Food Poisoning Law Blog

The Listeria outbreak linked to Whittier Farms milk took the lives of 4 people, 3 elderly men and an unborn baby. A recent article in the Worcester Telegram provides a look at how epidemiologists (infectious disease “detectives”) at the Massachusetts public health laboratory uncovered the source of the outbreak using DNA fingerprinting:

State health workers had little to go on when they began their investigations in November, and no idea that a sample of pasteurized milk would eventually be tied to an outbreak lasting at least six months and involving three counties.

. . . Health officials said their first evidence of an outbreak also wound up breaking the case. That happened in November when the family of an elderly man who had fallen ill told hospital officials he may have consumed unpasteurized apple cider purchased at a farm stand in Norfolk County. Hospital staff advised the family to bring the cider to local health officials. The family brought in both the cider and a bottle of coffee-flavored milk purchased at the same stand. The local health agent sent the samples on to the state lab.

. . . To track down the bacterial culprits, epidemiologists began work on the fourth floor of the state lab. The organisms that are cultured from the milk and cider samples are put in a solution, which is heated up to release DNA, according to Dr. Linda Han, director of the lab’s Division of Microbiology. The DNA is placed in a dish with gel to sit for a day. The gel-encased DNA then is cut up by enzymes, a process that takes about two hours.

Next, the DNA was placed in a four-sided GEL DOC 2000, a pulsed-field gel electrophoresis (PFGE) machine, to obtain a genetic fingerprint. Over 20 hours, the machine sent alternate electrical pulses to the DNA, one side at a time. The ultraviolet light made the DNA “glow,” and a specialized software program photographed the deadly bacteria’s unique “barcodes.” The barcodes — or fingerprints — were uploaded into a computer, and laboratorians (laboratory analysts, technicians and scientists) then see whether they matched other genetic profiles already in the system.

. . . Officials were amazed when they discovered that the fingerprint of listeria bacteria in the milk sample provided by the patient’s family exactly matched the fingerprint of listeria found in a milk sample taken from the Whittier bottling plant.

While epidemiologists were required to go back 120 days to see whether there were any other genetic matches, they looked back several months more than that, and determined there were matches with four other patterns in their database.

We commend the epidemiologists and others who uncovered the source of this outbreak and went beyond what was required to find victims from as far back as June of 2007. Our experience is that knowing the source of a loved ones illness gives the families some closure and aids in the healing process. To contact a lawyer at Pritzker | Ruohonen about a Listeria lawsuit, please call toll-free at 1-888-377-8900 or submit the firm’s free case consultation form.