Comparison of Direct Immunofluorescence and Giemsa Staining in Chlamydia trachomatis Follicular Conjunctivitis

Background: Chlamydia trachomatis is the most common sexually transmitted bacterial infection and can cause various types of human eye disease. There are two general methods for diagnosis of chlamydial infection; cell culture and non-culture tests. Objectives: In this study we evaluated the prevalence of C. trachomatis in follicular conjunctivitis and compared the two rapid direct methods [direct immunofluorescence (DIF) and Giemsa staining] used in diagnosis of chlamydial conjunctivitis. Patients and Methods: In this descriptive and comparative study, 285 patients with follicular conjunctivitis were recruited and admitted to the referral laboratory unit of Farabi Eye Hospital of Tehran and 570 conjunctival scrapings from their right and left eyes were collected and subsequently stained via DIF and Giemsa staining. Results: In this study, 109 (50 males and 59 females) patients (38.24%) had positive results with DIF technique and most of these patients aged 21 - 30 and 11 - 20 years respectively. A number of 47 patients (27 males and 20 females) (16.49%) had positive results with Giemsa staining and in compared to DIF, sensitivity and specificity of Giemsa method was 38.53% and 97.16% respectively. Conclusions: Compared with Giemsa staining, DIF is a suitable test with high sensitivity and specificity and the choice test for rapid diagnosis of chlamydial conjunctivitis for routine purposes.