Cytomegalovirus infection classification

Overview

Cytomegalovirus infection can be classified based on the organ system involved into the following:

It is the most common clinical manifestation of cytomegalovirus infection.
Retinitis is initially unilateral but progress to affect the contralateral side in the absence of therapy and immunosuppression.
In patients with CD4 < 50cells/mm³ bilateral retinal involvement is high.
Peripheral retinitis can be asymptomatic or present with floaters, scotomata, or peripheral visual field defects whereas central retinal lesions or lesions impinging on the macula or optic nerve are result in decreased visual acuity and central field defects.
On fundus examination the following findings can be demonstrated:
- Fluffy yellow-white retinal lesions, with or without intraretinal hemorrhage.
- Inflammation of the vitreous can be demonstrated in patients with severe immunosuppression.
- Blood vessels appear sheathed.
- If left untreated, retinitis is a rapidly progressive condition and on fundus examination it demonstrates a characteristic brushfire pattern, with a granular, white leading edge advancing before an atrophic gliotic scar.

Colitis is seen in 5 to 10% of patients with AIDS and cytomegalovirus end organ disease.
Colitis presents with weight loss, anorexia, abdominal pain, debilitating diarrhea, fever and malaise. Patients with perforation of the bowel present with acute abdominal pain.
CT abdomen in patients with cytomegalovirus colitis demonstrates colonic thickening.
Complications of cytomegalovirus colitis include bowel perforation and hemorrhagic enteritis.
Colonoscopy demonstrates mucosal lesions and the diagnosis is confirmed by the presence of characteristic intranuclear and intracytoplasmic inclusions on microscopic examination of the colonic biopsy.

Cytomegalovirus esophagitis can be seen in few patients with AIDS and cytomegalovirus end organ disease.
Patients present with symptoms of odynophagia, nausea, mid-epigastric or retrosternal discomfort and fever.
Endoscopy will reveal ulcers in the distal esophagus and diagnosis is confirmed by the demonstration of characteristic intranuclear inclusion bodies in the endothelial cells of the biopsy specimen.
Culture of cytomegalovirus from the esophageal biopsy is not sufficient to confirm the diagnosis in the absence of microscopic findings as majority of patients with low CD4 counts have positive culture.

Cytomegalovirus pneumonitis is a uncommon condition and is usually asymptomatic.
It is usually diagnosed on bronchoalveolar lavage and co-exists with an underlying pulmonary infection.
Chest X-Ray demonstrates diffuse pulmonary interstitial infiltrates and diagnosis confirmation requires a correlation of the clinical features to imaging findings.

Cytomegalovirus infection of the neurological system includes dementia, ventriculoencephalitis and polymyeloradiculopathies. Diagnosis of neurological disease requires correlation between the clinical symptoms and a positive PCR for cytomegalovirus of the cerebrospinal fluid.

CMV Encephalitis
- Patients with cytomegalovirus encephalitis presents with fever, lethargy and confusion.
- Cerebrospinal fluid demonstrates lymphocytic pleocytosis, low-to-normal glucose levels, and normal-to-elevated protein levels.
CMV Ventriculoencephalitis
- Patients have an acute onset of symptoms with focal neurological deficits, cranial nerve palsies, nystagmus and rapid progression to death.
- Presence of periventricular enhancement on CT or MRI is highly suggestive of CMV infection.
CMV polyradiculomyelopathy
- Patients present with similar features of Guillian Barre Syndrome.
- Patients with bladder incontinence and paraplegia with gradual worsening of symptoms over weeks.
- Cerebrospinal fluid analysis demonstrates neutrophilic pleocytosis, low glucose levels and elevated protein levels.