Antifungal
Modern Tests That Detect Hidden Fungal Infections Fast
Feb
Fungal infections are a growing concern in modern healthcare, affecting millions of people worldwide. While some fungal infections are superficial and easily treatable, others can be invasive, difficult to diagnose, and life-threatening. The early detection of fungal infections is crucial for effective treatment and improved patient outcomes. However, traditional diagnostic methods often fall short in terms of speed and accuracy.
In recent years, advancements in medical technology have led to the development of modern tests that can detect hidden fungal infections quickly and reliably. These innovative diagnostic tools are revolutionizing the way healthcare professionals approach fungal infections, enabling earlier intervention and better patient care. This article explores the importance of early detection, the limitations of traditional diagnostic methods, and the cutting-edge technologies that are transforming the landscape of fungal infection diagnosis.
The Importance of Early Detection of Fungal Infections
Prevalence and impact of fungal infections
Fungal infections affect a significant portion of the global population, with estimates suggesting that over 1 billion people suffer from fungal diseases[1]. These infections range from common superficial conditions like athlete’s foot and onychomycosis to life-threatening invasive infections such as candidiasis and aspergillosis. The impact of fungal infections on public health is substantial, leading to increased morbidity, mortality, and healthcare costs.
Challenges in diagnosing fungal infections
Diagnosing fungal infections can be challenging due to several factors. Many fungal infections present with nonspecific symptoms that mimic other conditions, making clinical diagnosis difficult. Additionally, traditional diagnostic methods, such as culture-based techniques, often lack sensitivity and specificity, leading to delayed or missed diagnoses[2].
Consequences of delayed diagnosis
Delayed diagnosis of fungal infections can have serious consequences for patients. In the case of invasive fungal infections, such as invasive aspergillosis, a delay in diagnosis and treatment initiation can lead to rapid disease progression, organ failure, and increased mortality rates. Moreover, delayed diagnosis can result in the overuse of broad-spectrum antibiotics, contributing to the growing problem of antimicrobial resistance[3].
The need for rapid and accurate diagnostic tests
Given the challenges and consequences associated with diagnosing fungal infections, there is a pressing need for rapid and accurate diagnostic tests. Early detection of fungal infections allows for prompt and targeted antifungal therapy, improving patient outcomes and reducing the risk of complications. Furthermore, accurate diagnosis helps optimize antifungal stewardship, reducing the unnecessary use of antifungal agents and mitigating the development of antifungal resistance.
Traditional Methods for Diagnosing Fungal Infections
Culture-based methods
Culture-based methods have been the gold standard for diagnosing fungal infections for many years. These methods involve collecting clinical samples, such as blood, sputum, or tissue, and culturing them on specialized media to promote fungal growth. Once the fungi are isolated, they can be identified based on their morphological characteristics and biochemical properties[4]. However, culture-based methods have several limitations, including slow turnaround times (often several days to weeks), low sensitivity, and the potential for false-negative results.
Microscopy and histopathology
Microscopic examination of clinical samples can provide rapid insight into the presence of fungal elements. Techniques such as direct microscopy, where samples are treated with potassium hydroxide (KOH) to dissolve human cells and reveal fungal structures, can be useful for diagnosing superficial infections. Histopathology, which involves examining tissue sections under a microscope, can help identify fungal invasion in deeper tissues[5]. However, microscopy and histopathology rely heavily on the expertise of the examiner and may not always provide definitive identification of the specific fungal pathogen.
Serological tests
Serological tests detect antibodies produced by the host immune system in response to fungal infections. These tests, such as enzyme-linked immunosorbent assay (ELISA) and immunodiffusion, can be useful for diagnosing endemic mycoses and monitoring treatment response. However, serological tests may lack sensitivity in immunocompromised patients and can be influenced by factors such as cross-reactivity and the timing of sample collection[6].
Limitations of traditional methods
While traditional methods have been the mainstay of fungal diagnosis, they have several limitations that can hinder early detection and accurate identification of fungal infections. These limitations include:
- Slow turnaround times
- Low sensitivity and specificity
- Dependence on viable fungal cells for culture
- Requirement for invasive sample collection procedures
The limitations of traditional methods have driven the development of modern diagnostic tests that aim to overcome these challenges and improve the early detection of fungal infections.
