Transmission of Cytomegalovirus ( <scp>CMV</scp> ) from CMV‐Seropositive Organ Donors to CMV‐Seronegative Pediatric Solid Organ Transplant ( <scp>SOT</scp> ) Recipients

BACKGROUND: The risk factors for donor-acquired (DA) CMV transmission in CMV-seronegative pediatric solid organ transplant (SOT) recipients (R-) receiving organs from CMV-seropositive donors (D+) remain unknown in the era of routine antiviral prophylaxis. METHODS: DA-CMV transmission was defined as CMV antigenemia/DNAemia and/or seroconversion in a D+/R- recipient by 13 months post-transplant. DA-CMV transmission, along with donor and recipient demographics, was studied in a retrospective cohort of CMV D+/R- children who had a SOT at the Stollery Children's Hospital from 2000 to 2018. All patients were expected to receive at least 3 months of CMV-active antiviral prophylaxis. RESULTS: 105 CMV D+/R- pediatric SOT recipients (48 liver, 35 heart, 4 lung, 18 kidney) were analyzed; DA-CMV transmission occurred in 58 patients (55%). Frequency of DA-CMV transmission was highest in lung (75%), followed by liver (69%), then kidney (61%), and was lowest in heart recipients (31%). Median time to DA-CMV transmission was 4.8 months (3.4-6.7). In a multivariable cox regression model including organ, donor and recipient age and sex, risk of DA-CMV transmission was significantly lower in heart versus liver recipients (HR 0.30, 95% CI 0.14, 0.65, p = 0.003). CONCLUSION: Understanding factors that result in non-transmission of CMV to seronegative recipients despite receiving a seropositive organ may guide more targeted use of antiviral prophylaxis in pediatric SOT recipients.