Chlamydia and the adolescent girl. The enzyme immunoassay as a screening tool
K. Soren and E. Willis
Department of Pediatrics, University of Chicago Pritzker School of Medicine, Wyler Children's Hospital.
To evaluate the enzyme immunoassay for Chlamydia detection in a population
of sexually active urban adolescent girls, 100 endocervical screens using
both immunoassay and tissue cell culture were performed. Prevalence of
Chlamydia trachomatis was 35%, with more than two thirds of infected
adolescents being asymptomatic. When compared with cell culture, the
immunoassay was determined to have a sensitivity of 74%, a specificity of
98%, and positive and negative predictive values of 96% and 88%,
respectively. Adolescents with false-negative immunoassay test results were
more likely to lack evidence of cervical inflammation on examination and
have lower-titer infections than their peers with positive results. When
the immunoassay was matched against culture for test of cure after therapy,
a 10% false-positive rate was found. We conclude that the immunoassay is a
useful screening technique for detection of Chlamydia in high-risk
adolescent populations; however, its limitations with respect to decreased
sensitivity in asymptomatic girls and poor positive predictive value in the
context of tests of cure must be appreciated.
