The Animal Parasites of Man

by Harold Benjamin Fantham; Max Braun; J. W. W. Stephens; Fred. V. Theobald

The following forms may be transmitted from DOMESTIC ANIMALS to MAN:—

(1) S. scabiei var. equi. Male, 0·2 to 0·23 mm. long, 0·16 to 0·17 mm. broad. Female, 0·40 to 0·42 mm. long, 0·28 to 0·32 mm. broad. The horse is the normal host.

(2) S. scabiei var. ovis. Male, 0·22 mm. long, 0·16 mm. broad. Females, 0·32 to 0·44 mm. long, 0·24 to 0·36 mm. broad. This mite lives on sheep, and passes over to goats and human beings; it may also be artificially transferred to horses, oxen and dogs.[353]

(3) S. scabiei var. capræ. Male, 0·24 mm. long, 0·188 mm. broad. Female, 0·345 mm. long, 0·342 mm. broad. On goats, passing from them to horse, ox, sheep, pig and man. On the latter, in contradistinction to the varieties (1) and (2), it produces a severe affection.

(4) S. scabiei var. cameli. Frequently observed in man, chiefly in Africa. A few cases have been observed in Europe; the affection induced by it is severe.

(5) S. scabiei var. aucheniæ. Male, 0·245 mm. long, 0·182 mm. broad. Female, 0·34 mm. long, 0·264 mm. broad. It lives on the llama, and may be transmitted to man.

(6) S. scabiei var. suis. Male, 0·25 to 0·35 mm. long, 0·19 to 0·3 mm. broad. Female, 0·4 to 0·5 mm. long, 0·3 to 0·39 mm. broad. In the domestic pig and wild boar; occasionally also in man. The settlement, however, is usually of short duration.

(7) S. scabiei var. canis. Male, 0·19 to 0·23 mm. long, 0·14 to 0·17 mm. broad. Female, 0·29 to 0·38 mm. long, 0·23 to 0·28 mm. broad. In the house-dog, and also, not unusually, in human beings.

(8) and (9) S. scabiei var. vulpis and S. scabiei var. leonis of the fox and lion have likewise been observed on man.

These are all distinct species and should read as follows: S. canis, Gerl.; S. ovis, Mégn.; S. equi, Gerl.; S. dromedarii, Gerv. (cameli, Mégn.); S. aucheniæ, Raill.; S. suis, Gerl.; S. vulpis, Fürst.; S. leonis, Can.