Rapid Communication: Experimental Infection of Domestic Cats with Bartonella henselae by Inoculation of Ctenocephalides fells (Siphonaptera: Pulicidae) Feces

Caged cat fleas, Ctenocephalides felis (Bouché), were fed on 6 cats; 3 cats were injected with 5 x 10(7) colony forming units of Bartonella henselae intradermally and 3 cats were injected with an equal volume of saline. After the fleas fed for 4 d, 5 groups of 50 B. henselae-exposed fleas were caged and allowed to feed on 5 cats for 6 d. Five cats each were injected intradermally with 1 ml of saline containing 45 mg of feces from B. henselae-exposed fleas. Five cats were fed 50 B. henselae-exposed fleas and 45 mg of fresh feces from B. henselae-exposed fleas. Five cats received all 3 treatments by using fleas and feces collected from cats inoculated with saline (controls). Cats were bled weekly and tested by culture and serology. The cats that were injected with feces from infected fleas were positive by culture for B. henselae at 1 or 2 wk after exposure and were the only cats to become bacteremic or seropositive by week 20.