Bartonella henselae as a cause of acute-onset febrile illness in cats

Breitschwerdt, Edward B; Broadhurst, Jack J; Cherry, Natalie A

Although involving only three cases, these findings are unique for several reasons. The owner, a veterinary technician, worked for a veterinarian who systematically pursued an infectious disease diagnosis, in association with acute-onset lethargy and febrile illness. Addition ally, there was consistency in preventive healthcare (vaccines and parasiticides), diagnostic testing, and the dose and duration of azithromycin administration. BAPGM enrichment blood culture/PCR followed by DNA sequencing documented B henselae infection in cases 2 and 3 at illness onset and at the time of case 2's fever recrudescence, whereas case 1 initially tested PCR negative. Two possibilities for the negative BAPGM enrichment blood culture/PCR results seem most likely. Following experimental blood transfusion transmission of B henselae to cats, Kordick and Breitschwerdt documented prolonged periods of abacteremia (weeks to months) in some cats. 4 Thus, it is possible that case 1 did not have circulating B henselae organisms at the time of specimen collections in September 2012. Alternatively, case 1 could have been infected by a flea, unknowingly introduced into the household, following case 3's adoption in August 2012. This possibility could explain the negative WB results, the negative PCR results and the subsequent PCR positive results and documentation of seroconversion by WB. Based upon 16S-23S ITS DNA sequence alignments, all three kittens were initially infected with the same B henselae genotype.