Trichinella is a genus of parasitic roundworms that can infect humans and various animals, primarily through the consumption of undercooked meat, especially pork. The most common species, Trichinella spiralis, causes a disease known as trichinosis, which can lead to symptoms like nausea, diarrhea, and muscle pain. Infection occurs when larvae are released from cysts in the intestines, where they mature and reproduce. The larvae then migrate to muscle tissues, causing inflammation. Proper cooking of meat to safe temperatures can prevent infection and reduce the risk of trichinosis.