MRCM Weekly Fungal Diagnostics UpdateWeekly Fungal Diagnostics Update
Issue 1 | Week 26 • 29 June 2026
Critical appraisal of the week’s most important papers in fungal diagnostics
This Week at a Glance
| Category | Papers |
|---|---|
| ⭐ Practice-changing | 0 |
| ✅ Practice-supporting | 4 |
| 🔬 Primarily methodological | 1 |
| 🌍 Surveillance / Public Health | 1 |
This week’s themes
Rather than a single breakthrough, this week’s literature reflects three important developments in fungal diagnostics.
Firstly, Aspergillus serology continues to mature. The standout paper compares three commercially available Aspergillus antibody assays for diagnosing chronic pulmonary aspergillosis (CPA) in patients with previous or active pulmonary tuberculosis. Importantly, the study goes beyond simple assay comparison by using a prospective multicentre design and latent class analysis to address one of the biggest challenges in CPA diagnostics—the absence of a true gold standard.
Secondly, molecular diagnostics continue to strengthen their place in routine practice. Studies of PCR for invasive aspergillosis and mucormycosis reinforce a familiar message: molecular tests are unlikely to replace conventional mycology, but they can provide clinically valuable information when culture is slow, insensitive or negative despite strong clinical suspicion.
Finally, fungal diagnostics are expanding beyond individual patient care. Two papers demonstrate how molecular techniques are increasingly being applied to healthcare environmental monitoring and Candida auris wastewater surveillance, reflecting the growing role of diagnostic laboratories in infection prevention and public health.
None of this week’s papers is likely to alter routine laboratory practice immediately. However, several strengthen existing diagnostic pathways and highlight where future developments are most likely to occur.
⭐ Paper of the Week
Which Aspergillus antibody assay performs best for diagnosing chronic pulmonary aspergillosis?
Evidence classification: ✅ Practice-supporting
Why this matters
Chronic pulmonary aspergillosis remains one of the most challenging fungal diseases to diagnose. Symptoms are often non-specific, radiological appearances overlap with other chronic lung diseases, and microbiological confirmation is frequently difficult. Consequently, Aspergillus IgG serology has become a cornerstone of CPA diagnosis, particularly when interpreted alongside imaging and clinical findings.
The need for reliable serological testing is especially important in countries with a high burden of pulmonary tuberculosis (PTB), where CPA is now recognised as a common long-term complication. Several commercial antibody assays are available, but relatively few prospective studies have compared their performance head-to-head in clinically relevant patient populations.
This week’s paper addresses that gap.
Study at a glance
Researchers undertook a two-year prospective multicentre diagnostic evaluation involving 340 adults with active or previously treated pulmonary tuberculosis.
Each participant underwent testing with three commercially available Aspergillus antibody assays:
- Bordier Aspergillus fumigatus IgG ELISA
- LDBio Aspergillus IgG/IgM ICT lateral flow assay
- Era Biology Aspergillus IgG ICT lateral flow assay
Importantly, CPA was not diagnosed using a single laboratory test.
Instead, the investigators used a consensus composite reference standard incorporating:
- clinical features,
- radiological findings,
- microbiological evidence, and
- immunological assessment.
This reflects current international practice much more closely than studies comparing assays against fungal culture alone.
The authors also performed latent class analysis (LCA)—a sophisticated statistical technique that estimates disease status without assuming that any single diagnostic test is perfectly accurate. In fungal diagnostics, where true gold standards are often lacking, LCA provides an important additional perspective on assay performance.
What did the study find?
Among the 340 participants, 24 patients fulfilled criteria for CPA, representing a prevalence of just over 7%.
Using the conventional consensus diagnosis, the Bordier ELISA demonstrated the strongest overall diagnostic performance, combining high sensitivity with excellent specificity.
The LDBio lateral flow assay showed particularly high specificity, making it attractive as a rapid screening test where laboratory infrastructure may be limited.
Interestingly, when the authors applied latent class analysis, the estimated diagnostic performance of the LDBio assay improved substantially. This suggests that at least some apparent discrepancies between the assays and the consensus diagnosis may reflect limitations of the reference standard itself rather than shortcomings of the assay.
The Era Biology lateral flow assay demonstrated acceptable diagnostic performance but appeared less discriminating than the other two platforms.
Critical appraisal
This is one of the strongest CPA diagnostic papers published in recent months.
