TYPHUS FEVER, TRENCH FEVER, ETC. 949 



excrement of lice that have bitten trench fever patients may be 

 infectious when it comes in contact with lesions on the skin. 



Byam 40 showed that as late as 300 to 400 days after the onset 

 of the disease, trench fever patients can still infect lice. This is of 

 great importance in appraising the epidemiological possibilities of 

 carriers. Lice could also be infected by patients during the periods 

 of remission. 



Both the British and the American commission showed that the 

 virus is probably not transmitted through the eggs of the louse. 

 The British commission reported that the headlouse can transmit 

 the disease through its excreta in the same way as the body louse. 

 Other insects, however, did not seem to carry the disease. 



As to the causative agent, little is definitely known. Toepfer, 41 

 da Rocha-Lima 42 and other German observers who have studied 

 Rickettsia bodies in typhus fever were encouraged to undertake 

 similar studies in connection with trench fever because of the 

 similarity of the means of conveyance of the two diseases. These 

 observers, as well as Jungmann 43 succeeded in finding Rickettsia 

 bodies in the intestines of lice fed on trench fever patients. Da 

 Rocha4jima comparing lice that had bitten individuals who did not 

 have trench fever with those fed on trench fever patients found 

 that 72 per cent of the insects found on the trench fever patients 

 showed Rickettsia bodies, but 20 per cent of those fed on normal 

 people showed similar ones. Arkwright, Bacot and Duncan 44 found 

 similar Rickettsia bodies in a large number of lice that had fed 

 several times on sixty-four trench fever patients. They found the 

 bodies in only one out of many lots of insects fed on normal people. 

 Their experiments seem to indicate that when Rickettsia bodies 

 appear in the excrement of lice after feeding, these excrements were 

 infectious. 



It is quite clear that no positive conclusions can be drawn, 

 especially in view of the frequent finding of Rickcttsia-like bodies 

 in lice that have had no connection with this disease. The clue 

 furnished by the finding of Rickettsia, however, must be followed, 



40 Byam, et al., Trench Fev?r, Brit. War Office Commit. Eep., Oxford Press, 

 1919; Bycm, Proc. Roy. Soc. Med., 13, 1919, 19. 



41 Toepfer, Munch, mod. Woch., 03, 1916, 1495. 



42 da It ocha- Lima, Munch, mod. Woc-h., 04, 1917. 

 "Jungmann, Dent, med. Woch., 64, 1917, 359. 



"Arkwright, Bacot and Duncan, Proc. Koy. Soc. Med., 13, 1919, 23. 



