The deaths of a Nebraska man in his 80s and a 95-year-old Missouri woman, plus five cases of Listeria infection in Kansas, were confirmed Friday by state health departments, increasing the toll in the multistate outbreak caused by contaminated cantaloupes from Colorado’s Jensen Farms.  

The confirmations bring the total number of people infected with outbreak-associated strains of Listeria monocytogenes to at least 61, with 10 or more deaths.

The federal Centers for Disease Control and Prevention (CDC) has not done an official update since Sept. 21 when it reported 55 persons sickened by Listeria monocytogenes in 14 states, with eight dead.

Kansas has eight cases of listeriosis, including two deaths, with five cases now confirmed to be part of the outbreak. Missouri was investigating two cases of listeriosis, one of those is now confirmed to be connected to the contaminated cantaloupe.

Addition of the cases means the cantaloupe-caused 2011 Listeria outbreak is now larger than Canada’s 2008 Listeria outbreak, which was caused by contaminated ready-to-eat meats.  

It remains to be seen whether the current Listeria outbreak will turn out to be as deadly.   Canada saw 23 deaths out of 57 cases for a fatality rate of 40 percent.  The median age of the victims in the ongoing Listeria outbreak is 78.  

Listeriosis, the illness caused by Listeria, primarily occurs among older adults, persons with weakened immune systems, pregnant women,a d newborns. Symptoms include fever, muscle aches, diarrhea and vomiting.  Symptoms typically occur three to 70 days after exposure.

The number of infected persons identified in each state is as follows:  California (1), Colorado (14), Illinois (1), Indiana (1), Kansas (5), Maryland (1), Missouri (1), Montana (1), Nebraska (4), New Mexico (10), Oklahoma (8), Texas (9), Virginia (1), West Virginia (1), Wisconsin (2), and Wyoming (1).

Jensen Farms recalled its Rocky Ford-brand cantaloupes on Sept. 14. Initially, the FDA said the melons were distributed to 17 states by Texas-based Frontera Produce, but Friday the agency said the contaminated cantaloupes went to 25 states.

The recalled cantaloupes were shipped from July 29 through September 10, 2011 to Arkansas, Arizona, California, Colorado, Idaho, Illinois, Kansas, Minnesota, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, and Wyoming, the FDA said.

Because cantaloupe shelf life can be as long as two weeks, it is possible that some of the recalled product could still be in commerce or in home refrigerators. The FDA advised consumers to check with their retailer to find out where the cantaloupe they purchased originated, adding that it is the retailers’ responsibility to know the source of their products.

The cantaloupe may be labeled: Colorado Grown, Distributed by Frontera Produce, USA, Pesticide Free,, Sweet Rocky Fords. Some cantaloupes may also have been unlabeled.

If consumers have the recalled cantaloupe in their home, is should be discarded immediately.

Symptoms of listeriosis include fever and muscle aches, often preceded by diarrhea or other gastrointestinal symptoms. Almost everyone who is diagnosed with listeriosis has “invasive” infection, in which the bacteria spread beyond the gastrointestinal tract. The symptoms vary with the infected person:

Pregnant women: Pregnant women typically experience only a mild, flu-like illness. However, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.

Persons other than pregnant women: Symptoms, in addition to fever and muscle aches, can include headache, stiff neck, confusion, loss of balance, and convulsions.