This systematic review and meta-analysis aimed to examine the performance of polymerase chain reaction (PCR) assays for diagnosing mucormycosis. A standardised search was conducted from conception to December 3rd 2024 using PubMed, Embase, Global Health, and Cochrane library. Original studies that used PCR-based methods on any human specimen to diagnose mucormycosis were analysed for eligibility. Using a bivariate meta-analysis, the diagnostic performance of PCR was examined against the European Organisation for Research and Treatment of Cancer-Mycoses Study Group Education and Research Consortium 2020 (EORTC-MSGERC) definitions of proven and probable invasive mould disease, which was modified to include all patients at risk of mucormycosis. The study protocol was registered on the PROSPERO database (CRD42023478667). Of 4855 articles, a total of 30 met inclusion criteria, including 5920 PCR reactions on 5147 non-duplicate specimens from 819 cases of proven/probable mucormycosis and 4266 patients who did not meet the EORTC-MSGERC 2020 criteria. According to specimen type, sensitivity of PCR varied (p < 0.001) whereas specificity was similar (p = 0.662). Bronchoalveolar lavage fluid offered the highest sensitivity of 97.5% (95% CI 83.7-99.7%), specificity of 95.8% (95% CI 89.6-98.4%), positive likelihood ratio (LR+) of 23.5, and negative likelihood ratio (LR-) of 0.03. Tissue provided sensitivity of 86.4% (95% CI 78.9-91.5%), specificity of 90.6% (95% CI 78.1-96.3%), LR+ of 9.2, and LR- of 0.15. Blood provided reduced sensitivity of 81.6% (95% CI 70.1-89.4%), specificity of 95.5% (95% CI 87.4-98.5%), DOR of 95, LR+ of 18.3, and LR- of 0.19. Formalin-fixed paraffin-embedded specimens yielded the lowest sensitivity of 73.0% (95% CI 61.0-82.3%), highest specificity of 96.4% (CI 95% 87.5-99.0%), LR+ of 20.2, and LR- of 0.28. The covariates best explaining heterogeneity of the overall analysis were specimen type, study design (cohort versus case-control) and disease prevalence while patient population (COVID-19 versus other) and PCR (conventional versus quantitative) had less impact on heterogeneity. This meta-analysis confirms the high performance of PCR for diagnosing mucormycosis and supports the instatement of PCR detection of free-DNA in blood, BALF and tissue into future updated definitions and diagnostic guidelines for mucormycosis. None.

This meta-analysis examines the comparative diagnostic performance of polymerase chain reaction (PCR) for the diagnosis of Pneumocystis pneumonia (PCP) on different respiratory tract samples, in both human immunodeficiency virus (HIV) and non-HIV populations. A total of 55 articles met inclusion criteria, including 11 434 PCR assays on respiratory specimens from 7835 patients at risk of PCP. QUADAS-2 tool indicated low risk of bias across all studies. Using a bivariate and random-effects meta-regression analysis, the diagnostic performance of PCR against the European Organisation for Research and Treatment of Cancer–Mycoses Study Group definition of proven PCP was examined. Quantitative PCR (qPCR) on bronchoalveolar lavage fluid provided the highest pooled sensitivity of 98.7% (95% confidence interval [CI], 96.8%–99.5%), adequate specificity of 89.3% (95% CI, 84.4%–92.7%), negative likelihood ratio (LR⁻) of 0.014, and positive likelihood ratio (LR⁺) of 9.19. qPCR on induced sputum provided similarly high sensitivity of 99.0% (95% CI, 94.4%–99.3%) but a reduced specificity of 81.5% (95% CI, 72.1%–88.3%), LR⁻ of 0.024, and LR⁺ of 5.30. qPCR on upper respiratory tract samples provided lower sensitivity of 89.2% (95% CI, 71.0%–96.5%), high specificity of 90.5% (95% CI, 80.9%–95.5%), LR⁻ of 0.120, and LR⁺ of 9.34. There was no significant difference in sensitivity and specificity of PCR according to HIV status of patients. On deeper respiratory tract specimens, PCR negativity can be used to confidently exclude PCP, but PCR positivity will likely require clinical interpretation to distinguish between colonization and active infection, partially dependent on the strength of the PCR signal (indicative of fungal burden), the specimen type, and patient population tested. This graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/pcr-on-respiratory-tract-specimens-of-immunocompromised-patients-to-diagnose-pneumocystosis-pcp-a-systematic-review-and-meta-analysis-89aa7a50-efbc-4ebb-8f20-c17d207e8d8e?utm_campaign=tidbitlinkshare&utm_source=ITP

Amongst the treatable cause of blindness among young people, fungal keratitis ranks high. There are an estimated 1,051,787 to 1,480,916 eyes affected annually, with 8–11% of patients having to have the eye removed. Diagnosis requires a corneal scraping, direct microscopy and fungal culture with a large number of airborne fungi implicated. Treatment involves the intensive application of antifungal eye drops, preferably natamycin, often combined with surgery. In low-resource settings, inappropriate corticosteroid eye drops, ineffective antibacterial therapy, diagnostic delay or no diagnosis all contribute to poor ocular outcomes with blindness (unilateral or bilateral) common. Modern detailed guidelines on fungal keratitis diagnosis and management are lacking. Here, we argue that fungal keratitis should be included as a neglected tropical disease, which would facilitate greater awareness of the condition, improved diagnostic capability, and access to affordable antifungal eye medicine.

