Survey for zoonotic rickettsial pathogens in northern flying squirrels, Glaucomys sabrinus, in California.

Epidemic typhus, caused by Rickettsia prowazekii, is maintained in a southern flying squirrel (Glaucomys volans) sylvatic cycle in the southeastern United States. The northern flying squirrel (Glaucomys sabrinus) has not been previously associated with R. prowazekii transmission.