The use of direct immunofluorescence and nested polymerase chain reaction in diagnosing perinatal infections of Chlamydia trachomatis

Abstract

Background: Chlamydia infection is the most frequently reported infectious, sexually transmitted disease (STD). Generally, Chlamydia trachomatis (C. trachomatis) infection of neonates is the result of perinatal exposure to the mother's infected cervix.

Objectives: The aim of the study was to estimate the frequency of infection caused by C. trachomatis in newborn infants. In this study of C. trachomatis perinatal infection, 107 infants born at the Wroclaw Medical University Clinic of Gynecology and Obstetrics (Poland) were tested to investigate whether C. trachomatis was present in swabs taken from the eyes and throats of children.

Material and methods: Each specimen was tested using the direct immunofluorescence test (DIF) and the nested polymerase chain reaction (PCR) method.

Results: The presence of C. trachomatis, irrespective of the origin of the swabs (ocular or from the throat), was confirmed in 62 newborns, amounting to 57.6% of the tested population. The occurrence of C. trachomatis in ocular swabs was confirmed in 35 children (32.7%). In the material taken from the throat, there were 48 newborns considered chlamydia-positive (44.9%). In the specimens taken from both the ocular and pharyngeal locations, there was a higher proportion of positive results while using the nested-PCR method in comparison to the DIF test. The specificity of the DIF method with reference to the nested-PCR was 67.9% for ocular swabs. In the material taken from the throat, the sensitivity of the DIF method with reference to the nested-PCR was 75.0% and the specificity was 62.1%.

Conclusions: Because of the importance of perinatal infections, it is recommended to perform a study among a larger group of patients in order to gain more reliable results.

Keywords: Chlamydia trachomatis; infection; newborn.