Advances in Molecular Diagnostics for Fungal Infections
Polymerase Chain Reaction (PCR)-based assays
Polymerase Chain Reaction (PCR)-based assays have emerged as a powerful tool for detecting fungal pathogens. These tests amplify specific regions of fungal DNA, allowing for rapid and sensitive detection of fungi directly from clinical samples. Real-time PCR assays, such as the Aspergillus PCR test, have shown high sensitivity and specificity in diagnosing invasive aspergillosis[7]. Additionally, multiplex PCR assays can simultaneously detect multiple fungal pathogens, streamlining the diagnostic process.
| Sensitivity | Specificity | Turnaround time | |
|---|---|---|---|
| PCR-based assays | High | High | Hours |
| Culture-based methods | Low to moderate | High | Days to weeks |
DNA sequencing and fungal identification
DNA sequencing technologies have revolutionized fungal identification by providing a more accurate and definitive approach compared to traditional methods. Sequencing of the internal transcribed spacer (ITS) region of fungal ribosomal DNA has become a standard method for identifying fungi to the species level[8]. Next-generation sequencing (NGS) technologies, such as whole-genome sequencing and targeted sequencing panels, offer even greater resolution and the ability to detect rare or novel fungal pathogens.
Antigen detection tests
Antigen detection tests, such as the galactomannan (GM) assay and the β-D-glucan (BDG) assay, have improved the early diagnosis of invasive fungal infections. The GM assay detects a polysaccharide antigen released by Aspergillus species during growth, while the BDG assay detects a cell wall component common to many pathogenic fungi[9]. These tests can provide rapid results and are particularly useful in high-risk patient populations, such as those with hematological malignancies or undergoing transplantation.
The role of molecular diagnostics in clinical practice
Molecular diagnostic methods have become increasingly integrated into clinical practice, complementing traditional methods and improving the accuracy and speed of fungal diagnosis. The use of molecular tests has led to earlier detection of fungal infections, enabling prompt initiation of targeted antifungal therapy and improved patient outcomes. However, it is essential to interpret molecular test results in the context of clinical findings and to consider factors such as sample quality and the potential for contamination.
Antigen Detection Tests for Fungal Infections
Galactomannan (GM) assay
The galactomannan (GM) assay is a widely used antigen detection test for diagnosing invasive aspergillosis. Galactomannan is a polysaccharide antigen released by Aspergillus species during growth and can be detected in serum, bronchoalveolar lavage fluid (BAL), and other clinical samples. The GM assay has demonstrated high sensitivity and specificity, particularly in immunocompromised patients[10]. However, false-positive results can occur due to cross-reactivity with other fungi, certain antibiotics, and food products containing galactomannan.
β-D-glucan (BDG) assay
The β-D-glucan (BDG) assay detects a cell wall component common to many pathogenic fungi, including Aspergillus, Candida, and Pneumocystis species. BDG is released into the bloodstream during fungal infection and can be measured using colorimetric or turbidimetric methods. The BDG assay has shown high sensitivity for detecting various invasive fungal infections[11]. However, false-positive results can occur due to exposure to certain medical products, such as cellulose hemodialysis filters and some antibiotics.
Cryptococcal antigen (CrAg) test
The cryptococcal antigen (CrAg) test is used for diagnosing cryptococcal meningitis, a life-threatening fungal infection caused by Cryptococcus neoformans and Cryptococcus gattii. The CrAg test detects the capsular polysaccharide antigen of Cryptococcus species in serum, cerebrospinal fluid (CSF), and other clinical samples. The test has high sensitivity and specificity and is particularly useful in HIV-positive patients and other immunocompromised individuals[12].
Advantages and limitations of antigen detection tests
Antigen detection tests offer several advantages over traditional diagnostic methods, including:
- Rapid turnaround time (hours to days)
- High sensitivity and specificity
- Ability to detect fungal infections in the absence of viable organisms
- Non-invasive sample collection (e.g., serum)
However, antigen detection tests also have some limitations, such as:
- Potential for false-positive results due to cross-reactivity
- Reduced sensitivity in certain patient populations (e.g., non-neutropenic patients)
- Limited availability and higher costs compared to traditional methods
Despite these limitations, antigen detection tests have become valuable tools for the early diagnosis of fungal infections, guiding timely and appropriate antifungal therapy.