Background: Polymerase chain reaction (PCR) is highly sensitive and specific for the rapid diagnosis of invasive fungal disease (IFD) but is not yet widely implemented due to concerns regarding limited standardisation between assays, the lack of commercial options and the absence of clear guidance on interpreting results. Objectives and Methods: This review provides an update on technical and clinical aspects of PCR for the diagnosis of the most pertinent fungal pathogens, including Aspergillus, Candida, Pneumocystis jirovecii, Mucorales spp., and endemic mycoses. Summary: Recent meta-analyses have demonstrated that quantitative PCR (qPCR) offers high sensitivity for diagnosing IFD, surpassing conventional microscopy, culture and most serological tests. The reported specificity of qPCR is likely underestimated due to comparison with imperfect reference standards with variable sensitivity. Although the very low limit of detection of qPCR can generate false positive results due to procedural contamination or patient colonisation (particularly in pulmonary specimens), the rates are comparable to those observed for biomarker testing. When interpreting qPCR results, it is essential to consider the pre-test probability, determined by the patient population, host factors, clinical presentation and risk factors. For patients with low to moderate pre-test probability, the use of sensitive molecular tests, often in conjunction with serological testing or biomarkers, can effectively exclude IFD when all tests return negative results, reducing the need for empirical antifungal therapy. Conversely, for patients with high pre-test probability and clinical features of IFD, qPCR testing on invasive specimens from the site of infection (such as tissue or bronchoalveolar lavage fluid) can confidently rule in the disease. The development of next-generation sequencing methods to detect fungal infection has the potential to enhance the diagnosis of IFD, but standardisation and optimisation are essential, with improved accessibility underpinning clinical utility.

Talaromycosis is an invasive fungal disease endemic to Southeast Asia. While culture is essential in identification, susceptibility testing, and typing, the low sensitivity and long turnaround times limit its clinical utility. Several promising monoclonal antibody–based (MAb) antigen-detection assays have been evaluated in large patient cohorts. This includes the MAb-Mp1p and MAb-4D1 enzyme immunoassays and their point-of-care platforms. Quantitative polymerase chain reaction (qPCR) assays targeting the 5.8S or 18S region of ribosomal RNA have been developed. These antigen and qPCR assays are highly specific and more sensitive than blood culture, making them excellent rapid rule-in tests for talaromycosis in people with a compatible clinical syndrome. Metagenomic next-generation sequencing is emerging as a promising tool for non-bias detection of talaromycosis. Host-based diagnostics targeting antibodies, interferon-gamma release, and transcriptomics are being actively developed. This review summarizes recent advances in the diagnosis of talaromycosis and provides expert recommendations on the application of these novel tests to improve the diagnostic algorithm and management of talaromycosis.

Recurrent vulvovaginal candidiasis (RVVC) is a debilitating, chronic condition that affects over 138 million (6%) women of reproductive age annually. We performed a retrospective audit of RVVC referrals to our tertiary care Candida clinic to evaluate the impact of the significantly updated British Association of Sexual Health and HIV (BASHH) 2019 vulvovaginal candidiasis guidelines on patient outcomes, the principles of which were implemented at our centre at the onset of the guideline revision process in 2017. A total of 78 women referred with suspected RVVC in 2017–2020 were included. Their mean symptom duration prior to referral was 6.7 years. RVVC was the definitive diagnosis in 73% of cases. In the 27% of patients without RVVC, the most common diagnoses were acute VVC (29%), vulval eczema (14%), dry skin (14%) and vulvodynia (10%). Of those with RVVC, 60% were diagnosed with an additional diagnosis, most commonly vulval eczema or vulvodynia. Only 12% of women had been counselled on appropriate vulval skin care, the mainstay of RVVC management. Long-term antifungal suppression was initiated in 68% of women. Azole-resistant Candida, for which there is no licensed treatment available in the UK, was identified in 23% of women with RVVC. In the follow-up, 82% of patients reported good control of symptoms using antifungal suppression therapy and recommended skin care, 16% had partial symptom control with some “flare-ups” responding to treatment, none reported poor control and for 2% this information was not available. RVVC-related morbidity can be reduced by following the principles outlined in the BASHH guidelines.