Methicillin-Resistant Staphylococcus aureus Nasal Carriage among Surgical Patients, Patient Relatives and Healthcare Workers in a Teaching Hospital in Uyo, Southsouth Nigeria

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major bacteria pathogens implicated in hospital and community-associated infections.

Aim: This study aimed to determine the prevalence and multidrug-resistant (MDR) pattern of Methicillin-resistant S. aureus carriage among surgical patients, patient relatives and healthcare workers (HCW) in a tertiary health facility in Uyo-Nigeria.

Study Design: This was a cross-sectional hospital-based study.

Place and Duration of Study: University of Uyo Teaching Hospital, Uyo-Nigeria, between April and October 2016.

Methodology: Swab samples were collected from the anterior nares of 200 participants and cultured using standard bacteriological methods for the isolation of S. aureus. MRSA strains were identified phenotypically using both Oxacillin and Cefoxitin discs diffusion methods while possession of the mecA gene was detected by PCR method.

Results: Overall, S. aureus and MRSA carriage rates among the participants were 102 (51.0%) and 22 (11.0%), respectively. Population-specific carriage rates of S. aureus and MRSA among surgical patients (n=65) were 41 (63.1%) and 15 (23.1%); patient relatives (n=65), 22 (33.8%) and 4 (6.2%), while HCW (n=70) were 39 (55.7%) and 3 (4.7%), respectively. The rate of HCW MRSA carriage increased as year of service increased but increment was not statistically significant. All the 22 MRSA isolates were MDR and highly resistant to commonly used antibiotics such as Ciprofloxacin (86.4%), Trimethoprim/Sulphamethoxazole (81.8%), Tetracycline (77.3%), Erythromycin (72.7%) and Gentamycin (68.1%). Eighteen (82%) of the MRSA strains possessed the mecA gene. Vancomycin-resistant strains (VRSA) were 2 (9.1%). MRSA strains sharing similar drug-resistant combination were observed among surgical patients, patient relatives and HCW either within or in related wards.

Conclusion: The high nasal carriage of MRSA and high frequency of MDR strains among surgical patients in this study emphasize the need for regular surveillance and strengthening of basic infection control measures in hospitals. The use of Vancomycin as drug of choice in MRSA therapy is still desirable.