The number of victims is continuing to rise from the deadliest outbreak of food borne illness in a generation.

The Centers for Disease Control and Prevention today confirmed two more deaths from listeria linked to cantaloupe from Jensen Farms in Colorado, bringing the federal government’s official count to 15 deaths. Eighty-four people, most of them over the age of 60, have been sickened in the outbreak. Nearly all were hospitalized.

That’s up from Wednesday when the agency reported 72 illnesses and 13 deaths.

Before this, the most deaths caused by tainted food in more than a decade had come in 2008, when peanut butter products from the Peanut Corporation of America were behind a salmonella outbreak that sickened 691 people and killed nine.

The CDC has never recorded an outbreak of listeria in cantaloupe but it can be a particularly lethal pathogen.

In 1985, Mexican-style cheese was behind a rash of listeriosis cases that killed 29 people.

And this outbreak in cantaloupe, in all likelihood, is ongoing. After a person is exposed to listeria it can incubate inside the body for months.

“People who consumed the cantaloupe some time ago may continue to develop illness in the coming days and weeks,” CDC Director Thomas Frieden told reporters this week. “So we do anticipate that there will be a rising number of cases in the days and weeks to come.”