Outbreak of invasive aspergillosis among renal transplant recipients

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

Risk factors for the development of invasive aspergillosis after kidney transplantation: Systematic review and meta-analysis

To investigate risk factors for invasive aspergillosis (IA) after kidney transplantation (KT), we conducted a systematic search in PubMed and EMBASE to identify studies published until June 2020. We included case-control or cohort design studies comprising KT recipients with a diagnosis of IA, defined according to the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group criteria, and assessed risk factors for the development of IA. Random-effect models meta-analysis served to pool data. We identified eleven case-control studies (319 IA cases and 835 controls). There was an increased risk of IA among recipients with underlying chronic lung diseases (odds ratio [OR] = 7.26; 95% confidence interval [CI] = 1.05-50.06) and among those with diabetic nephropathy (OR = 1.65; 95% CI = 1.10-2.48). Requiring posttransplant hemodialysis (OR = 3.69; 95% CI = 2.13-6.37) or surgical reintervention (OR = 6.28; 95% CI = 1.67-23.66) were also associated with an increased risk. Moreover, a positive link was identified between IA and posttransplant bacterial infection (OR = 7.51; 95% CI = 4.37-12.91), respiratory tract viral infection (OR = 7.75; 95% CI = 1.60-37.57), cytomegalovirus infection or disease (OR = 2.67; 95% CI = 1.12-6.32), and acute graft rejection (OR = 3.01; 95% CI = 1.78-5.09). In contrast, receiving a kidney from a living donor was associated with a reduced risk (OR = 0.65; 95% CI = 0.46-0.93). KT recipients that accumulate several of these conditions should be closely monitored and a low threshold of suspicion for IA should be maintained. Future studies should explore the benefit of mold-active prophylaxis to this subgroup of KT recipients at highest risk.

A review on the consumption of vended fruits: microbial assessment, risk, and its control

Fruits are very beneficial to health and their consumption has been recommended in daily diets. However, when fresh fruits are harvested and processed into sliced ready-to-eat or vended forms for sale, hygienic procedures are neglected. Thus, they are easily infested by pathogens. In addition, uneducated vendors who sell these fruits often display or hawk them on the streets in contaminated containers, utensils, or dirty environments. This poses a great threat to the health of consumers. In the light of this realization, some microbial assessments have been carried out to ascertain the safety of these vended fruits, thus making it a necessity to exploit the outcomes of some of these microbial assessments on vended fruits in order to sensitize the consumers on the effect of their consumption and mitigate risk by improving their quality. This will assist to lower certain health concerns, an outbreak of diseases, and death.

Invasive Aspergillosis in solid-organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines provide information on epidemiology, diagnosis, and management of Aspergillus after organ transplantation. Aspergillus is the most common invasive mold infection in solid-organ transplant (SOT) recipients, and it is the most common invasive fungal infection among lung transplant recipients. Time from transplant to diagnosis of invasive aspergillosis (IA) is variable, but most cases present within the first year post-transplant, with shortest time to onset among liver and heart transplant recipients. The overall 12-week mortality of IA in SOT exceeds 20%; prognosis is worse among those with central nervous system involvement or disseminated disease. Bronchoalveolar lavage galactomannan is preferred for the diagnosis of IA in lung and non-lung transplant recipients, in combination with other diagnostic modalities (eg, chest CT scan, culture). Voriconazole remains the drug of choice to treat IA, with isavuconazole and lipid formulations of amphotericin B regarded as alternative agents. The role of combination antifungals for primary therapy of IA remains controversial. Either universal prophylaxis or preemptive therapy is recommended in lung transplant recipients, whereas targeted prophylaxis is favored in liver and heart transplant recipients. In these guidelines, we also discuss newer antifungals and diagnostic tests, antifungal susceptibility testing, and special patient populations.

Transplant tourism and invasive fungal infection

BACKGROUND

Deceased and live-related renal transplants (RTXs) are approved procedures that are performed widely throughout the world. In certain regions, commercial RTX has become popular, driven by financial greed.

