Prevalence of Causative Organisms in Corneal Ulcers Seen at Sekuru Kaguvi Eye Unit, Harare, Zimbabwe

Abstract

Objective: To investigate the prevalence of organisms causing corneal ulcers, determine frequency of ocular risk factors and assess the value of Gram stain in initial identification of pathogens. Design: A descriptive cross sectional study. Setting: Sekuru Kaguvi Eye Unit at Parirenyatwa Group of Hospitals in Harare, Zimbabwe. Materials and Methods: We enrolled 43 patients with corneal ulcers for the study, Demographic data was obtained, measurement of visual acuity was done by Snellen’s chart and a Topcon Slit Lamp was used to determine the characteristics of ulcers for all the patients. Corneal scrapings were obtained and examined by microscopy and culture methods to determine etiologic organisms. Positivity rates between Gram stain and culture methods were compared. Main Outcome Measures: Prevalence of different bacterial isolates in corneal ulcers, risk factors to infection and laboratory methods used for detection. Results:. Gram-positive cocci were the most prevalent organisms found (54%) followed by E. coli (18%). Pseudomonas, Klebsiella and Narcodia constituted about 9% each. Trauma, use of traditional eye medicine and previous viral disease were the common risk factors. Conclusion: Bacteria were the only organisms identified and Gram-positive cocci were the most common isolates. Gram stain of corneal smears was not reliable in initial recognition of offending pathogens.