Canterbury DHB

CMV Prevention

CMV infection can cause serious problems particularly in allografted patients where either the donor or recipient or both are CMV seropositive indicating previous exposure. Our CMV disease control strategy includes preventing primary infection from blood products in previously uninfected patients, identifying and treating incipient CMV disease and in patients at high risk of disease, administering prophylactic treatment.

For a definitive discussion of the management of CMV infection in HSCT see Emery, V., M. Zuckerman, et al. (2013). "Management of cytomegalovirus infection in haemopoietic stem cell transplantation." Br J Haematol 162(1): 25-39.

Definitions

• CMV viraemia: Positive CMV Q-PCR in blood of an asymptomatic patient.
• CMV disease: Symptomatic end organ disease due to CMV.

Potential recipients of haemopoietic stem cell transplants

• All blood products issued by the NZBS are leucodepleted which is effective in preventing CMV transmission. Therefore, selection of CMV negative blood products for patients who are likely to undergo transplantation is not necessary.

CMV Monitoring

• All allogeneic transplant patients in whom either the donor and/or recipient are CMV seropositive who are undergoing allogeneic transplantation are to have CMV monitoring by Q-PCR regardless of CMV treatment.
• Patient/donor CMV seronegative transplants do not require monitoring.
• CMV PCR should be performed weekly from day +10 and stopped at day +100 provided CMV has not been detected and the patient is well without GvHD. Otherwise, ongoing monitoring is guided by the consultant.

Note: Canterbury Health Laboratories reports CMV viral load in International Units/mL (iu/mL). The local conversion for the current Abbott assay is: IU/mL x 0.64 = copies/mL. Therefore a threshold of 1000 copies/mL is equivalent to approximately 1500 iu/mL. See section on CMV Infection - Treatment for a discussion of triggers for starting treatment.

Allografts (Standard or RIC)

Primary prophylaxis with ganciclovir is not generally recommended, as toxicity outweighs efficacy.

• Pre-emptive treatment for CMV infection is individualised and usually occurs after discussion with ID colleagues. Situations in which pre-emptive treatment is commonly started include (but are not limited to) when the CMV viral load is rising (detectable CMV titre followed by higher titre one week later). See section on treatment of CMV below.
• Give ganciclovir 5 mg/kg BD IV (or valganciclovir 900 mg BD PO). This can be discontinued once the PCR becomes negative, provided the patient is asymptomatic. Treatment can be repeated as required. Doses should be adjusted based on renal function.
• Patients symptomatic with possible CMV disease should be treated for CMV irrespective of viral load. Negative CMV PCR does not exclude CMV disease.
• See the ganciclovir and valganciclovir Data Sheets on Medsafe.

Allografts (Standard or RIC) at LOW Risk for CMV viraemia

When both the patient and donor are CMV seronegative, all patients receiving allografts are at Low Risk.

• No prophylaxis or monitoring is currently recommended.
• CMV infections should be considered if the patient becomes unwell.

Other intensively treated patients

• No monitoring or prophylaxis is recommended.
• CMV infections should be considered in any intensively treated patient with a febrile illness.

Topic Code: 9322