Fifteen people have now died after consuming cantaloupe contaminated with the listeria monocytogenes bacteria, the Centers for Disease Control and Prevention said Friday.

At least 84 people in 19 states have become ill with the bacteria, the agency said. And the number of illnesses could still grow, added the CDC, citing reporting lags and how the disease can develop slowly in some people.

On Tuesday, the CDC was reporting 13 deaths and 72 illnesses in what was already then the deadliest food-borne illness outbreak in the United States since 1998.

Five people have died in New Mexico from eating the tainted cantaloupes, the CDC said. Three people died in Colorado, two in Texas and one each in Kansas, Maryland, Missouri, Nebraska and Oklahoma.

Illnesses have also been reported in Alabama, Arkansas, California, Illinois, Indiana, Montana, North Dakota, Virginia, West Virginia, Wisconsin and Wyoming.

Most of those who fell ill are more than 60 years old, the CDC said. Doctors also are closely monitoring the pregnancies of two women who ate contaminated cantaloupe, with the agency noting that listeriosis can cause miscarriages and stillbirths.

Older adults and people with compromised immune systems are also especially susceptible.

Public health investigators have traced the source of the bacteria to a farm in Granada, Colorado.

The grower, Jensen Farms, issued a recall for its Rocky Ford-brand cantaloupes on Sept. 14. By now, the cantaloupes should all be off store shelves, the CDC said.

The agency warned that people should not eat Rocky Ford cantaloupes, even if they have eaten part of one and have not yet fallen ill. It also said that consumers should be wary of eating any cantaloupes if they don’t know where they came from.