Frequency of Viral Monitoring to Detect Cytomegalovirus Infection and Prevent Disease in Solid Organ Transplant Recipients: An International, Multicenter Cohort Study

Cytomegalovirus (CMV) disease in solid organ transplant recipients (SOTr) can be prevented by antiviral prophylaxis or preemptive therapy (PET). The optimal CMV monitoring frequency remains unclear and it is debated whether CMV surveillance after prophylaxis (SAP) is needed. CMV IgG donor (D)+/recipient (R)- or R+ SOTr in Zürich, Lausanne, and Copenhagen (2008-2021) were followed for six months after stop of CMV prophylaxis or transplantation if no prophylaxis was given. Associations between monitoring intervals and CMV disease were analyzed by Cox regression. Numbers needed to test (NNT) with monitoring intervals of ≤7 vs >7 days were calculated. Among 3,411 SOTr, CMV monitoring interval of 8-14 or >14 days vs ≤7 days were associated with higher risk of CMV disease (adjusted hazard ratio (95%-CI), 4.74 (2.17-10.36), and 3.98 (1.92-8.26), respectively). The increased risk of CMV disease associated with monitoring intervals >7 days was consistent across subgroups. The first three months of PET/SAP, NNT (95%-CI) was 11 (8-19) for D+/R- vs 71 (35-218) for R+ SOTr, and did not differ between PET and SAP. Our findings support weekly CMV monitoring during first three months at risk, regardless of CMV preventative strategy. Close monitoring is more efficient in D+/R- SOTr, reflected by lower NNTs.