The prospective multicentre design is an important strength because it reduces many of the biases associated with retrospective sample-bank studies. The patient population is also clinically appropriate. Rather than comparing assays using carefully selected laboratory samples, the investigators evaluated consecutive adults with active or previous pulmonary tuberculosis—the very population in whom CPA screening is most relevant.
The second major strength is the use of a composite clinical reference standard. Diagnosing CPA is rarely straightforward and almost never depends on a single investigation. Incorporating clinical, radiological, microbiological and immunological evidence provides a far more realistic assessment than simply comparing serology with fungal culture.
Perhaps the most interesting methodological feature is the use of latent class analysis.
Clinical microbiologists are well aware that fungal diagnostics often lack perfect reference standards. Histopathology, culture, serology and molecular tests all have limitations, meaning that “true disease status” can be difficult to establish. Latent class analysis attempts to estimate this underlying disease state statistically, reducing reliance on any one imperfect test.
The inclusion of LCA strengthens the paper considerably and makes it more informative than many previous comparative serology studies.
Nevertheless, some limitations remain.
Only 24 participants had CPA, meaning that estimates of sensitivity are still based on relatively small numbers and should therefore be interpreted cautiously.
There is also the possibility of incorporation bias, since the Bordier ELISA contributed to the immunological component of the consensus CPA diagnosis. The latent class analysis partly addresses this concern, but readers should bear it in mind when interpreting the apparent superiority of the ELISA using the conventional reference standard.
Finally, the study population consisted entirely of patients with active or previous pulmonary tuberculosis. Laboratories should therefore be cautious about assuming identical performance in CPA associated with COPD, bronchiectasis, sarcoidosis or non-tuberculous mycobacterial disease.
MRCM View
This paper supports rather than changes current practice.
Laboratories already using validated Aspergillus IgG ELISA assays can be reassured that this study provides further evidence supporting their continued use as the primary laboratory test for CPA.
Perhaps more importantly, the findings strengthen the evidence for rapid lateral flow testing, particularly the LDBio assay, as a practical screening tool in settings where laboratory infrastructure is limited or where rapid triage is needed.
Rather than identifying a single “winner”, the study reinforces an important principle: different assays may be best suited to different healthcare settings. Laboratory ELISA and point-of-care lateral flow testing should be viewed as complementary approaches rather than competing technologies.
Future studies involving broader respiratory populations and larger numbers of CPA cases will be important to determine how well these findings translate beyond tuberculosis-associated disease.
Should this change laboratory practice?
Not immediately.
However, laboratories reviewing their CPA diagnostic pathways should find this paper reassuring. It provides further evidence supporting established ELISA-based diagnosis while adding weight to the growing case for incorporating validated lateral flow assays into screening programmes, particularly in resource-limited settings.
For centres involved in international health, tuberculosis services or global laboratory partnerships, this paper is particularly relevant.
Read the original paper
Evaluation of Three Aspergillus Antibody Assays for Screening of Chronic Pulmonary Aspergillosis: Prospective Diagnostic Accuracy Study
Diagnostic Microbiology and Infectious Disease (2026)
DOI: https://doi.org/10.1016/j.diagmicrobio.2026.117524
PubMed: Please use the journal DOI above or the confirmed PubMed record for the article (the initially circulated PMID link requires verification before publication).
Research Highlights
PCR strengthens its role in invasive aspergillosis diagnosis—but conventional mycology still matters
Evidence classification: ✅ Practice-supporting
Why this matters
Over the past decade, PCR has steadily moved from an experimental technique towards routine clinical use in the diagnosis of invasive aspergillosis (IA). Although international guidelines increasingly recognise PCR as part of the diagnostic pathway, questions remain regarding its performance in routine practice and how results should be interpreted alongside conventional mycology.
This study provides further evidence supporting PCR as an adjunctive investigation.
Study at a glance
Researchers evaluated a commercial real-time PCR assay in 50 patients with suspected invasive aspergillosis, comparing PCR with microscopy and conventional fungal culture.
PCR detected more positive cases than either microscopy or culture and demonstrated good overall diagnostic performance when compared with culture.
What did they find?
The study reported high diagnostic sensitivity for PCR together with good specificity, supporting previous evidence that molecular testing can detect Aspergillus DNA in patients whose cultures remain negative.
However, perhaps the most important observation is not the numerical performance itself, but what those numbers actually represent.
Culture remains an imperfect reference standard for invasive aspergillosis. A PCR-positive, culture-negative result may represent:
- genuine invasive disease,
- early infection,
- non-viable organisms following antifungal treatment,
- colonisation, or
- contamination.
