Contribution of the anaerobic blood culture vial for the recovery of Candida glabrata: A retrospective multicentric study.

Although Candida spp are aerobic microorganisms, some Candida strains, mainly Candida glabrata, can be recovered from anaerobic blood culture vials. We assessed the contribution of the anaerobic vials for the diagnosis of candidemia, especially for C. glabrata. We conducted a multicenter retrospective study including eight university or regional hospitals. A single episode of monomicrobial candidemia per patient was included from September 1st, 2016, to August 31st, 2019. The characteristics of all aerobic and anaerobic blood culture vials sampled within 2 h before and after the first positive blood culture vials were recorded (type of vials, result, and for positive vials time-to-positivity and Candida species). Overall, 509 episodes of candidemia were included. The main species were C. albicans (55.6%) followed by C. glabrata (17.1%), C. parapsilosis (4.9%), and C. tropicalis (4.5%). An anaerobic vial was positive in 76 (14.9%) of all episodes of which 56 (73.8%) were due to C. glabrata. The number of C. glabrata infections only positive in anaerobic vials was 1 (2.6%), 1 (11.1%), and 15 (37.5%) with the BACT/ALERT 3D the BACT/ALERT VIRTUO and the BACTEC FX instrument, respectively (P < 0.01). The initial positivity of an anaerobic vial was highly predictive of the isolation of C. glabrata with the BACTEC FX (sensitivity of 96.8%). C. glabrata time-to-positivity was shorter in anaerobic vial than aerobic vial with all instruments. Anaerobic blood culture vials improve the recovery of Candida spp mainly C. glabrata. This study could be completed by further analyses including mycological and pediatric vials. LAY SUMMARY: Although Candida spp are aerobic microorganisms, C. glabrata is able to grow in anaerobic conditions. In blood culture, the time-to-positivity of C. glabrata is shorter in anaerobic than aerobic vials. Only the anaerobic vial was positive in up to 15 (37.5%) C. glabrata bloodstream infections.

Interpretation of very low avidity indices acquired with the Liaison XL Toxo IgG avidity assay in dating toxoplasmosis infection.

Congenital toxoplasmosis is an important cause of complications in pregnancy. Toxoplasmosis is often asymptomatic and thus serological tests are usually performed to screen for it. A first serum which exhibit both IgG and IgM may be due to nascent toxoplasmosis seroconversion, non-specific IgM reaction, or residual IgM. The IgG avidity test has been proposed to identify latent infections. A high index excludes recent toxoplasmosis whereas an intermediate or low index only suggests a recent infection, the caveats being that some people with latent Toxoplasma gondii infection show IgG with low or intermediate avidity. In this study, we investigated the ability of the Liaison XL Toxo IgG avidity (DiaSorin, Saluggia, Italy) assay to confirm recent infection when IgG avidity index is very low (≤ 0.1). Four thousand two hundred ninety-seven sera exhibiting both IgG and IgM were included and avidity was performed on the Liaison device according to the manufacturer's recommendations. One hundred twenty-six sera on the 297 sera which exhibited very low IgG avidity indices (≤ 0.1) could be exploited: 97% of sera with IgG avidity indices < 0.05 actually corresponded to recent infection (less than 3 months). A similar but less pronounced trend was observed for the sera exhibiting indices between 0.05 and 0.1 (69% corresponded to recent infections). The IgG avidity index data we obtained with the Liaison XL Toxo device are similar to those obtained with other devices. This body of consistent results underlines the interest of very low IgG avidity indices as a sign of probable recent toxoplasmosis.

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.