METHODS

This retrospective, descriptive study was performed at the Royal Hospital from 2013 to 2015. Data were collected from the national kidney transplant registry of Oman. All transplant cases retrieved were divided into two groups: live-related RTX performed in Oman and commercial-unrelated RTX performed abroad. These groups were then divided again into those with and without evidence of fungal infection, either in the wound or renal graft.

RESULTS

A total of 198 RTX patients were identified, of whom 162 (81.8%) had undergone a commercial RTX that was done abroad. Invasive fungal infections (IFIs) were diagnosed in 8% of patients who had undergone a commercial RTX; of these patients, 76.9% underwent a nephrectomy and 23.1% continued with a functioning graft. None of the patients with RTXs performed at the Royal Hospital contracted an IFI. The most common fungal isolates were Aspergillus species (including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, and Aspergillus nigricans), followed by Zygomycetes. However, there was no evidence of fungal infection including Aspergillus outside the graft site. Computed tomography (CT) findings showed infarction of the graft, renal artery thrombosis, aneurysmal dilatation of the external iliac artery, fungal ball, or just the presence of a perigraft collection. Of the total patients with IFIs, 23.1% died due to septic shock and 53.8% were alive and on hemodialysis. The remaining 23.1% who did not undergo nephrectomy demonstrated acceptable graft function.

CONCLUSIONS

This is the largest single-center study on commercial RTX reporting the highest number of patients with IFI acquired over a relatively short period of time. Aspergillus spp were the main culprit fungi, with no Candida spp being isolated. A high index of suspicion might be the most reasonable means to reduce the possible very poor outcomes. Improving legal transplant programs and strengthening the associated laws could prevent commercial transplant tourism.

Renal Allograft Aspergillus Infection Presenting With Obstructive Uropathy: A Case Report

BACKGROUND

Isolated renal allograft aspergillosis is rare and usually presents with fever and decreased glomerular filtration rate. Presentation with obstructive uropathy caused by aspergillus fungal balls is much less common. We report a young male patient who presented with obstructive uropathy secondary to isolated renal allograft aspergillus infection 6 weeks after transplant. He was treated with nephrectomy and antifungal medications.

CASE PRESENTATION

A 29-year-old Saudi male patient had a recent living non-related kidney transplantation in Pakistan. Early Post-transplant course was complicated by acute cellular rejection (Banff Class IB) which was managed successfully with pulse steroid and anti-thymocyte globulin. The patient presented again to our emergency room on fortieth day post-transplant with a complaint of decreased urine output and passing white particles in his urine. This presentation was three Three weeks after treatment for cellular rejection, the urine fungal culture showed growth of Aspergillus fumigatus, and ultrasound imaging of the allograft kidney revealed mild to moderate hydronephrosis with echogenic materials within the renal pelvis. Biopsy of the transplanted kidney showed severe necrotizing granulomatous inflammation and fungal elements consistent with aspergillus species. The patient was given voriconazole as an antifungal agent and was weaned from immunosuppressive medication. The patient eventually required intermittent hemodialysis and underwent surgical allograft nephrectomy.

CONCLUSION

Suboptimal environmental and infection prevention and control precautions can explain this type of infection. It is important for clinicians to have a high index of suspicion and to investigate for fungal infection as a rare cause of obstructive uropathy in high-risk patients.

Risk Factors Associated With Early Invasive Pulmonary Aspergillosis in Kidney Transplant Recipients: Results From a Multinational Matched Case-Control Study

Risk factors for invasive pulmonary aspergillosis (IPA) after kidney transplantation have been poorly explored. We performed a multinational case-control study that included 51 kidney transplant (KT) recipients diagnosed with early (first 180 posttransplant days) IPA at 19 institutions between 2000 and 2013. Control recipients were matched (1:1 ratio) by center and date of transplantation. Overall mortality among cases was 60.8%, and 25.0% of living recipients experienced graft loss. Pretransplant diagnosis of chronic pulmonary obstructive disease (COPD; odds ratio [OR]: 9.96; 95% confidence interval [CI]: 1.09-90.58; p = 0.041) and delayed graft function (OR: 3.40; 95% CI: 1.08-10.73; p = 0.037) were identified as independent risk factors for IPA among those variables already available in the immediate peritransplant period. The development of bloodstream infection (OR: 18.76; 95% CI: 1.04-339.37; p = 0.047) and acute graft rejection (OR: 40.73, 95% CI: 3.63-456.98; p = 0.003) within the 3 mo prior to the diagnosis of IPA acted as risk factors during the subsequent period. In conclusion, pretransplant COPD, impaired graft function and the occurrence of serious posttransplant infections may be useful to identify KT recipients at the highest risk of early IPA. Future studies should explore the potential benefit of antimold prophylaxis in this group.

