Pulmonary aspergillosis: a clinical update

Aspergillus spp may cause a variety of pulmonary diseases, depending on immune status and the presence of underlying lung disease. These manifestations range from invasive pulmonary aspergillosis in severely immunocompromised patients, to chronic necrotizing aspergillosis in patients with chronic lung disease and/or mildly compromised immune systems. Aspergilloma is mainly seen in patients with cavitary lung disease, while allergic bronchopulmonary aspergillosis is described in patients with hypersensitivity to Aspergillus antigens. Recent major advances in the diagnosis and management of pulmonary aspergillosis include the introduction of non-invasive tests, and the development of new antifungal agents, such as azoles and echinocandins, that significantly affect the management and outcome of patients with pulmonary aspergillosis. This review provides a clinical update on the epidemiology, risk factors, clinical presentation, diagnosis and management of the major syndromes associated with pulmonary aspergillosis.

Emerging fungal pathogens in pulmonary disease

PURPOSE OF REVIEW

Invasive fungal infections of the lung have been increasing due to the increase of the population most at risk. This review aims to describe some of the emerging fungal pathogens and their complex management.

RECENT FINDINGS

With the increase in immunosuppressed populations, physicians are increasingly encountering uncommon fungal pathogens that historically have been difficult to identify and treat. Many of these fungal infections present with similar clinical features and often show similar histopathological changes. Treatment options are more complex because of an increasing number of antifungals that have become available for clinical use. The correct usage of these antifungals in addressing emerging fungal infections is unclear, however. Drawing from in-vitro and in-vivo susceptibility testing and case reports, some deductions may be made for the best empirical treatment of these deadly diseases. In general, the newer triazoles (voriconazole and posiconazole) and the use of combination therapy have shown promise.

SUMMARY

Invasive fungal infections are on the increase and contribute significantly to overall mortality, particularly among transplant recipients. With the lack of well designed controlled clinical studies, physicians will need to draw from previously described cases and in-vitro susceptibility testing to optimize therapy.

Public Health Surveillance for Coccidioidomycosis in Arizona

Coccidioidomycosis or Valley Fever is a fungal disease that occurs primarily in the southwestern United States. Of the estimated 150,000 U. S. coccidioidomycosis infections per year, approximately 60% occur in Arizona, making this state the focal point for investigation of the disease. In this manuscript, we describe the epidemiology of coccidioidomycosis reported in Arizona over the last decade, hypotheses for the findings, and Arizona's response to the rising epidemic. Coccidioidomycosis surveillance data in Arizona consist of basic demographics of all laboratory and physician-diagnosed cases, the reporting of which has been mandated by law since 1997. The rate of reported coccidioidomycosis has more than quadrupled over the last decade from 21 cases per 100,000 population in 1997 to 91 cases per 100,000 in 2006 (P < 0.001). Case rates in older age groups (>/=65 years old) have more than doubled since 2000 (P < 0.001). These data demonstrate the rising coccidioidomycosis epidemic in Arizona, especially among the elderly. The increase in the numbers of reported cases can be partially explained by the institution of mandatory laboratory reporting in 1997, but the cause of the persistent rise after 1999 is unknown. Further investigation of coccidioidomycosis will not only assist with the development of public health interventions to control this disease in Arizona and the southwestern United States, but will also provide important information to prepare for a bioterrorism event caused by this select agent.

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.

Fungal infections in solid organ transplantation

Fungal infections in solid organ transplant recipients continue to be a significant cause of morbidity and mortality. Candida spp. and Aspergillus spp. account for most invasive fungal infections. The incidence of fungal infection varies with type of solid organ transplant. Liver transplant recipients have highest reported incidence of candida infections while lung transplant recipients have highest rate of Aspergillus infections. Recent epidemiological studies suggest the emergence of resistant strains of candida as well as mycelial fungi other than Aspergillus in these patients. The current review incorporates the recent changes in the epidemiology of fungal infections in solid organ transplant recipients and highlights the newer data on the diagnosis, prophylaxis and treatment of fungal infections in these patients.

