Community-acquired Legionnaires' disease in a renal transplant recipient with unclear incubation period: the importance of molecular typing

Transplant recipients are at risk of developing Legionnaires' disease (LD) because of impaired cellular immunity. Here, we describe a renal transplant recipient who developed LD at least 10 days after hospital admission and transplantation. The hospital water network was initially suspected, but further testing determined that the probable source was the patient's domestic water supply. Our report also suggests that the patient's immunosuppressed state may have switched potential colonization to pneumonia.

Fatal NosocomialLegionella pneumophilaInfection Due to Exposure to Contaminated Water From a Washbasin in a Hematology Unit

A fatal nosocomial infection withLegionella pneumophilaserogroup 5 occurred in a patient with leukemia. Isolates recovered from both the potable water supply and the patient showed an identical genomic profile. With no other exposure identified, the water from the washbasin was evidently the source of infection.

Fungaemia caused by Fusarium proliferatum in a patient without definite immunodeficiency

Recent literature has shown the growing importance of opportunistic fungal infections due to Fusarium spp. However, disseminated fusariosis remains rare in patients without neutropenia. We report a case of fungaemia in a 78-year-old French woman without definite immunodeficiency. Fusarium proliferatum grew from both central and peripheral blood cultures. Fever was the only clinical sign of the infection. An appropriate antifungal therapy with voriconazole led to the recovery of the patient. An environmental investigation was undertaken but failed to find a reservoir of Fusarium spores. A contaminated central venous catheter might have been the source of fungaemia.

Hospital washbasin water: risk of Legionella-contaminated aerosol inhalation

The contamination of aerosols by washbasin water colonized by Legionella in a hospital was evaluated. Aerosol samples were collected by two impingement technologies. Legionella was never detected by culture in all the (aerosol) samples. However, 45% (18/40) of aerosol samples were positive for Legionella spp. by polymerase chain reaction, with measurable concentrations in 10% of samples (4/40). Moreover, immunoassay detected Legionella pneumophila serogroup 1 and L. anisa, and potentially viable bacteria were seen on viability testing. These data suggest that colonized hospital washbasins could represent risks of exposure to Legionella aerosol inhalation, especially by immunocompromised patients.

Incidence of hospital-acquired pneumonia, bacteraemia and urinary tract infections in patients with haematological malignancies, 2004-2010: a surveillance-based study

Objective

This study charted incidence trends of hospital-acquired (HA) pneumonia, bacteraemia and urinary tract infections (UTI) in a haematology department.

Methods

Prospective surveillance of hospital-acquired infections (HAI) was undertaken in a 42-bed haematology department of a university hospital. All patients hospitalized ≥48 hours between 1^st January 2004 and 31^st December 2010 were included. Definitions of HAI were based on a standardized protocol. The incidence was the number of events per 1000 patient-days at risk; only the first HAI was counted. Multivariate Poisson regression was fitted to assess temporal trends.

Results

Among 3 355 patients (58 063 patient-days at risk) included, 1 055 (31%) had HAI. The incidence of HA pneumonia, HA bacteraemia and HA UTI was respectively 3.3, 12.0 and 2.9 per 1000 patient-days at risk. HA bacteraemia incidence increased by 11% (95% confidence interval: +6%, +15%, P<0.001) per year, independently of neutropenia, central venous catheterization (CVC) and haematological disease. The incidences of HA pneumonia and HA UTI were stable. The most frequently isolated pathogens were Aspergillus spp. (59.2%) for pneumonia, coagulase-negative Staphylococcus (44.2%) for bacteraemia and enterobacteria (60%) for UTI.

Conclusion

The incidence of bacteraemia increased, indicating that factors other than CVC exposure, including chemotherapy with its impact on the immune system, could explain this trend. Further analytic studies are needed to explore the factors that could explain this trend.

Early-onset ventilator-associated pneumonia incidence in intensive care units: a surveillance-based study

Background

The incidence of ventilator-associated pneumonia (VAP) within the first 48 hours of intensive care unit (ICU) stay has been poorly investigated. The objective was to estimate early-onset VAP occurrence in ICUs within 48 hours after admission.

Methods

We analyzed data from prospective surveillance between 01/01/2001 and 31/12/2009 in 11 ICUs of Lyon hospitals (France). The inclusion criteria were: first ICU admission, not hospitalized before admission, invasive mechanical ventilation during first ICU day, free of antibiotics at admission, and ICU stay ≥ 48 hours. VAP was defined according to a national protocol. Its incidence was the number of events per 1,000 invasive mechanical ventilation-days. The Poisson regression model was fitted from day 2 (D2) to D8 to incident VAP to estimate the expected VAP incidence from D0 to D1 of ICU stay.

