Cytomegaloviruses49

The name cytomegalovirus was chosen on account of the swollen state of virus-infected cells. The virus is widespread.

Primary infections occur in 40-60% of individuals and the virus persists in the host for life (latent infection). Reactivation is common. Infection may be tranplacental (congenital) or by other methods as close contact, sexual intercourse, breast feeding, blood transfusion and organ transplantation.

Clinical features: Most infections are asymptomatic:
1. Congenital infection: It may cause still birth or abortion. In 5% of infected babies, congenital abnormalities occur "cytomegalic inclusion disease". The most common features of the syndrome are growth retardation, microcephaly, hepatosplenomegaly, thrombocytopenia and blindness.

2 Mononucleosis syndrome; similar to that caused by EBV. However, pharyngitis and lymphadenophaty are unusual and heterophil antibodies are not found.

3 Infection in immunocomproised patients; my manifest as pneumonitis, encephalitis, hepatitis, retinitis...etc.

Lab diagnosis

1. Isolation of the virus from throat washings or urine on tissue culture.
2. Detection of viral DNA by PCR or hybridization assay.
3. Detection of viral antigens in urine or saliva.
4. Serodiagnosis: Detection of CMV IgM or rising titre of IgG by EIA or latex agglutination assay.

Treatment
Ganiclovir has been used successfully in treatment of CMV infections in immunosuppressed patients.

Prevention and control

-Screening blood donors and organ donors and exclusion of seropositive ones.
- Vaccines are under trial.