Incidence of nosocomial aspergillosis in patients with leukemia over a twenty-year period

Incidence of invasive aspergillosis following remission-induction chemotherapy for acute leukemia: a retrospective cohort study in a single Canadian tertiary care centre

BACKGROUND

The decision to use universal primary antimould prophylaxis to prevent invasive aspergillosis in patients with acute leukemia depends on the incidence of infection at individual centres. We determined our institution's incidence of invasive aspergillosis among patients who received remission-induction chemotherapy for acute leukemia to evaluate the potential benefits of primary antimould prophylaxis.

METHODS

We conducted this retrospective cohort study at a Canadian tertiary care centre. From the central pharmacy registries, we retrieved records for all adult patients for whom remission-induction chemotherapy for acute leukemia was prescribed between 2008 and 2010. We retrieved clinical, microbiologic, pathologic and radiologic data from the patients' medical charts. The primary outcome was a diagnosis of probable or proven invasive aspergillosis up to 180 days after resolution of aplasia.

RESULTS

We retrieved records for 123 patients with acute leukemia. Twenty-two of these patients did not receive the prescribed chemotherapy and were excluded from the analysis. Of the 101 patients included, 77 (76.2%) had acute myeloid leukemia. Overall, 136 courses of chemotherapy were administered, with more than 1 course administered to 26 (25.7%) of the 101 patients. In 9 of the patients (8.9%; 95% confidence interval 4.2%-16.2%), invasive aspergillosis was diagnosed (3 proven and 6 probable cases) a median of 19 (range 11-34) days after initiation of chemotherapy. In 7 (78%) of these 9 patients, invasive aspergillosis occurred during the first course of chemotherapy. Three patients died within the first year after diagnosis of invasive aspergillosis.

INTERPRETATION

We found a high incidence (8.9%) of invasive aspergillosis at our centre. This finding triggered the introduction of targeted antimould prophylaxis for patients with acute leukemia who were undergoing remission-induction chemotherapy.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Effectiveness of preventive measures for hemato-oncologic patients undergoing stem cell transplantation during a period of hospital construction

BACKGROUND

Aspergillus spp are ubiquitous spore-forming fungi. Construction work, renovation, demolition, or excavation activities within a hospital or in surrounding areas increase the risk for aspergillus infection in susceptible patients and are the main cause of nosocomial aspergillus outbreaks.

METHODS

We investigated the efficacy of infection control measures on the frequency of fungal infection among hemato-oncologic patients undergoing stem cell transplantation during excavation and construction work of an adjacent hospital building. Clinical isolates from these patients obtained before and during the excavation and construction period were analyzed. Preventive measures consisted in the implementation of a multibarrier concept to protect these patients from fungal infection.

RESULTS

There was no record of any clinical isolate of Aspergillus spp in the observation period before the beginning of the groundwork. However, 3 clinically significant isolates of Aspergillus spp were detected in respiratory tract specimen of 2 patients after the beginning of excavation and demolition work, which were found to be community acquired.

CONCLUSION

Although our data cannot demonstrate the efficacy of infection control measures during construction work, it can be concluded that excavation work close to immunocompromised patients is safe if a bundle of preventive measures is implemented before groundwork.

Hospital epidemiology and infection control in acute-care settings

Health care-associated infections (HAIs) have become more common as medical care has grown more complex and patients have become more complicated. HAIs are associated with significant morbidity, mortality, and cost. Growing rates of HAIs alongside evidence suggesting that active surveillance and infection control practices can prevent HAIs led to the development of hospital epidemiology and infection control programs. The role for infection control programs has grown and continues to grow as rates of antimicrobial resistance rise and HAIs lead to increasing risks to patients and expanding health care costs. In this review, we summarize the history of the development of hospital epidemiology and infection control, common HAIs and the pathogens causing them, and the structure and role of a hospital epidemiology and infection control program.

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.

