Prevalence of methicillin-resistant Staphyloccocus aureus and associated risk factors on admission to a specialist care eye hospital

Background: Staphylococcus aureus is known to be a frequent pathogen in hospital settings, with its well-known and resistant forms to the anti-staphylococcal penicillins. Reports on community carnage outside hospital settings have been feared to be on the increase due to the frequency of reported cases on admission to hospitals. We undertook this study to determine the prevalence of, and to establish predictors for, nasal carnage of methicillin-resistant S. aureus (MRSA) at the time of admission to a specialist care eye hospital. Materials and Methods: A prospective survey was conducted at King Khaled Eye Specialist Hospital (KKESH), Riyadh, during three differing weeks randomly selected from the year 1999. The first 100 patients admitted during those three weeks were selected according to inclusion criteria. The hospital is a 220-bed tertiary ophthalmic care facility, with an average 7,500 admissions per year. Nasal bacterial swabs were taken within 48 hours of admission and tested for all strains of S. aureus and sensitivity to methicillin. Detailed interviews were conducted about medical history and habitual environment. Results: Of 306 nasal cultures tested, none was isolated for MRSA and 102 (33%) were sensitive to methicillin (MSSA). We found 0% nasal carriage rate for MRSA. Respondents had difficulty with questions related to antibiotic administration. No identifiable medical or environmental risk factors could be found. Conclusion: Nasal swabs of patients admitted to KKESH did not reveal MRSA colonization, indicating that MRSA may not be prevalent in the community at present.