Methicillin-resistant Staphylococcus aureus: Diagnosis Treatment Prevention by Nurses Note

 Methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) infection has rapidly increased over the last 5–10 years. Although largely associated with hospital and residential homes, it is increasingly common in community settings. Community MRSA is partly due to ‘silent’ healthcare acquisition during the previous year. Once MRSA is established within healthcare environments, it is difficult to eradicate.

Prevention of Methicillin-resistant Staphylococcus aureus

Prevention depends on the identification and isolation of carriers of MRSA, elimination of potential reservoirs, prevention of transmission, and protocol-driven antibiotic usage to prevent development. Unrecognized MRSA carriage (e.g. asymptomatic skin colonization) is present in about 3% of hospital patients and about 30% of ICU admissions and constitutes the main reservoir and source of hospital transmission. Antibiotic restriction policies and protocols, combined with reduced usage and avoidance of some antibiotics (e.g. quinolones, cephalosporins), decreases MRSA infection rates.

Bone Marrow Aspiration and Biopsy: Indication Procedure Complications

Detection of Methicillin-resistant Staphylococcus aureus

Detection requires active surveillance, especially in high-risk patients. These include patients over 75 years old, those treated with antibiotics within the last 6 months, patients hospitalized within the last year, those with a urinary catheter at admission, and especially patients on critical care units. Early diagnosis, using rapid molecular screening techniques, and prompt patient isolation reduce MRSA acquisitions.

Decolonization of Methicillin-resistant Staphylococcus aureus

Decolonization aims to reduce MRSA carriage, an important risk factor for subsequent infection and transmission. Although intranasal mupirocin and chlorhexidine-based skin cleaning are commonly used, evidence for benefit is limited. However, environmental cleaning and disinfection may be effective.

Antibiotic therapy for Methicillin-resistant Staphylococcus aureus

MRSA may be resistant to fluoroquinolones (~80%), macrolides (~70%), trimethoprim (~35%), gentamicin (12%), and mupirocin (12%).

Most MRSA isolates are susceptible to tetracycline, fusidic acid, and rifampicin. Treatment with vancomycin, teicoplanin, and linezolid should be reserved for patients with severe line-related or neutropenic sepsis, burns, serious soft tissue infections, and prosthetic valve infections.A minimum treatment period of 14 days is required for bacteraemia and longer in endocarditis. Vancomycin and teicoplanin levels must be monitored to ensure therapeutic levels and avoid toxicity. Tetracyclines, trimethoprim, and combinations of rifampicin and fusidic acid are effective in cellulitis, urinary and respiratory tract infections, and as part of eradication therapy. Inadequate therapy may contribute to excess mortality in critically ill patients.