WHITE BEAR LAKE, Minn. -- A fatal, nationwide outbreak of listeriosis believed confined to hot dogs and deli meats has apparently spread to include nearly 1,000 cases of possibly contaminated milk, as well as chicken burritos.
Federal health officials, however, report that it is too early to determine if these instances of contamination are related. However, the sudden proliferation of individual cases is directly the result of heightened diligence.
Specifically, better reporting procedures have heavily contributed to increased detection of the bacteria, said Tom Skinner, public affairs specialist for the Atlanta-based Center of Disease Control.
"Our surveillance systems in the United States are allowing us to better detect these outbreaks when they occur, which is certainly a good thing, so that we can take measures to prevent other cases from occurring," said Skinner.
Contributing to CDC's sharper surveillance has been the use of a sophisticated identification system developed by the organization four years ago called pulsenet, he said.
"We're actually able to take isolates from patients and fingerprint the bacteria," explained Skinner. "[We] compare that to isolates taken from products to see if there's a match."
Skinner added that pulsenet allows CDC to conclude what the infected consumer may have eaten and what actually caused their illness.
Testing played a part in causing the latest round of recalls, said officials. First, Kohler Mix Specialities, a division of Minneapolis-based Michael Foods Inc., announced a voluntary recall of single serve cartons of milk produced for Minneapolis-based Land O'Lakes, after traces of Listeria monocytogenes were discovered.
The recall includes all single serve 10-ounce cartons of Land O'Lakes brand 2%, reduced fat milk containing code dates of February 10 and February 11 printed on the carton's seal.
And in an unrelated action, the Food Safety and Inspection Service division of the U.S. Department of Agriculture, Washington, added 1,121 cases, or 26,975 pounds, of 5.5-ounce chicken burritos to the list of possibly contaminated foods.
The burritos, which were manufactured by Chicago-based Culinary Foods, were voluntarily recalled after a routine sample taken by an FSIS agent tested positive for the Listeria monocytogenes bacteria, according to David Silberberg, executive vice president for the burrito manufacturer.
Silberberg said the burritos were not produced for the retail channel, but for a specific customer in the food-service industry.
"We know which locations it went to and we verbally notified those locations and followed with a letter," said Silberberg.
He said FSIS is continuing its investigation that will include additional testing at Culinary Foods' plant where the chicken burritos were processed. He said that plant in question has continued to operate following the recall notification. It was first time the company ever faced a Listeria outbreak, he added.
"It was a product that was tested in the field," explained Silberberg. "Due to the nature of the Listeria monocytogenes, [the chicken burritos shipment] could have picked it up anywhere along the [distribution] chain. We don't know."
In the case of the milk recall, a consumer initiated the investigation. According to Terry Nagle, a spokesman for Land O'Lakes, the man said he had fallen ill after consuming some of the product. The milk he purchased had an "off-smell and was lumpy." Another consumer had also called with similar complaints, he said.
Nagle said the calls prompted the company to begin performing its own tests on the milk. The procedure revealed -- in addition to the milk being spoiled -- the presence of Listeria micro-organisms. Subsequent testing done by an outside company hired by Land O'Lakes confirmed the findings, he noted.
Following the results, Nagle said the Minnesota Department of Agriculture was called in to perform tests at the Kohler Mix Specialties' plant where the milk was manufactured.
"We definitely found some samples that had Listeria," said Nagle. "How it could have occurred, we don't know."
The products in question, which were manufactured December 23 and 24, have since been pulled off shelves and taken from vending machines, said Nagle.
"We don't believe it's possible to buy it anywhere," he said. "On the other hand, that doesn't mean that a consumer might not have it somewhere in their refrigerator."
The suspect products were inscribed with the plant code PLT 27-416 and were distributed to a number of food-service outlets in Minnesota, Wisconsin, Iowa, North Dakota, South Dakota, Nebraska, Illinois and Indiana.
The single-serve cartons are typically distributed through food-service operations, including restaurants, as well as in convenience stores, service stations and, in some instances, deli areas of grocery stores, said Nagle.
At present, there have been no reported cases of illness related to the Listeria contamination, outside of the initial complaints, he said.
According to Mark Witmer, director of corporate communications and public relations for Michael Foods, Kohler joined the recall effort after Land O'Lakes testing of the product.
"We don't know how much we pulled back, but the production lot was under 1,000 cases," said Witmer. "In the abundance of caution, we initiated the recall in conjunction with Land O'Lakes."
Witmer said its Kohler Mix Specialties plant that produced the affected milk wasn't shut down due to the fact that library samples from the production day in question all tested negative.
"None of library samples show any Listeria, so the suspicion is that something in the downstream distribution is causing the problem," said Witmer.
If a product containing Listeria monocytogenes is consumed, the bacteria can turn into a sometimes virulent strain called listeriosis. Listerosis is a condition that attacks the immune systems of children, the elderly or individuals with weakened systems due to disease or chemotherapy treatments. People with healthy immune systems rarely contract listeriosis.
The milk recall follows a steady stream of withdrawals concerning possibly Listeria-contaminated meat products from companies like as Oscar Mayer Foods and Bil Mar Foods, as well Thorn Apple Valley, Southfield, Mich. Federal investigators from the CDC have calculated the death toll from the outbreak at 12 persons, all of which consumed Bil Mar products.
In that case, the first wrongful death lawsuit has been brought against Sara Lee by a Chicago law firm representing John Bodnar, of Memphis, Tenn.
The suit alleges that Bodnar's wife, Helen, died of Listeria monocytogenes meningitis last October after eating allegedly contaminated Ball Park-brand hot dogs manufactured by Bil Mar, which has laid off more than 240 employees due to the outbreak at the plant, which has been closed since December.