This is a non-inferiority study evaluating clinical improvement rate when using MRSA nasal swabs to guide discontinuation of vancomycin for empiric coverage for MRSA pneumonia.

Current clinical guidelines recommend including vancomycin in initial empiric therapy if risk factors for MRSA infection are present, or there is a high incidence of MRSA locally. Prolonged exposure to vancomycin, however, has been linked with the risk of vancomycin-associated kidney failure. Studies have reported that a MRSA nasal swab may be used to predict the presence of MRSA pneumonia. Specifically, pneumonia patients with negative MRSA nasal swabs are 95-99% likely to not have pneumonia due to MRSA. There is limited data, however, evaluating the use of a MRSA nasal swab to guide vancomycin therapy. Accordingly, in this study, pneumonia patients in the intervention arm will have empiric vancomycin discontinued following a negative MRSA nasal swab. In the control arm, patients vancomycin will not be discontinued based on the MRSA nasal swab result. The rate of clinical resolution will be compared between these two study arms.

Inclusion Criteria:

• Age >= 18 years old
• Patients admitted to Charleston Area Medical Center (CAMC) through the Emergency Department who meet the CDC criteria for pneumonia.
• Nasal surveillance culture for MRSA obtained in the Emergency Department
• Patients receiving vancomycin and additional antibiotic therapy for gram-negative coverage

Exclusion Criteria:

• Persistent vasopressor requirements when MRSA nasal swab results are available
• Patients not meeting the CDC criteria for pneumonia
• Patients presenting to the ED with leukopenia (≤4000) without previous documentation of normal or elevated WBC
• Patients receiving empiric MRSA antibiotic therapy other than vancomycin for pneumonia
• Patients with the diagnosis of lung abscess
• Patients not receiving vancomycin therapy before MRSA nasal swab results are reported
• Immunocompromised individuals. i.e. patients with AIDS/HIV, vasculitis on immune suppressor therapy, steroid therapy for more than one week prior admission or who received chemotherapy in the last 3 months
• Patients who do not have a MRSA nasal swab obtained in the ED
• Nares swab obtained after the completion of the first administered dose of an antibiotic with activity against MRSA
• Patients with MRSA bacteremia
• Patients with chronic tracheostomy

All patients admitted to Charleston Area Medical Center through the Emergency Department with a diagnosis of pneumonia will be evaluated for potential enrollment.