Risk factors of severity in community-acquired staphylococcal pneumonia

Abstract

Background Staphylococcus aureus causes severe forms of community-acquired pneumonia (CAP), namely staphylococcal pleuropneumonia in young children and staphylococcal necrotizing pneumonia in older patients. Methicillin resistance and the Panton-Valentine leukocidin (PVL) toxin have both been associated with poor outcome in severe CAP, but their respective roles are unclear. Methods Prospective multicenter cohort study of severe staphylococcal CAP conducted in 77 pediatric and adult intensive care units in France between January 2011 and December 2016. Clinical features and outcomes were compared between toddlers (<3 years of age) and older patients with PVL-positive CAP; and between older patients with PVL-negative or PVL-positive CAP. Risk factors for mortality were identified using multivariate Cox regression. Results Of 163 included patients, aged one month to 87 years, 85 (52.1%) had PVL-positive CAP; there were 20 (12.3%) toddlers, among whom 19 (95%) had PVL-positive CAP. The features of PVL-positive CAP in toddlers matched with the historical description of staphylococcal pleuropneumonia, with a lower mortality (n = 3/19, 15%) compared to PVL-positive CAP in older patients (n=31/66, 47%). Mortality in older patients was independently predicted by PVL-positivity (hazard ratio 1.81, 95% CI, 1.03 to 3.17) and methicillin resistance (2.37, 95% CI 1.29 to 4.34). As genetic diversity was comparably high in PVL-positive and PVL-negative isolates, confounding by microbial population structure was unlikely. Conclusion PVL was associated with staphylococcal pleuropneumonia in toddlers and was a risk factor for mortality in older patients with severe CAP, independently of methicillin resistance. Funded by the French ministry of Health (PHRC 2010-A01132-37)

Lower respiratory tract infection with <i>Staphylococcus aureus</i> in sickle-cell adult patients with severe acute chest syndrome - the STAPHACS Study

“…5 The genotypic analysis demonstrated a significant clonal diversity, with a 62% rate of toxin genes, similarly to colonizing and pathogenic S. aureus strains. 15 While the PVL strains may be involved in necrotizing community-acquired pneumonia, 13 the 2 ACS episodes were not associated with necrotizing pulmonary lesions, and had favorable outcomes.…”

“…Finally, antibiotic therapy targeting MSSA on admission of patients with ACS having a prior S. aureus infection may be warranted. 10) 2 ( 10) 2 ( 10) 2 (10) 1 (5) 1 (5) 1 (5) 1 (5) 1 (5) 1 (5) 1 (5) 1 (5) Table 2 [13][14][15][16][17][18][19] 3 [3][4] 16 [10][11][12][13][14][15][16][17][18][19][20][21] 3 [3][4] 0.31 0.47…”

“…We identified two MRSA, accounting for 3% of the S. aureus strains, a rate higher than that usually reported in community-acquired pneumonia, 4 but lower than the 16% rate in a recent series concerning community acquired pneumoniae. 13 SCD patients are regularly hospitalized and exposed to repeat antimicrobial therapies, which could partly explain this proportion. Nevertheless, a pediatric series suggested a similar rate of MRSA oropharyngeal carriage between SCD and non-SCD populations.…”