Staphylococcus aureus Community-acquired Pneumonia: Prevalence, Clinical Characteristics, and Outcomes.
BACKGROUND
Prevalence of Staphylococcus aureus community-acquired pneumonia (CAP) and its clinical features remain incompletely understood, complicating empirical selection of antibiotics.


METHODS
Using a multicenter, prospective surveillance study of adults hospitalized with CAP, we calculated the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) among all CAP episodes. We compared the epidemiologic, radiographic, and clinical characteristics of S. aureus CAP (per respiratory or blood culture) with those of pneumococcal (per respiratory or blood culture or urine antigen) and all-cause non-S. aureus CAP using descriptive statistics.


RESULTS
Among 2259 adults hospitalized for CAP, 37 (1.6%) had S. aureus identified, including 15 (0.7%) with MRSA and 22 (1.0%) with MSSA; 115 (5.1%) had Streptococcus pneumoniae Vancomycin or linezolid was administered to 674 (29.8%) patients within the first 3 days of hospitalization. Chronic hemodialysis use was more common among patients with MRSA (20.0%) than pneumococcal (2.6%) and all-cause non-S. aureus (3.7%) CAP. Otherwise, clinical features at admission were similar, including concurrent influenza infection, hemoptysis, multilobar infiltrates, and prehospital antibiotics. Patients with MRSA CAP had more severe clinical outcomes than those with pneumococcal CAP, including intensive care unit admission (86.7% vs 34.8%) and in-patient mortality (13.3% vs 4.4%).


CONCLUSIONS
Despite very low prevalence of S. aureus and, specifically, MRSA, nearly one-third of adults hospitalized with CAP received anti-MRSA antibiotics. The clinical presentation of MRSA CAP overlapped substantially with pneumococcal CAP, highlighting the challenge of accurately targeting empirical anti-MRSA antibiotics with currently available clinical tools and the need for new diagnostic strategies.
['Self|Wesley H|WH|', 'Wunderink|Richard G|RG|', 'Williams|Derek J|DJ|', 'Zhu|Yuwei|Y|', 'Anderson|Evan J|EJ|', 'Balk|Robert A|RA|', 'Fakhran|Sherene S|SS|', 'Chappell|James D|JD|', 'Casimir|Geoffrey|G|', 'Courtney|D Mark|DM|', 'Trabue|Christopher|C|', 'Waterer|Grant W|GW|', 'Bramley|Anna|A|', 'Magill|Shelley|S|', 'Jain|Seema|S|', 'Edwards|Kathryn M|KM|', 'Grijalva|Carlos G|CG|']
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D000900:Anti-Bacterial Agents D002487:Centers for Disease Control and Prevention, U.S. D017714:Community-Acquired Infections D062665:Epidemiological Monitoring D005260:Female D006801:Humans D008297:Male D055624:Methicillin-Resistant Staphylococcus aureus D008875:Middle Aged D011023:Pneumonia, Staphylococcal D015995:Prevalence D011446:Prospective Studies D013211:Staphylococcus aureus D014481:United States D055815:Young Adult
Staphylococcus aureus pneumonia antibiotics