Prevalence and factors associated with Staphylococcus aureus nasal colonisation in orthopaedic patients at a tertiary care hospital in Kenya

Staphylococcus aureus is an important organism in orthopaedic practice as it is the most common cause of orthopaedic infections including surgical site infections (SSIs), osteomyelitis and septic arthritis. Carriers of S. aureus are predisposed to developing invasive staphylococcal infections. Knowledge of a patient’s carrier status before surgery together with interventions to eliminate the carrier state have been shown to reduce post-operative infections by S. aureus. A cross-sectional study carried out at Kenyatta National Hospital orthopaedic wards from 1 June 2019 to 30 September 2019. To determine the prevalence and factors associated with nasal colonisation by S. aureus among patients who have been admitted to undergo surgery. Consecutive sampling was done until the required sample size was achieved. Nasal swabs were taken from patients at admission for culture. Data concerning comorbid conditions as well as healthcare associated risk factors was collected. The overall prevalence of colonisation by S. aureus at admission was found to be 24.7% whereas the overall prevalence of colonisation by Methicillin Resistant S. aureus (MRSA) was found to be 3.03%. The prevalence of colonisation by S. aureus is high amongst patients being admitted to orthopaedic wards at Kenyatta National Hospital when compared with previous studies and amongst these are those who are colonised by MRSA. The prevalence of MRSA calls for the need of screening programmes to curtail spread within hospital and community settings.