THE CANADIAN ENTOMOLOGIST. 103 



THE TRANSMISSION OF TYPHUS FEVER BY LICE. 



In a recent paper* some interesting experiments are recorded by 

 Drs. T. Goldberger and T. F. Anderson, which indicate that not only the 

 body louse ( Pediadus vestimenti) but the head louse (P. capitis) also 

 may transmit the virus of typhus fever. These authors had previously 

 shown that Brill's disease, which appears to be endemic in New York 

 City, is identical with the typhus fever of Mexico, which, accordingly, may 

 be identical with the European typhus fever. Evidence of the ability of 

 lice to. transmit typhus fever has been previously adduced by several 

 investigators. In 1909, NicoUe, Comte and Conseil demonstrated that 

 body lice (P. vestimefiti), which had been allowed to feed upon an 

 infected bonnet monkey ( M.. siniais), were able to transmit typhus fever 

 to two other monkeys, somewhere between the first and seventh day after 

 feeding. In the following year, Ricketts and Wilder, who were working 

 in Mexico, reported the successful transmission of the virus of typhus 

 fever by P. vestimenti from man to monkey and from monkey to monkey. 

 They were also able'to infect a monkey by intradermal inoculation with 

 the abdominal contents of infected lice, and similar experiments were 

 successfully carried out by Wilder in 1911. Drs. Goldberger and Ander- 

 son commenced their work in 1909, They have confirmed the results of 

 previous workers in regard to the body louse (P. vestimenti) and have 

 also shown that the head louse (P. capitis) is able to transmit Mexican 

 typhus fever from man to monkey by the subcutaneous injection of a 

 saline suspension of crushed and infected head lice and almost certainly 

 by its bite. The typhus virus is able to retain its virulence in the body 

 of the head louse for twenty to twenty-four hours. The authors' conclu- 

 sions are as follows : 



1. The body louse (P. vestimenti) may become infected with typhus. 

 The virus is contained in the body of the infected louse and is trans- 

 missible by subcutaneous injection of the crushed insect or its bite. 



2. The head louse (P. capitis) may become infected with virus. 

 The virus is contained in the body of the infected louse and may be trans- 

 mitted by cutaneous injection of the crushed insect, and, we believe, also 

 by its bite. 



These results are of great interest to the entomologist. One by one 

 our most common insects affecting man have been shown to be important 

 factors in the transmission of disease ; the house fly carries typhoid and 



*"The Transmission of Typhus Fever, with Special Reference to Trans- 

 mission by the Head Louse ( Pediculns capitis)." ^^ Public Health Reports" of the 

 U.S. Public Health and Marine Hospital Service, Washington. W. C. 27, No. 9, 

 ist March, 1912, pp. 297-307. 



