Consider resistance if CMV DNA titres not decreasing despite appropriate treatment
Resistance genotyping available
Prevention of disease in transplant patients
Risk of reactivation is determined by the specific transplantation and the donor/recipient serostatus
Asymptomatic viremia precedes CMV disease by about a week
Solid-organ transplant
Donor+/Recipientâ high risk, with the the donor organ infecting the recipient
Donorâ/Recipient+ intermediate risk
Donor+/Recipient+ intermediate risk
Donorâ/Recipientâ lowest risk
High and intermediate risk patients get prophylaxis with valganciclovir 900 mg po bid for about 6 months
Hematologic stem cell transplant
Donor±/Recipient+ high risk
Donor+/Recipientâ intermediate risk
Donorâ/Recipientâ lowest risk
Preemptive monitoring with weekly CMV DNA PCR starting week 2 or 3
Treat if greater than threshold (1454 at McMaster) or if rising titre with symptoms
Expect 1-log drop within 2 weeks (lab-dependent)
Continue treatment until PCR is negative
Complications
Even when dormant, can cause mild immunosuppression that predisposes to fungal infections
Asymptomatic shedding in lungs during intercurrent illness
Viremia with influenza-like illness
End-orgam damage
CMV colitis
Retinitis in AIDS patient (CD4 < 50-100)
Organ inflammation of solid-organ transplants
Pneumonitis in stem cell transplants
References
^Michael J. Cannon, D. Scott Schmid, Terri B. Hyde. Review of cytomegalovirus seroprevalence and demographic characteristics associated with infection. Reviews in Medical Virology. 2010;20(4):202-213. doi:10.1002/rmv.655.
^Jutta K. Preiksaitis, R. P. Bryce Larke, Glory J. Froese. Comparative seroepidemiology of cytomegalovirus infection in the Canadian Arctic and an Urban center. Journal of Medical Virology. 1988;24(3):299-307. doi:10.1002/jmv.1890240307.