Nasal Carriage Rate of Healthcare-Associated Methicillin Resistant Staphylococcus Aureus Among Laboratory Staff at a Tertiary Hospital in Calabar, Nigeria

Methicillin-resistant Staphylococcus aureus (MRSA) poses significant challenges in healthcare settings, particularly among healthcare-exposed populations. Professional scientists and laboratory personnel represent understudied high-risk groups requiring comprehensive surveillance. To determine the nasal carriage rate of MRSA among professional scientists and interns at University of Calabar Teaching Hospital (UCTH), Nigeria. A cross-sectional study was conducted involving 100 randomly selected subjects across five laboratories at UCTH. Nasal swabs were collected and processed bacteriologically for S. aureus identification. Cefoxitin disk diffusion testing was performed to determine methicillin resistance patterns. Of 100 samples examined, 97 (97%) exclusively harbored S. aureus while 3 (3%) showed no bacterial growth. Distribution among worker categories revealed laboratory workers and cleaners had 100% colonization each, followed by fourth-year medical laboratory science students with 39 (97%) colonization, and intern medical laboratory scientists with 18 (90%) colonization. The difference in colonization rates among groups was statistically significant (X² = 26.4536; p = 0.00002). Across laboratories, Microbiology/Parasitology, Chemical Pathology, and Haematology each had 20 (100%) bacterial growth, while Histopathology had 18 (90%). Among 97 S. aureus isolates, 20 (20.6%) were cefoxitin-resistant (MRSA) and 77 (79.4%) were sensitive. High S. aureus nasal carriage (97%) with notable MRSA prevalence (20.6%) among healthcare laboratory personnel necessitates enhanced infection control measures and targeted surveillance programs.