Ventilator-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) Pneumonia in a Patient with a Negative MRSA Nasal Swab.

BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is associated with high morbidity and mortality. Recently, MRSA testing by nasal swab has been utilized to "exclude" pneumonia caused by MRSA, given its high negative-predictive value (NPV). We present, however, a case of MRSA pneumonia diagnosed by endotracheal aspirate culture (EAC) in a patient with a negative MRSA nasal swab. CASE REPORT A 58-year-old woman presented with septic shock and respiratory failure. Chest X-ray (CXR) on admission was unrevealing; however, computed tomography (CT) revealed multifocal pneumonia. Intensive Care Unit (ICU)-level care was required for mechanical ventilation and vasopressors. She initially improved with treatment of community-acquired pneumonia (CAP) and was extubated on hospital day 6; however, she then developed a fever, tachycardia, and respiratory distress necessitating re-intubation later that day. Repeat CXR demonstrated a new left lower lobe infiltrate. Blood cultures were drawn and vancomycin and cefepime were started to cover for ventilator-associated pathogens. An EAC and nasal swab were collected to test for MRSA. The next day (day 7), the MRSA nasal swab returned negative, and vancomycin was discontinued. Our patient continued to experience fevers, worsening leukocytosis, and ongoing vasopressor need. On hospital day 9, the EAC results were obtained, and were positive for MRSA. Vancomycin was restarted and our patient recovered. CONCLUSIONS Negative MRSA nasal screening may be considered grounds to de-escalate empiric MRSA antibiotics if MRSA prevalence is low. However, in critically ill patients with high risk and suspicion for MRSA pneumonia, discontinuing empiric MRSA coverage should be done with caution or clinicians should wait until respiratory culture results are obtained before de-escalating antibiotics.

Characteristics and local risk factors of community-acquired and health-care-associated Staphylococcus aureus pneumonia.

This study aims at identifying characteristics, risk factors and mortality of community-acquired (CAP) and health-care-associated pneumonia (HCAP) by Staphylococcus aureus (S. aureus). We retrieved adults with S. aureus CAP or HCAP diagnosed by blood or pleural effusion culture in 2.6 years, and compared with those of Streptococcus pneumoniae (S. pneumoniae) CAP or HCAP diagnosed by blood or respiratory culture, or urine antigen. We found 18 patients with CAP and 9 HCAP due to S. aureus (female 33%, 66.6 ± 12.4 years-old), and 48 patients with CAP and 15 HCAP due to S pneumoniae (female 41%, 69.5 ± 17.5 years). Diabetes mellitus (52% vs. 24%, p = 0.019), hemodialysis (11% vs. 0%, p = 0.046), skin lesions (44% vs. 0%, p < 0.001), cavitary nodules (37% vs. 1.6%, p < 0.001) and pleural effusions (48% vs. 18%, p = 0.007) were more common in staphylococcal than pneumococcal group. Three patients with staphylococcal pneumonia had acute myocardial infarction. Pneumonia severity index (139 ± 52 vs. 109 ± 43, p = 0.005) and 30-day mortality (41% vs. 9.5%, p = 0.001) were higher in staphylococcal group. Multivariate analysis showed underlying disease (especially cancer and cirrhosis), risk class 4/5, altered mentality, shock and bilateral pneumonia were risk factors for 30-day mortality.

Impact of Prior-to-Admission Methicillin-Resistant Staphylococcus aureus Nares Screening in Critically Ill Adults With Pneumonia.

BACKGROUND: The high negative predictive value (NPV) of a negative nasal methicillin-resistant Staphylococcus aureus (MRSA) result in suspected MRSA pneumonia is well established; however, data are limited on the NPV of samples collected prior to hospital admission for critically ill patients. OBJECTIVE: To evaluate the predictive characteristics of MRSA nares screening performed prior to hospital admission in critically ill adult patients diagnosed with pneumonia. METHODS: A retrospective analysis was conducted in critically ill patients with pneumonia and MRSA nares screening within 60 days of respiratory culture. The primary outcome was NPV of MRSA nares for MRSA pneumonia using samples within 60 days compared to in-hospital respiratory cultures. A sensitivity analysis was performed for samples within 30 days. Secondary outcomes were prevalence, positive predictive value (PPV), sensitivity, specificity, and MRSA pneumonia risk factors. RESULTS: The NPV for MRSA nares screening collected prior to hospital admission was high at 98% (95% CI = 96%-99%) for samples collected within 60 days (n = 243) and 99% (95% CI: 94%-99.9%) for samples within 30 days (n = 119). Specificity for MRSA nares collected 60 days prior to admission (96%, 95% CI: 93-98) and 30 days (96%, 95% CI: 91%-99%) were both high. PPV and sensitivity were lower. Risk factors for MRSA pneumonia were similar. CONCLUSION AND RELEVANCE: MRSA nares screening within 60 days of intensive care unit admission has a high NPV and specificity for MRSA pneumonia in critically ill patients and may be a powerful stewardship tool for avoidance of empirical anti-MRSA therapy.