Consequently, apparent disagreement between PCR and culture should not automatically be interpreted as poor PCR performance.
Critical appraisal
This is a useful practice-supporting study but has several important limitations.
The study population is relatively small, comprising only 50 patients, and appears to represent experience from a single centre. Larger multicentre evaluations would provide greater confidence in the findings.
More importantly, culture is not an ideal comparator for evaluating Aspergillus PCR because culture itself lacks sensitivity. Modern evaluations increasingly use composite clinical reference standards incorporating host factors, imaging, galactomannan and expert clinical assessment.
The findings therefore fit well with current international thinking rather than redefining it.
MRCM View
This paper reinforces the growing role of PCR as one component of an integrated diagnostic strategy rather than a replacement for conventional mycology.
PCR is particularly valuable when clinical suspicion remains high despite negative cultures, but laboratories should continue interpreting molecular results within the wider clinical context.
Should this change practice?
Not immediately.
However, laboratories that have not yet incorporated Aspergillus PCR into diagnostic pathways should recognise that the accumulating evidence supporting its clinical value continues to grow.
Read the paper
PubMed: https://pubmed.ncbi.nlm.nih.gov/42297108/
DOI: https://doi.org/10.1016/j.ijmmb.2026.101172
Mucorales PCR continues to mature as a diagnostic tool
Evidence classification: ✅ Practice-supporting
Why this matters
Rapid diagnosis of mucormycosis remains one of the greatest challenges in clinical mycology.
Unlike invasive aspergillosis, there is currently no widely adopted circulating biomarker equivalent to galactomannan or β-D-glucan. Diagnosis therefore depends largely on tissue sampling, histopathology, culture and increasingly molecular testing.
This six-year experience from a national reference laboratory provides valuable real-world evidence.
Study at a glance
Investigators reviewed routine Mucorales PCR testing performed between 2018 and 2024 within both a national reference laboratory and tertiary hospital.
PCR findings were compared with culture, histopathology and pan-fungal sequencing across multiple specimen types.
What did they find?
The study supports Mucorales PCR as a practical adjunct to conventional diagnostics.
Its principal advantage lies in speed. PCR can identify Mucorales DNA more rapidly than conventional culture and may detect infection even when viable organisms are difficult to recover.
The authors also highlight the considerable variation in available laboratory-developed PCR assays, reflecting the current lack of standardisation across laboratories.
Critical appraisal
The principal strength of this study is its real-world setting. Rather than evaluating carefully selected research specimens, the investigators analysed routine diagnostic testing over several years.
Interpretation nevertheless remains specimen-dependent.
Positive PCR from tissue or another sterile site carries considerably greater diagnostic weight than detection from respiratory samples, where colonisation and contamination become increasingly important considerations.
The retrospective design also means that specimen selection, prior antifungal therapy and sampling bias cannot be fully controlled.
MRCM View
This study strengthens existing evidence that Mucorales PCR deserves a place within specialist fungal diagnostic pathways.
Its greatest value is likely to be in situations where early confirmation may influence urgent antifungal therapy or surgical decision-making.
Should this change practice?
Reference laboratories should continue developing validated Mucorales PCR services, particularly for high-risk patient groups.
The paper supports expansion of existing services rather than introducing an entirely new diagnostic approach.
Read the paper
PubMed: https://pubmed.ncbi.nlm.nih.gov/42284037/
Wastewater surveillance opens a new frontier for Candida auris
Evidence classification: 🌍 Surveillance / Public Health
Why this matters
Candida auris has become one of the world’s most important healthcare-associated fungal pathogens.
Because colonised patients may remain undetected for prolonged periods, infection prevention increasingly relies on active surveillance rather than simply responding to clinical infections.
This study explores whether wastewater monitoring could provide an early warning system.
Study at a glance
Researchers validated molecular detection of Candida auris DNA in wastewater as a potential surveillance tool for healthcare systems.
What did they find?
The study demonstrates that molecular detection of C. auris from wastewater is technically feasible and could contribute to surveillance programmes.
Rather than identifying infected individuals, wastewater surveillance has the potential to detect the presence of C. auris within a healthcare catchment before outbreaks become clinically apparent.
Critical appraisal
This is an innovative paper that sits firmly within public health rather than clinical diagnostics.
A positive wastewater sample cannot determine:
- whether patients are colonised or infected,
- how many individuals are involved,
- where transmission is occurring, or
- whether environmental persistence is responsible.
