Comparison of two enzyme immunoassays to culture for the diagnosis of chlamydial conjunctivitis and respiratory infections in infants

Perinatally acquired Chlamydia trachomatis associated morbidity in young infants

OBJECTIVE

This study was designed to evaluate the spectrum of morbidity associated with perinatally acquired Chlamydia trachomatis in infants < or =12 weeks of age, and to determine its relationship to maternal Chlamydia trachomatis status.

METHODS

DESIGN

Retrospective review of maternal and infant records.

SETTING

Large inner city teaching hospital.

PATIENTS

A cohort of 530 symptomatic infants < or =12 weeks of age who were tested for Chlamydia trachomatis infection in the upper respiratory tract during a 2-year period from January 1993 to December 1994.

RESULTS

During the study period, 70/530 (13.2%) patients tested positive for Chlamydia trachomatis from the conjunctiva and/or the nasopharynx. Complete medical records of 66 of these infants were available for review. Forty-eight of 66 (73%) infants had conjunctivitis, 13/66 (20%) had pneumonia, 5/66 (7%) had both conjunctivitis and pneumonia. Thirteen of 66 (20%) infants were hospitalized, 7 for pneumonia and 6 for ophthalmia, accounting for 68 hospital days. In 55/66 (83%), maternal records were available for review. Nineteen of 55 (35%) mothers had documented Chlamydia trachomatis infection at delivery or during pregnancy that had not been treated; 16/55 (29%) mothers tested negative for Chlamydia trachomatis sometime during pregnancy but were not retested at delivery, 8/55 (14%) were treated for Chlamydia trachomatis during pregnancy but status at delivery regarding reinfection was not evaluated. In 12/55 (22%) mothers, no prenatal testing was documented.

CONCLUSIONS

This study demonstrates significant morbidity in early infancy associated with perinatally acquired Chlamydia trachomatis infection. There is need for studies evaluating the importance of adequate maternal testing and treatment to reduce perinatal transmission.

Use of polymerase chain reaction for the detection of Chlamydia trachomatis in ocular and nasopharyngeal specimens from infants with conjunctivitis

BACKGROUND

Chlamydia trachomatis is the most common identifiable infectious cause of neonatal conjunctivitis. Nonculture tests including enzyme immunoassays and direct fluorescent antibody tests have been shown to perform well for the diagnosis of chlamydial conjunctivitis with sensitivities and specificities > or = 90%. However, the performance with respiratory specimens has been less than satisfactory.

METHODS

We compared a new, commercially available polymerase chain reaction (PCR) assay, Roche AMPLICOR (Roche Diagnostic Systems, Branchburg, NJ) with culture for the detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis. We also evaluated AMPLICOR for the detection of C. trachomatis in the urine of mothers of positive infants.

RESULTS

Ocular and nasopharyngeal specimens from 75 infants with conjunctivitis were obtained for culture and PCR. AMPLICOR was equivalent to culture for eye specimens and more sensitive than culture for nasopharyngeal specimens. The sensitivity, specificity and positive and negative predictive values of PCR compared with culture for conjunctival specimens were 92.3, 100, 100 and 98.4%, respectively. The sensitivity, specificity and positive and negative predictive values for nasopharyngeal specimens were 100, 97.2, 60 and 100%, respectively. We also detected C. trachomatis by PCR in the urine of 12 mothers of culture positive infants.

CONCLUSIONS

PCR performed comparably to culture for detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis.

Evaluation of a new optical immunoassay for diagnosis of neonatal chlamydial conjunctivitis

The BioStar OIA Chlamydia test (BioStar, Inc., Boulder, Colo.) is a novel immunoassay system that uses changes in reflection of light to directly detect chlamydial antigen in clinical specimens. We compared the optical immunoassay (OIA) with culture for detecting Chlamydia trachomatis in ocular specimens from infants with suspected chlamydial conjunctivitis. We initially performed a retrospective evaluation, testing 152 ocular specimens previously collected for culture with the OIA. The sensitivity and specificity were 94.2 and 97%, respectively. A subsequent prospective study evaluating 37 ocular specimens from infants with suspected C. trachomatis conjunctivitis revealed a sensitivity and specificity of 100 and 92.6%, respectively.

Comparison of a chemiluminometric immunoassay with culture for diagnosis of chlamydial infections in infants

The performance of Magic Lite (CIBA-Corning), a chemiluminescent immunoassay (CIA), was compared with that of culture for the diagnosis of neonatal chlamydial conjunctivitis and respiratory infection. We performed a retrospective evaluation of 51 ocular and 96 nasopharyngeal specimens previously collected for culture testing with the CIA. The sensitivities for the ocular and the nasopharyngeal specimens were 91 and 91.7%, respectively. The specificities for both sites were 100%. A subsequent prospective study evaluating 71 ocular and 38 nasopharyngeal specimens revealed sensitivities of 83.3 and 20%, respectively. The specificities for both sites were 100%. The CIA performed favorably, compared with culture, for the diagnosis of chlamydial conjunctivitis; however, the CIA appeared less sensitive for the diagnosis of respiratory infection, including pneumonia.