ABSTRACT
A commercially available isothermal amplification of SARS-CoV-2 RNA was applied to self-collected saliva samples using dry dental cotton rolls, which were held in the mouth for two minutes. Of 212 tests, isothermal amplification yielded three (0.14%) invalid results, 120 (56.6%) positive results and 89 (42%) negative results. Compared to reference RT-PCR assays routinely performed simultaneously on nasopharyngeal swabs, excluding the three invalid isothermal amplification assays and one RT-PCR invalid assay, these figures indicated that 119/123 (96.7%) samples were positive in both methods and 85/85 samples were negative in both methods. Four positive buccal swabs which were missed by the isothermal amplification, exhibited Ct values of 26-34 in reference RT-PCR assays. Positive isothermal amplification detection was achieved in less than 10 min. Supervision of the self-sampling procedure was key to achieve these performances. These data support the proposal to use the protocol reported in this paper, including supervised buccal self-sampling, to screen people suspected of having COVID-19 at the point of care.
ABSTRACT
The prognosis of central nervous system infections caused by enteroviruses partially depends on the viral genotype, which is not provided by current point-of-care diagnostic methods. In this study, next-generation sequencing identified an echovirus 9 directly from the cerebrospinal fluid of a patient presenting with meningitis.
Subject(s)
Central Nervous System Infections/diagnosis , Echovirus 9/genetics , Echovirus Infections/diagnosis , Echovirus Infections/epidemiology , Genotype , High-Throughput Nucleotide Sequencing/methods , Meningitis, Viral/diagnosis , Adult , Central Nervous System Infections/epidemiology , Central Nervous System Infections/virology , Echovirus 9/classification , Echovirus 9/pathogenicity , Echovirus Infections/cerebrospinal fluid , Female , France/epidemiology , Humans , Meningitis, Viral/epidemiology , Meningitis, Viral/virology , Phylogeny , RNA, Viral/genetics , Whole Genome SequencingABSTRACT
Infectious meningitis is a medical urgency and rapid detection of the causative pathogen into the cerebrospinal fluid (CSF) is mandatory to guide the management of patients. We compared the performances of the multiplexed PCR FilmArray® ME panel with standard microbiological analyses, for rapid diagnosis of infectious meningitis. All the CSF samples received in our routine laboratory for the diagnosis of infectious meningitis were prospectively analyzed by the FilmArray® ME panel for the detection of fourteen targets in parallel to standard routine real-time PCR assays and bacterial culture. We reviewed clinical and biological records of patients for whom a discrepant result was obtained to achieve a definite diagnosis. Among 1124 CSF samples tested over a 43-week period, 113 (10.1%) and 87 (7.74%) were positive using the FilmArray® ME panel and the standard techniques, respectively. Among 40 CSF samples which yielded discrepant results, 34 were positive only using the FilmArray® ME panel and 6 were positive only using standard techniques. A total of 16/34 (47.1%) FilmArray® ME panel-positive CSF, and 6/6 (100%) of standard technique-positive CSF were interpreted as true positive. We were able to estimate the sensitivity, the specificity, the positive predictive value, and the negative predictive value of the FilmArray® ME panel at 94.2%, 98.2%, 84.3%, and 99.4%, respectively. The FilmArray® ME panel is an efficient tool for the rapid diagnosis of infectious meningitis at the point-of-care. Its higher sensitivity compared with that of standard molecular biology and culture techniques yields an increase of true positive diagnosis.
