Fifteen people are now confirmed dead and another 84 sickened in the recent listeriosis outbreak in the United States, according to the Centers for Disease Control and Prevention (CDC) in Atlanta.

The illnesses began after July 31, and have been reported in 19 states.

Five of the listeriosis-related deaths occurred in New Mexico, three in Colorado, two in Texas, and one each in Kansas, Maryland, Missouri, Nebraska, and Oklahoma, the CDC reported Friday.

The CDC has traced the outbreak to cantaloupes grown at Jensen Farms in Granada, Colo., following the finding of listeria monocytogenes in a sample from there.

The Food and Drug Administration (FDA) has advised consumers to throw out the recalled melons.

It can take more than two months for a person exposed to the bacteria to fall ill, which means it is often difficult to identify a food that carried the pathogen. Different from some other bacteria, listeria is capable of growing well at low temperatures, thus making it hard to eliminate it from refrigerated food-processing areas.

Symptoms of the infection include fever, muscle aches, diarrhea, headache, a stiff neck, and confusion, the Colorado public-health department said. The infection can also cause miscarriages and stillbirths.

People in high-risk groups for contracting the infection should avoid unpasteurized soft cheeses, refrigerated smoked seafood, and deli meats unless they have been reheated to 165 degrees Fahrenheit.

The FDA has recommended that consumers rinse all raw produce, including cantaloupes, under running water.

In a related event, produce seller True Leaf Farms has recalled 90 cartons of chopped and bagged romaine lettuce because of potential Listeria monocytogenes contamination.

A random sample of romaine lettuce taken by the FDA tested positive for the bacteria.