Bartonella henselae Antibodies in Serum and Oral Fluid Specimens from Cats

Abstract

Cats are the primary reservoir host for <i>Bartonella henselae</i><i>(B. henselae</i>), an etiological agent of human bartonellosis, including cat scratch disease. Although <i>Bartonella</i> DNA has been amplified from salivary swabs from cats, dogs and humans, we are not aware of studies investigating <i>Bartonella</i> antibodies in oral fluid (OF). Using inhouse and commercial immunofluorescence antibody assays (IFA), the objective of this study was to detect and compare antibodies against <i>B. henselae</i> in paired OF and serum specimens from cats. Specimens were collected from shelter and client-owned cats. For serum specimens, <i>B. henselae</i> seroreactivity was 78% for both the inhouse and commercial IFA assays and 56.8% for OF specimens. Comparing serum and OF specimens, there was moderate Kappa agreement (Cohen's k = 0.434) for detection of <i>B. henselae</i> antibodies. Oral fluid antibodies were more likely measurable in cats with high <i>B. henselae</i> serum antibody titers when compared with low antibody titers. In conclusion, <i>B. henselae</i> OF IFA antibody measurements were less sensitive compared to serum IFA measurements of ≥1:64. Oral fluid antibodies were detected more often in cats with high <i>B. henselae</i> serum antibody titers. Therefore, OF antibodies, detectable by IFA, is of limited utility for epidemiological or diagnostic testing in cats.