CLIA CMV

Human cytomegalovirus (CMV, Human Herpesvirus 5, HHV 5) is a member of the Herpetoviridae family. In humans, it is mainly transmitted by the respiratory apparatus or urogenital tract. The disease is usually asymptomatic or mild, the latent infection can be reactivated in pregnancy, serious disease, stress, or immunosuppressive treatment. An individuum can be reinfected by a different CMV strain. CMV infection during pregnancy causes developmental defects. The virus is easily transmitted through the placenta during primary infection (in 30-50 % of cases); during the reactivation stage, transplacental transmission occurs in only 1% of cases. CMV infection belongs to the TORCH syndrome.

Serological methods are used for the detection of specific IgA, IgM, and IgG (avidity) antibodies to CMV in laboratory diagnosis of the infection.

Antibodies of IgA class are a sign of an active infection – primary infection as well as reactivation. Production of IgM antibodies usually increases a few weeks after infection or reactivation and then decreases slowly. IgM determination alone cannot discriminate primary infection from reactivation. Specific IgG seroconversion indicates primary infection. The method of IgG avidity detection is used for discrimination between primary infection and reactivation. It is important for the risk assessment of congenital transmission.