Cytomegalovirus infection

Cytomegalovirus (CMV) infection often presents asymptomatically or as an infectious mononucleosis-like syndrome (fever, lymphadenopathy, and atypical lymphocytosis) in people with normal immune systems.

In immunocompromised people (patients with AIDS and transplant recipients), the disease manifests with fever, bone marrow suppression, and tissue-invasive conditions such as pneumonitis, hepatitis, colitis, nephritis, and retinitis.

In fetuses, CMV infection can lead to cytomegalic inclusion disease, characterised by severe neurological abnormalities, intellectual disability, and hearing defects.

Tests for diagnosis include: serology, pp65 antigenaemia test, histopathology, and nucleic acid amplification and detection systems, most commonly quantitative polymerase chain reaction-based assays.

In immunocompetent people, infection is usually self-limiting; therefore, treatment is generally not indicated.

For patients with compromised immune function, oral valganciclovir or intravenous ganciclovir are the preferred treatments. Maribavir is recommended for refractory disease, while intravenous foscarnet and cidofovir are less preferred agents due to associated toxicities.

CMV is a ubiquitous beta-herpes virus that infects the majority of humans. Primary infection in individuals with normal immune function is typically asymptomatic. Following primary infection, CMV establishes lifelong latency in various host cells, with periodic sub-clinical reactivations controlled by a functioning immune system. When reactivation (or primary infection) occurs in patients with severely compromised immune function (such as transplant recipients or patients with AIDS and a CD4 count <50 cells/microlitre), uncontrolled CMV replication often ensues, which leads to the clinical manifestations characterised by fever, bone marrow suppression, and tissue-invasive disease.​​[1]Razonable RR, Humar A. Cytomegalovirus in solid organ transplant recipients - guidelines of the American Society of Transplantation Infectious Diseases Community of Practice. Clin Transplant. 2019 Sep;33(9):e13512. http://www.ncbi.nlm.nih.gov/pubmed/30817026?tool=bestpractice.com [2]HIV.gov, US National Institutes of Health. Guidelines for the prevention and treatment of opportunistic infections in adults and adolescents with HIV. Jul 2021 [internet publication]. https://clinicalinfo.hiv.gov/en/guidelines/adult-and-adolescent-opportunistic-infection/cytomegalovirus-disease?view=full ​​​​