Late aspergilloma of a renal allograft without need for operative management: a case report and review of the literature

Aspergillus infection localized to the renal allograft is a rare and potentially life-threatening infection and typically requires a combination of operative and medical management. We report the case of a renal allograft aspergilloma in a renal transplant patient presenting 2 years post transplant, successfully managed non-surgically. To our knowledge, this is the first report of a patient presenting with an allograft aspergilloma so long after transplantation and being successfully managed with antifungal therapy alone.

Approach to the Solid Organ Transplant Patient with Suspected Fungal Infection

In solid organ transplant (SOT) recipients, invasive fungal infections (IFIs) are associated with significant morbidity and mortality. Detection of IFIs can be difficult because the signs and symptoms are similar to those of viral or bacterial infections, and diagnostic techniques have limited sensitivity and specificity. Clinicians must rely on knowledge of the patient's risk factors for fungal infection to make a diagnosis. The authors describe their approach to the SOT recipient with suspected fungal infection. The epidemiology of IFIs in the SOT population is reviewed, and a syndromic approach to suspected IFI in SOT recipients is described.

In-hospital transfer is a risk factor for invasive filamentous fungal infection among hospitalized patients with hematological malignancies: a matched case-control study

OBJECTIVE

Immunocompromised patients now benefit from a longer life expectancy due to advanced medical techniques, but they are also weakened by aggressive treatment approaches and are at high risk for invasive fungal disease. We determined risk factors associated with an outbreak of invasive filamentous fungal infection (IFFI) among hospitalized hemato-oncological patients.

METHODS

A retrospective, matched, case-control study was conducted between January 1, 2009, and April 31, 2011, including 29 cases (6 proven, 8 probable, and 15 possible) of IFFI and 102 matched control patients hospitalized during the same time period. Control patients were identified from the hospital electronic database. Conditional logistic regression was performed to identify independent risk factors for IFFI.

RESULTS

Overall mortality associated with IFFI was 20.7% (8.0%-39.7%). Myelodysplastic syndrome was associated with a higher risk for IFFI compared to chronic hematological malignancies. After adjustment for major risk factors and confounders, >5 patient transfers outside the protected environment of the hematology ward increased the IFFI risk by 6.1-fold. The risk increased by 6.7-fold when transfers were performed during neutropenia.

CONCLUSION

This IFFI outbreak was characterized by a strong association with exposure to the unprotected environment outside the hematology ward during patient transfer. The independent associations of a high number of transfers with the presence of neutropenia suggest that affected patients were probably not sufficiently protected during transport in the corridors. Our study highlights that a heightened awareness of the need for preventive measures during the entire care process of at-risk patients should be promoted among healthcare workers.

An Approach to a Pulmonary Infiltrate in Solid Organ Transplant Recipients

The onset of a pulmonary infiltrate in a solid organ transplant (SOT) recipient is both a challenging diagnostic and therapeutic challenge. We outline the potential aetiologies of a pulmonary infiltrate in a SOT recipient, with particular attention paid to fungal pathogens. A diagnostic and empirical therapy approach to a pulmonary infiltrate, especially invasive fungal disease (IFD) in SOT recipients, is provided.

Invasive fungal infections in solid organ transplant recipients

Invasive fungal infections are a major problem in solid organ transplant (SOT) recipients. Overall, the most common fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Development of invasive disease hinges on the interplay between host factors (e.g., integrity of anatomical barriers, innate and acquired immunity) and fungal factors (e.g., exposure, virulence and resistance to prophylaxis). In this article, we describe the epidemiology and clinical features of the most common fungal infections in organ transplantation. Within this context, we review recent advances in diagnostic modalities and antifungal chemotherapy, and their impact on evolving prophylaxis and treatment paradigms.

