Overview
Cytomegalovirus (CMV) is a herpes virus that infects the salivary glands, liver, spleen, lungs, eyes, and other organs, resulting in enlarged cells with intranuclear inclusions. Infection is usually only seen in immunocompromised people (e.g. HIV or immunosuppressive drugs).
Pathophysiology
CMV infects cells via endocytosis and replicates inside cell nuclei, resulting in intranuclear inclusion bodies that have an ‘Owl’s eye’ appearance. After infection, it can remain latent and reactivate if a person becomes immunocompromised or ill.
Associations
CMV is associated with:
- Infectious mononucleosis:
- Heterophile antibody (Monospot) test is negative
- Lymphadenopathy and sore throat tend to be milder
- Usually seen in immunocompromised people
- Congenital infection – usually occurs in people experiencing primary CMV infection
- Features in the neonate include small for gestational age, hepatomegaly, petechiae, retinitis, hearing loss, and microcephaly.
- CMV retinitis – in people with HIV and a CD4+ count <100/mm3
- Reactivation with azathioprine and cyclophosphamide. Corticosteroids alone do not usually cause reactivation, but can when combined with these.
- Transplant recipients – due to immunosuppression
- CMV polyradiculopathy – ascending leg weakness and loss of bladder and bowel control
- CMV colitis – fever and diarrhoea