Results

Totally, 367 (10.8%) of 3,387 patients in 45,760 patient-days developed VAP within the first 9 days. The predicted cumulative VAP incidence at D0 and D1 was 5.3 (2.6-9.8) and 8.3 (6.1-11.1), respectively. The predicted cumulative VAP incidence was 23.0 (20.8-25.3) at D8. The proportion of missed VAP within 48 hours from admission was 11% (9%-17%).

Conclusions

Our study indicates underestimation of early-onset VAP incidence in ICUs, if only VAP occurring ≥ 48 hours are considered to be hospital-acquired. Clinicians should be encouraged to develop a strategy for early detection after ICU admission.

Invasive aspergillosis in patients with hematologic malignancies: incidence and description of 127 cases enrolled in a single institution prospective survey from 2004 to 2009

BACKGROUND

The study objectives were: 1) to report on invasive aspergillosis patients in a hematology department; and 2) to estimate its incidence according to the hematologic diagnosis.

DESIGN AND METHODS

A prospective survey of invasive aspergillosis cases was undertaken between January 2004 and December 2009 in the hematology department of a university hospital. Meetings with clinicians, mycologists and infection control practitioners were organized monthly to confirm suspected aspergillosis cases. Demographic characteristics, clinical and complementary examination results were recorded prospectively. Information on hospitalization was extracted from administrative databases. Invasive aspergillosis diagnosis followed the European Organization for Research and Treatment of Cancer criteria, and proven and probable IA cases were retained. A descriptive analysis was conducted with temporal trends of invasive aspergillosis incidence assessed by adjusted Poisson regression.

RESULTS

Overall, 4,073 hospitalized patients (78,360 patient-days) were included in the study. In total, 127 (3.1%) patients presented invasive aspergillosis. The overall incidence was 1.6 per 1,000 patient-days (95% confidence interval: 1.4, 1.9) with a decrease of 16% per year (-1%, -28%). The incidence was 1.9 per 1,000 patient-days (1.5, 2.3) in acute myeloid leukemia patients with a decrease of 20% per year (-6%, -36%). Serum Aspergillus antigen was detected in 89 (71%) patients; 29 (23%) had positive cultures, and 118 (93%), abnormal lung CT scans. One-month mortality was 13%; 3-month mortality was 42%. Mortality tended to decrease between 2004 and 2009.

CONCLUSIONS

Invasive aspergillosis incidence and mortality declined between 2004 and 2009. Knowledge of invasive aspergillosis characteristics and its clinical course should help to improve the management of these patients with severe disease.

Risk factors for invasive aspergillosis in acute myeloid leukemia patients prophylactically treated with posaconazole

Invasive aspergillosis (IA) is an important cause of morbidity and mortality in neutropenic patients with hematological malignancies. To investigate the immediate and mid-term benefits of posaconazole prophylaxis in AML patients undergoing first induction chemotherapy and to study the infection risk factors, we prospectively studied the IA incidence in these patients at our hospital between years 2007 and 2008; then we compared them to a matched control group without prophylaxis. There were 55 and 66 patients in each group respectively. At day 32 post-induction, two probable cases (3.6%) were scored in the prophylaxis group compared to 8 cases (12.1%) in the control group (4 possible and 4 probable). At day 100, it reached 7.27% and 15.5% respectively. Kaplan-Meier analysis at day 100 showed lower mortality rate in the prophylaxis group compared to the control group [3.64% (n = 2, none due to IA) and 10.61% (n = 7, four due to IA) respectively, P = 0.002]. Multivariate analysis showed age and lack of response to induction as independent infection risk factors. Posaconazole prophylaxis resulted in lower incidence of IA and significantly improved survival. Patient's age and response to induction treatment are two independent infection risk factors, and need more attention during future clinical trials linked to antifungal prophylaxis.

Aspergillosis: nosocomial or community-acquired?

Discrimination between nosocomial and community infections is important for investigation and prevention. Nosocomial and hospital-acquired infections require appropriate hospital control measures to avert additional cases. Nosocomial infections (NI) occur during hospitalization or are caused by microorganisms acquired during hospital stay. Such infections should not be evident when patients are admitted to the hospital. Furthermore, the definition of NI is based on epidemiological criteria, such as the time lapse between admission and onset, or microbiological criteria. This definition might be difficult to apply to invasive aspergillosis (IA) which often afflicts patients with severe immunosuppression or transplantation. Identification of the source may be difficult which could arise outside or inside the hospital. Another significant issue is the lack of valid and reproducible data on the incubation period. The incubation duration of IA is influenced by different individual or environmental determinants, including the severity of immunosuppression and air quality. The criteria of causality are also a means of discussing the contribution of hospital vs. community determinants of IA. The definition of nosocomial IA remains difficult. A better understanding of early events related to IA onset will help to prevent this disease for which the prognosis remains negative.

Estimating attributable mortality due to nosocomial infections acquired in intensive care units

BACKGROUND

The strength of the association between intensive care unit (ICU)-acquired nosocomial infections (NIs) and mortality might differ according to the methodological approach taken.