Pseudallescheriasis: a summary of patients from 1980-2003 in a tertiary care center

CONTEXT

Pseudallescheria boydii is being increasingly isolated in immunocompromised patients.

OBJECTIVE

To present 24 years of data on patients from whom P. boydii was isolated.

DESIGN

Retrospective review of archival laboratory data and patient charts at a tertiary care hospital with a full service mycology laboratory. All patients evaluated from whom P. boydii was isolated between 1980 and 2003 were included in this study.

RESULTS

Twenty-four patients from whom P. boydii had been isolated were identified. The majority of cases represented pulmonary involvement, particularly in cystic fibrosis patients. Three additional patients had infections in surgical or traumatic lesions of the head and 4 had disseminated disease. Invasive disease was associated with underlying malignancy or transplantation and resulted in death secondary to the fungal infection in the majority of cases.

CONCLUSIONS

Pseudallescheria boydii may cause significant disease in humans. Invasive infections with P. boydii are often misdiagnosed and inadequately treated. Aggressive treatment of locally invasive disease may be of value in preventing rapid and fatal dissemination with this organism.

Critical care perspective on immunotherapy in lung transplantation

Lung transplantation is now a viable therapeutic option in the care of patients with advanced pulmonary parenchymal or pulmonary vascular disease. Lung transplantation, however, with chronic posttransplant immunosuppression, creates a uniquely vulnerable population of patients likely to experience significant life-threatening complications requiring intensive care. The introduction of several novel immunosuppressive agents, such as sirolimus and mycophenolate mofetil, in conjunction with more established agents such as cyclosporine and tacrolimus, has greatly increased treatment options for lung transplant recipients and likely contributed to improved short-term transplant outcomes. Modern transplant immunosuppression, however, is associated with a host of complications such as opportunistic infections, renal failure, and thrombotic thrombocytopenic purpura. The main focus of this review is to provide a comprehensive summary of modern immunotherapy in lung transplantation and to increase awareness of the serious and potentially life-threatening complications of these medications.

Coccidioidomycosis: a review and update

Coccidioidomycosis occurs in arid and semi-arid regions of the New World from the western United States to Argentina. Highly endemic areas are present in the southwest United States. Coccidioides species live in the soil and produce pulmonary infection via airborne arthroconidia. The skin may be involved by dissemination of the infection, or by reactive eruptions, such as a generalized exanthem or erythema nodosum. Interstitial granulomatous dermatitis and Sweet's syndrome have recently been recognized as additional reactive signs of the infection. Coccidioidomycosis is a "great imitator" with protean manifestations. Cutaneous findings may be helpful clues in the diagnosis of this increasingly important disease.

Human and canine pulmonary blastomycosis, North Carolina, 2001-2002

We investigated a cluster of blastomycosis in 8 humans and 4 dogs in a rural North Carolina community. Delayed diagnosis, difficulty isolating Blastomyces dermatitidis in nature, and lack of a sensitive and specific test to assess exposure make outbreaks of this disease difficult to study.

[Pathogenesis and environmental factors in ventilator-associated pneumonia]

Respiratory infections in intubated patients can derive from endogenous or exogenous sources. The major route for acquiring endemic ventilator-associated pneumonia (VAP) is oropharyngeal colonization by endogenous flora and leakage of contaminated secretions into the lower respiratory tract. However, a not inconsiderable percentage of VAP results from exogenous nosocomial colonization, especially pneumonias caused by resistant bacteria such as methicillin-resistant Staphylococcus aureus and multiresistant Acinetobacter baumannii or Pseudomonas aeruginosa, as well as by Legionella spp or filamentous fungi, such as Aspergillus. This article reviews the pathogenesis of VAP and the role of the intensive care environment as a source of pathogenic microorganisms.

