Fungal keratitis in patients with corneal ulcer attending Minilik II Memorial Hospital, Addis Ababa, Ethiopia

Abstract

Background: Fungal keratitis is an important cause of corneal blindness all over the world. Although there are several reports on fungal keratitis from developing and developed countries, fungal keratitis in Ethiopia is poorly known. The aim of this study was to determine the prevalence of fungal keratitis and spectrum of fungi implicated in causing the infection.

Methods: The present study was a single institutional cross-sectional study carried out in Minilik II Memorial Hospital eye clinic, Addis Ababa, Ethiopia from September 2014 to August 2015. Corneal scraping was obtained under aseptic condition with sterile 21 gauge needle by an ophthalmologist from patients suspected of microbial keratitis. Each scraping was inoculated onto Sabouraud Dextrose Agar in C-shaped streaks and incubated at 25 °C aerobically for four weeks. Cultures of mycelia fungi were identified by examining macroscopic and microscopic characteristics of their colonies. Yeasts were identified by employing biochemical and assimilation test procedures and using CHROMagar Candida culture. All data were coded, double entered and analyzed using SPSS version 20.

Result: Out of 153 cases of microbial keratitis, fungi were recovered from 69 patients giving fungal keratitis prevalence of 45.1. Patients from rural areas were significantly affected than patients in urban regions (P = 0.005). Age groups of 25-34 (P = 0.017) and 15-24 years (P = 0.008) were significantly affected. Fungal keratitis was significantly associated with farmers (P = 0.0001), daily laborers (P = 0.0001), unemployed (P = 0001) and students (P = 0.004). Fungal keratitis was statistically associated with trauma (P = 0.006), and diabetes (P = 0.024). Seventy six fungal isolates were recovered, of which molds accounted 63 (82.9 %) of the total isolates. Fusarium and Aspergillus species were the two predominant molds accounting 27.6 and 25 % of the total isolates respectively. Yeast isolates accounted only 17.1 %.

Conclusion: High prevalence of fungal keratitis recorded in the present study, highlights the need for nationwide study on fungal keratitis and precise identification of the causative fungi and institution of appropriate treatment strategy.

Keywords: Filamentous fungi; Fungal keratitis; Risk factors; Yeasts.