OBJECTIVE

To assess the association between ICU-acquired NIs and mortality using the concept of population-attributable fraction (PAF) for patient deaths caused by ICU-acquired NIs in a large cohort of critically ill patients.

SETTING

Eleven ICUs of a French university hospital.

DESIGN

We analyzed surveillance data on ICU-acquired NIs collected prospectively during the period from 1995 through 2003. The primary outcome was mortality from ICU-acquired NI stratified by site of infection. A matched-pair, case-control study was performed. Each patient who died before ICU discharge was defined as a case patient, and each patient who survived to ICU discharge was defined as a control patient. The PAF was calculated after adjustment for confounders by use of conditional logistic regression analysis.

RESULTS

Among 8,068 ICU patients, a total of 1,725 deceased patients were successfully matched with 1,725 control patients. The adjusted PAF due to ICU-acquired NI for patients who died before ICU discharge was 14.6% (95% confidence interval [CI], 14.4%-14.8%). Stratified by the type of infection, the PAF was 6.1% (95% CI, 5.7%-6.5%) for pulmonary infection, 3.2% (95% CI, 2.8%-3.5%) for central venous catheter infection, 1.7% (95% CI, 0.9%-2.5%) for bloodstream infection, and 0.0% (95% CI, -0.4% to 0.4%) for urinary tract infection.

CONCLUSIONS

ICU-acquired NI had an important effect on mortality. However, the statistical association between ICU-acquired NI and mortality tended to be less pronounced in findings based on the PAF than in study findings based on estimates of relative risk. Therefore, the choice of methods does matter when the burden of NI needs to be assessed.

Reduction of Invasive Aspergillosis Incidence among Immunocompromised Patients after Control of Environmental Exposure

BACKGROUND

The objective of the study was to assess the impact of the relocation of an adult hematological intensive care unit on invasive aspergillosis (IA) incidence.

METHODS

A quasi-experimental study, including a control group and an intervention group that both underwent pretest and posttest evaluations, was conducted in the 3 adult hematological intensive care units (each composed of 14 single rooms) in a university hospital from 14 April 2005 through 1 February 2006. One of these units was relocated from the main building to an adjoining modular construction. In this unit, 4 rooms were equipped with laminar airflow before relocation; all rooms were equipped with positive pressure isolation after relocation. The 2 other units (control group), each containing 8 rooms with laminar airflow, did not undergo environmental modification. The diagnostic criteria for IA were based on the criteria of the European Organization for Research and Treatment of Cancer.

RESULTS

In total, 356 hospitalized patients were included. Of the 21 cases of IA, 18 were nosocomial, and 3 were of undetermined origin. In the relocated unit, the incidence of IA decreased from 13.2% (9 patients) before relocation to 1.6% (1 patient) after relocation (P=.018). Eight of the 9 patients with IA before relocation stayed in rooms without specific air treatment. The rate of IA did not change in the control group. Patient characteristics were similar in each unit before and after relocation.

CONCLUSION

We detected a straightforward association between environmental modification and decreased IA incidence, which emphasizes the use of an environmental strategy, including high-efficiency air filtration, in the prevention of IA.

[Indicators of quality for hospital antisepsis]

In any health care institution, the most important quality indicator for antisepsis is the existence of systems of reference of use, secondly the knowledge of those systems and then the compliance by the different classes of professionals. These refrentials must be regularly evaluated and updated according to general consensus.

[Hospital infection in maternity homes]

The results of the prospective survey of hospital infections in mothers and newborns at the obstetrical clinic of the Edouard Herriot Hospital in Lyon are presented. Surveillance lasting six successive years covered 18,026 deliveries with or without the use of cesarean section. The incidence of hospital infections (not taking into account cases of bacteriuria) was 1.6% in parturient women not subjected to cesarean section and 11.7% in those having had this operation. Urinary tract and parietal infections, endometritis were in leading cases. The average incidence of hospital infection in newborns was 2.68%, the leading clinical manifestations being peripheral staphylococcal lesions in the form of pustules.

[Nosocomial septicemia and pseudobacteremia caused by Serratia marcescens]

An epidemiological survey was carried out which included a dual epidemic of septicaemia and pseudo-bacteremia caused by Serratia marcescens. The survey enabled 15 septicaemias and 43 pseudobacteremias to be detected in a regional hospital between March and August, 1983. Two mishandlings were at the origin of the outbreak: citrated tube normally reserved for coagulation tests were severely contaminated by Serratia marcescens, and inaccurate samplings had been made. Once the mechanisms of contamination were found, specific preventive measures put an end to the epidemic. The authors insist on the need for uncontaminated tubes and citrate solutions and for the development of precise sampling methods which are essential to avoid the occurrence of pseudo-bacteremia or septicaemia. It is important to detect such epidemics at an early stage by an efficient control of nosocomial infections, thus avoiding their extension.