Treatment of invasive fungal infections in clinical practice: a multi-centre survey on customary dosing, treatment indications, efficacy and safety of voriconazole

Invasive fungal infections are frequent and often deadly complications in patients with malignant hematological diseases. Voriconazole is a third generation triazole antifungal with broad activity against most clinically relevant fungal pathogens. Clinical practice often deviates from insights gained from controlled randomized trials. We conducted a multi-centre survey to evaluate efficacy, safety, treatment indications and dosing of voriconazole outside clinical trials. Patients receiving voriconazole were documented via electronic data capturing. An analysis was conducted after submission of 100 episodes from September 2004 to November 2005. Voriconazole was administered for suspected or proven invasive fungal infection (IFI) (57%), as empirical treatment in patients with fever of unknown origin (21%) and secondary (19%) as well as primary (3%) prophylaxis of IFI. Investigators’ assessment of fungal infection often diverted from EORTC/MSG 2002 criteria. A favorable response was reported in 61.4% for suspected or proven IFI and 52.4% for empirical treatment. Mortality was 15%, 26.7% of which was attributable to IFI. Breakthrough fungal infections occurred in four (21.1%) patients with voriconazole as secondary prophylaxis. Toxicity and adverse events comprised elevated liver enzymes and visual disturbances. Although indications frequently deviated from clinical evidence and legal approval, voriconazole showed efficacy and safety, comparable to major controlled clinical trials. Data from this survey demonstrate the difficulty of putting drugs to their approved use in IFI.

A double-blind trial on prophylactic voriconazole (VRC) or placebo during induction chemotherapy for acute myelogenous leukaemia (AML)

OBJECTIVES

Invasive fungal infections remain a frequent cause of morbidity and mortality in long-term neutropenic patients. The availability of tolerable broad-spectrum antifungals like voriconazole stimulated the discussion about optimal timing of antifungal therapy. We conducted a trial to analyze the efficacy and safety of voriconazole in the prevention of lung infiltrates during induction chemotherapy for acute myelogenous leukaemia (AML).

METHODS

This was a prospective, randomised, double-blind, placebo-controlled phase III trial in AML patients undergoing remission induction chemotherapy. Oral voriconazole 200 mg twice daily or placebo was administered until detection of a lung infiltrate or end of neutropenia. Primary efficacy parameter was the incidence of lung infiltrates until day 21 after initiation of chemotherapy. Secondary objectives were incidence of infections, length of stay in hospital, time to antifungal treatment, time to first fever, and drug safety.

RESULTS

A total of 25 patients were randomly assigned to receive voriconazole (N=10) or placebo (N=15). Incidence of lung infiltrates until day 21 was 0 (0%) in the voriconazole and 5 (33%) in the placebo group (P=0.06). Average length of stay in hospital was shorter in the voriconazole group (mean 31.9 days) than in the placebo group (mean 37.3 days, P=0.09). Four patients were diagnosed with hepatosplenic candidiasis until a 4 week follow-up, all in the placebo group (P=0.11). Adverse events and toxicity did not differ between the two treatment groups. The trial was stopped prematurely when another trial demonstrated reduced mortality by antifungal prophylaxis with posaconazole, thus rendering further randomisation against placebo unethical.

CONCLUSION

In AML patients undergoing induction chemotherapy, prophylactic oral voriconazole 200 mg twice daily resulted in trends towards reduced incidences of lung infiltrates and hepatosplenic candidiasis. Voriconazole was safe and well tolerated.

Emerging dermatologic issues in the oncology patient

The spectrum of skin diseases that occurs in the oncology patient differs somewhat from that seen in other immunosuppressed populations. We review the cutaneous manifestations of invasive mold infections in the leukemia/lymphoma population. Aspergillus mold infections are now the leading infectious cause of death in this population. We also review the pustular eruption caused by a new class of chemotherapy for solid malignancies. An update on cutaneous graft-versus-host disease appears elsewhere in this journal. Cutaneous squamous cell carcinomas and basal cell carcinomas occur more frequently in the chronic lymphocytic leukemia and non-Hodgkin's lymphoma population; this is discussed, as is the more aggressive clinical course of these tumors.

