. Preventive medicine and hygiene. ia. The disease does not affect man. It isconfined to cattle, and is of very great economic importance. Texasfever is an infection which should be understood by all sanitarians, on TICKS 289 account of its scientific and historic importance. The cause of this in-fection and its mode of transmission were ascertained in 1893 by Smithand Kilborne. The discovery that the tick is the intermediate host ofTexas fever opened an entirely new principle in the sanitary sciences Texas fever is caused by a protozoon parasite. This parasite wasfirst named Pyrosoma higeminu
. Preventive medicine and hygiene. ia. The disease does not affect man. It isconfined to cattle, and is of very great economic importance. Texasfever is an infection which should be understood by all sanitarians, on TICKS 289 account of its scientific and historic importance. The cause of this in-fection and its mode of transmission were ascertained in 1893 by Smithand Kilborne. The discovery that the tick is the intermediate host ofTexas fever opened an entirely new principle in the sanitary sciences Texas fever is caused by a protozoon parasite. This parasite wasfirst named Pyrosoma higeminum on account of the twin-like, pear-shaped forms commonly seen in the red corpuscles. This genus waschanged by Patton in 1895 to Piroplasma. These terms having beenpreoccupied, the present name of the parasite is Babesia higemina.^ The contagium is carried by the cattle tick, Boophilus hovis, nowMargaropus annuJatus. The tick lives upon the skin and feeds upon theinfected blood, becomes sexually mature at the last molt; the female. Fig. 46.—The Texas Fever Tick {Margaropus annulatus). drops to the ground and lays about 2,000 eggs; the newly hatched larvaeattach themselves to the skin of a fresh host, which they infect. Thisexplains the long extrinsic period of incubation in this disease, 40-60days; 30 days of which are required for the development of the larvae andthe remainder for the development of the parasite within the host, ROCKY MOUNTAIN SPOTTED FEVER This disease, also called tick fever and spotted fever, is an interest-ing infection which occurs chiefly in the Bitter Eoot Valley of Montana,centering around Missoula. Cases also occur in the neighboring statesof Idaho and Wyoming, also Washington and California. The symptomsclosely resemble those of typhus fever, including a petechial and Goldberger have shown that typhus fever of Mexico, calledtabardillo, is not transmissible to guinea-pigs, while Eicketts and alsoKing independently demonstrated that
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Keywords: ., bookauthorwh, bookcentury1900, bookdecade1910, booksubjecthygiene
