Each year, approximately one in six Americans will get sick from the food they eat, according to the Centers for Disease Control and Prevention. While the chances of contracting a life-threatening illness are slim, you can get sick from eating undercooked ham. To reduce your risk, cook fresh hams and other hams that require preparation until they reach a minimum internal temperature of 145 degrees Fahrenheit. Then, let the ham rest for three minutes before serving and eating it.


Caused by the Trichinella spiralis parasite, trichinosis — also known as trichinellosis — can be the result of eating undercooked ham. To reduce the risk of trichinosis, the USDA has implemented several guidelines that help ensure that no trichinosis-infected products reach supermarket shelves. However, if you raise pork or buy from a local supplier, your pork might be infected with this parasite, which can easily be killed by cooking your ham to the 145 degrees Fahrenheit.

S. Aureus

A bacterial infection linked to undercooked ham and other food products, Staphylococcus aureus comes from improper food-handling procedures. Cooking the ham to a safe internal temperature will kill the bacteria. If the bacteria are not destroyed — or if they are reintroduced to the ham through improper food handling — the bacteria can release a harmful toxin that will not be destroyed by heating the ham again.

Pork Tapeworm

Thanks to federal regulations regarding the proper feeding of domestic food animals, pork tapeworm infections are rare in the United States. However, depending on where you purchased your ham, infection from Taenia solium is a possibility if your ham isn’t fully cooked.

Other Possibilities

Undercooked ham can harbor a number of other types of organisms that can make you ill. These organisms include Yersinia entercolitica, Clostridium botulinum, Salmonella, Listeria monocytogenes and Escherichia coli. These organisms can cause severe intestinal problems, but they are easily taken care of by cooking your ham properly.

When to See the Doctor

While developing a foodborne illness from undercooked ham is a possibility, the severity of the infection can depend on several factors, including how many of the harmful microorganisms were in your ham and how much of the ham you ate. Most of the time, symptoms of foodborne illness will begin between four and 48 hours after you’ve eaten the infected ham. Consult your healthcare provider if you experience nausea, vomiting, fever or abdominal discomfort. If you experience bloody diarrhea, excessive vomiting or diarrhea, or a combination of fever, headache and stiff neck, or if your symptoms last longer than three days, see your doctor immediately. When you speak with your doctor, mention that you ate ham, possibly undercooked, to help her diagnose your problem.