An outbreak of histoplasmosis in the city of Blumenau, Santa Catarina

Acute pulmonary histoplasmosis is rarely diagnosed and is often confused with tuberculosis. Most knowledge of the disease has been derived from descriptions of epidemics in which a number of individuals were exposed to the same source of infection. Isolation of Histoplasma capsulatum var. capsulatum from soil samples is conclusive evidence of an epidemic focus. This is the first report of an outbreak of histoplasmosis, in which two cases were reported and the fungus was isolated at the focus of the epidemic, in the state of Santa Catarina. Further epidemiological studies are needed in order to determine the prevalence of the infection statewide.

Characterization of Candida species isolated from cases of lower respiratory tract infection

OBJECTIVES

(1) To identify and characterize the Candida species isolates from lower respiratory tract infection. (2) to determine the rate of isolation of Candida species from sputum samples.

METHODS

This study was carried out in the Department of Microbiology, Manipal Teaching Hospital, Pokhara, Nepal from June 2002 to January 2003. A total of 462 sputum samples were collected from patients suspected lower respiratory tract infection. The samples were processed as Gram staining to find out the suitability of the specimen, cultured on Sabouraud's Dextrose Agar (SDA) and also on blood agar and chocolate agar to identify the potential lower respiratory tract pathogens. For the identification of Candida, sputum samples were processed for Gram stain, culture, germ tube test, production of chlamydospore, sugar fermentation and assimilation test. For the identification of bacteria, Gram stain, culture, and biochemical tests were performed by standardized procedure.

RESULT

Out of 462 samples, 246 (53.24%) samples grew potential pathogens of lower respiratory tract. Among them Haemophilus influenzae 61(24.79%) and Streptococcus pneumoniae 57 (23.17%) were the predominant bacterial pathogens. Candida species were isolated from 30 samples (12.2%). The majority of Candida species amongst the Candida isolates were Candida albicans 21(70%) followed by Candida tropicalis 4(13.33%). Candida krusei 3(10%), Candida parapsilosis 1(3.33%) and Candida stellatoidea 1(3.33%). The highest rate of isolation of Candida was between the age of 71 and 80.

CONCLUSION

Candida isolation from sputum samples is important as found in the present study in which Candida species were the third most common pathogen isolated from patients with lower respiratory tract infection.

[Osteoarticular coccidioidomicosis. Clinical and pathological study of 36 Mexican patients]

Coccidioidomycosis (CM) is primarily a lung disease. Systemic spread occurs in 1% of cases and one of its manifestation is osteoarthritis.

AIM

To describe the clinical and pathological characteristics of 36 patients with osteoarthritis by Coccidioides immitis (COA).

MATERIAL AND METHODS

The surgical pathology records of two medical institutions were reviewed; patients with clinical diagnosis of osteoarthritis and definitive histopathological diagnosis of COA were included in the study. Results were analyzed by contingence tables (RXC) and chi2 test.

RESULTS

Twenty six adults (19 men, seven women) and 10 children (seven males, three females) were studied. The chi2 analysis demonstrated a predominance of disease in men (72.2%, p = 0.008). There was no difference between males and females in relation to history of mycotic disease or diagnosis of lung disease after the diagnosis of COA. Bone involvement (76% of cases) was more frequent that pure joint lesions and the predominant radiological lesion was of lytic type. 30.5% of patients (11 cases) had multiple bone lesions and eight of them were men with multiple vertebral bone lesions.

DISCUSSION

The COA was the only manifestation of disease in 83% of the patients. Therefore is important to consider this etiology in patients of endemic area. The clinical and radiological spectrum of COA is wide and may include a dentigerous and synovial cyst or simulates metastatic disease. The recognition of the clinical manifestations of COA may contribute to an opportune diagnosis and treatment.

Histoplasmosis cluster, golf course, Canada

We report a cluster of 4 cases of acute histoplasmosis (1 culture proven and 3 with positive serology, of which 2 were symptomatic) associated with exposure to soil during a golf course renovation. Patients in western Canada with compatible symptoms should be tested for histoplasmosis, regardless of their travel or exposure history.