Bioavailability and population pharmacokinetics of voriconazole in lung transplant recipients

This study was undertaken to characterize the pharmacokinetics and bioavailability of voriconazole in adult lung transplant patients during the early postoperative period, identify factors significantly associated with various pharmacokinetic parameters, and make recommendations for adequate dosing regimens. Thirteen lung transplant patients received two intravenous infusions (6 mg/kg, twice daily [b.i.d.]) immediately posttransplant followed by oral doses (200 mg, b.i.d.) for prophylaxis. Blood samples (9/interval) were collected during one intravenous and one oral dosing interval from each patient. Voriconazole plasma concentrations were measured by high-pressure liquid chromatography (HPLC). NONMEM was used to develop pharmacokinetic models, evaluate covariate relationships, and perform Monte Carlo simulations. There was a good correlation (R(2) = 0.98) between the area under the concentration-time curve specific for the dose evaluated (AUC(0-∞)) and trough concentrations. A two-compartment model adequately described the data. Population estimates of bioavailability, clearance, V(c), and V(p) were 45.9%, 3.45 liters/h, 54.7 liters, and 143 liters. Patients with cystic fibrosis (CF) exhibited a significantly lower bioavailability (23.7%, n = 3) than non-CF patients (63.3%, n = 10). Bioavailability increased with postoperative time and reached steady levels in about 1 week. V(p) increased with body weight. Bioavailability of voriconazole is substantially lower in lung transplant patients than non-transplant subjects but significantly increases with postoperative time. CF patients exhibit significantly lower bioavailability and exposure of voriconazole and therefore need higher doses. Intravenous administration of voriconazole during the first postoperative day followed by oral doses of 200 mg or 400 mg appeared to be the optimal dosing regimen. However, voriconazole levels should be monitored, and the dose should be individualized based on trough concentrations as a good measure of drug exposure.

Epidemiology of invasive aspergillosis and risk factors in non neutropaenic patients

INTRODUCTION

Invasive aspergillosis is a major cause of mortality in allogeneic bone marrow transplant recipients and patients treated for blood malignancies. The diagnostic tools, treatments and preventive strategies, essentially developed for neutropaenic patients, have not been assessed in populations whose immune systems are considered to be competent.

STATE OF THE ART

Beside the standard picture of chronic Aspergillus infection, the incidence of invasive aspergillosis is increasing in non neutropaenic patients, such as those with chronic lung diseases or systemic disease treated with long-term immunosuppressive drugs and solid organ transplant recipients. This study reviews the specific features of invasive aspergillosis in non neutropaenic subjects (NNS) and discusses the value of the diagnostic tools and treatment in this population.

PROSPECTS

A better understanding of the pathophysiology and the epidemiological characteristics of invasive aspergillosis would provide a means of adapting the staging and classification of the disease for NNS.

CONCLUSIONS

Invasive aspergillosis is under diagnosed in NNS who may already be colonised when they receive immunosuppressive treatment; this can lead to an adverse outcome in patients who are considered to be a moderate risk population.

Pseudoaneurysm of the iliac artery secondary to Aspergillus infection after kidney transplantation

Infectious complications are the top causes of morbidity and mortality in patients who undergo renal transplantation. We report a patient who received a cadaveric renal transplant in Mainland China. One year post-transplantation, the patient had right buttock pain with radiation to the leg. Swelling and tenderness over the right groin was also found. Magnetic resonance imaging revealed a multilobulated cystic lesion, about 8 x 7 cm, at the right iliac fossa and presacral region extending to the posterior aspect of the graft kidney and up to the right psoas muscle. Drainage of the intra-abdominal abscess was performed. The abscess culture showed presence of Aspergillus spp. The patient had received steroids, tacrolimus and mycophenolate mofetil, which could be a risk factor for fungal infection. The cause of Aspergillus infection in our patient remains unclear. It may have been due to immune system insufficiency of the patient rendering the patient prone to infection. Pseudoaneurysm formation of the internal iliac artery following Aspergillus infection after kidney transplantation is rarely reported. Although it is a dilemma, once a severe situation such as pseudoaneurysm with aspergillosis presents, graft removal is suggested.

