Incidence des bactériémies et fongémies aux hôpitaux universitaires de Strasbourg de 2005 à 2007

Changing aetiology of healthcare-associated bloodstream infections at three medical centres in Taiwan, 2000-2011

This multicentre surveillance study was conducted to investigate the trends in incidence and aetiology of healthcare-associated bloodstream infections (HCA-BSIs) in Taiwan. From 2000 to 2011 a total of 56 830 HCA-BSIs were recorded at three medical centres, and coagulase-negative staphylococci (CoNS) were the most common pathogens isolated (n = 9465, 16·7%), followed by E. coli (n = 7599, 13·4%). The incidence of all HCA-BSIs in each and all hospitals significantly increased over the study period owing to the increase of aerobic Gram-positive cocci and Enterobacteriaceae by 4·2% and 3·6%, respectively. Non-fermenting Gram-negative bacteria, Bacteroides spp. and Candida spp. also showed an increase but there was a significant decline in the numbers of methicillin-resistant S. aureus. In conclusion, the incidence of HCA-BSIs in Taiwan is significantly increasing, especially for Enterobacteriaceae and aerobic Gram-positive cocci.

Vancomycin MICs do not predict the outcome of methicillin-resistant Staphylococcus aureus bloodstream infections in correctly treated patients

BACKGROUND

Recent studies have reported a greater probability of vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections caused by strains with a vancomycin MIC ≥ 1.5 mg/L. However, previous reports included patients treated without adjustments based on vancomycin serum levels and with different methods to evaluate MICs, which may render different results.

METHODS

Over a 5 year period (2005-09), vancomycin MICs were determined for 361 MRSA isolates recovered from 309 patients with bloodstream infection using microdilution and the Etest simultaneously. The relationship between the vancomycin MICs determined by each method was assessed. To assess the outcome of patients treated with vancomycin, 104 patients for whom serum vancomycin levels had been determined were selected.

RESULTS

The percentage of MRSA strains with MIC values ≥ 1.5 mg/L according to the Etest was 66.5% compared with only 3.6% according to microdilution. No correlation between mortality and any MIC value obtained with either method was observed, independently of the vancomycin serum levels measured.

CONCLUSIONS

There is a poor correlation between vancomycin MIC values obtained by microdilution and by Etest. No association between mortality rate and any MIC value was observed, not even in patients with suboptimal vancomycin trough serum levels. These data do not support replacing or complementing the standard microdilution test with the Etest for determination of MICs of vancomycin in microbiology laboratories.

Pneumococcus infections: is the burden still as heavy?

The death rate of invasive pneumococcal infections decreased by 100 fold in one century. This tremendous improvement was due mainly to antibiotic use and multiple attempts at antipneumococcal vaccinations; thus, this was true only for developed countries. However, in France, the incidence has increased, over the last 10 years, in all age classes except for children vaccinated by the heptavalent pneumococcal conjugate vaccine. The incidence of these infections remains high, when associated to some risk factors such as HIV infection, malignant blood diseases, solid cancers, bronchial diseases, or alcohol abuse. The pneumococcal vaccine should be prescribed first to patients with those risk factors. A change of serotypes distribution has been observed in children with a decrease of vaccine serotypes and predominance of related or non-vaccine serotypes. This reflects the effectiveness of vaccination and the need of to regularly update the vaccine. Thus, pneumococcal infections have been increasing and vaccination should be more widely proposed.

Incidence of bacteremia at the time of ICU admission and its impact on outcome

CONTEXT

Blood culture is routinely taken at the time of admission to the intensive care unit (ICU) for patients suspected to have infection. We undertook this study to determine the incidence of bacteremia at the time of ICU admission and to assess its impact on the outcome.

METHODS

Retrospective cohort study from all the admissions in ICU, in whom blood cultures sent at the time of admission were analyzed. Data regarding patient demographics, probable source of infection, previous antibiotic use and ICU course was recorded. Severity of illness on admission was assessed by acute physiology and chronic health evaluation II score.

STATISTICAL ANALYSIS

Qualitative data were analyzed using Chi-square or Fisher Exact test and quantitative data were analyzed using Student's t-test. Primary outcome measure was ICU mortality.

RESULTS

Of 567 patients, 42% patients were on antibiotics. Sixty-four percent of the patients were direct ICU admission from casualty, 10.76% were from wards and 6.17% from other ICUs, and 19.05% were transfers from other hospitals. Blood cultures were positive in 10.6% patients. Mortality was significantly higher in patients with positive blood cultures (45% vs. 13.6%; P=0.000). On univariate analysis, only previous antibiotic use was statistically associated with higher mortality (P=0.011). Bacteremic patients who were already on antibiotics had a significantly higher mortality (OR 12.9, 95% CI: 1.6-100).

CONCLUSIONS

Blood cultures may be positive in only minority of the patients with suspected infection admitted to ICU. Nevertheless, the prognosis of those patients with positive blood culture is worse, especially if culture is positive in spite of the patient being on antibiotics.

Incidence of bacteremia at the time of ICU admission and its impact on outcome

CONTEXT

Blood culture is routinely taken at the time of admission to the intensive care unit (ICU) for patients suspected to have infection. We undertook this study to determine the incidence of bacteremia at the time of ICU admission and to assess its impact on the outcome.

METHODS

Retrospective cohort study from all the admissions in ICU, in whom blood cultures sent at the time of admission were analyzed. Data regarding patient demographics, probable source of infection, previous antibiotic use and ICU course was recorded. Severity of illness on admission was assessed by acute physiology and chronic health evaluation II score.

STATISTICAL ANALYSIS

Qualitative data were analyzed using Chi-square or Fisher Exact test and quantitative data were analyzed using Student's t-test. Primary outcome measure was ICU mortality.

RESULTS

Of 567 patients, 42% patients were on antibiotics. Sixty-four percent of the patients were direct ICU admission from casualty, 10.76% were from wards and 6.17% from other ICUs, and 19.05% were transfers from other hospitals. Blood cultures were positive in 10.6% patients. Mortality was significantly higher in patients with positive blood cultures (45% vs. 13.6%; P=0.000). On univariate analysis, only previous antibiotic use was statistically associated with higher mortality (P=0.011). Bacteremic patients who were already on antibiotics had a significantly higher mortality (OR 12.9, 95% CI: 1.6-100).

CONCLUSIONS

Blood cultures may be positive in only minority of the patients with suspected infection admitted to ICU. Nevertheless, the prognosis of those patients with positive blood culture is worse, especially if culture is positive in spite of the patient being on antibiotics.