ABSTRACT
The Lumipulse(R) G SARS-CoV-2 Ag assay performance was evaluated on prospectively collected saliva and nasopharyngeal swabs (NPS) of recently ill in- and outpatients and according to the estimated viral load. Performances were calculated using RT-PCR positive NPS from patients with symptoms [≤] 7 days and RT-PCR negative NPS as gold standard. In addition, non-selected positive NPS were analyzed to assess the performances on various viral loads. This assay yielded a sensitivity of 93.1% on NPS and 71.4% on saliva for recently ill patients. For NPS with a viral load > 103 RNA copies/mL, sensitivity was 96.4%. A model established on our daily routine showed fluctuations of the performances depending on the epidemic trends but an overall good negative predictive value. Lumipulse(R) G SARS-CoV-2 assay yielded good performance for an automated antigen detection assay on NPS. Using it for the detection of recently ill patient or to screen high-risk patients could be an interesting alternative to the more expensive RT-PCR.
Subject(s)
NasopharyngitisABSTRACT
IntroductionWe assessed the usefulness of SARS-CoV-2 RT-PCR cycle thresholds (Ct) values trends produced by the LHUB-ULB (a consolidated microbiology laboratory located in Brussels, Belgium) for monitoring the epidemics dynamics at local and national levels and for improving forecasting models. MethodsSARS-CoV-2 RT-PCR Ct values produced from April 1, 2020, to May 15, 2021, were compared with national COVID-19 confirmed cases notifications according to their geographical and time distribution. These Ct values were evaluated against both a phase diagram predicting the number of COVID-19 patients requiring intensive care and an age-structured model estimating COVID-19 prevalence in Belgium. ResultsOver 155,811 RT-PCR performed, 12,799 were positive and 7,910 Ct values were available for analysis. The 14-day median Ct values were negatively correlated with the 14-day mean daily positive tests with a lag of 17 days. In addition, the 14-day mean daily positive tests in LHUB-ULB were strongly correlated with the 14-day mean confirmed cases in the Brussels-Capital and in Belgium with coinciding start, peak and end of the different waves of the epidemic. Ct values decreased concurrently with the forecasted phase-shifts of the diagram. Similarly, the evolution of 14-day median Ct values was negatively correlated with daily estimated prevalence for all age-classes. ConclusionWe provide preliminary evidence that trends of Ct values can help to both follow and predict the epidemics trajectory at local and national levels, underlining that consolidated microbiology laboratories can act as epidemic sensors as they gather data that are representative of the geographical area they serve.
Subject(s)
COVID-19ABSTRACT
Background: Whether the risk of multidrug resistant bacteria (MDRB) acquisition in the intensive care unit (ICU) is increased during the COVID-19 crisis is unknown. Our aim was to measure the rate of MDRB acquisition in patients admitted in COVID-19 ICU and to compare it with pre-COVID-19 controls.Methods: This single center case control study included adult patients admitted to COVID-19 ICUs for more than 48h. Patients were screen twice a week for MDRB carriage during ICU stay. We compared the rate of MDRB acquisition of COVID-19 patients with a cohort of patients admitted for subarachnoid hemorrhage (SAH) and matched on length of ICU stay using a competing risk analysis.Results: Among 72 patients admitted to the COVID-19 ICUs, 24 (33%) patients acquired 31 MDRB during ICU stay. The rate of MDRB acquisition was 30/1000 patient-days. Patients that acquired MDRB had received more antimicrobial therapy [22 (92%) vs 34 (78%, p=0.05] and had a longer exposure time [12 days (8-18) vs 5 days (2-18), p=0.02]. The rate of MDRB acquisition in matched SAH patients was 18/1000 patient-days. When compared to SAH retrospective cohort, being admitted to a COVID-19 ICU was associated with a numerically higher proportion of MDRB acquisition. This association did not reach statistical significance in the multivariable competing risk analysis (sHR 1.71 (CI 95% 0.93-3.21).Conclusion: Acquisition of MDRB was frequent during the COVID-19 first wave in ICU patients. Despite physical isolation, it was similar to patients admitted to the same ICU in previous years.