Echinococcus multilocularis is a parasitic tapeworm that primarily infects foxes, dogs, and other canids. It causes a disease known as alveolar echinococcosis in humans, which can lead to severe liver damage. The parasite's eggs are shed in the feces of infected animals and can contaminate soil, water, and food sources. Humans typically become infected by ingesting the eggs, often through contaminated hands or food. Once inside the body, the larvae can form cysts, which grow and can spread to other organs. Early diagnosis and treatment are crucial to manage the infection effectively.