So far, at least 55 people across 14 states have been infected and eight have died in the deadly outbreak caused by Listeria-contaminated cantaloupe, the Centers for Disease Control and Prevention (CDC) reported Wednesday.

As of 5 p.m. Eastern Time, the number of confirmed cases and deaths had doubled since last week, and the toll likely will rise, given the age of most victims and the severity of their illnesses. The CDC’s update on the outbreak says most of those sickened are over 60, and of 43 patients with available information, all were hospitalized.

State health departments are investigating 13 additional suspected cases of outbreak-linked listeriosis, and it’s possible that people who ate the tainted cantaloupe are infected with Listeria but aren’t sick — yet. The incubation period for the bacteria is about three weeks, although it can take as long as two months for listeriosis to develop after exposure to contaminated food.

On Sept. 14, Jensen Farms of Colorado, the implicated grower, recalled Rocky Ford/Frontera-brand cantaloupes that had been shipped between July 29 and Sept. 10 to 17 states: Illinois, Wyoming, Tennessee, Utah, Texas, Colorado, Minnesota, Kansas, New Mexico, North Carolina, Missouri, Nebraska, Oklahoma, Arizona, New Jersey, New York and Pennsylvania. At the time, however, the Food and Drug Administration cautioned: “further distribution is possible,” and some of the states reporting illnesses are not on the initial shipping list. The FDA has provided label information and other details about the recalled cantaloupe, but nothing about stores that received the melons.

Phyllis Entis, author of the eFoodAlert website, said that is one of the frightening — and frustrating — aspects of this outbreak for consumers.  “No one in authority is releasing information on where the contaminated cantaloupes were sold. FDA has said nothing. Jensen has said nothing. Colorado has said nothing,” she wrote. “Only a few supermarket chains have posted recall information.”

Entis has compiled on eFoodAlert what possibly is the best available list of retailers, but she added, “The  refusal of FDA and most state agencies to provide this information is unconscionable. And it puts the health of the general public at risk unnecessarily.”

The onset of illnesses for all the confirmed outbreak patients was Aug. 4 or later, according to the CDC. Colorado reports 14 outbreak cases, New Mexico 10, Texas nine, Oklahoma eight, Nebraska  four and Wisconsin two. Single cases have been reported in California, Illinois, Indiana, Maryland, Montana, Virginia, West Virginia and Wyoming. Of the eight deaths confirmed so far, four were in New Mexico and two were in Colorado.  Maryland and Oklahoma each have reported single fatalities.

Kansas is trying to determine if eight cases of listeriosis, including two deaths, are connected to the outbreak. State health officials there say they typically see fewer than six listeriosis illnesses each year but, so far in 2011, there have been nine cases, including those that may be associated with the bad cantaloupe.

Missouri has said tests are pending for two cases, including one death, that may be connected to the Colorado cantaloupe.

Ages of those confirmed to be part of the outbreak range from 35 to 96 years; the median age is 78. Most have underlying health problems, the CDC reported.

Earlier this week, the FDA said Listeria monocytogenes bacteria matching some of the outbreak strains was found in Jensen Farms cantaloupes at a Denver store and in a sick person’s home, as well as in samples taken from unspecified machinery at the grower’s Granada, CO packaging plant.

There’s still no word on how the cantaloupes became contaminated.  The FDA has said the  grower has been working cooperatively with federal and state microbiologists, environmental health specialists and veterinarians in Colorado, trying to figure that out.


CDC Outbreak Map: