Influenza (flu) is one of the most famous illnesses which pigs share with humans. This illness is harbored in the lungs of pigs during the summer months and tends to affect pigs and humans in the cooler months. Sausage contains bits of pigs' lungs, so those who eat pork sausage tend to suffer more during epidemics of influenza
Pig meat contains excessive quantities of histamine and imidazole compounds, which can lead to itching and inflammation; growth hormone, which promotes inflammation and growth; sulphur-containing mesenchymal mucus, which leads to swelling and deposits of mucus in tendons and cartilage, resulting in arthritis, rheumatism, etc.
Eating pork can also lead to gallstones and obesity, probably due to its high cholesterol and saturated fat content. The pig is the main carrier of the taenia solium worm, which is found it its flesh. These tapeworms are found in human intestines with greater frequency in nations where pigs are eaten. This type of tapeworm can pass through the intestines and affect many other organs, and is incurable once it reaches beyond a certain stage.
One in six people in the US and Canada has trichinosis from eating trichina worms which are found in pork. Many people have no symptoms to warn them of this, and when they do, they resemble symptoms of many other illnesses. These worms are not noticed during meat inspections, nor are they killed by salting or smoking. Few people cook the meat long enough to kill the trichinae. The rat (another scavenger) also harbors this disease. There are dozens of other worms, germs, diseases and bacteria which are commonly found in pigs, many of which are specific to the pig, or found in greater frequency in pigs.