Experiments on Ascaris Infection in Hong Kong

Abstract

AN important paper by Capt. F. H. Stewart, Indian Medical Service, appeared in the British Medical Journal for July i, giving the life-history of Ascaris lumbricoides, which is extremely common both in man and the pig at Hong Kong, where the author is stationed with the 74th Punjabis. In this preliminary communication he showed that the parasite presents an alternation of hosts. Thus, when ripe eggs reach the alimentary canal of the rat or mouse the larva are liberated, and six days after infection they are found in the blood-vessels of the lungs and liver, and the host is seriously ill with pneumonia. They next pass from the blood-vessels into the air-vesicles of the lung, causing haemorrhage into them. On the tenth day they occur only in the vesicles and in the bronchi. If the disease does not prove fatal, the host recovers on the eleventh or twelfth day, whilst on the sixteenth day it is free from parasites. The affected animals could readily contaminate by the nose or mouth the food of man or the dust and earth of his surroundings.