Emerging Technologies for Rapid Fungal Diagnosis
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) mass spectrometry has emerged as a rapid and accurate method for identifying fungal pathogens. This technology analyzes the unique protein profiles of fungi, generating a “fingerprint” that can be compared to a database for identification at the species or even strain level. MALDI-TOF has shown high accuracy in identifying yeasts and filamentous fungi directly from clinical samples[13]. The rapid turnaround time (minutes to hours) and minimal sample preparation requirements make MALDI-TOF an attractive option for busy clinical laboratories.
Peptide Nucleic Acid Fluorescence In Situ Hybridization (PNA-FISH)
Peptide Nucleic Acid Fluorescence In Situ Hybridization (PNA-FISH) is a molecular diagnostic technique that uses fluorescently labeled probes to detect specific fungal DNA sequences directly in clinical samples. PNA probes have a higher affinity for complementary DNA sequences compared to traditional DNA probes, resulting in improved sensitivity and specificity. PNA-FISH has been successfully used for the rapid identification of Candida species in blood cultures, allowing for the prompt initiation of targeted antifungal therapy[14].
Nanoparticle-based biosensors
Nanoparticle-based biosensors are an emerging technology that utilizes the unique properties of nanomaterials to detect fungal biomarkers. These biosensors can be designed to target specific fungal antigens, enzymes, or nucleic acids, producing a measurable signal upon binding. Nanoparticle-based biosensors offer the potential for high sensitivity, specificity, and rapid detection of fungal pathogens[15]. Some examples include gold nanoparticle-based colorimetric assays and magnetic nanoparticle-based immunoassays for the detection of fungal antigens.
Challenges and future directions
While emerging technologies hold promise for improving the speed and accuracy of fungal diagnosis, several challenges need to be addressed before their widespread implementation in clinical practice. These challenges include:
- Standardization of sample preparation and testing protocols
- Establishment of comprehensive reference databases for fungal identification
- Validation of the clinical performance of new diagnostic platforms
- Cost-effectiveness and accessibility of emerging technologies
As research and development continue, it is expected that emerging technologies will become more refined, affordable, and integrated into routine fungal diagnostics, ultimately improving patient care and outcomes.
Clinical Applications of Modern Fungal Diagnostic Tests
Invasive aspergillosis
Invasive aspergillosis is a life-threatening fungal infection that primarily affects immunocompromised patients, such as those with hematological malignancies or undergoing transplantation. Early diagnosis is crucial for improving patient outcomes. Modern diagnostic tests, such as the Aspergillus PCR and galactomannan assay, have significantly enhanced the ability to detect invasive aspergillosis in its early stages[16]. The use of these tests in combination with traditional methods, such as culture and histopathology, has led to improved sensitivity and specificity in diagnosing invasive aspergillosis.
Invasive candidiasis
Invasive candidiasis, including candidemia, is a common healthcare-associated infection with high morbidity and mortality rates. Rapid identification of the causative Candida species is essential for guiding appropriate antifungal therapy. Modern diagnostic tests, such as MALDI-TOF mass spectrometry and PNA-FISH, have demonstrated high accuracy in identifying Candida species directly from blood cultures[17]. The timely identification of Candida species has led to the prompt initiation of targeted antifungal therapy, resulting in improved patient outcomes and reduced healthcare costs.
Cryptococcal meningitis
Cryptococcal meningitis is a life-threatening fungal infection of the central nervous system, primarily affecting immunocompromised individuals, particularly those with HIV/AIDS. The cryptococcal antigen (CrAg) test has become a cornerstone in the diagnosis of cryptococcal meningitis. The CrAg test can be performed on serum, plasma, or cerebrospinal fluid (CSF) and has high sensitivity and specificity[18]. The rapid turnaround time of the CrAg test has enabled earlier diagnosis and initiation of antifungal therapy, leading to improved patient survival.
Integration of modern diagnostic tests into clinical practice
The integration of modern fungal diagnostic tests into clinical practice has revolutionized the management of invasive fungal infections. These tests have enabled:
- Earlier detection of fungal infections
- Accurate identification of fungal pathogens
- Timely initiation of appropriate antifungal therapy
- Monitoring of treatment response and disease progression
However, it is essential for clinicians to understand the strengths and limitations of each diagnostic test and to interpret results in the context of the patient’s clinical presentation and risk factors. The optimal use of modern fungal diagnostic tests requires close collaboration between clinicians, microbiologists, and laboratory professionals to ensure the appropriate selection, interpretation, and utilization of these valuable tools.
