The Dynamics of Hookworm Disease in Northern Fur Seals

blood and enter the bronchi of the lungs. There they are coughed up through the trachea into the throat and swallowed. This is referred to as the pulmonary route of infection and historically had been considered the only route of hookworm infection. In the small and large intestine the worms attach to the wall of the intestine and suck blood, mature, and lay eggs, which pass out with the feces and are deposited in soil. The eggs hatch and release infective larvae that repeat the infection process. It has been known for many years that in fur seals and sea lions only pups died of hookworm infections, but it was not understood why. This became the source of an interesting case study in which a young researcher made an exciting discovery.