Molecular Epidemiology of Multidrug-Resistant Pseudomonas aeruginosa Acquired in a Spanish Intensive Care Unit: Using Diverse Typing Methods to Identify Clonal Types.

The increasing number of infections from multidrug-resistant P. aeruginosa (MDRPA) has compromised the selection of appropriate treatment in critically ill patients. Recent investigations have shown the existence of MDRPA global clones that have been disseminated in hospitals worldwide. We aimed to describe the molecular epidemiology and genetic diversity of the MDRPA acquired by Intensive Care Units (ICU) patients in our hospital. We used phenotypic methods to define the MDRPA and molecular methods were used to illustrate the presence of carbapenemase encoding genes. To characterize the MDRPA isolates, we used MALDI-TOF biomarker peaks, O-antigen serotyping, and multi-locus sequence typing analyses. Our data show that the most widely distributed MDRPA clone in our ICU unit was the ST175 strain. These isolates were further investigated by the whole-genome sequencing technique to determine the resistome profile and phylogenetic relationships, which showed, as previously described, that the MDR profile was due to the intrinsic resistance mechanisms and not the carbapenemase encoding genes. In addition, this study suggests that the combination of environmental focus and cross-transmission are responsible for the spread of MDRPA clones within our ICU unit. Serotyping and MALDI-TOF analyses are useful tools for the early detection of the most prevalent MDRPA clones in our hospital. Using these methods, semi-directed treatments can be introduced at earlier stages and healthcare professionals can actively search for environmental foci as possible sources of outbreaks.

Repeated influenza vaccination for preventing severe and fatal influenza infection in older adults: a multicentre case-control study.

BACKGROUND: The effectiveness of repeated vaccination for influenza to prevent severe cases remains unclear. We evaluated the effectiveness of influenza vaccination on preventing admissions to hospital for influenza and reducing disease severity. METHODS: We conducted a case-control study in 20 hospitals in Spain during the 2013/14 and 2014/15 influenza seasons. Community-dwelling adults aged 65 years or older who were admitted to hospital for laboratory-confirmed influenza were matched with inpatient controls by sex, age, hospital and admission date. The effectiveness of vaccination in the current and 3 previous seasons in preventing influenza was estimated for inpatients with nonsevere influenza and for those with severe influenza who were admitted to intensive care units (ICUs) or who died. RESULTS: We enrolled 130 inpatients with severe and 598 with nonsevere influenza who were matched to 333 and 1493 controls, respectively. Compared with patients who were unvaccinated in the current and 3 previous seasons, adjusted effectiveness of influenza vaccination in the current and any previous season was 31% (95% confidence interval [CI] 13%-46%) in preventing admission to hospital for nonsevere influenza, 74% (95% CI 42%-88%) in preventing admissions to ICU and 70% (95% CI 34%-87%) in preventing death. Vaccination in the current season only had no significant effect on cases of severe influenza. Among inpatients with influenza, vaccination in the current and any previous season reduced the risk of severe outcomes (adjusted odds ratio 0.45, 95% CI 0.26-0.76). INTERPRETATION: Among older adults, repeated vaccination for influenza was twice as effective in preventing severe influenza compared with nonsevere influenza in patients who were admitted to hospital, which is attributable to the combination of the number of admissions to hospital for influenza that were prevented and reduced disease severity. These results reinforce recommendations for annual vaccination for influenza in older adults.

Factors associated with 30-day mortality in elderly inpatients with community acquired pneumonia during 2 influenza seasons.