Nosocomial fungal infections: epidemiology, diagnosis, and treatment

Invasive fungal infections are increasingly common in the nosocomial setting. Furthermore, because risk factors for these infections continue to increase in frequency, it is likely that nosocomial fungal infections will continue to increase in frequency in the coming decades. The predominant nosocomial fungal pathogens include Candida spp., Aspergillus spp., Mucorales, Fusarium spp., and other molds, including Scedosporium spp. These infections are difficult to diagnose and cause high morbidity and mortality despite antifungal therapy. Early initiation of effective antifungal therapy and reversal of underlying host defects remain the cornerstones of treatment for nosocomial fungal infections. In recent years, new antifungal agents have become available, resulting in a change in standard of care for many of these infections. Nevertheless, the mortality of nosocomial fungal infections remains high, and new therapeutic and preventative strategies are needed.

Hospital-wide prospective mandatory surveillance of invasive aspergillosis in a French teaching hospital (2000-2002)

A multidisciplinary working group devoted to epidemiological surveillance of invasive aspergillosis (IA) was created in January 2000 in Grenoble University Hospital. This article presents the results of a three-year IA surveillance. The multidisciplinary working group surveyed all hospitalized patients, and the mycology laboratory detected most suspected IA cases. Cases were reviewed monthly by the Aspergillosis Committee, and were classified according to international consensus criteria. Possible nosocomial acquisition was determined. Among the 490 alerts, 74 IA cases were observed: six proven cases (8%), 36 (49%) probable cases and 32 (43%) possible cases. The incidence was 4.4 (95% CI 3.4-5.4) IA/100 000 patient-days. Among the proven and probable IA cases, we observed 10 nosocomial cases and six cases of undetermined origin. No cases were noted in the protected rooms in the haematology unit. Only one cluster of cases (three nosocomial cases) was detected in the haematology unit. Forty-three percent of cases (N=32) were hospitalized in the haematology unit, and all other cases were hospitalized elsewhere. This three-year survey found a high rate of non-nosocomial IA cases and a high frequency of IA cases hospitalized in units other than haematology. Thus, this study shows the importance of IA surveillance in haematology units and all high-risk units.

The epidemiology and prevention of invasive aspergillosis

Over the past two decades, the incidence of invasive aspergillosis (IA) has risen inexorably. This is almost certainly the consequence of the more widespread use of aggressive cancer chemotherapy regimens, the expansion of organ transplant programmes and the advent of the acquired immunodeficiency syndrome (AIDS) epidemic. Despite the development of new approaches to therapy, IA still remains a life-threatening infection in immunocompromised patients and is the most important cause of fungal death in cancer patients. It is clear that the prevention of severe fungal infection by the use of effective infection control measure should be the priority of the teams involved in managing at-risk patients. The evidence from clinical and molecular epidemiological studies is reviewed and current thinking on sources and routes of transmission of the organism are discussed. Our increasing understanding of these has led to the development of a variety of environmental and general strategies for the prevention of IA. It is anticipated that these, coupled with the use of prophylactic antifungal agents active against Aspergillus spp., will have a significant impact upon the morbidity and mortality associated with this infection.

Invasive aspergillosis in severely neutropenic patients over 18 years: impact of intranasal amphotericin B and HEPA filtration

The impact of intranasal amphotericin B and high-efficiency particulate air (HEPA) filtration on the incidence of invasive aspergillosis was reviewed in patients from 1977 to 1994 undergoing intensive chemotherapy. Overall, the incidence of proven invasive aspergillosis was reduced from 24.4% (1977-1984) to 7.1% (1985-1991) (P < 0.001) following the introduction of intranasal prophylaxis, but when probable cases of aspergillosis were included and lymphoma cases excluded, there was no change in incidence. Following the introduction of HEPA filtration, patient exposure to aspergillus spores as measured by air sampling was markedly reduced and there were no new cases of invasive aspergillosis. HEPA filtration proved effective in reducing invasive aspergillosis and has allowed increasingly aggressive treatment regimens to be introduced.

