Seroprevalence of Bartonella henselae Immunoglobulin G and Associated Risk Factors Among Adults Undergoing Health Screening in Urban Korea

Bartonella henselae (B. henselae), the causative agent of cat-scratch disease, is a zoonotic pathogen transmitted mainly through pet-related injuries. Although infection is usually mild and self-limiting, severe complications have been reported. Despite increasing pet ownership in Korea, data on human exposure to B. henselae remain limited. This study aimed to estimate the seroprevalence of B. henselae and to identify associated factors among adults undergoing health screening in urban Korea. A total of 509 adults undergoing routine health screening between August 2023 and February 2024 were enrolled. Data on demographics and pet exposure were collected using structured questionnaires. B. henselae immunoglobulin G (IgG) was detected using an indirect immunofluorescence assay, and associations with potential risk factors were analysed. The overall seroprevalence of B. henselae was 15.7% (80/509). Seropositivity was associated with younger age (p = 0.008), owning ≥ 2 pets (p = 0.031), and pet-related scratches (p = 0.002) or bites (p = 0.003). No significant associations were observed with sex, region, housing type, or underlying medical conditions. IgG seropositivity reflects prior exposure and cannot distinguish between past and current infection. This study provides insights into the distribution of B. henselae IgG seropositivity among adults undergoing routine health screening in urban Korea. Pet-related injuries, particularly scratches and bites, were more strongly associated with seropositivity than pet ownership alone and may reflect exposure history rather than causal effects.