The Direct Development of Hookworms after Oral Infection

A group of Japanese workers have revived a much controverted question by their persistence in the view that lung migration of larval hookworms is essential to their later development. This opinion is founded upon recent experimental studies with the dog hookworm, Ancylostoma caninum, in both normal and abnormal hosts. Miyagawa and his assistants noted (9, 10) that larvae isolated from the trachea of previously infected puppies gave a higher percentage development (90 per cent average in 4 pups) upon oral administration than was obtained with normal infective larvae (75 per cent in 3 pups). The rate of development was increased to an average of 93 per cent in 3 puppies infected with larval hookworms obtained from the intestine of a previously infected dog after having completed their migration within the normal host.