Impact of MRSA nasal swab screening and PCR in pneumonia treatment and antimicrobial stewardship: A systematic review and meta-analysis.

BACKGROUND

The rise of multidrug-resistant bacteria in hospitals, especially methicillin-resistant Staphylococcus aureus (MRSA), presents a major challenge in managing pneumonia, a leading cause of morbidity and mortality in intensive care. Early exclusion of MRSA infection is vital for guiding appropriate antibiotic therapy, as unnecessary or prolonged anti-MRSA treatment increases mortality, hospital stay, and adverse effects such as nephrotoxicity.

PURPOSE: To evaluate the effectiveness and safety of nasal polymerase chain reaction (PCR) screening for MRSA in de-escalating antibiotic therapy in hospitalized pneumonia patients.

METHODS

A systematic review and meta-analysis of observational retrospective studies assessing the impact of nasal MRSA PCR screening in hospitalized pneumonia patients. Inclusion criteria focused on outcomes like therapy duration, acute kidney injury, hospital stay, and mortality.

RESULTS

Six studies (1,649 patients) were included. Random-effects models showed a significant reduction in vancomycin duration (-0.98 days; 95 % confidence interval (CI) [-1.61, -0.59]) and a non-significant decrease in acute kidney injury (Odds ration (OR) 0.53; 95 % CI [0.26, 1.08]). No significant effect was observed for hospital stay (-0.20 days; 95 % CI [-0.85, 0.45]) or mortality (OR 0.68; 95 % CI [0.45-1.02]). The reduction in therapy was greater in non-community-acquired pneumonia subgroups (-1.55 vs. -0.68 days). However, most studies lacked consistent reporting on the timing of screening and subgroup analyses.

CONCLUSION

Nasal PCR screening for MRSA is a safe and effective tool to support antibiotic de-escalation in pneumonia, reducing vancomycin exposure and potentially improving outcomes. Further studies are needed to define optimal screening timing and evaluate its role across specific patient populations.