Seroepidemiology of Bartonella vinsonii subsp berkhoffii exposure among healthy dogs.
OBJECTIVE: To determine seroprevalence of antibodies to Bartonella vinsonii subsp berkhoffii and risk factors for seropositivity among working dogs owned by the US government. DESIGN: Cross-sectional study. ANIMALS: 1,872 dogs. PROCEDURE: An ELISA was used to detect antibodies to B vinsonii subsp berkhoffii. RESULTS: Antibodies to B vinsonii subsp berkhoffii were detected in 162 dogs (8.7%; 95% confidence interval, 7.4 to 10.0%). Dogs living in the southeast, plains states, southwest, and south-central were significantly more likely to be seropositive than were dogs living in other regions of the United States. German Shepherd-type dogs were significantly less likely to be seropositive than were dogs of other breeds, and dogs entering training programs or that had been rejected from a training program were significantly more likely to be seropositive than were dogs used for narcotics detection and dogs trained to patrol or detect explosives. Dogs used by the border patrol or Federal Aviation Administration were more likely to be seropositive than were dogs used by the Department of Defense or customs service. Odds that dogs would be seropositive were significantly higher for dogs stationed in the southern United States, the northeastern United States, or a foreign country, compared with dogs stationed in all other regions of the United States. CONCLUSIONS AND CLINICAL RELEVANCE: Overall, 8.7% of this diverse group of healthy dogs was found to be seropositive for antibodies to B vinsonii subsp berkhoffii, and seropositivity rates were associated with location, suggesting either that there are multiple vectors for the organism or that the major vector for the organism depends on geographic and environmental factors.