How long until it’s an Entertainment News headline:

It’s the deadliest outbreak of foodborne illness in 25 years! Here’s what celebrities are doing to protect themselves!

As I told CBS Radio a couple of hours ago, I find top-10 lists of most-dead people by food distasteful; all outbreaks are tragic, especially when a bug like listeria preys on the most vulnerable in society.

And the lists are so U.S.-centric.

What about Ontario (that’s in Canada): 1985, 19 of 55 affected people at a London, nursing home died after eating sandwiches contaminated with E. coli O157. Or listeria in Maple Leaf deli meats in 2008 – 24 dead.

Or Scotland (that’s over there). 1996, 22 dead and over 500 sick from E. coli O157 in roast beef sandwiches.

Earlier today, the U.S. Centers for Disease Control reported that 23 people had died and 116 people had been confirmed as ill with any of the four outbreak-associated strains of Listeria monocytogenes in cantaloupe from Jensen Farms in Colorado. In addition, one woman pregnant at the time of illness had a miscarriage.

The deadliest-outbreak-in-25-years headlines soon followed.

The FDA and CDC have had teams in Jensen Farms fields and packing sheds, testing the soil, water and surfaces for clues. A report on the FDA's findings is anticipated in the coming weeks.

About 800 laboratory-confirmed cases of Listeria infection are reported each year in the United States and typically 3 or 4 outbreaks are identified. The foods that typically cause these outbreaks have been deli meats, hot dogs, and Mexican-style soft cheeses made with unpasteurized milk. Produce is not often identified as a source, but sprouts caused an outbreak in 2009, and celery caused an outbreak in 2010.

The U.S. Centers for Disease Control confirmed that 100 persons infected with any of the four outbreak-associated strains of Listeria monocytogenes have been reported to CDC from 20 states, including 18 deaths.

Is food local when it’s distributed to 20 U.S. states?

The cantaloupe from Jensen Farms in Colorado near the Kansas border likes to bill itself as local and pesticide-free, but I’d rather buy listeria-free cantaloupe from almost anywhere. Geographical knowledge is no substitute for microbiological safety.

U.S. Food and Drug Commissioner Margaret Hamburg said Tuesday that the agency is still investigating the cause of the outbreak. Officials have said they are looking at the farm’s water supply and possible animal intrusions among other things in trying to figure out how the cantaloupes became contaminated.

What retailers bought these melons? Who did the food safety audits for those retailers that concluded thumbs up for these melons?

The hunt by Colorado scientists' to identify the source of a national listeria outbreak that has been linked to eight deaths involved two weeks of brainstorming, studying blood samples and confiscating half-eaten food from patients' refrigerators.

Health officials also shopped for grocery-store cantaloupe before pinpointing a single farm in Holly as the source.

State epidemiologist Alicia Cronquist thought it slightly odd when she learned two people were sickened by listeria bacteria within days.

When two more reports arrived at the state health department in late August, Cronquist figured she was dealing with an outbreak.

In the early stages of Colorado's investigation, county health authorities used 15-page questionnaires to interview patients and their families about what they ate and where they bought it.

"The vast majority of people are elderly," Cronquist said. "The average age is in the 80s and they are quite ill. Their family members are at their bedside, and we are asking them to remember food that they ate a month ago. They are actually very difficult interviews."

Meanwhile, the bacteria in patients' blood was isolated, and state microbiologist Hugh Maguire's labs deconstructed the DNA profiles to see whether they had listeria strains in common.

Those profiles were uploaded into a CDC database of data from across the nation.

Scientists pulled food from patients' homes, including typical listeria suspects like deli meats, hot dogs and dairy products.

By Sept. 2, the state food lab determined that two patients had matching strains and two other patients matched in a separate strain. With hundreds of strains of listeria, two or more can be on the same food.

Epidemiologists in patients' home counties interviewed the patients to look for patterns while the state health department faxed and emailed a listeria alert to doctors, hospitals and labs.

When Cronquist checked a CDC database tracking foods that listeria victims reported eating, she found that all the patients she was tracking had eaten cantaloupe.

Health authorities purchased 15 cantaloupes at three grocery stores and tested the rind and flesh for listeria bacteria. They also were testing patients' leftover melon. Maguire's lab fast-tracked the genetic matching, setting aside some of the lab's other, more routine work.

A week after the first public warning, health authorities announced they had linked the source of the poisoning to cantaloupe.

As more patient blood samples arrived at the state lab, they fell into three distinct strains. Cantaloupe taken from patients' refrigerators had the same strains but no sticker naming the farm. In interviews, though, patients volunteered that the cantaloupe said 'Rocky Ford' on it or was extra sweet.

By tracking the melon purchases of patients back to the distribution trucks, investigators from the state and the Food and Drug Administration narrowed the focus to two farms and sampled soil and machinery.

Two days after warning people not to eat Rocky Ford cantaloupe, health officials announced they had pinpointed the farm.

Jensen Farms in Holly recalled its cantaloupes Sept. 14, while farmers in the Rocky Ford region miles away lamented how their produce was swept into early warnings about cantaloupe.

Meanwhile, 7NEWS in Denver has confirmed the investigation is expanding beyond Jensen Farms and that a company that sprays treated human waste – biosolids -- confirmed to 7NEWS it has been contacted by investigators. State investigators confirmed they want to know if biosolids may have caused the contamination.

Parker Ag Services vice president Mike Shearp told 7NEWS that government investigators have questioned him in recent days as to where those biosolids were applied. He said the substance was applied to a field directly across from a Jensen Farms field years ago.

Shearp maintained that the contamination will not be traced back to his operation.

Colorado State University animal science professor Lawrence Goodridge said, "If processed properly, there should not be pathogens. If they are not processed properly, if the wastewater treatment process breaks down, they could be (a) source of pathogenic bacteria such as salmonella, listeria and other pathogens."

A spokeswoman with Jensen Farms said the company does not use biosolids in its operation.

The U.S. Food and Drug Administration announced today it found Listeria monocytogenes in samples of Jensen Farms’ Rocky Ford-brand cantaloupe taken from a Denver-area store and on samples taken from equipment and cantaloupe at the Jensen Farms’ packing facility. Tests confirmed that the Listeria monocytogenes found in the samples matches one of the three different strains of Listeria monocytogenes associated with the multi-state outbreak of listeriosis.

The U.S. Centers for Disease Control updated the official outbreak count to 35 persons infected with the outbreak-associated strains of Listeria monocytogenes, including four deaths, from 10 states.

Jensen Farms voluntarily recalled its Rocky Ford-brand cantaloupes a week ago in response to the multi-state outbreak of listeriosis. Cantaloupes from other farms in Colorado, including farms in the Rocky Ford growing area, have not been linked to this outbreak.

Jensen Farms is helping federal and state authorities determine how the cantaloupes became contaminated.

The FDA’s root-cause investigation and environmental assessment includes the on-site expertise of FDA and state of Colorado microbiologists, environmental health specialists, veterinarians and investigative officers. The experts conducting the assessment will analyze the evidence, determine the most likely cause of contamination and identify potential controls to help prevent contamination in the future. The FDA will use the findings to help inform agency policy regarding Listeria and produce food safety best practices.

Jensen Farms shipped the recalled cantaloupes from July 29 through Sept. 10 to at least 17 states with possible further distribution.

For additional information about the recalled products, including product labels: http://www.fda.gov/Safety/Recalls/ucm271879.htm.

A table of cantaloupe- (or rock melon) related outbreaks is available at http://bites.ksu.edu/cantaloupe-related-outbreaks.