Evaluation of CLINITEST® Rapid Covid-19 + Influenza antigen test in a cohort of symptomatic patients in an emergency department

Alfredo Maldonado-Barrueco; Almudena Gutiérrez-Arroyo; Iván Bloise; María de Ceano-Vivas; Angélica Rivera-Nuñez; Rosario Torres Santos-Olmos; Dolores Montero Vega; Julio García-Rodríguez; SARS-CoV-2 working group

doi:10.1007/s10096-024-04788-w

Evaluation of CLINITEST® Rapid Covid-19 + Influenza antigen test in a cohort of symptomatic patients in an emergency department

Eur J Clin Microbiol Infect Dis. 2024 Feb 29. doi: 10.1007/s10096-024-04788-w. Online ahead of print.

Authors

Alfredo Maldonado-Barrueco¹, Almudena Gutiérrez-Arroyo², Iván Bloise², María de Ceano-Vivas³, Angélica Rivera-Nuñez⁴, Rosario Torres Santos-Olmos⁴, Dolores Montero Vega², Julio García-Rodríguez²; SARS-CoV-2 working group

Affiliations

¹ Clinical Microbiology Department, Hospital Universitario La Paz, Madrid, Spain. alfredo.maldonado@salud.madrid.org.
² Clinical Microbiology Department, Hospital Universitario La Paz, Madrid, Spain.
³ Paediatric Emergency Department, Hospital Universitario La Paz, Madrid, Spain.
⁴ Adults Emergency Department, Hospital Universitario La Paz, Madrid, Spain.

PMID: 38421466
DOI: 10.1007/s10096-024-04788-w

Abstract

Objectives: Rapid management of patients with respiratory tract infections in hospital emergency departments is one of the main objectives since the concurrent circulation of respiratory viruses following the SARS-CoV-2 pandemic. The use of new combined point-of-care antigen tests for detecting influenza A/B and SARS-CoV-2 represents an advantage in response time over the molecular tests. The objective was to evaluate the suitability of the CLINITEST® Rapid Covid-19 + Influenza Antigen test (Siemens Healthineers, Germany) (RCIA test) by measuring the sensitivity, specificity, Cohen's kappa, and cut-off values.

Methods: Nasopharyngeal samples were collected from a randomised group of symptomatic patients of all ages at emergency department during January-February 2023. In parallel, these patients were screened for influenza A/B, and SARS-CoV-2 using RT-PCR. The Ct (cycle threshold) values were collected for positive [RT-PCR (+) /RCIA test (+)] and false negative [(RT-PCR (+) /RCIA test (-)] samples. A subanalysis was performed in the paediatric population (< 16 years-old).

Results: We included 545 patients (55.8% females) with a median age of 7 years-old (IQR: 1-66.5). The RCIA test showed a sensitivity of 59.7% [95%CI: 46.9-67.33] for influenza A, 65.6% [95%CI: 49.5-80.3] for influenza B, and 76.9% [95%CI: 45.8-84.8] for SARS-CoV-2. The specificity was between 90.7%-99.7% with a moderate/high level of agreement with RT-PCR (kappa score: 0.6-0.8) for the three respiratory viruses included in the RCIA test.

Conclusions: The sensitivity of the RCIA test is insufficient for screening of patients, including patients with low Ct values (Ct > 20). Despite its good specificity and Cohen's kappa value, its use as a screening test is not comparable to RT-PCR systems in the ED environment with a high number of false negative results.

Keywords: Antigen test; Clinitest; Emergency department; Influenza A/B; Point-of-care; RT-PCR; Respiratory infection; SARS-CoV-2; Viruses.