Please check viral load before requesting CMV genotyping and drug resistance analysis. A minimum CMV viral load of 3.0 log copy/mL is required for successful analysis.
Diagnostic Use
CMV resistance to antiviral drugs occurs most frequently in patients on prolonged antiviral therapy and is particularly associated with prolonged oral ganciclovir therapy. Thus HIV patients with CMV retinitis are at risk, also transplant patients receiving ganciclovir prophylaxis for CMV disease or prolong treatment due to CMV related problems.
Immunocompromised patients.
Patients with defects in cell-mediated immunity are more susceptible to CMV infection (solid organ transplant, haematopoietic stem cell transplant, HIV infected, recipients of chemotherapy, congenital immune deficiencies). CMV disease in immunocompromised patients may be due to primary infection, reactivation or re-infection. Symptoms vary in severity and site affected. Frequent manifestations include retinitis, colitis and pneumonitis, in addition to non-specific symptoms such as malaise, fever, myalgia, leukopenia, thrombocytopenia and mild hepatitis.
Congenital / Perinatal infection
Congenital CMV infection can occur as a result of maternal primary infection or reactivation. Congenital infections can have severe manifestations: intra-uterine growth retardation, jaundice, petechiae, myocarditis, pneumonitis, chorioretinitis, neurological symptoms and sequelae. Peri-partum infection can occur via exposure to the birth canal or breast milk. Urine and saliva are the most sensitive specimen types for the diagnosis of congenital / post-partum CMV in new-borns.
Immunocompetent
CMV infection in immunocompetent individuals is usually asymptomatic. Symptomatic infection in immunocompetent hosts manifests as a mononucleosis-like syndrome (prolonged fever, myalgia, atypical lymphocytosis, mild hepatitis), although can cause severe disease (colitis, meningoencephalitis, haemolytic anaemia, thrombocytopenia, arterial or venous thrombosis, ocular complications, hepatitis, pneumonitis.
Source: LabPlus Test Guide
Microbiology - Virology
VREP
Dedicated EDTA tubes required, minimum 4mL whole blood
Please refer to separating guide in Additional Information section below
Testing referred to LabPlus Auckland
Add-on requests for resistance testing can be performed to a sample for CMV viral load if VL is sufficient. Testing cannot be added to samples previously tested for CBC testing. Please contact Virology ext 80356 to discuss.
CMV resistance
CMV genotyping
10 days