10 DISEASES DUE TO PROTOZOA 



periods is due to the formation of antibodies such as agghitinins and 

 parasiticidal substances, but some spiroch^etes resist this attempt at 

 cure and cause a relapse when they are in sufficient numbers. Resistant 

 types of spirochastes develop during and after an attack. Spiroch^etes 

 are usually present in the peripheral blood from the onset of the fever 

 until the crisis, then suddenly and totally disappear, possiblv collect- 

 ing in the spleen. They have never been found in the excretions or 

 secretions. Some immunity is caused after an attack, but onlv for 

 that specific spirillum. Gozony concludes that infection is possible 

 through the damaged skin, healthy mucous membrane of the 

 alimentary or genital tract, or possibly by the conjunctiva}. It is 

 proved that the parasite is carried by the bed bug, Cimex lectularius, 

 and lice by direct inoculation. The spiroch^etes multiplv by longi- 

 tudinal and transverse fission. They are hereditarily transmitted from 

 adult to young lice, and are thus maintained in nature. 



The infection can be transmitted from mother to foetus. On this 

 point Nattan-Larrier, Breinl and Kinghorn conclude that — 



Both S. recurrentis and S. duttoni have been proved to transmit 

 infection to the foetus in 80 per cent, of cases, but the number of 

 spirochastes penetrating the placenta is not great ; this fact would 

 explain the long incubation, small blood infection and short persistence 

 of the parasite in the blood in these foetal infections, but their virulence 

 is not attenuated. 



When pregnancy is nearing the end there may be a serious illness 

 with death of the foetus in utero. No lesions of the uterus are necessary 

 to facilitate the passage of the spirochaetes. 



Very little immunitv is given to young born of an infected mother. 



INCUBATION. 



Two to ten days, never after the fourteenth day, sometimes on the 

 same day. 



SYMPTOMATOLOGY. 



Onset. — This is usually sudden with rheumatic-like pains, head- 

 ache and constipation, which sometimes precede the rigors. There is 

 severe frontal headache, pains in the back, limbs and epigastrium; 

 weakness, giddiness, convulsions in the young, flushed face, injected 

 conjunctivae, fever to io3°-io4° F., pulse-rate to 1 10-120, respirations 

 increased, sometimes nausea and vomiting. 



Course. — The skin becomes yellowish, hot and moist. 



There is often a rose-coloured macular eruption on the thorax^ 

 abdomen and legs for one or two days. 



The temperature keeps up until the eighth day, third to fourth day 

 in Serbian cases. 