Instead, wastewater surveillance should be viewed as an additional layer of epidemiological intelligence.
Future studies will need to establish practical sampling strategies, action thresholds and cost-effectiveness.
MRCM View
This is one of the most interesting papers of the week.
Although unlikely to influence routine microbiology laboratories immediately, it demonstrates how fungal diagnostics are increasingly supporting infection prevention and healthcare epidemiology.
Should this change practice?
Not yet.
However, laboratories involved in regional surveillance programmes should watch developments closely over the next few years.
Read the paper
PubMed: https://pubmed.ncbi.nlm.nih.gov/42329041/
DOI: https://doi.org/10.1128/spectrum.02508-25
Molecular methods complement—not replace—culture for environmental fungal monitoring
Evidence classification: 🔬 Primarily methodological
Why this matters
Hospitals increasingly monitor their environments for fungal contamination, particularly during construction work, water damage incidents and outbreaks affecting highly immunocompromised patients.
Rapid molecular detection offers obvious advantages in speed, but how should it be integrated with conventional fungal culture?
Study at a glance
This study compared rapid molecular techniques with conventional culture for detecting fungal contamination in healthcare environments.
What did they find?
Molecular methods detected fungal DNA rapidly and appeared more sensitive than conventional culture.
However, the two approaches answer fundamentally different questions.
Culture detects viable organisms capable of growth.
PCR detects fungal DNA, regardless of whether organisms remain viable.
Critical appraisal
The study provides a useful reminder that greater analytical sensitivity does not necessarily translate into greater clinical usefulness.
Environmental fungal DNA may persist long after viable organisms have disappeared.
Conversely, viable fungi may sometimes escape molecular detection because of sampling variability or assay limitations.
The future of environmental surveillance is therefore likely to involve both technologies rather than replacement of one by the other.
MRCM View
The message is reassuring rather than revolutionary.
Laboratories already using environmental culture should not view molecular testing as a replacement, but centres undertaking outbreak investigations may increasingly benefit from combining both approaches.
Should this change practice?
No.
Instead, the paper encourages laboratories to think about how molecular and culture methods can be integrated into comprehensive environmental surveillance programmes.
Read the paper
PubMed: https://pubmed.ncbi.nlm.nih.gov/42315582/
DOI: https://doi.org/10.1017/ice.2026.10491
Worth Watching
Can mould-specific IgG cut-offs improve the diagnosis of hypersensitivity pneumonitis?
Evidence classification: 🟡 Practice-supporting (Respiratory diagnostics)
Why this matters
Although not strictly a fungal infection paper, this study is highly relevant to laboratories performing fungal serology.
Mould-specific IgG testing is increasingly requested when investigating suspected hypersensitivity pneumonitis (HP), yet interpretation remains difficult. A positive IgG result indicates exposure to fungal antigens rather than disease itself, and laboratories often struggle with the question:
“What constitutes an abnormal result?”
This diagnostic accuracy study involving 219 participants attempts to establish clinically useful serum mould-specific IgG cut-offs.
Critical appraisal
This is an important area of research because laboratory interpretation remains inconsistent between assay platforms and populations.
However, readers should remember that hypersensitivity pneumonitis is fundamentally a multidisciplinary diagnosis. Serum IgG should always be interpreted alongside:
- exposure history,
- high-resolution CT findings,
- bronchoalveolar lavage (where appropriate),
- pathology, and
- multidisciplinary clinical review.
Cut-offs derived from one assay platform or geographical region may not transfer directly to another laboratory.
MRCM View
Although this paper is unlikely to alter fungal infection diagnostics directly, it is relevant for respiratory physicians, immunologists and laboratories reporting mould-specific IgG.
Further multicentre validation will be important before new cut-offs are widely adopted.
Read the paper
PubMed:
https://pubmed.ncbi.nlm.nih.gov/42329009/
Laboratory Take-home Messages
This week’s evidence suggests:
1. CPA serology continues to strengthen.
The comparative Aspergillus antibody study provides reassuring evidence supporting established ELISA testing while highlighting the growing role of validated lateral flow assays in rapid screening and resource-limited settings.
2. PCR is becoming part of routine fungal diagnostics—not a replacement for conventional mycology.
Both the invasive aspergillosis and mucormycosis studies reinforce PCR’s value as an adjunctive investigation that should always be interpreted alongside clinical, radiological and conventional laboratory findings.
