Staphylococcus aureus: prevalence among normal healthy individuals

ABSTRACT

To determine the prevalence of Staphylococcus aureus among normal healthy individuals in relation to age, gender and site of isolation. This cross sectional study was carried out among normal healthy individuals in the age group 15-65 years, at Gulf Medical University and Gulf Medical College Hospital and Research Center, Ajman. The study included a detailed proforma of all the volunteers. The nasal and throat swabs were collected with strict aseptic precautions and were subjected to direct microscopic examination and culture on appropriate media. Staphylococcal isolates were subjected for Tube Coagulase test and growth on Mannitol Salt Agar [MSA] and were grouped as Staphylococcus aureus and Coagulase Negative Staphylococci [CoNS]. Of the 127 human volunteers screened, 67 were from GMU [22 were staff and 45 M.B.B.S students] and 60 volunteers from GMCH and RC, Ajman [doctors, staff nurses and ward boys]. Staph, aureus isolation was the highest among the 21-30 year age group [37%] with male predominance [59.6%] and mostly from the nasal swabs [56.45%]. The yield of Staph. aureus isolates from the nasal mucosa and throat were only from 49 normal individuals, hence the prevalence of Staph. aureus in our study being 38.5%. Among the total 124 Stapylococcal isolates, 62 [50%] were Staph. aureus and 62 [50%] were coagulase negative staphylococci. Of the 62 Staph aureus isolates, 35 [56.45%] were from nasal swabs and 27 [43.54%] from throat swabs. Of the 62 coagulase negative Staphylococcus isolates, 44 [70%] were from nasal swab, four [6%] from throat swab and 14 [22%] were from both nasal and throat swabs. The study indicates an alarming prevalence rate of Staph. aureus. Hence we conclude that the data observed reflected the need for a complete revision for all the infection control programs at GMU and GMCH and RC which includes education programs, aseptic techniques, hospital hygiene and periodic microbiological surveillance in order to control the spread of infection