“PREVALENCE OF SECONDARY BACTERIAL INFECTIONS AND ADENOVIRUS CO-DETECTION IN RECENT SPORADIC OUTBREAKS OF CONJUNCTIVITIS IN LUCKNOW, INDIA: A MICROBIOLOGICAL AND MOLECULAR STUDY”

Abstract

Background: Acute infectious conjunctivitis remains a significant public health burden, particularly in tropical regions like India. While viral agents, especially adenoviruses, are frequently implicated in large-scale outbreaks, the role of primary and secondary bacterial infections in sporadic cases is often underestimated, leading to potential mismanagement. This study aimed to determine the prevalence of bacterial pathogens and their co-infection with adenovirus in patients presenting with conjunctivitis during a recent sporadic outbreak in and around Lucknow, Uttar Pradesh.

Methods: A cross-sectional study was conducted on 50 patients clinically diagnosed with infectious conjunctivitis. Conjunctival swabs were collected aseptically from each patient. Samples were processed for bacterial culture using standard microbiological techniques on three media: Sheep Blood Agar, Chocolate Agar, and MacConkey Agar. Isolates were identified based on colony morphology, Gram staining, and biochemical tests. Furthermore, 10 samples were selectively sent for Polymerase Chain Reaction (PCR) testing for adenovirus detection.

Results: Out of 50 samples processed, 30 (60%) showed no bacterial growth. Among the culture-positive samples (20, 40%), Staphylococcus epidermidis was the most prevalent organism, isolated from 12 patients (24% of total, 60% of positive cultures), followed by Streptococcus pneumoniae, isolated from 8 patients (16% of total, 40% of positive cultures). No other bacterial pathogens were isolated. From the 10 samples subjected to PCR, 2 (20%) tested positive for adenovirus. Both adenovirus-positive samples were from the culture-negative group.

Conclusion: This study highlights a high prevalence (40%) of bacterial involvement in sporadic conjunctivitis cases in Lucknow, predominantly caused by commensal bacteria like S. epidermidis and classic pathogens like S. pneumoniae. The absence of adenovirus in culture-positive samples suggests distinct etiologies. These findings underscore the critical importance of microbiological diagnosis to guide appropriate, targeted antibiotic therapy, thereby avoiding the empirical use of broad-spectrum antibiotics and mitigating the risk of antimicrobial resistance.