3. Better statistics are improving diagnostic studies.
The CPA paper demonstrates the value of latent class analysis, acknowledging that fungal diseases rarely have a perfect diagnostic gold standard. Future diagnostic evaluations should increasingly adopt similar approaches.
4. Molecular diagnostics are expanding beyond patient diagnosis.
Environmental surveillance and wastewater monitoring illustrate the growing contribution of molecular methods to infection prevention, outbreak investigation and public health.
5. Interpretation remains the laboratory’s greatest contribution.
New technologies continue to improve analytical performance, but no test replaces expert interpretation. Appropriate specimen selection, understanding assay limitations and integrating laboratory findings with clinical information remain central to high-quality fungal diagnostics.
Editor’s Summary
This week’s literature reinforces an important message.
The future of fungal diagnostics is not simply about replacing culture with molecular testing.
Instead, the most successful diagnostic pathways increasingly combine:
- conventional mycology,
- serology,
- molecular diagnostics,
- imaging,
- clinical assessment, and
- expert multidisciplinary interpretation.
The standout paper this week—the prospective comparison of Aspergillus antibody assays—illustrates this perfectly. By combining robust clinical assessment with modern statistical analysis, it provides meaningful evidence for improving CPA diagnosis without claiming that any single assay can replace careful clinical judgement.
Similarly, the PCR studies remind us that molecular tests are most valuable when answering clinically important questions quickly, particularly when conventional culture performs poorly.
Finally, the environmental and wastewater papers suggest that fungal diagnostics are entering a new phase, with laboratories contributing not only to individual patient care but increasingly to infection prevention and public health surveillance.
None of this week’s studies is immediately practice-changing.
Collectively, however, they provide further evidence that fungal diagnostics continue to evolve towards integrated, multimodal diagnostic pathways rather than reliance on any single laboratory technique.
Papers Featured This Week
| Paper | Evidence | Recommended Reading |
|---|---|---|
| Aspergillus antibody assays for CPA | ✅ Practice-supporting | ⭐⭐⭐⭐⭐ Essential |
| Real-time PCR for invasive aspergillosis | ✅ Practice-supporting | ⭐⭐⭐⭐ Recommended |
| Mucorales PCR | ✅ Practice-supporting | ⭐⭐⭐⭐ Recommended |
| Candida auris wastewater surveillance | 🌍 Surveillance | ⭐⭐⭐ Worth reading |
| Environmental molecular diagnostics | 🔬 Methodological | ⭐⭐⭐ Worth reading |
| HP mould-specific IgG cut-offs | 🟡 Practice-supporting | ⭐⭐ Specialist interest |
Editorial Note
MRCM Weekly Fungal Diagnostics Update provides an independent critical appraisal of recently published literature relevant to clinical mycology and fungal diagnostics.
Our aim is not to replace the original research articles but to help busy clinicians and laboratory scientists identify the most important new studies, understand their strengths and limitations, and assess their potential impact on current practice.
Readers are encouraged to consult the original publications before implementing changes to clinical or laboratory protocols.
References
- Evaluation of Three Aspergillus Antibody Assays for Screening of Chronic Pulmonary Aspergillosis: Prospective Diagnostic Accuracy Study. Diagnostic Microbiology and Infectious Disease (2026). DOI: https://doi.org/10.1016/j.diagmicrobio.2026.117524
- Utility of Real-time PCR in the Diagnosis of Invasive Aspergillosis. Indian Journal of Medical Microbiology (2026). PubMed: https://pubmed.ncbi.nlm.nih.gov/42297108/ DOI: https://doi.org/10.1016/j.ijmmb.2026.101172
- Mucorales PCR for the Rapid Diagnosis of Mucormycosis: Six Years of Testing in a National Reference Laboratory and Tertiary Hospital. PubMed: https://pubmed.ncbi.nlm.nih.gov/42284037/
- Validation of Molecular Detection of Candida auris from Wastewater. PubMed: https://pubmed.ncbi.nlm.nih.gov/42329041/ DOI: https://doi.org/10.1128/spectrum.02508-25
- Comparing Rapid Molecular and Culture Methods for Detecting Fungal Contamination in Healthcare Environments. PubMed: https://pubmed.ncbi.nlm.nih.gov/42315582/ DOI: https://doi.org/10.1017/ice.2026.10491
- Cut-offs for Serum Mold-specific IgG Levels for Hypersensitivity Pneumonitis: A Diagnostic Test Accuracy Study of 219 Subjects. PubMed: https://pubmed.ncbi.nlm.nih.gov/42329009/