Epidemiological and microbiological profile of infective keratitis in Ahmedabad

Context: Study of patients attending tertiary care ophthalmology institute at Ahmedabad. Aims: To study the microbiological etiology and epidemiological factors associated with suppurative keratitis. Settings and Design: A total of 150 corneal scrapings were evaluated from patients presenting with corneal ulcers at a tertiary ophthalmology center, Ahmedabad from July 2007 to June 2008. Materials and Methods: Scrapings were subjected to Gram stain, potassium hydroxide preparation and culture for bacterial and fungal pathogens. Socio-demographic data and risk factors were recorded. Results: Ninety percent (135/150) people with corneal ulcers had trauma as predisposing factor for keratitis. Trauma due to wooden objects was the leading cause (46/135) followed by vegetable matter and stone injury (23/135). Microbial etiology was established in 59.3% (89/150) of scrapings. Out of 89 positive isolates, 65.1% (58/89) were bacterial while 34.9% (31/89) were fungal. Among the bacterial isolates, 60.3% (35/58) were Gram-positive cocci while 39.7% (23/58) were Gram-negative bacilli. The most common bacterial isolate was Staphylococus aureus (32.7%, 19/58) followed by coagulase-negative Staphylococci (25.8%, 15/58) and Pseudomonas (18.9%, 11/58). Among the 31 fungal pathogens, Aspergillus species was the most common (35.4% 11/31), followed by Fusarium species (22.5%, 7/31). Conclusion: Trauma with wooden material is the most common predisposing factor for suppurative keratitis. Males were more affected than females. Bacterial ulcers were more common than fungal in areas in and around Ahmedabad. Staphylococcus aureus and Aspergillus were the commonest bacterial and fungal isolates respectively. Geographical variation persists in microbial etiology of suppurative keratitis.