400 



DISEASES OF UNCERTAIN .ETIOLOGY 



(12) TRENCH FEVER. 

 DEFINITION. 



It is a specific infectious disease caused by a resistant filterable 

 virus in the blood plasma, transmitted b\- lice. 



DISTRIBUTION. 



Flanders, Mesopotamia, Salonica, and Italy. 



SEPT 



OCT. 



Trench fever. 



^ETIOLOGY. 



The causative organism is present in the blood plasma, and is 

 transmitted naturally by the louse. 



The blood is always infective in the earlv stages. 



The organism is not filterable. Spirochetes have been blamed. 



The virus has been recovered from the urine and from mixed 

 sputum and saliva, but not from the faeces. 



SYMPTOMATOLOGY. 



The incubation period is fourteen to thirtv davs, or in some cases 

 shorter. 



The onset is sudden, with headache, dizziness, pains in the legs 

 (shin pains), back, and behind the eyeballs, pyrexia i03°-i04° F., 



