A Lateral Flow Immunoassay test performance in SARS-CoV-2 seroprevalence surveys: a validation study among healthcare workers

Ronan Garlantézec (1, 2) , Christopher Heslan (1, 2) , Emilie Tadie (3) , Pierre Tattevin (4, 5) , V. Thibault (1, 2) , Christophe Paris (1, 2)

1 Irset - Institut de recherche en santé, environnement et travail
2 EHESP - École des Hautes Études en Santé Publique [EHESP]
3 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]
4 BRM - ARN régulateurs bactériens et médecine
5 Biosit : Biologie - Santé - Innovation Technologique - Structure Fédérative de Recherche en Biologie et Santé de Rennes

The objective of this study was to evaluate the validity and reliability of NG-Test® when used as a finger-prick test on healthcare workers and to compare it to the ELISA Wantai Immunoassay. Fifty-one healthcare workers who were RT-PCR SARS-CoV-2 positive and 59 who were RT-PCR SARS-CoV-2 negative accepted to participate in this study. They were subjected to an NG-Test® finger-prick test and collection of a blood sample on the same day. A second NG-Test® on another finger was performed for the first 30 cases and controls and read blinded to the first. Sera obtained from blood samples were used to perform the Wantai SARS-CoV-2 ELISA. The interobserver agreement for the NG-Test® test was perfect (kappa coefficient = 100% [98%–100%]). The sensitivity of NG-Test® was estimated to be 85% [71.9%–92.3%] and the specificity 98.3% [95.0%–100.0%]) for both IgG and IgM. The percentage of agreement between the Wantai immunoassay and NG-Test® was 92.73% for IgG (Kappa = 0.85 [0.75–0.95]) and 65.45% (Kappa = 0.42 [0.26–0.58]) for IgM. Our study highlights the need to validate rapid immunoassay tests under real-life conditions. If NG-Test® is used in seroprevalence surveys, we recommend that its diagnostic performance be taken into consideration to obtain a reliable estimation.

Mots clés: COVID-19; SARS-CoV-2; immunoassays; serological test

Domaines: Sciences du Vivant [q-bio]

Ronan Garlantézec, Christopher Heslan, Emilie Tadie, Pierre Tattevin, V. Thibault, et al.. A Lateral Flow Immunoassay test performance in SARS-CoV-2 seroprevalence surveys: a validation study among healthcare workers. Emerging Microbes and Infections, 2020, 9 (1), pp.2547-2549. ⟨10.1080/22221751.2020.1852893⟩. ⟨hal-03038403⟩