Agreement between two real-time commercial PCR kits and an in-house real-time PCR for diagnosis of mucormycosis.

Mucormycosis is a severe and emerging invasive fungal infection associated with high mortality rates. Early diagnosis is crucial for initiating specific antifungal treatment, with molecular tools currently representing the most efficient diagnostic approach. Presently, a standardized in-house real-time PCR method is widely employed for diagnosing mucormycosis. Our study aimed to evaluate the agreement for the Mucorales DNA detection between two commercial real-time PCR assays-the Fungiplex Mucorales Real-Time PCR Kit and the MycoGENIE Aspergillus-Mucorales spp. Real-Time PCR Kit-in comparison with the in-house PCR. We retrospectively analyzed 58 samples previously identified as positive for Mucorales using the in-house PCR. These samples, obtained from 22 patients with proven or probable mucormycosis, were tested with both commercial kits. Additionally, samples from 40 patients without mucormycosis served as negative controls. Our findings revealed that the MycoGENIE Kit demonstrated superior performance in detecting Mucorales DNA in samples identified as positive by the in-house PCR. Notably, we observed minimal variability in cycle threshold (CT) values when comparing the results of the MycoGENIE Kit with those of the in-house PCR, with an average difference of 1.8 cycles. In contrast, the Fungiplex Kit exhibited a larger discrepancy in CT values compared to the in-house PCR, with an average difference of 4.1 cycles. The MycoGENIE Kit exhibited very good agreement (kappa of 0.82) with the in-house PCR for detecting Mucorales DNA across various sample types. These findings are important for the choice of kits that could be used to diagnose mucormycosis in clinical microbiology laboratories. IMPORTANCE: Early diagnosis of mucormycosis is crucial for initiating effective treatment. The detection of Mucorales DNA by PCR in serum has revolutionized the diagnosis of this infection. However, the use of in-house methods can be time consuming. The availability of a commercial kit eliminates the need for in-house assay development, reducing laboratory workload and ensuring consistent performance across different healthcare settings. Currently, there are several commercial assays available, but many have limited evaluation. In this study, we compared two commercial kits and found that the MycoGENIE Kit offers a promising alternative to the in-house method.

Clinical and biological diagnosis and follow-up of patients treated for endovascular infections due to Coxiellaburnetii.

The objective of this study was to evaluate the effectiveness of the recommended treatment for endovascular infections due to Coxiella burnetii. This single-center retrospective study was conducted in 13 patients with endovascular infection due to C. burnetii between January 2001 and December 2020 for a definite or possible endovascular infection due to C. burnetii with a minimum follow-up of 18 months post-infection. Clinical and biological data, including serology, blood and tissue PCR results, doxycycline and hydroxychloroquine assays were collected. Among the 13 patients, 11 had endocarditis (8 definite and 3 possible) and 2 had a vascular infection. At the time of diagnosis, fever was present in only 46% of cases. In case of endocarditis, 73% of patients had a pathological echocardiography. Biologically, the CRP level was low (52 mg/l ± 44). Autoimmune antibodies (antinuclear factor, neutrophil anticytoplasm) were present in 23% of patients. At the time of diagnosis, tissue PCR was very sensitive (100%) unlike blood or serum (29%). Blood levels of doxycycline and hydroxychloroquine were within expected values. Only one patient experienced treatment failure at two years, requiring surgery. For the 7 patients whose phase I IgG titres fell below 1/800, a minimum of 18 months of treatment was necessary. In the long term, the clinical and biological cure was 100% and 92% respectively, underlining the importance of monitoring the serum dosages of doxycycline and hydroxychloroquine. Given its sensitivity, tissue PCR could be added to the major Duke criteria.

Fungal infections in mechanically ventilated patients with COVID-19 during the first wave: the French multicentre MYCOVID study.

BACKGROUND: Patients with severe COVID-19 have emerged as a population at high risk of invasive fungal infections (IFIs). However, to our knowledge, the prevalence of IFIs has not yet been assessed in large populations of mechanically ventilated patients. We aimed to identify the prevalence, risk factors, and mortality associated with IFIs in mechanically ventilated patients with COVID-19 under intensive care. METHODS: We performed a national, multicentre, observational cohort study in 18 French intensive care units (ICUs). We retrospectively and prospectively enrolled adult patients (aged ≥18 years) with RT-PCR-confirmed SARS-CoV-2 infection and requiring mechanical ventilation for acute respiratory distress syndrome, with all demographic and clinical and biological follow-up data anonymised and collected from electronic case report forms. Patients were systematically screened for respiratory fungal microorganisms once or twice a week during the period of mechanical ventilation up to ICU discharge. The primary outcome was the prevalence of IFIs in all eligible participants with a minimum of three microbiological samples screened during ICU admission, with proven or probable (pr/pb) COVID-19-associated pulmonary aspergillosis (CAPA) classified according to the recent ECMM/ISHAM definitions. Secondary outcomes were risk factors of pr/pb CAPA, ICU mortality between the pr/pb CAPA and non-pr/pb CAPA groups, and associations of pr/pb CAPA and related variables with ICU mortality, identified by regression models. The MYCOVID study is registered with ClinicalTrials.gov, NCT04368221. FINDINGS: Between Feb 29 and July 9, 2020, we enrolled 565 mechanically ventilated patients with COVID-19. 509 patients with at least three screening samples were analysed (mean age 59·4 years [SD 12·5], 400 [79%] men). 128 (25%) patients had 138 episodes of pr/pb or possible IFIs. 76 (15%) patients fulfilled the criteria for pr/pb CAPA. According to multivariate analysis, age older than 62 years (odds ratio [OR] 2·34 [95% CI 1·39-3·92], p=0·0013), treatment with dexamethasone and anti-IL-6 (OR 2·71 [1·12-6·56], p=0·027), and long duration of mechanical ventilation (>14 days; OR 2·16 [1·14-4·09], p=0·019) were independently associated with pr/pb CAPA. 38 (7%) patients had one or more other pr/pb IFIs: 32 (6%) had candidaemia, six (1%) had invasive mucormycosis, and one (<1%) had invasive fusariosis. Multivariate analysis of associations with death, adjusted for candidaemia, for the 509 patients identified three significant factors: age older than 62 years (hazard ratio [HR] 1·71 [95% CI 1·26-2·32], p=0·0005), solid organ transplantation (HR 2·46 [1·53-3·95], p=0·0002), and pr/pb CAPA (HR 1·45 [95% CI 1·03-2·03], p=0·033). At time of ICU discharge, survival curves showed that overall ICU mortality was significantly higher in patients with pr/pb CAPA than in those without, at 61·8% (95% CI 50·0-72·8) versus 32·1% (27·7-36·7; p<0·0001). INTERPRETATION: This study shows the high prevalence of invasive pulmonary aspergillosis and candidaemia and high mortality associated with pr/pb CAPA in mechanically ventilated patients with COVID-19. These findings highlight the need for active surveillance of fungal pathogens in patients with severe COVID-19. FUNDING: Pfizer.