Relationships Among Complement-Fixing Values, Infectious Endpoints, and Death Curves in Experimental Coxiella Burnetii Infection

Under certain conditions, the time necessary for 50% of the chick embryos infected with Coxiella burnetii to die varies inversely and in a regular manner with the log of the complement-fixing value of the inoculum. The number of infectious doses of C. burnetii in a suspension, as titrated in chick embryos and confirmed in guinea pigs, varies directly with the complement-fixing value of the inoculum. Under certain conditions a predictable relationship exists with C. burnetii between complement-fixing power, number of infectious doses, and the 50% death point in chick embryos.