Large numbers of eggs are produced by the parasite which are passed out with the feces, which becomes the only infectious material.

In a city provided with water-closets and a system of sewerage there would be no means of extension of infection.

The eggs in the feces in conditions of warmth and moisture develop into small crawling larvae which can penetrate the skin, producing inflammation of this, known in the region as the ground itch.

The larvae enter the circulation and are carried to the lungs, where they perforate the capillaries and reach the inner surface; from this they pass along the windpipe, and then by way of the gullet and stomach reach their habitat, the small intestine.

Unfortunately, the habits and poverty of the people in every way facilitate the extension of the infection.
There is no proper disposal of the feces, few of the houses have even a privy attached to them, and the feces are distributed in the vicinity of the houses.