Prognostic factors of severe community-acquired staphylococcal pneumonia in France.

PURPOSE: Staphylococcus aureus causes severe forms of community-acquired pneumonia (CAP), namely staphylococcal pleuropneumonia in young children and staphylococcal necrotising pneumonia in older patients. Methicillin resistance and the Panton-Valentine leukocidin (PVL) toxin, as well as less specific factors, have been associated with poor outcome in severe CAP, but their roles are unclear. METHODS: A prospective multicentre cohort study of severe staphylococcal CAP was conducted in 77 paediatric and adult intensive care units in France between January 2011 and December 2016. After age-clustering, risk factors for mortality, including pre-existing conditions, clinical presentation, laboratory features, strain genetic lineage, PVL, other virulence factors and methicillin resistance were assessed using univariate and multivariable Cox and LASSO (least absolute shrinkage and selection operator) regressions. RESULTS: Out of 163 included patients, aged 1 month to 87 years, 85 (52.1%) had PVL-positive CAP; there were 20 (12.3%) patients aged <3 years (hereafter "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 (three (15%) out of 19) compared to PVL-positive CAP in older patients (31 (47%) out of 66). Mortality in older patients was predicted by PVL-positivity (hazard ratio (HR) 1.81, 95% CI 1.03-3.17) and methicillin resistance (HR 2.37, 95% CI 1.29-4.34) independently from S. aureus lineages and the presence of other determinants of virulence. 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, S. aureus genetic background and other virulence factors.

Predictive Value of the Methicillin-Resistant Staphylococcus aureus Nasal Swab for Methicillin-Resistant Staphylococcus aureus Ventilator-Associated Pneumonia in the Trauma Patient.

Background: Many trauma centers have empiric treatment algorithms for ventilator-associated pneumonia (VAP) treatment prior to culture results that include antibiotic agents for methicillin-resistant Staphylococcus aureus (MRSA) coverage that can have adverse effects. This is the only study to evaluate risk factors and MRSA nasal swabs to risk-stratify trauma patients for MRSA VAP, thereby potentially limiting the need for empiric vancomycin. Patients and Methods: This was a single institution retrospective cohort study. Adult patients admitted to the trauma intensive care unit (ICU) between January 2013 and December 2017 who had a MRSA nasal swab and subsequently met criteria for VAP were included. Demographics, risk factors for MRSA pneumonia, and culture results were collected. Results: A total of 140 patients met inclusion criteria. The negative predictive value (NPV) of MRSA nasal swab at predicting subsequent MRSA pneumonia was 97%. The sensitivity, specificity, and positive predictive value were 50.0%, 96.2%, and 44.4%, respectively. Smokers were more likely to develop MRSA pneumonia, odds ratio: 7.0 (p = 0.02). When considering non-smokers with a negative MRSA nasal swab, NPV was 100%. Conclusions: This is the only study to date that assesses the utility of MRSA nasal swab and risk factor data to guide empiric VAP antibiotic therapy in trauma patients. Smoking was found to be a risk factor for MRSA pneumonia. The use of MRSA nasal swabs in combination with smoking status to guide empiric use of MRSA coverage antibiotic agents is recommended because of a 100% NPV. When utilized, as many as 68% of patients may safely be spared MRSA coverage antibiotic agents and the related adverse effects.

Community-acquired methicillin-resistant Staphylococcus aureus pneumonia in a children's hospital. Our ten-year experience. / Neumonía por Staphylococcus aureus resistente a meticilina adquirido de la comunidad en un hospital pediátrico. Nuestra experiencia de 10 años.

