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A hospital based study on the prevalence of conjunctivitis due to Chlamydia trachomatis
J Malathi1, H N Madhavan, K L Therese
1Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Insights
Polymerase chain reaction (PCR) detected Chlamydia trachomatis in conjunctivitis cases in Chennai. Cryptic plasmid PCR showed higher sensitivity than other methods for diagnosing this infection.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Limited studies in India have utilized polymerase chain reaction (PCR) to determine Chlamydia trachomatis prevalence in conjunctivitis.
- This study aimed to assess C. trachomatis prevalence in Chennai and compare findings with previous research.
Purpose of the Study:
- To determine the prevalence of Chlamydia trachomatis causing conjunctivitis in patients attending ophthalmic hospitals in Chennai.
- To compare the diagnostic sensitivity of different laboratory methods for C. trachomatis detection.
Main Methods:
- Conjunctival swabs from 255 patients were tested using fluorescent antibody test (FAT), culture, and PCR for cryptic plasmid and major outer membrane protein (MOMP) gene.
- An infant with ophthalmia neonatorum was also included in the study.
Main Results:
- Cryptic plasmid PCR identified C. trachomatis in 4.9% of specimens (4.7% of patients).
- FAT and culture showed lower sensitivity (18.8%) compared to PCR methods.
- The infant with ophthalmia neonatorum tested positive for C. trachomatis using all methods.
Conclusions:
- A significant decline in adult chlamydial conjunctivitis prevalence was observed over a decade in Chennai.
- PCR, particularly using cryptic plasmid primers, is the most sensitive method for detecting C. trachomatis in conjunctivitis patients.
Background & Objectives:
Very few studies have been done in India to determine the prevalence of Chlamydia trachomatis causing conjunctivitis using polymerase chain reaction (PCR) methods. Hence the prevalence of primary conjunctivitis due to C. trachomatis among individuals attending ophthalmic hospitals in Chennai was determined and compared with our earlier results.
Methods:
A total of 328 conjunctival swabs from 255 (both eyes 73 and one eye 182) patients were investigated by fluorescent antibody test (FAT) on direct smears, culture and PCRs for cryptic plasmid and major outer membrane protein (MOMPI) gene of C. trachomatis. An infant with ophthalmia neonatorum was also included.
Results:
Among these 328 specimens processed, 16 (4.9%) from 12 (4.7%) patients were positive by cryptic plasmid PCR. Among these, 3 from 2 patients were positive by FAT (direct smear), culture and PCR for MOMP 1 gene. Both eyes of the infant with ophthalmia neonatorum were positive by all the methods. The sensitivity of FAT and culture (18.8%) was lower compared to PCR.
Interpretation & Conclusion:
A significant decrease in the prevalence of adult chlamydial conjunctivitis has occurred in the 10-year period among patients reporting to the ophthalmic hospitals in Chennai. PCR using cryptic plasmid primers was found to be the most sensitive method to detect C. trachomatis in patients with conjunctivitis.