Listeria infections traced to cantaloupes have been blamed for at least 13 deaths. The number may be as high as 16.

An operator of a fruit and vegetable stand near Denver holds a California-grown cantaloupe for sale at her business (Ed Andrieski/AP)

At least 72 illnesses in 18 states possibly related to the outbreak have been reported to the Centers for Disease Control and Prevention, the Associated Press reports. The outbreak, the deadliest in a decade, was traced back to Jensen Farms in Colorado. The company recalled the cantaloupes earlier this month.

(Read more about the latest Listeria outbreak.)

While this outbreak is serious, there are many variables to consider. Here’s what you should know.

The infected cantalope may have been in crates labeled with these stickers. (

What are the symptoms?: Fever, muscle aches and gastrointestinal issues are the usual symptoms. It can take four weeks for signs of illness to arise.

If the infection has spread to the nervous system, a person may experience headache, stiff neck, confusion, loss of balance and convulsions, according to the Mayo Clinic.

Who is affected?: Anyone can be infected, but the infection usually causes serious illness in the elderly and immunocompromised. In pregnant women, it can cause premature delivery, miscarriage, still birth and health problems for the fetus. It generally does not cause serious illness in healthy people.

The CDC estimates that 260 people of the 1,600 who become seriously ill with listeria die each year. That’s about one in five.

How is it treated?

The infection does not always require treatment. In serious cases it is treated with antibiotics. But even with treatment, it can still be fatal.

Information above from the CDC.