INTRODUCTION: Community-acquired methicillinresistant Staphylococcus aureus (CA-MRSA) infections have increased in recent years. CAMRSA necrotizing pneumonia and empyema are now more common in children. OBJECTIVES: To determine the prevalence of CA-MRSA pneumonia and its clinical and epidemiological characteristics compared to Streptococcus pneumoniae (SP) pneumonia in the same population. MATERIAL AND METHODS: Descriptive, observational, cross-sectional study of patients hospitalized due to CA-MRSA pneumonia at Hospital de Niños Víctor J. Vilela (period: January 2008-December 2017). RESULTS: Out of 54 Staphylococcus aureus pneumonia cases, 46 (85 %) corresponded to CA-MRSA. The rate of CA-MRSA pneumonia ranged from 4.9/10 000 (2008) to 10/10 000 hospital discharges (2017). Sepsis/septic shock was observed in 41 %; empyema, in 96 %; pneumothorax, in 35 %; 90 % of cases required pleural drainage and 55 %, surgical debridement. Also, 65 % of patients were admitted to the intensive care unit (ICU); half of them required assisted mechanical ventilation. Two patients died. Strain resistance: 17 %, gentamicin; 13 %, erythromycin; and 11 %, clindamycin. Compared to SP pneumonia, CAMRSA pneumonia showed a higher risk for sepsis (95 % confidence interval; relative risk: 7.38; 3.32- 16.38) and admission to the ICU (RR: 4.29; 2.70- 6.83). No patient died due to SP pneumonia. CONCLUSIONS: The prevalence of CA-MRSA pneumonia doubled in the past decade. Compared to SP pneumonia, CA-MRSA pneumonia was more commonly accompanied by sepsis and septic shock, admission to the ICU, and ventilatory support requirement.

Introducción. Las infecciones por Staphylococcus aureus resistente a meticilina adquirido de la comunidad (SARM-AC) se han incrementado en los últimos años. Neumonías necrotizantes y empiemas por SARM-AC son cada vez más frecuentes en niños. Objetivos. Determinar la prevalencia de neumonías por SARM-AC y sus características clínico-epidemiológicas, en comparación con las neumonías por Streptococcus pneumoniae (SP) en la misma población. Material y métodos. Estudio descriptivo, observacional, transversal, de pacientes internados con neumonía por SARM-AC en el Hospital de Niños Víctor J. Vilela (período: 1/2008-12/2017). Resultados. De 54 neumonías por Staphylococcus aureus, 46 (el 85 %) fueron SARM-AC. El índice de neumonías por SARM-AC varió de 4,9/10 000 (2008) a 10/10 000 egresos (2017). Presentaron sepsis/shock séptico el 41 %; empiema, el 96 %; neumotórax, el 35 %; requirieron drenaje pleural el 90 % y toilette quirúrgica el 55 %. Ingresaron a Terapia Intensiva el 65 %; la mitad necesitó asistencia respiratoria mecánica. Hubo dos muertes. Resistencia de las cepas: el 17 % a gentamicina, el 13 % a eritromicina, el 11 % a clindamicina. En las neumonías por SARM-AC vs. las neumonías por SP, se observó mayor riesgo de sepsis (IC 95 %; RR 7,38; 3,32-16,38) e ingreso a Terapia Intensiva (RR 4,29; 2,70-6,83). No hubo muertes por SP. Conclusiones. La prevalencia de neumonías por SARM-AC se duplicó durante la última década. Comparadas con las neumonías por SP, las neumonías por SARM-AC se acompañaron, más frecuentemente, de cuadros de sepsis y shock séptico, ingreso a Terapia Intensiva y asistencia respiratoria.

Risk Factor Evaluation for Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa in Community-Acquired Pneumonia.