Community-acquired pneumonia (CAP) refers to pneumonia unrelated to hospitals or extended-care facilities. The aim of this study was to determine factors associated with 30-day mortality in patients with CAP aged ≥ 65 y admitted to 20 hospitals in 7 Spanish regions during the 2013-14 and 2014-15 influenza seasons. Logistic regression was used to identify factors associated with 30-day mortality. The adjusted model included variables selected by backward elimination with a cut off of < 0.02. A total of 1928 CAP cases were recorded; 60.7% were male, 46.67% were aged 75-84 years, and 30-day mortality was 7.6% (n = 146). Pneumococcal vaccination had a significant protective effect (OR 0.68, 95% CI, 0.48-0.96; p = 0.03) and influenza vaccination in any 3 preceding seasons slight protective effect against CAP (OR 0.72, 95% CI, 0.51-1.02;p = 0.06). Factors significantly associated with 30-day mortality were having a degree of dependence (aOR 3.67, 95% CI, 2.34-5.75; p < 0,001); age ≥ 85 y (OR 3.01, 95% CI, 1.71-5.30; p < 0.001), liver impairment (aOR 2.41, 95% CI, 1.10-5.31; p = 0.03); solid organ neoplasm (aOR 2.24, 95% CI, 1.46-3.45; p < 0.001), impaired cognitive function (aOR 1.93, 95% CI, 1.22-3.05; p = 0.005), and ICU admittance (aOR2.56, 95% CI, 1.27-5.16; p = 0.009); length of stay (aOR 1.56, 95% CI, 1.02 - 2.40; p = 0.04) and cardio-respiratory resuscitation (aOR 7.75, 95% CI, 1.20 - 49.98; p = 0.03). No association was observed for other comorbidities such as chronic pulmonary obstructive disease (COPD) or heart conditions in the adjusted model. Offering both pneumococcal and influenza vaccination to the elderly may improve 30-day mortality in patients with CAP.

Effect of influenza vaccination on the prognosis of hospitalized influenza patients.

OBJECTIVES: This study aimed to assess whether influenza vaccination reduces the risk of severe and fatal outcomes in influenza inpatients aged ≥65 years. METHODS: During the 2013-2014 influenza season persons aged ≥65 years hospitalized with laboratory-confirmed influenza were selected in 19 Spanish hospitals. A severe influenza case was defined as admission to the intensive care unit, death in hospital or within 30 days after admission. Logistic regression was used to compare the influenza vaccination status between severe and non-severe influenza inpatients. RESULTS: Of 433 influenza confirmed patients, 81 (19%) were severe cases. Vaccination reduced the risk of severe illness (odds ratio: 0.57; 95%CI: 0.33-0.98). The cumulative number of influenza vaccine doses received since the 2010-2011 season was associated with a lower risk of severe influenza (odds ratio: 0.78; 95% CI 0.66-0.91). CONCLUSION: Adherence to seasonal influenza vaccination in the elderly may reduce the risk of severe influenza outcomes.

Influenza vaccine effectiveness in preventing inpatient and outpatient cases in a season dominated by vaccine-matched influenza B virus.

Studies that have evaluated the influenza vaccine effectiveness (VE) to prevent laboratory-confirmed influenza B cases are uncommon, and few have analyzed the effect in preventing hospitalized cases. We have evaluated the influenza VE in preventing outpatient and hospitalized cases with laboratory-confirmed influenza in the 2012-2013 season, which was dominated by a vaccine-matched influenza B virus. In the population covered by the Navarra Health Service, all hospitalized patients with influenza-like illness (ILI) and all ILI patients attended by a sentinel network of general practitioners were swabbed for influenza testing, and all were included in a test-negative case-control analysis. VE was calculated as (1-odds ratio) × 100. Among 744 patients tested, 382 (51%) were positive for influenza virus: 70% for influenza B, 24% for A(H1N1)pdm09, and 5% for A(H3N2). The overall estimate of VE in preventing laboratory-confirmed influenza was 63% (95% confidence interval (CI): 34 to 79), 55% (1 to 80) in outpatients and 74% (33 to 90) in hospitalized patients. The VE was 70% (41 to 85) against influenza B and 43% (-45 to 78) against influenza A. The VE against virus B was 87% (52 to 96) in hospitalized patients and 56% in outpatients (-5 to 81). Adjusted comparison of vaccination status between inpatient and outpatient cases with influenza B did not show statistically significant differences (odds ratio: 1.13; p = 0.878). These results suggest a high protective effect of the vaccine in the 2012-2013 season, with no differences found for the effect between outpatient and hospitalized cases.