Source : The Journal of Infectious Diseases, 30 May 2020, jiaa305, https://doi.org/10.1093/infdis/jiaa305

Auteur : M Traugott, S W Aberle, J H Aberle, H Griebler, M Karolyi, E Pawelka, E Puchhammer-Stöckl, A Zoufaly, L Weseslindtner


ABSTRACT

We comparatively assessed sensitivities and specificities of four commercial ELISAs and two rapid tests in 77 patients with PCR confirmed SARS-CoV-2 infection, grouped by intervals since symptom onset. While test sensitivities were low (<40%) within the first 5 days post disease onset, IgM-, IgAand total antibody-ELISAs increased in sensitivity to >80% between the 6th and 10th day post symptom onset. The evaluated tests (including IgG and rapid tests) provided positive results in all patients at or after the 11th day post onset of disease. Specificities of the ELISAs were 83% (IgA), 98% (IgG) and 97% (IgM and total antibodies).

BACKGROUND

SARS-Coronavirus 2 (SARS-CoV-2), a new Betacoronavirus, is currently causing a massive pandemic with severe consequences for the health-care systems worldwide [1, 2]. While polymerase chain reaction (PCR) based tests quickly became the cornerstone of SARS-CoV-2 diagnosis, the potential of antibody tests has not been comprehensively evaluated. Depending on respective infection stages, antibody assays could nonetheless significantly complement PCR based testing [3, 4]. Multiple commercial enzyme-linked immunoassays and rapid tests (lateral flow immunossays) have recently become available, but their diagnostic ability has to be thoroughly evaluated and compared before they can be widely used in the clinical setting [5, 6]. Here, we compared the diagnostic ability of four ELISAs, which assess SARS-CoV-2-specific antibodies of immunoglobulin classes (Euroimmun SARS-CoV-2 IgA and IgG, Wantai SARS-CoV-2 IgM and total antibodies), and two rapid tests (Wantai SARS-CoV-2 Ab Rapid Test and 2019-nCoV IgG/IgM Rapid Test) in 77 patients with symptomatic SARS-CoV-2 infection.

 


Télécharger l’article complet


Source : JAMA Auteur : Sood N. et al.

ANALYSE:

Commentateur : Dr David REY. Objectif :
  • Déterminer la séroprévalence du SARS-CoV-2 dans un échantillon de la population de Los Angeles (tirée au sort, avec des quotas par sous-groupe selon âge, sexe, et distribution ethnique).
Principaux résultats :
  • 35 personnes, soit 4,06% ont une sérologie positive.
  • Positivité plus élevée chez les hommes, les 35-54 ans et les afro-américains.
  • Au final, la prévalence pondérée est de 4,65%.
Conclusion : 
  • Séroprévalence COVID-19 population adulte à Los Angeles: 4,65%.
Lire toute l’analyse ICI.


Source : JAMA Network

Auteur : Jennifer Abbasi


Medical News & Perspectives

As coronavirus disease 2019 (COVID19) raged around the globe in late March, hundreds of San Miguel County, Colorado, residents turned out for a blood test. Standing 6 feet apart outside a Telluride school gym, they waited for the blood draw that would tell themwhether they had mounted an immune response to the disease-causing virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—a sign that they’d been infected.


Télécharger l’article complet


Source : Clinical Infectious Diseases, ciaa310, 21 March 2020 Auteur : Li Guo, Lili Ren, Siyuan Yang, Meng Xiao, De Chang, Fan Yang, Charles S Dela Cruz, Yingying Wang, Chao Wu, Yan Xiao, Lulu Zhang, Lianlian Han, Shengyuan Dang, Yan Xu, Qiwen Yang, Shengyong Xu, Huadong Zhu, Yingchun Xu, Qi Jin, Lokesh Sharma, Linghang Wang, Jianwei Wang.

ANALYSE

Commentateur

Dr REY David

Objectif

Description de l’évolution du profil sérologique de patients COVID19 confirmés (PCR ou clinique) et validation d’un test sérologique.

Points forts

Première description d’un test sérologique, permet de rattraper les faux négatifs en PCR.

Points faibles

Pas de validation de test utilisant les IgG, pour la détection des infections anciennes. Taux de faux négatif pas clairement établi.

Conclusion

Sérologie IgM plus performante que PCR après J5,5. En début d’infection, PCR reste plus performante. Vous pouvez télécharger l’analyse ICI.  

© Les Hôpitaux Universitaires de Strasbourg 2020 - Tous droits réservés