Cytomegalovirus

Cytomegalovirus (CMV) is one of the herpes viruses. It is thought that around 50% of people have been exposed to the CMV virus although it only usually causes disease in the immunocompromised, for example people with HIV or those on immunosuppressants following organ transplantation.

Pathophysiology

• infected cells have a 'Owl's eye' appearance due to intranuclear inclusion bodies

Patterns of disease

Congenital CMV infection

• features include growth retardation, pinpoint petechial 'blueberry muffin' skin lesions, microcephaly, sensorineural deafness, encephalitiis (seizures) and hepatosplenomegaly

CMV mononucleosis

• infectious mononucelosis-like illness
• may develop in immunocompetent individuals

CMV retinitis

• common in HIV patients with a low CD4 count (< 50)
• presents with visual impairment e.g. 'blurred vision'. Fundoscopy shows retinal haemorrhages and necrosis, often called 'pizza' retina
• IV ganciclovir is the treatment of choice

CMV encephalopathy

• seen in patients with HIV who have low CD4 counts

CMV pneumonitis

CMV colitis