EJMS

Abstract

This study aimed to detect Acanthamoeba infection in different specimens obtained from patients with keratitis and its correlation with various host and risk factors. The study was carried out on 110 patients who were clinically suspected to have Acanthamoeba keratitis. The patients were divided into 2 groups according to contact lens use as 63 contact lens wearers (CLW) and 47 non contact lens wearers (NCLW). Obtained samples, including 110 corneal scrapings, 32 contact lenses, 32 contact lens storage cases and solutions, were subjected to cultivation on non-nutrient agar overlaid with Escherichia coli, direct smear and staining methods using trichrome and Giemsa stains. The results showed that Acanthamoeba infection was detected in 21 (19.1%) of clinically suspected cases; 17 (81%) of them were CLW and the remaining 4 (19%) positive cases were NCLW. These results revealed a significant association between Acanthamoeba infection and wearing of contact lenses (P <0.05). By examining 32 contact lenses, 32 contact lens storage cases and 32 contact lens solutions, there were 4(12.5%), 3 (9.4%) , 3 (9.4%) positive samples respectively. The difference between sources of sampling and detection of Acanthamoeba was statistically highly significant (P =0.001). In addition, the results revealed that the correlation between host factors (age, sex and residence) and Acanthamoeba infection among keratitic patients was statistically insignificant. The highest Acanthamoeba infection occurred in female keratitic patients aging 20- 30 years (47.6%) as most of them were CLW. Regarding risk factors, there was a significant correlation between Acanthamoeba infection and ocular trauma, history of contact lens use, history of swimming in swimming pools or canals (P = 0.02). In conclusion, Acanthamoeba keratitis is firmly associated with the use of improperly sterilized contact lenses, trauma or washing eyes with contaminated water. Further studies will be needed to realize the actual association between them.