The Prevalence of Nasal Carriage of Staphylococcus Aureus Among Healthcare Workers at a Tertiary Care Hospital in Assam with Special Reference to MRSA

Background: The recent years have witnessed the increasing resistance of Staphylococcus aureus to many antimicrobial agents. The most notable example is the emergence of Methicillin-resistant Staphylococcus aureus (MRSA), which was reported just one year after the launch of methicillin. The ecological niches of the S. aureus strains are the anterior nares. The identification of Staphylococcus aureus by using a proper antibiogram and the detection of methicillin resistant Staphylococcus aureus greatly contribute towards the effective treatment of the patients.

Aims And Objectives: To isolate Staphylococcus aureus from the nasal swabs of healthcare workers (HCWs) and to study their antimicrobial susceptibility patterns, which include methicillin resistance.

Materials And Methods: Nasal swabs were collected from the healthcare workers of various clinical departments of the hospital over a period of one year. The isolation of Staphylococcus aureus and their antimicrobial susceptibility patterns were carried out by standard bacteriological procedures.

Results: Staphylococcus aureus was isolated in 70 cases (22.22%). The prevalence of the S.aureus nasal carriage was higher among the male HCWs (54.28%) than among the female HCWs (45.71%). The carriage rate was the highest in the orthopaedics department, followed by those in the surgery and the gynaecology departments. All the Staphylococcus aureus isolates were sensitive to vancomycin and linezolid (100%). Penicillin and ampicillin were the most resistant, (90% and 88.6%) respectively. Methicillin resistance was seen in11.43% of the S.aureus isolates, both by the disc diffusion test and by the Oxacillin Resistance Screen Agar (ORSA) test.

Conclusions: The compliance with the sanitary and the antibacterial guidelines of the health professionals is the single most important factor in preventing nosocomial infections. Simple preventive measures like hand washing before and after the patient examination, the use of sterile aprons and masks in the postoperative wards, awareness during the examination of the immunocompromised patients, and avoiding touching one's nose during work, can reduce the disease transmission rate considerably.