BACKGROUND: The 2019 community-acquired pneumonia guidelines recommend using recent respiratory cultures and locally validated epidemiology plus risk factor assessment to determine empirical coverage of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. OBJECTIVE: To develop a methodology for evaluating local epidemiology and validating local risk factors for P aeruginosa and MRSA. METHODS: This multicenter, retrospective cohort evaluated adult patients admitted for pneumonia. Risk factors for MRSA and P aeruginosa were evaluated using multivariable logistic regression and reported as adjusted odds ratios (aORs). RESULTS: There were 10 723 cases evaluated. Lung abscess/empyema had the highest odds associated with MRSA (aOR = 4.24; P < 0.0001), followed by influenza (aOR = 2.34; P = 0.01), end-stage renal disease (ESRD; aOR = 2.09; P = 0.006), illicit substance use (aOR = 1.7; P = 0.007), and chronic obstructive pulmonary disease (COPD; aOR = 1.26; P = 0.04). For P aeruginosa, the highest odds were in bronchiectasis (aOR = 6.13; P < 0.0001), lung abscess/empyema (aOR = 3.36; P = 0.005), and COPD (aOR = 1.84; P < 0.0001). Isolated COPD without other risk factors did not pose an increased risk of either organism. CONCLUSION AND RELEVANCE: Influenza, ESRD, lung abscess/empyema, and illicit substance use were local risk factors for MRSA. Bronchiectasis and lung abscess/empyema were risk factors for Pseudomonas. COPD was associated with MRSA and Pseudomonas. However, isolated COPD had similar rates of MRSA and Pseudomonas pneumonia compared with the total population. This study established a feasible methodology for evaluating local risk factors.

Association of Staphylococcus aureus Colonization and Pneumonia in the Intensive Care Unit.

Importance: Carriage of Staphylococcus aureus is associated with S aureus infection. However, associations between S aureus carriage and the development of S aureus intensive care unit (ICU) pneumonia (SAIP) have not been quantified accurately, and interpretation of available data is hampered because of variations in definitions. Objective: To quantify associations of patient-related and contextual factors, including S aureus colonization status, with the occurrence of SAIP. Design, Setting, and Participants: This cohort study was conducted in ICUs of 30 hospitals in 11 European countries, geographically spread across 4 regions. Among patients with an anticipated length of stay 48 hours or longer who were undergoing mechanical ventilation at ICU admission, S aureus colonization was ascertained in the nose and lower respiratory tract. From this group, S aureus-colonized and noncolonized patients were enrolled into the study cohort in a 1:1 ratio. Data analysis was performed from May to November 2019. Main Outcomes and Measures: SAIP was defined as any pneumonia during the ICU stay developing 48 hours or more after ICU admission with S aureus isolated from lower respiratory tract specimens or blood samples. The incidence of SAIP was derived in the study cohort and estimated on the weighted incidence calculation for the originating overarching population, while taking competing events into account. Weighted risk factor analysis was performed using Cox multivariable regression. Results: The study cohort consisted of 1933 patients (mean [SD] age, 62.0 [16.0] years); 1252 patients (64.8%) were men, and 950 patients (49.1%) were S aureus carriers at ICU admission. In all, 304 patients (15.7%) developed ICU-acquired pneumonia, of whom 131 patients (6.8%) had SAIP. Weighted SAIP incidences were 11.7 events per 1000 patient-days in the ICU for S aureus-colonized patients and 2.9 events per 1000 patient-days in the ICU for noncolonized patients (overall incidence, 4.9 events per 1000 patient-days in the ICU). The only factor independently associated with SAIP was S aureus colonization status at ICU admission (cause-specific hazard ratio, 3.6; 95% CI, 2.2-6.0; P < .001). There were marked regional differences in SAIP incidence and cause-specific hazard ratios for colonization status. Conclusions and Relevance: SAIP incidence was 4.9 events per 1000 ICU patient-days for patients undergoing mechanical ventilation at ICU admission (or shortly thereafter). The daily risk of SAIP was 3.6 times higher in patients colonized with S aureus at ICU admission compared with noncolonized patients.

Healthcare-associated pneumonia: a prospective study in Spain.

