Community-Acquired MRSA Pneumonia in an Urban Community Hospital: Risk Factors, Presentation, and Outcomes

Abstract

PURPOSE: Community-acquired MRSA (CA-MRSA) pneumonia is an uncommon but potentially life-threatening disease. MRSA is generally not covered when treating CAP. Several small case series have described these patients. Certain clinical characteristics have been proposed that suggest MRSA as a pathogen. However, when to consider CA-MRSA is a subject of ongoing debate. The current study reviewed the risk factors, presentation, and outcomes of patients with CA-MRSA pneumonia in an urban community hospital. METHODS: A retrospective study of adult patients admitted to Jamaica Hospital with positive MRSA respiratory and blood cultures and a diagnosis of pneumonia from August 2011 to March 2013 were reviewed (N=218). Exclusion criteria included risk factors for HCAP and a diagnosis of pneumonia>48 hours after admission. Seventeen patients with confirmed CA-MRSA pneumonia were included. Risk factors, clinical presentation, radiological data and outcomes were reviewed. RESULTS: The average age was 69 years; 70% were ≥60 years old. The majority presented in the winter (70%). All but one had significant comorbidities, including chronic lung disease (35%), cardiac disease (24%), diabetes mellitus (59%) and AIDS (6%). Significant medications included oral steroids (12%), inhaled steroids (30%), and oral antibiotics within one week of admission (24%). In nearly half of cases, aspiration may have played a role in the pathogenesis of pneumonia (e.g. cardiac arrest with CPR, vomiting, neurological disorder, alcohol intoxication). Hemoptysis was seen in 6% and leukopenia in 12%. Imaging revealed cavitation in 6% and pleural effusion in 35%. Bilateral infiltrates were seen in 29%. Seventy-six percent were admitted to the ICU and 24% expired during admission. CONCLUSIONS: Patients with CA-MRSA pneumonia were generally over 60 years old and had comorbid conditions such as lung disease, cardiac disease, or DM, or were at risk for aspiration. Hemoptysis, leukopenia and cavitation, features previously reported to be associated with CA-MRSA, were uncommon in our sample.