Challenges and Future Directions in Fungal Diagnostics
Challenges in fungal diagnostics
Despite the advancements in modern fungal diagnostic tests, several challenges remain. One major challenge is the lack of standardization in sample preparation, testing protocols, and result interpretation across different laboratories and healthcare settings. This variability can lead to inconsistencies in diagnostic performance and difficulty in comparing results between institutions[19]. Additionally, the high cost and limited availability of some modern diagnostic tests may hinder their widespread implementation, particularly in resource-limited settings.
Future directions in fungal diagnostics
To address the challenges in fungal diagnostics, ongoing research and development efforts are focused on several key areas:
- Point-of-care testing: The development of rapid, easy-to-use, and affordable point-of-care diagnostic tests for fungal infections could greatly improve the early detection and management of these diseases, particularly in resource-limited settings[20].
- Multiplex assays: The development of multiplex assays that can simultaneously detect multiple fungal pathogens or resistance markers from a single sample could streamline the diagnostic process and provide more comprehensive information for clinical decision-making.
- Integration of diagnostic data: The integration of fungal diagnostic test results with other patient data, such as clinical history, imaging, and host immune status, could enhance the accuracy and clinical utility of diagnostic algorithms.
- Artificial intelligence and machine learning: The application of artificial intelligence and machine learning techniques to fungal diagnostics could help identify novel biomarkers, optimize testing strategies, and improve result interpretation[21].
Conclusion
Modern fungal diagnostic tests, including molecular assays, antigen detection tests, and emerging technologies, have greatly enhanced the ability to diagnose invasive fungal infections rapidly and accurately. The clinical application of these tests has led to improved patient outcomes, reduced healthcare costs, and better-informed clinical decision-making. However, challenges such as lack of standardization and limited accessibility need to be addressed to fully realize the potential of modern fungal diagnostics. Future research and development efforts should focus on point-of-care testing, multiplex assays, data integration, and the application of artificial intelligence to further advance the field of fungal diagnostics and ultimately improve the care of patients with invasive fungal infections.
The Impact of Modern Fungal Diagnostic Tests on Patient Outcomes
Improved early detection and diagnosis
The implementation of modern fungal diagnostic tests has significantly improved the early detection and diagnosis of invasive fungal infections. Traditional methods, such as culture and histopathology, often lack sensitivity and can take several days to provide results. In contrast, molecular assays and antigen detection tests can detect fungal pathogens with high sensitivity and specificity, often within hours of sample collection[22]. This rapid diagnosis allows for the timely initiation of appropriate antifungal therapy, which is crucial for improving patient outcomes and reducing mortality rates.
Targeted antifungal therapy
Modern fungal diagnostic tests have enabled the accurate identification of fungal pathogens at the species or even strain level. This information is essential for guiding the selection of targeted antifungal therapy. By identifying the specific fungal pathogen, clinicians can choose the most effective antifungal agent with the lowest risk of toxicity and resistance[23]. Targeted antifungal therapy has been shown to improve clinical response rates, reduce the duration of treatment, and minimize the development of antifungal resistance.
Monitoring treatment response and disease progression
Modern fungal diagnostic tests also play a crucial role in monitoring treatment response and disease progression. Serial monitoring of fungal biomarkers, such as galactomannan or beta-D-glucan, can provide valuable information on the effectiveness of antifungal therapy and the need for treatment modifications[24]. Declining biomarker levels often indicate a favorable response to treatment, while persistently elevated or increasing levels may suggest treatment failure or the development of antifungal resistance. This real-time monitoring of treatment response allows clinicians to make informed decisions about the duration and intensity of antifungal therapy, ultimately leading to better patient outcomes.
Reduction in healthcare costs
The use of modern fungal diagnostic tests has the potential to reduce healthcare costs associated with invasive fungal infections. Early and accurate diagnosis can prevent the unnecessary use of broad-spectrum antifungal agents, reduce the length of hospital stays, and avoid complications associated with delayed or inappropriate treatment. Studies have demonstrated that the implementation of rapid diagnostic tests, such as MALDI-TOF mass spectrometry and PNA-FISH, can lead to significant cost savings in the management of invasive fungal infections.