Voriconazole pharmacokinetics in liver transplant recipients

The objective of this study was to evaluate the pharmacokinetics of voriconazole and the potential correlations between pharmacokinetic parameters and patient variables in liver transplant patients on a fixed-dose prophylactic regimen. Multiple blood samples were collected within one dosing interval from 15 patients who were initiated on a prophylactic regimen of voriconazole at 200 mg enterally (tablets) twice daily starting immediately posttransplant. Voriconazole plasma concentrations were measured using high-pressure liquid chromatography (HPLC). Noncompartmental pharmacokinetic analysis was performed to estimate pharmacokinetic parameters. The mean apparent systemic clearance over bioavailability (CL/F), apparent steady-state volume of distribution over bioavailability (Vss/F), and half-life (t1/2) were 5.8+/-5.5 liters/h, 94.5+/-54.9 liters, and 15.7+/-7.0 h, respectively. There was a good correlation between the area under the concentration-time curve from 0 h to infinity (AUC0-infinity) and trough voriconazole plasma concentrations. t1/2, maximum drug concentration in plasma (Cmax), trough level, AUC0-infinity, area under the first moment of the concentration-time curve from 0 h to infinity (AUMC0-infinity), and mean residence time from 0 h to infinity (MRT0-infinity) were significantly correlated with postoperative time. t1/2, lambda, AUC0-infinity, and CL/F were significantly correlated with indices of liver function (aspartate transaminase [AST], total bilirubin, and international normalized ratio [INR]). The Cmax, last concentration in plasma at 12 h (Clast), AUMC0-infinity, and MRT0-infinity were significantly lower in the presence of deficient CYP2C19*2 alleles. Donor characteristics had no significant correlation with any of the pharmacokinetic parameters estimated. A fixed dosing regimen of voriconazole results in a highly variable exposure of voriconazole in liver transplant patients. Given that trough voriconazole concentration is a good measure of drug exposure (AUC), the voriconazole dose can be individualized based on trough concentration measurements in liver transplant patients.

Characterization of a novel gene for strain typing reveals substructuring of Aspergillus fumigatus across North America

Fifty-five epidemiologically linked Aspergillus fumigatus isolates obtained from six nosocomial outbreaks of invasive aspergillosis were subtyped by sequencing the polymorphic region of the gene encoding a putative cell surface protein, Afu3g08990 (denoted as CSP). Comparative sequence analysis showed that genetic diversity was generated in the coding region of this gene by both tandem repeats and point mutations. Each unique sequence in an outbreak cluster was assigned an arbitrary number or CSP sequence type. The CSP typing method was able to identify "clonal" and genotypically distinct A. fumigatus isolates, and the results of this method were concordant with those of another discriminatory genotyping technique, the Afut1 restriction fragment length polymorphism typing method. The novel single-locus sequence typing (CSP typing) strategy appears to be a simple, rapid, discriminatory tool that can be readily shared across laboratories. In addition, we found that A. fumigatus isolates substructured into multiple clades; interestingly, one clade consisted of isolates predominantly representing invasive clinical isolates recovered from cardiac transplant patients from two different outbreak situations. We also found that the A. fumigatus isolate Af293, whose genome has been sequenced, possesses a CSP gene structure that is substantially different from those of the other A. fumigatus strains studied here, highlighting the need for further taxonomic study.

Infecciones en el paciente con trasplante renal y pancreático

Infection can lead to graft loss and death in patients undergoing kidney and double kidney-pancreas transplantation. In this review, the prophylactic measures, the post-transplant timeline for the development of infections, and the most frequent infectious complications in patients with kidney and pancreas transplantation are described. Although great advances have been achieved in the prevention of infections, new problems have developed. Nosocomial bacterial infection with multidrug-resistant bacteria is an emerging complication. Cytomegalovirus is still the most frequent viral infection despite the advances in prevention measures. Moreover, in recent years polyomavirus type BK infection has been recognized as a major cause of renal graft loss. Knowledge of the infectious complications associated with these transplants and the risk factors for their occurrence will allow optimal therapeutic management of this patient population.

