Page:Tropical Diseases.djvu/897

XLV] contrary, the cultivating medium be kept at a higher temperature, the larvæ develop into male (0·7 mm.) and female (1·O mm.) rhabditic forms which, in time, produce in their turn filariform larvæ, similar to those obtained directly from the embryo in cold climates, and capable, on being swallowed by man, of developing into mature Strongyloides stercoralis.

This parasite must undoubtedly produce considerable irritation of the bowel, but its pathogenic role has not been definitely ascertained. It is usually present in large numbers, and has been found occasionally coiled up in the intestinal follicles.

Fig. 186.—Strongyloides stercoralis, female. (After Looss.)

The larvæ may pierce into the lacteals, and have been found in the blood. Van Durme has shown that, like the larvæ of Ankylostomum duodenale, the filariform larvæ of strongyloides may penetrate through the skin. Hitherto the use of anthelmintics has not proved effectual in procuring their expulsion. Sonsino recommends the prolonged exhibition of liquor ferri perchloridi in combination with small doses of thymol.

The prophylaxis for strongyloides is the same as that recommended for Ankylostomum duodenale.