Donor-derived bartonellosis in solid organ transplant recipients from unhoused donors in Alberta.

Bartonella quintana infection is rarely described to be transmitted through solid organ transplant (SOT). We report a cluster of using donor-derived B quintana infection and the attack rate from Bartonella seropositive donors. In this retrospective study of SOT recipients that received an organ from an unhoused deceased donor (UDD) in Alberta in 2022-2023, serology testing for Bartonella was performed indirect immunofluorescent assay on UDDs and recipients of UDDs with positive serology. Titers ≥1:64 were considered positive. During the study period, 31/32 UDDs were tested for immunoglobulin G to Bartonella (20 negative, 11 positive for B quintana and/or B henselae). Thirty-two organs were transplanted from the 11 seropositive donors. Six SOT recipients developed bartonellosis secondary to B quintana (4 SOT recipients received organs from 3 seropositive donors, and 2 SOT recipients from 1 UDD with no stored sample for testing). The attack rate for clinical disease from positive donors was 12.5% (4/32). The main presentation was skin nodules/papules (median 5.5 months) with bacillary angiomatosis in 4/6. Bartonella serology was positive in 5/6 SOT recipients (initially negative in 2) and blood B quintana quantitative polymerase chain reaction in 1. None had visceral involvement. All donors had history of substance use. This outbreak of bartonellosis reinforces the potential for unexpected donor-transmitted infections. Clinicians should be aware of high transmission of B quintana through transplant from infected UDDs.