Human cytomegalovirus (HCMV) replication dynamics in HCMV-naive and -experienced immunocompromised hosts

Abstract

Human cytomegalovirus (HCMV) can infect both HCMV-naive and -experienced transplant patients. In this study, the growth rate of HCMV in HCMV-naive hosts (1.82 units/day; 95% confidence interval [CI], 1.44-2.56 units/day) was shown to be significantly faster than the growth rate of virus in HCMV-experienced hosts undergoing recurrent infection (0.61 units/day; 95% CI, 0.55-0.7 units/day; P < .0001). The basic reproductive number (R0) for HCMV-naive liver transplant patients was 15.1 (95% CI, 8.9-44) but was only 2.4 (95% CI, 2.35-2.8) for HCMV-experienced transplant recipients, corresponding to an anti-HCMV immune efficacy of ∼84%, despite immunosuppressive therapy. The R0 values suggest that an anti-HCMV drug or vaccine with an efficacy of >93% (95% CI, 89%-98%) is required to eliminate viral growth during infection of HCMV-naive liver transplant recipients, whereas lower efficacy levels are sufficient to reduce the R0 value to <1 in hosts with prior HCMV immunity. © 2002 by the Infectious Diseases Society of America.