Comparative Study of Diagnostic Procedures for Congenital Cytomegalovirus Infection

Abstract

In a prospective study the incidence of congenital cytomegalovirus (CMV) infection was 2.2% (31 of 1412) as evidenced by viruria during the 1st wk of life. Among immunoserologic methods used to screen these neonates, the rheumatoid factor test, although non-specific, was the most convenient; its sensitivity for identifying [human] infants with CMV infection was 35-45% with no false-positives. The rates for correct and incorrect identification of neonates at risk was, respectively, 33% and 3.1% when testing for increased levels of Ig[immunoglobulin]M; 5% and 10% when testing for increased levels of IgA; 76% and 21% when testing for IgM anti-CMV (IgM immunofluorescent test) antibody and 0% when testing for IgA anti-CMV antibody. Rapid virologic diagnosis was achieved by assessing urine specimens. Confirmation by EM was possible in less than 1 h in 92% of cases. Detection of early induced CMV-specific nuclear antigens by anti-complement immunofluorescence was diagnostic in 91% of cases within 1 day of inoculation of specimens in tissue culture. Infectivity of CMV in urine was well preserved for at least 7 days at 4.degree. C. To achieve a rapid diagnosis of congenital CMV infection in sick and asymptomatic neonates, urine specimens may, if necessary, by transported at 4.degree. C to distant laboratories.