Abstract
Purpose: :
To identify the normal conjunctival flora and causative agents of a series of suppurative corneal ulcers from a rural population in Sierra Leone and compare it to published reports of ocular surface flora in the United States.
Methods: :
Conjunctival swabs obtained from healthy eyes of 213 residents of Masungbo, Sierra Leone were analyzed for microbial growth. Cultures of corneal ulcers were obtained from 12 eyes with suppurative ulcerating keratitis defined as the presence of an epithelial defect, clinical evidence of infection and hypopyon. Culturette swabs were sealed in culture tubes containing modified Stuart's transport media and sent to the NY Eye and Ear Infirmary Microbiology Laboratory. The swabs were subcultured onto 5% sheeps blood agar, chocolate agar, Sabouraud's media and thioglycolate broth. All inoculates were processed and identified using standard microbiological techniques and were speciated using either the VITEK–2 (BioMarieux, St. Louis, Mo) or by manual methods.
Results: :
184/213 (86%) of patients had positive cultures from their conjunctiva. The most commonly isolated organisms from conjunctival swabs were coagulase–negative staphylococcus (35.7%), fungal species (31.6%) and S. aureus (20.7%). The most commonly isolated organisms from cultured corneal ulcers were fungal species (66.7%), P. aeruginosa (41.6%), and S. aureus (8.3%).
Conclusions: :
The high prevalence of fungal colonization of healthy eyes may lead to a higher incidence of fungal keratitis than reported in the United States. The high incidence of fungal keratitis should be considered when beginning empiric therapy for corneal ulceration in rural Sierra Leone.
Keywords: keratitis • cornea: clinical science • bacterial disease