Aspergillosis: spectrum of disease, diagnosis, and treatment

Infections by Aspergillus species present a particular challenge. The organism, which is ubiquitous in the environment, causes allergic disease in otherwise healthy individuals and devastating disease in the immunosuppressed. This article examines the range of infections caused by Aspergillus species, the challenges of diagnosis, and current treatment options.

Outbreak of aspergillosis infections among lung transplant recipients

Aspergillus infections have been associated with building constructions. We reported, for the first time, an outbreak of aspergillosis in lung transplant recipients exposed to heavy building construction work during hospitalization. We reviewed the files of 115 patients who underwent lung transplantation between May 1994 and June 2005. Patients operated on from May 1994 to December 2003 (group 1) were compared with those operated on between January 2004 and June 2005 (group 2) for findings of aspergillosis on follow up. Thirty-six transplant recipients (31%) had evidence of Aspergillus colonization, including six of the 64 patients (9.4%) operated on from 1994 to 2003 and 30 of the 51 patients (59%) operated on in 2004-2005 (P=0.0001). Eight had aspergillosis, in all group 2 (P=0.001) compared with group 1. All infections occurred within the first 4 month after the transplantation. On comparison of the two groups for background and medical factors, the only difference found was the initiation of building construction at the hospital, close to the transplant ward, in early 2004. We concluded that lung transplant recipients are prone to Aspergillus colonization following exposure to building construction work, despite prophylactic treatment. Established guidelines for the prevention of aspergillosis should be implemented and enforced during construction activities in hospitals.

Infections Complicating Solid Organ Transplantation

The requirements for immune suppression after solid organ transplantation increases the risk of infection with a myriad of organisms. There are many unique and evolving aspects of infection after solid organ transplantation. Advances in immunosuppressive therapy and improved protocols for infection prophylaxis have resulted in changes in the timing and clinical presentation of opportunistic infections. Vigilance in the diagnostic evaluation of suspected infection in the solid organ transplant recipient is essential. This article reviews the basic evaluation and treatment options for many of the infectious conditions peculiar to the immunosuppressed patient.

Nosocomial aspergillosis in outbreak settings

Nosocomial aspergillosis represents a serious threat for severely immunocompromised patients and numerous outbreaks of invasive aspergillosis have been described. This systematic review summarizes characteristics and mortality rates of infected patients, distribution of Aspergillus spp. in clinical specimens, concentrations of aspergillus spores in volumetric air samples, and outbreak sources. A web-based register of nosocomial epidemics (outbreak database), PubMed and reference lists of relevant articles were searched systematically for descriptions of aspergillus outbreaks in hospital settings. Fifty-three studies with a total of 458 patients were included. In 356 patients, the lower respiratory tract was the primary site of aspergillus infection. Species identified most often were Aspergillus fumigatus (154 patients) and Aspergillus flavus (101 patients). Haematological malignancies were the predominant underlying diseases (299 individuals). The overall fatality rate in these 299 patients (57.6%) was significantly greater than that in patients without severe immunodeficiency (39.4% of 38 individuals). Construction or demolition work was often (49.1%) considered to be the probable or possible source of the outbreak. Even concentrations of Aspergillus spp. below 1 colony-forming unit/m(3) were sufficient to cause infection in high-risk patients. Virtually all outbreaks of nosocomial aspergillosis are attributed to airborne sources, usually construction. Even small concentrations of spores have been associated with outbreaks, mainly due to A. fumigatus or A. flavus. Patients at risk should not be exposed to aspergilli.

Late-onset invasive aspergillosis in organ transplant recipients in the current era

We assessed predictive factors and characteristics of patients with late-onset invasive aspergillosis in the current era of novel immunosuppressive agents. Forty transplant recipients with invasive aspergillosis were included in this prospective, observational study initiated in 2003 at our institutions. In 50% (20/40) of these patients, the infections were late-occurring. Receipt of sirolimus in conjunction with tacrolimus for refractory rejection or cardiac allograft vasculopathy (P=0.047) was significantly associated with late-onset infection. The use of depleting or non-depleting T or B-cell antibodies, either as induction or as antirejection therapy did not correlate with time to onset of invasive aspergillosis. Mortality at 90 days was 20% (4/20) for the patients with early-onset infection and 45% (9/20) for those with late-onset infection (P=0.17). Thus, nearly one-half of the Aspergillus infections in transplant recipients in the current era are late-occurring. These data have implications relevant for prophylactic strategies and guiding clinical management of transplant recipients presenting with pulmonary infiltrates.

