Comparison of Direct Immunofluorescence (DIF) Method and Giemsa Staining with PCR Method for Detection of Chlamydia trachomatis in Patients with Follicular Conjunctivitis

Background: Chlamydia trachomatis is the most common cause of chronic follicular conjunctivitis. As a rapid diagnosis is important in the reducing the long-term squeal of the diseases, the objective of this study was to compare the three methods, direct immunofluorescence (DIF), staining and PCR, for detection of Chlamydia trachomatis in patients with follicular conjunctivitis. Material and methods: Overall 90 patients with conjunctival were enrolled in this study smears were prepared for DIF and Giemsa staining. PCR amplification after Extraction performed using CT1 and CT5 primers designed from Omp1 gene. Results: Of the 90 patients, 28 (31.1%) were positive by DIF and 13 (14.4%) by Giemsa staining; and 35 patients (38.8%) showed positive results in PCR. Sensitivity, specificity, predictive positive value, and negative predictive value of DIF in comparison to PCR respectively were calculated as 88.33, 100, 100 and 88.70. Sensitivity, specificity, predictive positive value and negative predictive value of DIF in comparison to PCR respectively were calculated as 61.40, 100, 100 and 71.42. Therefore, sensitivity and negative predictive value of DIF are significantly higher than Giemsa staining. Conclusion: DIF is more sensitive and more reliable than Giemsa staining for detection of Chlamydia trachomatis in the conjunctiva samples of patients with follicular conjunctivitis.