The infectious disease hazards of eating raw pork

Pork chops, ham, sausages, all very delicious foods no doubt; however, one thing is very clear, pork products must be cooked thoroughly to kill potential pathogens in the raw meat. This brings me to a story that caught my eye in The Star.com concerning two Toronto restaurants.

Author of the piece, Graham Slaughter writes about “two trendy city restaurants”, Bar Isabel and The Black Hoof, serving raw pork dishes despite the obvious infectious disease risks and Canadian food safety regulations. Chefs from both restaurants made the following statements: “You’re really sucking out the soul by cooking it until it’s grey” and  “When it comes to super-high quality pork, the only way you do it justice is by serving it like this.”

A Trichinella spiralis cyst seen embedded in a muscle tissue specimen, in a case of trichinellosis.
Image/CDC

In fact, The Black Hoof chef, Jesse Grasso said,  “I’ll never stop knowing and believing it’s not going to hurt anyone,” adding that a single person has yet to fall ill.

However, the United States and Canada have regulations concerning the cooking of pork for a good reason–there are a number of human pathogens potentially present in pork that can cause serious illness and in some cases, death.

Let’s look at a list of infectious disease hazards in pork:

Trichinella spiralis

These parasitic roundworms are notorious for their history in human infections due to eating undercooked or raw pork. Although today it’s mostly seen in people who eat undercooked wild game, domestic pigs also can carry the worms. It is rare to see this parasite today because people know about the importance of thorough cooking and modern farming practices, which have reduced the number of infected pigs.

Trichinellosis, or trichinosis, may be asymptomatic or mild or it can be more serious with larval invasion of body tissues, which commonly includes muscle pain, fever, and weakness. Invasion of heart, brain, or lung tissue, and subsequent inflammation, sometimes leads to death.

Taenia solium

The “pork tapeworm” may cause little symptoms if you ingest larva in infected pig. However, ingestion of the T. solium egg can lead to a serious, potentially life threatening condition called cysticercosis, where the larva  can end up in the tissues, the eyes or the brain (neurocysticercosis).

Salmonella

This bacterial gastrointestinal illness causes nausea, vomiting, diarrhea, cramps, and fever, with symptoms generally lasting a couple of days and tapering off within a week.

E. coli

Enterotoxigenic Escherichia coli (ETEC) can not only cause symptoms like diarrhea, including bloody diarrhea, it sometimes causes kidney failure (hemolytic uremic syndrome) and death.

Yersinia enterocolitica

This relatively unknown to the public bacterial pathogen is very common in pork, according to a Consumer Reports study in 2012. Consumer Reports found 69 percent of raw pork chops and ground pork samples were contaminated with Yersinia enterocolitica.

Infection with Y. enterocolitica manifests as nonspecific, self-limiting diarrhea, but may cause a variety of autoimmune complications including reactive arthritis.

Other bacterial pathogens like Listeria monocytogenes and Staphylococcus aureus may potentially be present in pork (not an exhaustive list).

Viruses

A number of viral pathogens can be present in raw pork, including Hepatitis E, which is presently pretty rare in the US and Canada.  Hepatitis caused by HEV is clinically indistinguishable from hepatitis A disease. The disease usually is mild and self-resolves in 2 weeks, with no sequelae. However, chronic hepatitis has been reported in organ transplant recipients and in patients with active HIV infections. Epidemiologic studies have established an association between HEV-infected pregnant women and incidences of fatal fulminant hepatic failure.

Mr Slaughter reports in Canada, pork must be cooked to an internal temperature of 71C (160F) for at least 15 seconds to kill potential human pathogens. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page. Here are the USDA guidelines.

Going back to Mr. Grasso’s statement- “But I’ll never stop knowing and believing it’s not going to hurt anyone.” Do people have the right to eat raw foods like this, or drink raw milk? Sure, you can choose to ingest these foods; however, you should also know the risks so you can make an informed decision and not solely based on the “belief” of a chef.