Simultaneous Cultivation of Typhus Rickettsiae and Influenza Virus in the Developing Chick Embryo

(1) Developing chick embryos were inoculated with rickettsiae of typhus fever, following which the same eggs were reinoculated with the virus, of influenza. Two strains of rickettsiae were employed, namely, the Breinl strain of epidemic typhus and the Castaneda strain of murine (endemic) typhus. Also, 2 strains of influenza virus were employed, namely, the PR8 strain of influenza A and the Lee strain of influenza B. The groups of developing chick embryos inoculated with typhus and influenza, included the 4 possible combinations of rickettsiae and virus, viz. epidemic typhus-and influenza A, epidemic typhus and influenza B, murine typhus and influenza A, and murine typhus and influenza B.