OBJECTIVE: The aim of the study was to describe the epidemiological characteristics and factors related to outcome in Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated pneumonia (HCAP). METHODS: A 3-year prospective observational epidemiological case study of HCAP was conducted in seven Spanish hospitals. Microbiological and patient characteristics and outcomes were collected and classified by causative pathogen into 4 categories: "S. pneumoniae", "MRSA", "Others" and "Unknown". Patients were followed up 30 days after discharge. RESULTS: A total of 258 (84.6%) patients were enrolled (170 were men [65.9%]). Mean age was 72.4 years ± 15 years (95% CI [70.54-74.25]). The etiology of pneumonia was identified in 73 cases (28.3%): S. pneumoniae in 35 patients (13.6%), MRSA in 8 (3.1%), and other microorganisms in 30 patients (11.6%). Significant differences in rates of chronic obstructive pulmonary disease (p < 0.05), previous antibiotic treatment (p<0.05), other chronic respiratory diseases, inhaled corticosteroids (p <0.01), and lymphoma (p < 0.05) were observed among the four groups. Patients with MRSA pneumonia had received more previous antibiotic treatment (87.5%). Thirty-three (12.8%) patients died during hospitalisation; death in 27 (81.2%) was related to pneumonia. CONCLUSIONS: The etiology of HCAP was identified in only one quarter of patients, with S. pneumoniae being the most prevalent microorganism. Patients with chronic respiratory diseases more frequently presented HCAP due to MRSA than to S. pneumoniae. Death at hospital discharge was related in most cases to pneumonia.

Staphylococcus aureus Pneumonia in the Community.

Staphylococcus aureus is an emergent etiology of community-acquired pneumonia (CAP) over the past 2 decades, with severe community-acquired pneumonia (SCAP) caused by methicillin-resistant S. aureus (MRSA) leading to critical illness and death. S. aureus colonization is associated with a high incidence of pneumonia. Panton-Valentine leukocidin (PVL) is one of the most important virulence factors of S. aureus associated with serious complications. In recent years, community-associated MRSA (CA-MRSA) clones that caused infections in young adults and healthy individuals with no exposure to health care settings and no classical risk factors have emerged. Clinical features at admission including concurrent influenza infection, hemoptysis, multilobar infiltrates, and neutropenia should suggest S. aureus CAP. Sputum Gram stains, cultures (or tracheobronchial aspirates or bronchoalveolar lavage in mechanically ventilated patients), polymerase chain reaction (nasopharyngeal or oropharyngeal or lower respiratory tract specimens), and two sets of blood cultures should be obtained from patients presenting with severe S. aureus CAP. For CAP due to methicillin-susceptible S. aureus, first-line therapy is usually cefazolin, oxacillin, or ceftaroline. For CA-MRSA pneumonia, linezolid is recommended. If vancomycin or teicoplanin are used, combination with clindamycin or rifampicin should be considered in cases of PVL-positive MRSA CAP.

Childhood pneumonia in low-and-middle-income countries: An update.

OBJECTIVES: To review epidemiology, aetiology and management of childhood pneumonia in low-and-middle-income countries. DESIGN: Review of published English literature between 2013 and 2019. RESULTS: Pneumonia remains a major cause of morbidity and mortality. Risk factors include young age, malnutrition, immunosuppression, tobacco smoke or air pollution exposure. Better methods for specimen collection and molecular diagnostics have improved microbiological diagnosis, indicating that pneumonia results from several organisms interacting. Induced sputum increases microbiologic yield for Bordetella pertussis or Mycobacterium tuberculosis, which has been associated with pneumonia in high TB prevalence areas. The proportion of cases due to Streptococcus pneumoniae and Haemophilus influenzae b has declined with new conjugate vaccines; Staphylococcus aureus and H. influenzae non-type b are the commonest bacterial pathogens; viruses are the most common pathogens. Effective interventions comprise antibiotics, oxygen and non-invasive ventilation. New vaccines have reduced severity and incidence of disease, but disparities exist in uptake. CONCLUSION: Morbidity and mortality from childhood pneumonia has decreased but a considerable preventable burden remains. Widespread implementation of available, effective interventions and development of novel strategies are needed.

Prevalence of Staphylococcus aureus and Use of Antistaphylococcal Therapy in Children Hospitalized with Pneumonia.

Within a cohort of >2,000 children hospitalized with community-acquired pneumonia, staphylococcal pneumonia was rare (1%) but associated with adverse in-hospital outcomes. Despite this low prevalence, use of antistaphylococcal antibiotics was common (24%). Efforts are needed to minimize overuse of antistaphylococcal antibiotics while also ensuring adequate treatment for pathogen-specific diseases.

Clinical predictors of methicillin-resistant Staphylococcus aureus in nosocomial and healthcare-associated pneumonia: a multicenter, matched case-control study.

