Sanitation for medical officers by Vedder Edward Bright 1878-

Author:Vedder, Edward Bright, 1878-
Language: eng
Format: epub
Tags: Military hygiene
Publisher: Philadelphia, Lea & Febiger
Published: 1917-03-25T05:00:00+00:00

(Keeler, Military

are not being carried out efficiently. If fly breeding is controlled, fly screening is effective, and poisons and traps used to kill the few flies that enter the kitchen and mess hall, . there should be little opportunity for fly swatting, a method that is tim^Qonsuming and inefficient.

LICE.

Classification. —Order Hemiptera; suborder Aptera; family Pediculidae.

Genus i. Pediculus. 2 species, P. capitis and P. vesti-menti. Thorax and abdomen- separate.

Genus 2. Phthirius. P. inguinalis. Large thorax not separated from abdomen.

P. Capitis. Head Louse. —Of gray color, abdomen composed of seven segments, Male 1.6 mm. long by 0.7 mm. wide. Female 2.7 mm. long and i mm. wide. They live in the hair of the head, occasionally in the eyebrows and beard. The female attaches the eggs or nits to the hair at the base. The yoimg emerge on the sixteenth day and are adult on the eighteenth day. The yoimg resemble the adult except that they are smaller. Lice have an insatiable appetite, and must be fed at least once in twenty-four hours to keep them alive, and in a state of nature may bite several times a day. The adults are comparatively easily killed, but the eggs are very resistant. Anderson and Goldberger showed that it can transmit typhus, although it is probably not the usual transmitter. Foster described an epidemic of typhus in Mindanao due to capitis. We may assume that the young are not infected hereditarily.

P. Vestimenti. —^The clothing louse, often erroneously called the body louse. It never lives on the body but lives entirely in the clothes even when it bites. To find these lice the clothing must be searched, not the body. It is larger than P. capitis, the male being 3 mm. long by i mm. wide, the female 3 mm. long by i.i mm. wide. The abdomen is composed of eight segments. Head is less rounded than capitis and has longer antennae. Eggs are never laid on body hair, but in clothes, particularly in seams. The insect moves very rapidly and hides in folds and seams and many not be fotmd imless a thorough search is made. Evolution same as capitis. They also bite frequently and are difficult to keep

alive away from the body. A slight elevation of temperature kills them, and it is said that a man from Mexico City, where it is cool, comes down to Vera Cruz lousy but loses them all in a few days because of the increased heat. Body lice are said not to be found in the tropics. They also need a daily feed. Is the common transmitter of t)rphus. Not transmitted to young by heredity. The eggs are very resistant. Dry heat may not penetrate to them, especially when the clothing is placed in bags. Steam or boiling water are best. The fact that so many things have been suggested as disinfectants shows how imsatisfactory they are. The duration of Kfe on the body is not known, but it may be seven or eight weeks. As the

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