Pork tapeworms can infest the human brain. They are the most common cause of adult onset epilepsy in the world. Another type of brain worm can be contracted from eating fish. Approximately 1 in 6 US lambs is infected with toxoplasma brain parasites, with which about 10% of Americans are infected. There also is a rare condition called delusional parasitosis, where the patient believes they are infected with parasites even though they are not (though it can be caused by pork tapeworms in the brain). A higher rate of cancer deaths among those that handle and process meat has been potentially attributed to infection with animal viruses and chronic exposure to animal proteins. Bacteria-eating viruses (bacteriophages) have been approved as meat additives to reduce the risk of Listeria and Campylobacter found in processed meat and poultry products, but there is a concern they could spread toxin genes between bacteria.
Topic summary contributed by Ted.