The situations in which coverage for methicillin-resistant Staphylococcus aureus (MRSA) in the empirical treatment of nosocomial pneumonia (NP) or severe healthcare-associated pneumonia (HCAP) is needed are poorly defined, particularly outside intensive care units (ICUs). Our aim was to characterize if the risk of MRSA NP/HCAP can be defined by clinical variables. We designed an observational, retrospective, multicenter, case-control study to analyze the association between defined clinical variables and risk of MRSA NP/HCAP in non-ICU patients using conditional multivariable logistic regression. Cases and controls (1:2) with microbiological diagnosis were included. Controls were matched for hospital, type of pneumonia (NP or HCAP), and date of isolation. A total of 140 cases (77 NP and 63 HCAP) and 280 controls were studied. The variables associated with the risk of MRSA pneumonia were: (i) respiratory infection/colonization caused by MRSA in the previous year [odds ratio (OR) 14.81, 95% confidence interval (CI) 4.13-53.13, p < 0.001]; (ii) hospitalization in the previous 90 days (OR 2.41, 95% CI 1.21-4.81, p = 0.012); and (iii) age (OR 1.02, 95% CI 1.001-1.05, p = 0.040). The area under the receiver operating characteristic (ROC) curve for the multivariable model was 0.72 (95% CI 0.66-0.78). The multivariate model had a sensitivity of 74.5% (95% CI 65.3-83.6), a specificity of 63.3% (95% CI 56.0-70.6), a positive predictive value of 52.5% (95% CI 43.9-61.2), and a negative predictive value of 82.0% (95% CI 75.3-88.8) for the observed data. Clinical predictors of MRSA NP/HCAP can be used to define a low-risk population in whom coverage against MRSA may not be needed.

Rationale and design of ASPIRE-ICU: a prospective cohort study on the incidence and predictors of Staphylococcus aureus and Pseudomonas aeruginosa pneumonia in the ICU.

BACKGROUND: The epidemiology of ICU pneumonia caused by Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) is not fully described, but is urgently needed to support the development of effective interventions. The objective of this study is to estimate the incidence of S. aureus and P. aeruginosa ICU pneumonia and to assess its association with patient-related and contextual risk factors. METHODS: ASPIRE-ICU is a prospective, observational, multi-center cohort study nested within routine surveillance among ICU patients in Europe describing the occurrence of S. aureus and P. aeruginosa ICU pneumonia. Two thousand (2000) study cohort subjects will be enrolled (50% S. aureus colonized) in which specimens and data will be collected. Study cohort subjects will be enrolled from a larger surveillance population, in which basic surveillance data is captured. The primary outcomes are the incidence of S. aureus ICU acquired pneumonia and the incidence of P. aeruginosa ICU acquired pneumonia through ICU stay. The analysis will include advanced survival techniques (competing risks and multistate models) for each event separately as well as for the sub-distribution of ICU pneumonia to determine independent association of outcomes with risk factors.. A risk prediction model will be developed to quantify the risk for acquiring S. aureus or P. aeruginosa ICU pneumonia during ICU stay by using a composite score of independent risk factors. DISCUSSION: The diagnosis of pathogen-specific ICU pneumonia is difficult, however, the criteria used in this study are objective and comparable to those in the literature. TRIAL REGISTRATION: This study is registered on clinicaltrials.gov under identifier NCT02413242 .

Epidemiology and outcome of invasive fungal infections and methicillin-resistant Staphylococcus aureus (MRSA) pneumonia and complicated skin and soft tissue infections (cSSTI) in Lebanon and Saudi Arabia.

The objectives of this retrospective medical chart review study were to document the inpatient incidence, treatment, and clinical outcomes associated with invasive fungal infections (IFI) due to Candida and Aspergillus species, Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia and MRSA complicated skin and soft tissue infections (cSSTI) in the Middle East. This study evaluated 2011-2012 data from 5 hospitals in Saudi Arabia and Lebanon with a combined total of 207,498 discharges. Hospital medical chart data were abstracted for a random sample of patients with each infection type (102 patients - IFI, 93 patients - MRSA pneumonia, and 87 patients-MRSA cSSTI). Descriptive analysis found that incidence of IFI (per 1000 hospital discharges) was higher than MRSA cSSTI and MRSA pneumonia (IFI: 1.95 and 2.57; MRSA cSSTI: 2.01 and 0.48; and MRSA pneumonia 0.59 and 0.55 for Saudi Arabia and Lebanon, respectively). Median time from hospital admission to diagnosis and from admission to initiation of active therapy were 6 and 7 days, respectively, in IFI patients; median time from admission to diagnosis was 2days for both MRSA pneumonia and cSSTI, with a median of 4 and 2days from admission to MRSA-active antibiotic start, respectively. The mean hospital LOS was 32.4days for IFI, 32.4days for MRSA pneumonia and 26.3days for MRSA cSSTI. Inpatient mortality was higher for IFI (42%) and MRSA pneumonia (30%) than for MRSA cSSTI (8%). At discharge, 33% of patients with IFI and 27% and 9% of patients with MRSA pneumonia and cSSTI, respectively, were considered to have failed therapy. In conclusion, there is a significant burden of these serious infections in the Middle East, as well as opportunity for hospitals to improve the delivery of patient care for difficult-to-treat infections by promoting expedited diagnosis and initiation of appropriate antimicrobial therapy.

