Cytomegalovirus Ab

5-10 mL blood. Acute and convalescent (2 weeks) specimens are required.

EIA.

Method dependent.

Mononucleosis syndrome (with negative Epstein-Barr virus serology); acute hepatitis (after exclusion of HAV, HBV, HCV infection); possible congenital CMV infection;

screening of blood transfusion donors, donor and recipient before transplantation; and evaluation of patients with HIV infection.

IgG seroconversion from negative to positive is a reliable indicator of primary infection.

A stable positive result for total or IgG antibodies indicates past infection.

A 4-fold or greater rise in IgG usually represents recent infection, often due to reactivation or reinfection. However, this should be confirmed by viral detection, since 4-fold fluctuations in titre may occur in healthy individuals. 

Detection of IgM antibody can indicate recent infection but is not always a reliable indicator as IgM can persist for long periods.

IgG avidity determination may be used if diagnosis of acute primary infection is critical eg in early pregnancy.

In a neonate, the presence of IgM indicates intrauterine infection.