Geographic variations in microbial keratitis: an analysis of the peer-reviewed literature

Abstract

The epidemiology of microbial keratitis has been investigated in several studies by analysis of organisms cultured from corneal scrapes. However, a comparison of the frequency of different organisms causing keratitis in different parts of the world is lacking. The authors present a review incorporating an analysis of data from studies worldwide. The data provide a comparison of the frequency of culture-positive organisms found in different parts of the world. Associations between a country's gross national income and types of causative organism are explored. The highest proportion of bacterial corneal ulcers was reported in studies from North America, Australia, The Netherlands and Singapore. The highest proportion of staphylococcal ulcers was found in a study from Paraguay, while the highest proportion of pseudomonas ulcers was reported in a study from Bangkok. The highest proportions of fungal infections were found in studies from India and Nepal. The Spearman correlation coefficient demonstrated statistically significant correlations between gross national income and percentages of bacterial (0.85 (95% CI 0.68 to 0.91, p<0.0001)), fungal (-0.81 (95% CI -0.90 to -0.66, p<0.0001)) and streptococcal (-0.43 (95% CI -0.66 to -0.12, p=0.009)) isolates.

Corneal ulcer: a retrospective study of a cases seen at the Hospital das Clínicas, Federal University of Espirito Santo

“…Around the world, infectious keratitis is a major cause of morbidity and low visual acuity due to corneal opacity, ocular perforation, and endophthalmitis [1][2][3]5,6 . The severity of the disease depends on the aggressiveness of the agent, as well as adherence…”

Role of Biofilms in Fungal Keratitis- An Overview

“…It is seen mixed poly-microbial biofilms are common and can be considered even more complex communities of microbes that cooperatively interact in an altruistic manner [4]. The type of organisms causing keratitis depends on geographical conditions such as differences in climate, environment and occupational risk [5]. Bacterial keratitis, especially contact lens-associated infection, is caused by both Gram negative pathogens, such as P. aeruginosa and Serratia spp., and Gram positive organisms, such as S. aureus [6] and other staphylococcal species [5,7].…”

“…The type of organisms causing keratitis depends on geographical conditions such as differences in climate, environment and occupational risk [5]. Bacterial keratitis, especially contact lens-associated infection, is caused by both Gram negative pathogens, such as P. aeruginosa and Serratia spp., and Gram positive organisms, such as S. aureus [6] and other staphylococcal species [5,7]. The recognition of fungal biofilms brought attention to nosocomial infections and now it is believed that several fungal genera are capable of organizing into a biofilm [8].…”

Recognition of Corynebacterium pseudodiphtheriticum by Toll-like receptors and up-regulation of antimicrobial peptides in human corneal epithelial cells

“…Among microbial keratitis, bacterial infection is a major cause of corneal ulcers in India 1,2 and other developing countries. 3 Gram-positive bacteria are the most common cause of bacterial keratitis among Indian populations and are primarily associated with trauma related to agricultural work. 1,2 Although traditionally S. aureus is the most commonly isolated Gram-positive organisms, increasing cases of Corynebacterium infections are also being reported.…”