In conclusion, modern fungal diagnostic tests have had a profound impact on patient outcomes by improving early detection and diagnosis, enabling targeted antifungal therapy, facilitating the monitoring of treatment response and disease progression, and reducing healthcare costs. As these tests continue to evolve and become more widely available, their impact on patient care is expected to grow, ultimately leading to better outcomes for patients with invasive fungal infections.
Frequently Asked Questions
The most common types of invasive fungal infections include invasive aspergillosis, invasive candidiasis, cryptococcal meningitis, and mucormycosis. These infections often affect immunocompromised patients and can cause severe, life-threatening complications if not diagnosed and treated promptly.
Modern fungal diagnostic tests have significantly improved patient outcomes by enabling earlier detection and accurate identification of fungal pathogens. This allows for the timely initiation of targeted antifungal therapy, which increases the chances of successful treatment, reduces the duration of hospitalization, and minimizes the risk of complications and mortality associated with invasive fungal infections.
Examples of molecular diagnostic tests for fungal infections include PCR-based assays, such as real-time PCR and multiplex PCR, which can detect fungal DNA in clinical samples with high sensitivity and specificity. Other molecular tests include DNA sequencing, which can identify fungal species based on their genetic sequences, and PNA-FISH, which uses fluorescent probes to detect fungal pathogens directly from clinical specimens.
Antigen detection tests work by identifying specific fungal antigens in clinical samples, such as blood, serum, or bronchoalveolar lavage fluid. Examples of antigen detection tests include the galactomannan assay for invasive aspergillosis, the cryptococcal antigen test for cryptococcal meningitis, and the beta-D-glucan assay for various invasive fungal infections. These tests are often used in combination with other diagnostic methods to improve the accuracy of diagnosis.
Some of the main challenges in implementing modern fungal diagnostic tests include the lack of standardization in testing protocols and result interpretation across different laboratories, the high cost of some tests, and the limited availability of specialized equipment and trained personnel in resource-limited settings. Additionally, the complexity of some molecular tests may require dedicated laboratory facilities and expertise, which can limit their widespread use.
Clinicians and laboratories can work together to optimize the use of fungal diagnostic tests by establishing clear communication channels, developing standardized testing algorithms, and ensuring the appropriate selection and interpretation of tests based on the patient’s clinical presentation and risk factors. Regular training and education for both clinicians and laboratory staff can also help improve the understanding and utilization of these valuable diagnostic tools.
Emerging technologies in fungal diagnostics include next-generation sequencing (NGS), which can provide comprehensive genomic information on fungal pathogens, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, which can rapidly identify fungal species based on their unique protein profiles. Other promising technologies include nanoparticle-based assays, biosensors, and point-of-care testing devices that can facilitate rapid and accurate diagnosis of fungal infections in various healthcare settings.
Reference list
- Bongomin F, Gago S, Oladele RO, Denning DW. Global and multi-national prevalence of fungal diseases-estimate precision. J Fungi (Basel). 2017;3(4):57.
- Brown GD, Denning DW, Gow NA, Levitz SM, Netea MG, White TC. Hidden killers: human fungal infections. Sci Transl Med. 2012;4(165):165rv13.
- Patterson TF, Thompson GR 3rd, Denning DW, et al. Practice guidelines for the diagnosis and management of aspergillosis: 2016 update by the Infectious Diseases Society of America. Clin Infect Dis. 2016;63(4):e1-e60.
- Pappas PG, Kauffman CA, Andes DR, et al. Clinical practice guideline for the management of candidiasis: 2016 update by the Infectious Diseases Society of America. Clin Infect Dis. 2016;62(4):e1-50.
- Perfect JR, Dismukes WE, Dromer F, et al. Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(3):291-322.
- Wickes BL, Wiederhold NP. Molecular diagnostics in medical mycology. Nat Commun. 2018;9(1):5135.
- Schelenz S, Barnes RA, Barton RC, et al. British Society for Medical Mycology best practice recommendations for the diagnosis of serious fungal diseases. Lancet Infect Dis. 2015;15(4):461-474.
