Campylobacter outbreak traced to raw milk in Washington

campylobacterThe Bellingham Herald reported today on a Campylobacter jejuni outbreak that has been traced to the consumption of raw milk purchased from a Whatcom County, Washington, dairy. 

In December, the Whatcom County Health Department issued a warning to consumers that Campylobacter had been isolated from a sample of milk produced at the Pleasant Valley Dairy in Ferndale.  The Seattle Post-Intelligencer reported:

The bacteria were found in a routine testing sample taken Dec. 11, the department said.

Local health departments are reviewing Campylobacter illness reports that may be related to the milk, the news release said. Symptoms of the illness usually occur two to five days after ingestion and generally last for seven to 10 days.

The milk was sold in half-gallon plastic containers at the Pleasant Valley farm store and at Barganica, Community Food Co-op and Terra Organica in Bellingham; Skagit Valley Co-op in Mount Vernon; Arlington Health, Petosa's, Manna Mills, Tru Health and Bob's Corn Patch in Snohomish County; and Spuds in Seattle, the news release said.

Now, health officials are saying that at least five people became ill with Campylobacteriosis, the illness caused by the ingestion of Campylobacter bacteria, after drinking raw milk produced by the Pleasant Valley Dairy.  According to the story in the Herald:

Four Whatcom County residents and one Skagit County resident tested positive for the same campylobacter jejuni strain that was found in a routine sample of raw milk from Pleasant Valley Dairy. The dairy pulled that batch of milk from the shelves and has resumed its distribution of raw milk.

The dairy has changed its testing procedures to reduce the risk of releasing contaminated milk, the health department said.

Outbreaks traced to the consumption of raw milk are not all that uncommon.  The International Food Safety Network has posted a list of outbreaks on its website.

Raw milk truths

Jonathan Golab, or "Science", is a writer for The Stranger, a weekly Seattle newspaper.  He recently answered a reader's question about whether raw milk is healthy.  His answer, in part, was this:

Milk typically comes out of the cow (or goat or human) without any dangerous bacteria. But think of where most milking occurs—all sorts of unsanitary things may be occurring. Milk is a particularly dangerous food precisely because it is so nutritious; a miniscule amount of contaminating bacteria can multiply in the welcoming environment, greatly increasing the chance of someone becoming ill from ingesting it. Pasteurization works by killing any of the bacteria that find their way into the milk, before they can divide and make you sick later. This little step of heating dairy before storage and transport has been one of the most effective public-health inventions of all time.

There are no health benefits in drinking raw milk—the nutrients easily survive the heating.

Science's article is always relevant, especially when considering the public health impacts of the consumption of unpasteurized, or raw, dairy products such as milk.  In recent months, at least 87Kansans became ill with Campylobacter infections after consuming raw milk or cheese. 

Common foodborne pathogens

An article on HOI.com titled, "E. coli and Friends," gives a good description of several foodborne pathogens featured at www.foodborneillness.com.  Reporter Jen Christensen profiles E. coli, Salmonella, Campylobacter, and Listeria, and describes how health officials determine which pathogen is responsible for illness:

Tracking Down the Culprits

When stomach symptoms occur, people tend to attribute the cause to a “bug” rather than food. Clues suggesting a possible foodborne pathogen include severe symptoms and having more than one person is affected – especially if the symptoms occur in several families. A physician may contact the local health department to determine if other cases have been reported. In addition, stool samples may be sent to a lab for testing.

It can take quite a bit of detective work to track down a source of foodborne illness. Not everyone who eats a contaminated food product gets sick (typically the very young, very old, patients with chronic medical conditions and those with weak immune systems are most susceptible). The severity of symptoms may also vary.

Health officials gather data on patient characteristics, how long they have been sick and places they may have visited days before the onset of illness. Hopefully, common traits will begin to emerge, such as “everyone ate at the same restaurant” or “ate the same food.” Suspect food items may be tested for the presence of bacteria or toxins. As more clues emerge, experts may be able to narrow down or pinpoint the source of the problem. In some cases (as with the peanut butter/salmonella link recently), an investigation may lead to an extensive recall of a particular food item.

The E. coli Reference Center at Penn State University is the nation’s largest repository for E. coli strains, holding more than 70,000 strains collected over the last 40 years. The bacteria are frozen to enable researchers to study and track changes or genetic mutations that may make the illness more difficult to treat. Older samples are stored at room temperature in “slants,” or test tubes containing a solid growth medium to preserve the culture. The lab can also test a current sample for the bacteria and look for genes associated with those causing the most serious illness.

Dairy's milk tests negative for Campylobacter: Health officials say that doesn't mean other batches of milk weren't positive for bacteria.

The Utah county Health Department announced that all milk samples from the Payson dairy farm at the center of a controversy over whether its raw milk products were contaminated with Campylobacter tested negative for the bacterium. From a story in the Deseret Morning News:

"It's very possible that an earlier batch had been contaminated and all the traces worked their way out of the system," said Lance Madigan, Utah County Health Department spokesman.

A spokesman for the Utah Department of Agriculture and Food confirmed that the contamination could have happened at the dairy at an earlier date.

"We were testing to check the current batch of milk," said UDAF spokesman Larry Lewis. "This doesn't speak to the milk that may have contributed to the illness of these people, which would have been produced weeks before."

Utah County Health Department officials issued a health advisory Wednesday after receiving multiple reports of campylobacteriosis, a disease caused by ingesting bacteria commonly found in unpasteurized milk products and improperly prepared chicken.

Raw milk has led to numerous foodborne illness outbreaks, and is illegal in many states.