Version July 2025
| Serology | Quantitative PCR¶ | AntigenemiaΔ | Culture | Histopathology◊ | Resistance testing | |
| Immunocompetent | ||||||
| Acute or recent infection | IgM or fourfold increase of IgG | Plasma or whole blood | ||||
| Past infection | IgG | |||||
| Critically ill | Plasma or whole blood; consider BAL§ | |||||
| Immunocompromised | ||||||
| Assessing risk of CMV disease | IgG | |||||
| Diagnosis of disease | ||||||
| Plasma or whole blood | PBMCs | ||||
| Plasma or whole blood; consider BAL§ | PBMCs | BAL§ or lung tissue | BAL§ or lung tissue | ||
| Plasma or whole blood¥ | PBMCs¥ | Tissue | Tissue | ||
| CSF, plasma, whole blood | |||||
| Vitreous or aqueous fluid | |||||
| Decisions regarding preemptive therapy | Plasma or whole blood | PBMCs | ||||
| Monitoring response to therapy | Plasma or whole blood | PBMCs | ||||
| Treatment failure | Plasma or whole blood | PBMCs | Yes | |||
BAL: bronchoalveolar lavage; CMV: cytomegalovirus; CSF: cerebrospinal fluid; IgG: immunoglobulin G; IgM: immunoglobulin M; PBMCs: peripheral blood polymorphonuclear leukocytes; PCR: polymerase chain reaction.
* Refer to the UpToDate topic reviews on diagnosis of CMV for detailed recommendations regarding the use of these assays. This table does not address diagnostic testing for CMV infection in neonates with congenital or perinatal CMV infection. For details on diagnostic testing in newborns, refer to the UpToDate table on laboratory tests for the detection of CMV in neonates with suspected congenital infection and topic reviews on congenital and perinatal CMV infection.
¶ Quantitative PCR assays offer several advantages over the antigenemia assay, including better assay standardization, increased stability of the specimen, smaller specimen volume, and the ability to test patients with leukopenia. For these reasons, quantitative PCR assays are more widely used than the antigenemia test, and we prefer them for the diagnosis and monitoring of immunocompromised patients with CMV infection and disease.
Δ The CMV antigenemia assay is insensitive when the patient has a low neutrophil count (<1000 cells/microL).
◊ This includes histopathology and immunohistochemical staining.
§ Identification of CMV on a BAL specimen may be difficult to interpret, as shedding of virus from respiratory secretions is common, even in the absence of disease. Identification of CMV on lung tissue is the gold standard for the diagnosis of CMV pneumonitis.
¥ Negative results are common with gastrointestinal disease.