Infection control and bone marrow transplantation

BACKGROUND

Bone marrow transplantation for the treatment of malignancies is on the increase. Unfortunately, there are no well-validated infection control guidelines for this highly susceptible population.

METHODS

Literature was reviewed concerning infection risks and interventions to decrease risks for bone marrow transplant recipients.

RESULTS

Definitive information was generally lacking. However, basic "common sense" infection control recommendations for bone marrow transplantation were made in the following areas: air ventilation systems, design issues, environmental services, patient care issues, barrier precautions, nosocomial surveillance, and discharge planning. Recommendations must be tailored to each facility or setting.

CONCLUSION

We conclude that validation of many of these recommendations is necessary to provide optimum care for bone marrow transplant recipients.

Invasive aspergillosis in two patients with acute lymphoblastic leukaemia in complete remission

Invasive aspergillosis is a disease of the immunosuppressed patient. We describe two patients with acute lymphoblastic leukaemia who attained complete remission, with partial or complete bone marrow recovery, but who went on to develop fatal invasive aspergillosis contemporaneous with recovery of neutrophil counts. Quantitative recovery of peripheral blood neutrophil counts does not guarantee control of Aspergillus infection, perhaps due to functional neutrophil deficiencies post-chemotherapy, and specific defensive strategies adopted by the organism itself.

Aspergillus quadrilineatus, a new causative agent of fungal sinusitis

Aspergillus quadrilineatus was found to be the etiologic agent of pansinusitis in a patient suffering from acute nonlymphoblastic leukemia and who had undergone allogeneic bone marrow transplantation. A. quadrilineatus was cultured from biopsy specimens of the maxillary sinus, and tissue sections with fungal stains showed a necrotic area containing dichotomously branching septate hyphae, which is morphologically consistent with Aspergillus species. The patient was successfully treated with a combination of surgical debridement, granulocyte transfusions, and intravenous administration of amphotericin B-cholesterol sulfate colloidal dispersion. This is the first report of an infection caused by A. quadrilineatus.

Nosocomial pneumonia in patients having bone marrow transplant. Attributable mortality and risk factors

The authors performed a matched historic cohort study to determine the attributable mortality and risk factors for nosocomial pneumonia in bone marrow transplant (BMT) recipients. All patients with nosocomial pneumonia at a university tertiary care center were identified by a prospective surveillance system between 1980 and 1988. Control patients were selected from the population of BMT patients. The crude mortality for 55 patients with nosocomial pneumonia was 74.5% (95% confidence interval [CI95], 63% to 86%). The excess or attributable mortality was 61.8% (CI95, 43.7% to 80%). Aspergillus species represented the most frequent etiologic agent in this series, causing 20 of the 55 (36%) episodes. The attributable mortality of Aspergillus species pneumonia alone was 85% (CI95, 58.6% to 100%). For death in the hospital, the risk ratio for all 55 case patients relative to control patients was 9.5 (CI95, 4.1 to 22.1). To evaluate several risk factors simultaneously, a multiple logistic regression analysis using a conditional likelihood method was performed. A mathematical model with three variables best predicted nosocomial pneumonia in our patients: the occurrence of other nosocomial infections before the diagnosis of pneumonia, allogeneic BMT, and the use of methotrexate. The presence of other nosocomial infections before the diagnosis of pneumonia remained a significant independent risk factor, with an odds ratio of 13.27 (CI95, 2.51 to 70.2) after adjustment for the use of methotrexate and allogeneic BMT. Most importantly, effective methods for preventing nosocomial pneumonias in BMT recipients will have an enormous effect on crude mortality.