Breakdown of pulmonary host defense in the immunocompromised host: cancer chemotherapy

The number of immunocompromised patients is steadily increasing due to HIV infection, solid organ and stem cell transplantation, intensified chemotherapy, immunosuppression for autoimmune diseases, and a marked increase in the use of monoclonal antibodies. Prevention strategies for pulmonary infections and diagnostic methods have evolved and patient outcome has improved. However, therapies affecting the immune system are also given to older patients and patients with comorbidities. While the rate of pulmonary complications in HIV patients has dramatically decreased under antiretroviral therapy, we are seeing more patients with pulmonary problems after chemotherapy. Neutropenia is still the most important risk factor for bacterial and fungal infection. Flexible bronchoscopy with BAL remains an important diagnostic method with a low morbidity and high diagnostic yield in patients with pulmonary infiltrates following cancer chemotherapy.

Immunosuppression related to collagen-vascular disease or its treatment

Collagen-vascular diseases are associated with immune dysregulation and inflammation, leading to tissue destruction or compromise. Immunosuppression is more commonly associated with the drugs used to treat these disorders than with the diseases themselves. The newest agents being used to treat collagen-vascular diseases are the tumor necrosis factor (TNF)-alpha inhibitors. U.S. Food and Drug Administration-approved TNF-alpha inhibitors have differing effects on the immune system, reflecting their potency and mechanisms of action. They are particularly effective in breaking down granulomatous inflammation, which makes them effective treatment for sarcoidosis and Wegener's granulomatosis. This same property makes them likely to break down the host defense mechanism that normally contains pathogens such as mycobacteria and fungi in a dormant state, namely the physical and immunologic barrier formed by granulomas in the lung and elsewhere. The most common infection reported with the TNF-alpha inhibitors has been tuberculosis, which may manifest as pulmonary and/or extrapulmonary disease, with the latter being more common and severe than usual. Histoplasma capsulatum, Aspergillus, Cryptococcus neoformans, and Listeria monocytogenes have also been described in a number of cases, and their frequency is discussed.

Emmonsiosis of subterranean rodents (Bathyergidae, Spalacidae) in Africa and Israel

The presence of adiaspores of the fungal genus Emmonsia was examined in the lungs of 85 mole rats representing 3 subterranean genera: blind mole rats (Spalax galili and S. golani) from Israel, Ansell's mole-rats (Cryptomys anselli) from Zambia, and silvery mole-rats (Heliophobius argenteocinereus) from Malawi and Zambia. Emmonsiosis was found in 28% of the blind mole rats, 100% of the Ansell's mole-rats, but in none of the silvery mole-rats. Infection in African mole-rats was caused by Emmonsia parva, and infection in Israeli blind mole rats was caused by E. parva and E. crescens. The study indicates that the perennial burrow system of the Ansell's mole-rat forms an appropriate microhabitat for the saprophytic growth of E. parva in Lusaka region, Zambia. We suggest that factors contributing to the striking difference in prevalence of emmonsiosis between the two African mole-rat genera (Cryptomys, Heliophobius) may be their differing burrow types, burrow longevity, and social lives.

Outbreak of disseminated zygomycosis and concomitant pulmonary aspergillosis in breeder layer cockerels

Disseminated zygomycosis and concomitant pulmonary aspergillosis were diagnosed in breeder layer cockerels. Five- to 9-week-old breeder layer cockerels with a history of an increased mortality rate were presented to a diagnostic laboratory for examination. On necropsy, large, multifocal, firm, tan, nodules were observed in the lungs, air sacs, peritoneum, livers, spleens and kidneys. On histopathology, mixed populations of zygomycetes and Aspergillus hyphae were observed in the granulomas in the lungs, and zygomycete hyphae were observed in the granulomas in the air sacs, peritoneum, livers, spleens and kidneys. No bacteria were isolated from any of the lesions. Aspergillus fumigatus was isolated from the lung lesions only and hyphae that were consistent with those of a Rhizopus spp. were isolated from the lesions in several organs. Pullets, which were kept together with the cockerels from the day they were hatched, were not affected. The absence of infection in the pullets, which were kept together with the cockerels, suggests that the cockerels were either infected during incubation, with the fungi penetrating the egg shell, or that they were infected during hatching before they were mixed with the pullets.

