The latest listeria outbreak in cantaloupe melon is the deadliest of its kind to have hit the United States in the past decade. 16 lives have been lost and more cases are being reported by the day, but what are the causes and what symptoms should we be looking out for?

The outbreak has been traced back to Rocky Ford cantaloupes from Colorado. 18 states reported cases of the infection after 300,000 cases of cantaloupes were shipped from the Jensen Farms.

72 people have been reported to have contracted the illness from the melons, although most of the people that died were over 60. Pregnant women and the elderly are more vulnerable to getting ill from listeria due to their weaker immune systems.

Babies are also vulnerable to contracting the illness. Symptoms of listeria in babies include: vomiting, low interest in being fed and irritability.

The illness is expected to last for weeks, even though the melons have been recalled. Listeria has an incubation period of a month or more, so people who ate contaminated fruit last week may not see illnesses until next month, according to Thomas Frieden, director of the Centers of Disease Control (CDC).

Listeria is generally more deadly than illnesses like salmonella or E.coli, the CDC reported. Twenty-one people died in an outbreak of listeria poisoning in 1998 traced to contaminated hot dogs and possibly deli meats. Another large listeria outbreak in 1985 killed 52 people and was linked to Mexican-style soft cheese.

The CDC has urged anyone who has a contaminated melon to throw it out. Even though the melons were recalled on Sept.14, officials feel that not all of them were labeled and some could still be lurking in supermarket refrigerators. The FDA has warned people to check for the following labels: Colorado Grown, Distributed by Frontera Produce, or Sweet Rocky Fords. 

People should not try to wash bacteria from the tainted melons as they could risk spreading the bacteria inside of the fruit, ABC news reported.

Anyone who believes they have made contact with the contaminated fruit has been urged by the CDC to use bleach to wipe down the inside of the door handle on the refrigerator, as well as kitchen surfaces and cutting boards.

The CDC also issued everyday tips on how to prevent a listeria or e.coli contamination:

  • Thoroughly cook raw food from animal sources such as beef, pork or poultry to a safe internal temperature.
  • Rinse raw vegetables thoroughly under running water before eating.
  • Keep uncooked meats and poultry separate from vegetables and from cooked foods and ready-to-eat foods.
  • Do not drink raw and unpasteurized milk and do not eat foods that have unpasteurized milk in them.
  • Eat perishable and ready-to-eat foods as soon as possible.
  • Clean up spills in your refrigerator right away.

The main symptoms are: Fever, muscle aches, nausea, diarrhea. If the infection spreads to the nervous system people can experience headaches, confusion, changes in alertness, stiff neck, convulsions and a loss of balance.

The FDA and CDC announced on Wednesday that they expect the number of illnesses to carry on through October.