- Avni T, Leibovici L, Paul M. PCR diagnosis of invasive candidiasis: systematic review and meta-analysis. J Clin Microbiol. 2011;49(2):665-670.
- Lackner M, Caramalho R, Lass-Flörl C. Laboratory diagnosis of mucormycosis: current status and future perspectives. Future Microbiol. 2014;9(5):683-695.
- Cruciani M, Mengoli C, Loeffler J, et al. Polymerase chain reaction blood tests for the diagnosis of invasive aspergillosis in immunocompromised people. Cochrane Database Syst Rev. 2015;(10):CD009551.
- Arvanitis M, Ziakas PD, Zacharioudakis IM, Zervou FN, Caliendo AM, Mylonakis E. PCR in diagnosis of invasive aspergillosis: a meta-analysis of diagnostic performance. J Clin Microbiol. 2014;52(10):3731-3742.
- Mikulska M, Furfaro E, Viscoli C. Non-cultural methods for the diagnosis of invasive fungal disease. Expert Rev Anti Infect Ther. 2015;13(1):103-117.
- Ostrosky-Zeichner L, Alexander BD, Kett DH, et al. Multicenter clinical evaluation of the (1→3) beta-D-glucan assay as an aid to diagnosis of fungal infections in humans. Clin Infect Dis. 2005;41(5):654-659.
- Karageorgopoulos DE, Vouloumanou EK, Ntziora F, Michalopoulos A, Rafailidis PI, Falagas ME. β-D-glucan assay for the diagnosis of invasive fungal infections: a meta-analysis. Clin Infect Dis. 2011;52(6):750-770.
- Lamoth F, Cruciani M, Mengoli C, et al. β-Glucan antigenemia assay for the diagnosis of invasive fungal infections in patients with hematological malignancies: a systematic review and meta-analysis of cohort studies from the Third European Conference on Infections in Leukemia (ECIL-3). Clin Infect Dis. 2012;54(5):633-643.
- Pini P, Bettua C, Orsi CF, et al. Evaluation of serum (1 → 3)-β-D-glucan clinical performance: kinetic assessment, comparison with galactomannan and evaluation of confounding factors. Infection. 2016;44(2):223-233.
- Cuenca-Estrella M, Verweij PE, Arendrup MC, et al. ESCMID* guideline for the diagnosis and management of Candida diseases 2012: diagnostic procedures. Clin Microbiol Infect. 2012;18 Suppl 7:9-18.
- Ullmann AJ, Aguado JM, Arikan-Akdagli S, et al. Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline. Clin Microbiol Infect. 2018;24 Suppl 1:e1-e38.
- Wiederhold NP, Najvar LK, Bocanegra R, Kirkpatrick WR, Patterson TF, Thornton CR. Interlaboratory and interstudy reproducibility of a novel lateral-flow device and influence of antifungal therapy on detection of invasive pulmonary aspergillosis. J Clin Microbiol. 2013;51(2):459-465.
- Tang CM, Holden DW, Aufauvre-Brown A, Cohen J. The detection of Aspergillus spp. by the polymerase chain reaction and its evaluation in bronchoalveolar lavage fluid. Am Rev Respir Dis. 1993;148(5):1313-1317.
- Lass-Flörl C, Mutschlechner W, Aigner M, et al. Utility of PCR in diagnosis of invasive fungal infections: real-life data from a multicenter study. J Clin Microbiol. 2013;51(3):863-868.
- Morrissey CO, Chen SC, Sorrell TC, et al. Galactomannan and PCR versus culture and histology for directing use of antifungal treatment for invasive aspergillosis in high-risk haematology patients: a randomised controlled trial. Lancet Infect Dis. 2013;13(6):519-528.
- White PL, Wingard JR, Bretagne S, et al. Aspergillus polymerase chain reaction: systematic review of evidence for clinical use in comparison with antigen testing. Clin Infect Dis. 2015;61(8):1293-1303.
<16>Maertens J, Verhaegen J, Lagrou K, Van Eldere J, Boogaerts M. Screening for circulating galactomannan as a noninvasive diagnostic tool for invasive aspergillosis in prolonged neutropenic patients and stem cell transplantation recipients: a prospective validation. Blood. 2001;97(6):1604-1610.
