Practice bulletin no. 151: Cytomegalovirus, parvovirus B19, varicella zoster, and toxoplasmosis in pregnancy.

OBSTETRICS & GYNECOLOGY Background Cytomegalovirus Cytomegalovirus is a ubiquitous double-stranded DNA herpesvirus that is transmitted by sexual contact or direct contact with infected blood, urine, or saliva. After an incubation period of 28–60 days (mean, 40 days), CMV infection induces immunoglobulin M (IgM) antibody production followed by an immunoglobulin G (IgG) antibody response. Viremia can be detected for 2–3 weeks after primary infection (infection in a previously seronegative individual). Although adults with primary CMV infection are usually asymptomatic, individuals may experience a mononucleosis-like syndrome, with fever, chills, myalgias, malaise, leukocytosis, lymphocytosis, abnormal liver function, and lymphadenopathy (3). After the primary infection, CMV remains latent in host cells and recurrent, or secondary, infection can occur. Secondary infection (intermittent viral excretion in the presence of host immunity) can occur after reactivation of the latent endogenous CMV strain or by reinfection with a different exogenous viral strain (4). Prevalence of CMV immunity, in primary or secondary infection, varies significantly by geographic region, socioeconomic status, and ethnicity (5–7). The incidence of primary CMV infection among previously seronegative pregnant women in the United States ranges from 0.7% to 4%, with estimates of secondary infection ranging up to 13.5% (7–11). Vertical transmission of CMV may occur as a result of transplacental infection after primary Cytomegalovirus, Parvovirus B19, Varicella Zoster, and Toxoplasmosis in Pregnancy