Community-acquired pneumonia caused by methicillin-resistant Staphylococcus aureus in critically-ill patients: systematic review / Neumonía comunitaria por Staphylococcus aureus resistente a meticilina en paciente crítico: revisión sistemática

Introduction: Community-acquired pneumonia (CAP) is associated with high morbidity and mortality rates. Despite methicillin-resistant Staphylococcus aureus (MRSA) having often been associated with nosocomial pneumonia, the condition of some MRSA CAP patients is severe enough to warrant their being admitted to ICU. Objective: The purpose of this study is to conduct a systematic review of the literature on antibiotic treatment of MRSA CAP in critically-ill patients. Material and methods: An online search was conducted for locating articles on MRSA CAP in critically ill patients. Relevant publications were identified in PUBMED, the BestPractice database, UpToDate database and the Cochrane Library for articles published in English within the December 2001 - April 2016 time frame. Results: A total of 70 articles were found to have been published, 13 (18.8%) having been included and 57 (81.4%) excluded. Cohort studies were predominant, having totaled 16 in number (20.7%) as compared to one sole cross-sectional study (3.5%). Conclusions: The experience in the treatment of MRSA CAP in patients requiring admission to ICU is quite limited. Vancomycin or linezolid seem to be the treatments of choice for MRSA CAP, although there not be any specific recommendation in this regard. It may be useful to use alternative routes, such as administration via aerosolized antibiotics, continuous infusion or in association with other antibiotics (AU)

Introducción: La neumonía adquirida en la comunidad (NAC) está relacionada con unas tasas elevadas de morbi-mortalidad. A pesar de que Staphylococcus aureus resistente a meticilina (SARM) se ha relacionado frecuentemente con la neumonía nosocomial, algunos pacientes con NAC por este microorganismo revisten la suficiente gravedad como para precisar su ingreso en la UCI. Objetivos: Efectuar una revisión sistemática de la literatura sobre el tratamiento antibiótico de la NAC por SARM en pacientes críticos. Material y métodos: Se realizó una búsqueda de artículos sobre NAC por SARM en el paciente crítico. Se identificaron las publicaciones pertinentes en PUBMED, BestPractice database, UpToDate database y Cochrane Plus Library para artículos publicados en inglés desde diciembre del 2001 hasta abril del 2016. Resultados: Se encontraron 70 publicaciones, incluyendo 13 (18,8%) y excluyendo 57 (81,4%). Predominaron los estudios de cohortes con un total de 6 (20,7%), frente a una única publicación en forma de estudio transversal (3,5%). Conclusiones: La experiencia en el tratamiento de la NAC por SARM en pacientes que precisen ingreso en la UCI es muy limitada. La vancomicina o el linezolid parecen ser las terapias en las que se dispone de una mayor experiencia, aunque no existe ninguna recomendación específica al respecto. Puede ser útil la utilización de vías alternativas como la nebulizada, administración en perfusión continua o en asociación con otros antibióticos (AU)

Prevalence of and outcomes from Staphylococcus aureus pneumonia among hospitalized patients in the United States, 2009-2012.

