Diagnostic accuracy of the Abbott ID NOW SARS-CoV-2 rapid test for the triage of acute medical admissions.

BACKGROUND: Decisions to isolate patients at risk of having coronavirus disease 2019 (COVID-19) in the emergency department (ED) must be rapid and accurate to ensure prompt treatment and maintain patient flow whilst minimising nosocomial spread. Reverse transcription polymerase chain reaction (RT-PCR) assays are too slow to achieve this, and near-patient testing is being used increasingly to facilitate triage. The ID NOW severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) assay is an isothermal nucleic acid amplification near-patient test which targets the RNA-dependent RNA-polymerase gene. AIM: To assess the diagnostic performance of ID NOW as a COVID-19 triage tool for medical admissions from the ED of a large acute hospital. METHODS: All adult acute medical admissions from the ED between 31st March and 31st July 2021 with valid ID NOW and RT-PCR results were included. The diagnostic accuracy of ID NOW [sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)] was calculated against the laboratory reference standard. Discrepant results were explored further using cycle threshold values and clinical data. FINDINGS: Two percent (124/6050) of medical admissions were SARS-CoV-2 positive on RT-PCR. Compared with PCR, ID NOW had sensitivity and specificity of 83.1% [95% confidence interval (CI) 75.4-88.7] and 99.5% (95% CI 99.3-99.6), respectively. PPV and NPV were 76.9% (95% CI 69.0-83.2) and 99.6% (95% CI 99.5-99.8), respectively. The median time from arrival in the ED to ID NOW result was 59 min. CONCLUSION: ID NOW provides a rapid and reliable adjunct for the safe triage of patients with COVID-19, and can work effectively when integrated into an ED triage algorithm.

Staphylococcal scalded skin syndrome in an adult associated with methicillin-resistant Staphylococcus aureus.

We report the first adult case of staphylococcal scalded skin syndrome (SSSS) due to methicillin-resistant Staphylococcus aureus (MRSA). This case is particularly unusual as the MRSA produced toxic shock syndrome toxin 1 and enterotoxin, but not exfoliatoxin. SSSS was originally described in neonates and is thought to result from exfoliatins which produce subcorneal splitting of the epidermis and are only produced by certain strains of S. aureus. This case reflects the range of toxins that can be associated with SSSS and the clinical manifestations of MRSA infection in adult patients.