department said he expects the number of ill persons to grow because the for listeria can be up to a month. Unlike many pathogens, can grow at room and refrigerator temperatures. The FDA and CDC recommend anyone who may have one of the contaminated cantaloupes throw it out immediately.

About 800 cases of listeria are found in the United States each year, according to CDC, and there usually are three or four outbreaks. Most of these are traced to deli meat and soft cheeses, where listeria is most common.

Produce has rarely been the culprit, but federal investigators say they have seen more produce-related listeria illnesses in the last two years. It was found in sprouts in 2009 and celery in 2010.

While most healthy adults can consume listeria with no ill effects, it can kill the elderly and those with compromised immune systems. It is also dangerous to pregnant women because it easily passes through to the fetus. In the current , the median age of those sickened is 81.

Symptoms of listeria include fever and muscle aches, often with other gastrointestinal symptoms.