BACKGROUND: The burden of Staphylococcus aureus pneumonia is unknown despite being a major cause of mortality. We investigated national estimates of methicillin-resistant S aureus (MRSA) and methicillin-susceptible S aureus (MSSA) pneumonias and predictors of in-hospital mortality and hospital length of stay (LOS). METHODS: This was a retrospective analysis of the National Inpatient Sample from 2009-2012. Adult patients with an ICD-9-CM primary diagnosis code for MRSA or MSSA pneumonia were included. Data weights were used to derive national estimates. Prevalence rates were reported per 100,000 hospital discharges, with trends presented descriptively. RESULTS: There were 104,562 patients who had a primary diagnosis of S aureus pneumonia, with 81,275 from MRSA. MRSA pneumonia prevalence decreased steadily from 2009 (75.6 cases per 100,000 discharges) to 2012 (56.6 cases per 100,000 discharges), with MSSA pneumonia experiencing a slight decrease. Mortality rates decreased between 2009 and 2012 for MRSA pneumonia (7.9% to 6.4%) and MSSA pneumonia (6.9% to 4.7%; P = .008). LOS was higher for MRSA (6.9-7.8 days) compared with MSSA (6.1-6.4 days). CONCLUSIONS: The prevalence of MRSA pneumonia has decreased among hospitalized adults in the United States in recent years accompanied by improvements in mortality and LOS. Although the prevalence of MRSA pneumonia is declining, national vigilance is still warranted.

Healthcare-associated pneumonia with positive respiratory methicillin-resistant Staphylococcus aureus culture: Predictors of the true pathogenicity.

AIM: Although methicillin-resistant Staphylococcus aureus (MRSA) is commonly isolated from respiratory specimens in healthcare-associated pneumonia (HCAP), it is difficult to determine the causative pathogen because of the possibilities of contamination/colonization. The present study aimed to identify clinical predictors of the true pathogenicity of MRSA in HCAP. METHODS: Patients with HCAP with positive MRSA cultures in the sputum or endotracheal aspirates who were admitted to Seirei Mikatahara General Hospital, Hamamatsu, Japan, from 2009 to 2014 were enrolled. According to the administered drugs and the treatment outcomes, patients with true MRSA pneumonia (MP) and those with contamination/colonization of MRSA (false MP) were identified. Baseline characteristics were compared between groups, and clinical predictors of true MP were evaluated by logistic regression analyses. RESULTS: A total of 93 patients (mean age 78.7 ± 12.6 years) were identified and classified into the true MP (n = 16) or false MP (n = 77) groups. Although baseline characteristics were broadly similar between groups, the true MP group had significantly more patients with PaO2 ≤ 60 Torr/pulse oximetry saturation ≤90% and those with MRSA single cultivation. Both variables were significant predictors of true MP in multivariate analysis (odds ratio of PaO2 ≤ 60 Torr/pulse oximetry saturation ≤90%: 5.64, 95% confidence interval 1.17-27.32; odds ratio of MRSA single cultivation: 4.76, 95% confidence interval 1.22-18.60). CONCLUSIONS: Poor oxygenation and MRSA single cultivation imply the true pathogenicity of MRSA in HCAP with positive respiratory MRSA cultures. The present results might be helpful for the proper use of anti-MRSA drugs in this population. Geriatr Gerontol Int 2017; 17: 456-462.

Clinical utility of methicillin-resistant Staphylococcus aureus nasal polymerase chain reaction assay in critically ill patients with nosocomial pneumonia.

PURPOSE: This study investigated the diagnostic performance characteristics of a methicillin-resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) assay in critically ill patients with nosocomial pneumonia. MATERIALS AND METHODS: This retrospective, single-center study included adult patients admitted to an intensive care unit with suspected nosocomial pneumonia. Patients must have received an MRSA nasal PCR assay and respiratory culture within predetermined time intervals. The primary outcome included the diagnostic performance characteristics of the assay. Secondary outcomes included the change in negative predictive value (NPV) over time, rate of acute kidney injury, and cost avoidance associated with vancomycin and monitoring. RESULTS: In 400 patients meeting inclusion criteria, the prevalence of culture confirmed MRSA pneumonia was 9.3%. When compared to initial cultures, the PCR assay demonstrated 91.89% sensitivity and 84.3% specificity with a positive predictive value and NPV of 37.36% and 99.03%. The NPV decreased to 87.5% at 21.9 days. No difference was found in rates of acute kidney injury. A cost avoidance of $108 per patient was estimated in patients de-escalated based on negative results. CONCLUSION: In critically ill patients, an MRSA nasal PCR assay has a high NPV for nosocomial pneumonia and can be used to guide vancomycin de-escalation.