Epidemiology of Visceral Mycoses in Patients with Leukemia and MDS-Analysis of the Data in Annual of Pathological Autopsy Cases in Japan in 1989, 1993, 1997 and 2001-

To study the changes of visceral mycoses in autopsy cases, data on visceral mycosis cases with leukemia and myelodysplastic syndrome (MDS) reported in the Annual of the Pathological Autopsy Cases in Japan in 1989, 1993, 1997 and 2001 were analyzed. The frequency rate of visceral mycoses with leukemia and MDS was 27.9% (435/1,557) in 1989, 23.0% (319/1,388) in 1993, 22.3% (246/1,105) in 1997 and 25.1% (260/ 1,037) in 2001, which was clearly higher than the rate of cases without leukemia and MDS: 3.4%, 2.7%, 3.5% and 3.7%, respectively. Furthermore, in comparing the rate of mycoses in recipients of stem cell transplantation with that of non-recipients, that of recipients was about 10% higher. The predominant causative agents were Candida and Aspergillus, at approximately the same rate (Candida 33.6%, Aspergillus 33.3%) as in 1989. However, Aspergillus increased conspicuously in 1993 (Candida 22.3% Aspergillus 44.5%), and continued to increase (Candida 22.8%, Aspergillus 50.8% in 1997; Candida 16.9%, Aspergillus 54.2% in 2001). In aspergillosis and zygomycosis, the lung and bronchi comprised the most commonly infected organs: 74.7% and 75.6% of the total cases, respectively. Among a total of 1,260 cases with mycotic infections in the four years studied, acute lymphatic leukemia and acute myeloid leukemia were the major diseases (35.5% and 33.5%, respectively) followed by MDS (29.0%). Given these facts, we emphasize that a greater interest in mycoses should be taken by clinicians, and immunocompromised patients should be protected from opportunistic invasive fungal infections, especially aspergillosis.

Epidemiology and outcome of infections due to Aspergillus terreus: 10-year single centre experience

Aspergillus terreus, a less common pathogen, appears to be an emerging cause of infection at our institution, the Medical University Hospital of Innsbruck. Thus the epidemiology and outcome of A. terreus infections over the past 10 years was assessed. We analysed 67 cases of proven invasive aspergillosis (IA) according to the European Organisation for Research and Treatment of Cancer/Mycoses Study Group criteria, investigated antifungal susceptibility of amphotericin B (AMB), voriconazole and caspofungin and performed molecular typing of A. terreus. Patients with proven IA caused by A. terreus (n = 32) and non-A. terreus (n = 35) were evaluated. The two groups were comparable in terms of age, gender, underlying disease, antifungal prophylaxis and duration of neutropenia (P > 0.05). Leukaemia was the most common underlying malignancy. Fungal dissemination occurred in 63% of the patients. Aspergillus terreus infections were associated with a lower response rate to AMB therapy (20%), compared with 47% for patients with non-A. terreus infections (P < 0.05). In vitro, A. terreus was found to be resistant to AMB and molecular typing discriminated between patients isolates, showing a high strain diversity with 26 distinct types (I-XXVI) identified by combination of three primers. Aspergillus terreus infections displayed evidence of AMB resistance in vitro and in vivo and were associated with a high rate of dissemination and poor outcome; A. terreus causes systemic infections of endemic character in Tyrol, Austria. The onset of A. terreus infection depends not on the degree of immunosuppression but on environmental Aspergillus spp. exposure.