It's the deadliest food outbreak in more than a decade.
The Centers for Disease Control and Prevention says 13 deaths and at least 72 illnesses have been traced to the tainted fruit.
Three other deaths that may be connected are being investigated. Officials in New Mexico, Kansas and Wyoming said they are investigating additional deaths possibly linked to the tainted fruit.
The outbreak has been traced to Jensen Farms in Colorado, which has voluntarily recalled Rocky Ford Whole Cantaloupes, shipped between July 29 and Sept. 10.
The new death toll numbers include newly confirmed deaths in Kansas, Missouri, Nebraska and Texas.
Listeria generally only sickens the elderly, pregnant women and others with compromised immune systems. The CDC said the median age of those sickened is 78 and that one in five who contract the disease can die.
No information has been released on how the cantaloupe contamination may have happened. Authorities say the investigation is ongoing.
The Associated Press contributed to this report.