Aspergillus pulmonary infections in transplant recipients

Aspergillus infections are increasing in frequency in those undergoing solid organ and hematopoietic stem cell transplantation. The ongoing impact of Aspergillus infection on morbidity and mortality after transplantation makes this subject an area of intense clinical and research interest. This article discusses the evolving epidemiologic features of the infection and its management and diagnosis.

Aspergillus surveillance project at a large tertiary-care hospital

A one-year surveillance project was conducted at a large tertiary hospital, which had extensive indoor renovation and extensive demolition/building at several nearby sites. This study collected viable fungi samples in the hospital every six days and analysed 74 duct dust samples for Aspergillus fumigatus mycelial asp f1 protein. Mean total fungi were 257.8 cfu/m3 outdoors, 53.2 cfu/m3 in all indoor samples and 83.5 cfu/m3 in the bone marrow transplant patient rooms. Mean total aspergillus was 6.8 cfu/m3 outdoors, 12.1 cfu/m3 in all indoor samples and 7.3 cfu/m3 in the bone marrow transplant patient rooms. The five most prevalent Aspergillus species collected inside the hospital (mean cfu/m3) were Aspergillus niger 7.57 cfu/m3, Aspergillus candidus 1.72 cfu/m3, Aspergillus flavus 0.97 cfu/m3, A. fumigatus 0.88 cfu/m3 and Aspergillus glaucus 0.45 cfu/m3. In rooms undergoing duct cleaning, mean A. fumigatus concentrations were 11.0 cfu/m3. Forty-eight of 74 (65%) duct dust samples had measurable levels of asp f1 protein, with a mean level of 0.41 ppm and maximum level of 1.94 ppm. Three major incidents involved increased hospital aspergillus concentrations. A. niger levels reached 680 cfu/m3 in an organ transplant room after a water leak from a ceiling pipe. Total aspergillus concentrations rose to 77 cfu/m3 in a bone marrow transplant patient room after improper sealing and water infiltration of the unit's dedicated high-efficiency particulate air filter system. Total aspergillus levels of 160 cfu/m3 were recorded in a renovation area during wood cutting. The higher concentrations of aspergillus seen inside the hospital compared with outdoors and the various moisture/HEPA filter/renovation incidents suggest that numerous small to moderate sources of aspergillus exist in the hospital.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.

Aspergillus fumigatus variant with decreased susceptibility to multiple antifungals

Isolates of Aspergillus fumigatus that demonstrate resistance to itraconazole (ITZ) have been described previously; however, the prevalence and clinical significance of ITZ resistance are not completely understood. In this study we assessed the ITZ susceptibilities of 128 A. fumigatus isolates that caused invasive infection in 82 stem cell transplant patients before and after the use of ITZ in our institution (study period, 1991 to 2000). The MICs for 10 isolates obtained from seven patients were high, > or 1 microg/ml. The average ITZ MIC increased after institutional use of the drug began in 1995. The majority of the isolates for which MICs were high (6 of 10) and one isolate for which the MIC was low (0.06 microg/ml) demonstrated an unusual phenotype, appearing as predominantly white colonies. For all seven atypical isolates, voriconazole MICs were high (> or = 2 microg/ml), and minimal effective concentrations of caspofungin were high (> or 4 microg/ml). For two of the seven atypical isolates, amphotericin B MICs were high (> or 2 microg/ml). The isolates appeared white due to slow sporulation; however, after prolonged incubations, the isolates sporulated with no difference in conidial color or conidiophore morphology compared with typical isolates. Randomly amplified polymorphic DNA-PCR patterns of these isolates were distinct compared with those of other A. fumigatus isolates. Sequencing of 18S rRNA genes confirmed that all were A. fumigatus; however, the mitochondrial cytochrome b gene sequences of all the atypical isolates were unique. These data suggest the potential presence of a genetically unique, poorly sporulating variant of A. fumigatus that demonstrates decreased susceptibilities to several antifungals.