LOUSE BORNE DISEASES 295 



Mastigophora: Spirochaetacea: Spirochaetidae 



Spiroschaudinma carteri (Mackie) is the cause of ASIATIC RE- 

 LAPSING FEVER. IVIackie (1907) in India was the first to investigate 

 tlie transmission of relapsing fever by lice. He found a striking coinci- 

 dence between the cases of fever among Indian school children and the 

 prevalence of lice (Pedicidus corporis). Mackie found the spirochaete in 

 1-i per cent of the lice from the boys and 2.7 per cent of the lice from 

 the girls. He noted that the spirochaetes multiplied within the gut of 

 the lice and that they could be found in the ovary, testis and Malpighian 

 tubules of the insects, but did not find them in the ova laid by infected 

 insects. Bisset (1914) only found Spirochaetes in the gut and coelomic 

 cavity of the lice. The organism, Spiroschaudinma carteri Mackie, is 

 considered as a biological species not morphologically separable from S. 

 recwrrentis . 



Spiroschmidi/niiia herhera (Sergent and Foley) is the cause of 

 NORTH AFRICAN RELAPSING FEVER. Following up Mackie's 

 work, Sergent and Foley (1908) in Algeria carried out experiments with 

 lice and obtained positive results by the inoculation of a monkey {Cyno- 

 molgus cynocephalus) with a single, crushed, infected louse {Pediculus 

 corporis). Pediculus humanus has also been recorded as an intermediate 

 host. Nicolls, Blaizot and Conseil (1912), also working in North Africa, 

 found that when body lice were fed upon infected blood, the spirochaetes 

 disappeared rapidly from the insects' intestinal tract within 24 hours. 

 On the eighth to tenth day, typical, active spirochaetes reappeared in the 

 lice. Thousands of lice were allowed to bite monkeys and a man with 

 only negative results. Infection was obtained in one of the authors by 

 crushing an infected louse on excoriated skin, the incubation period of the 

 fever being five days. They determined in one experiment that the infec- 

 tivity of the lice was hereditarily transmitted. Eggs laid 12 to 20 days 

 after the parent lice had fed on relapsing fever blood were placed at 28° 

 C. and began to hatch on the seventh day. The young larval lice and 

 some unhatched eggs were now crushed and inoculated into a monkey 

 which subsequently developed relapsing fever. The spirochaetes were 

 not discoverable microscopically in the eggs. As the result of tlie work 

 of Sergent, Foley, Nicolle, Blaizot, Conseil and others, it is proven that 

 the lice are infectiVe, though inconstantly, up to five days after an 

 infective meal, and constantly on the sixth da}^ altjiough during this 

 period spirochaetes are absent ; on the eighth to ninth days the spiro- 

 chaetes may or may not be present and infectivity is exceptional. After 

 the spirochaetes become fully developed in the lice infectivity vanishes. 

 They may be infective up to the fifteenth day. The apyrexial stage of 

 the spirochaete in man and the developmental or granule stage in the 



