High specificity and sensitivity of Zika EDIII-based ELISA diagnosis highlighted by a large human reference panel

Abstract

BackgroundZika virus (ZIKV) and Dengue virus (DENV) are often co-endemic. The high protein-sequence homology of flaviviruses renders IgG induced by and directed against them highly cross-reactive against their antigen(s), as observed on a large set of sera, leading to poorly reliable sero-diagnosis.MethodsWe selected Domain III of the ZIKV Envelope (ZEDIII) sequence, which is virus specific. This recombinant domain was expressed and purified for the specific detection of ZEDIII-induced IgG by ELISA from ZIKV-RT-PCR-positive, ZIKV-IgM-positive, flavivirus-positive but ZIKV-negative, or flavivirus-negative sera. We also assessed the reactivity of ZEDIII-specific human antibodies against EDIII of DENV serotype 4 (D4EDIII) as a specific control. Sera from ZEDIII-immunized mice were also tested.ResultsCross-reactivity of IgG from 5,600 sera against total inactivated DENV or ZIKV was high (71.0% [69.1; 72.2]), whereas the specificity and sensitivity calculated using a representative cohort (242 sera) reached 90% [84.0; 95.8] and 92% [84.5; 99.5], respectively, using a ZEDIII-based ELISA. Moreover, purified human IgG against D2EDIII or D4EDIII did not bind to ZEDIII and we observed no D4EDIII reactivity with ZIKV-induced mouse polyclonal IgGs.ConclusionsWe developed a ZEDIII-based ELISA that can discriminate between past or current DENV and ZIKV infections, allowing the detection of a serological scar from other flaviviruses. This could be used to confirm exposure of pregnant women or to follow the spread of an endemic disease.

Accurate detection of Zika virus IgG using a novel immune complex binding ELISA

“…[18] developed a ZIKV-NS1 blockade-of-binding IgG ELISA based on detection by a monoclonal antibody, which reached 96% specificity using a wide variety of samples. Denis et al [23] tested ZIKV-ED3 as antigen in classical sandwich IgG ELISA with 5600 sera and found a high suitability of the protein as antigen for serological diagnostics (90% specificity), similarly to other studies with flaviviral ED3 antigens [7]. However, performance is often difficult to compare due to differences in sample panels used for validation.…”

“…Other ZIKV IgG tests have been developed [e.g. 3,18–22]. Balmaseda et al [18] developed a ZIKV‐NS1 blockade‐of‐binding IgG ELISA based on detection by a monoclonal antibody, which reached 96% specificity using a wide variety of samples.…”

Incidence of Zika Virus Infection from a Dengue Epidemiological Study of Children in Ratchaburi Province, Thailand

“…Several ZIKV immunoenzymatic assays have been developed with different formats. ELISA is an attractive alternative as an easy screening test for ZIKV infection with low cost [ 20 , 21 , 25 , 26 ].…”

Vector-Borne Transmission of the Zika Virus Asian Genotype in Europe

“…Earlier samples were tested by molecular approaches, whereas later ones were tested using in-house ELISA with a whole precipitated and inactivated virus, Zika EDIII recombinant protein (IgM and IgG antibodies to ZIKV), and confirmed by virus neutralization test. All cases were found positive in ELISA, Zika EDIII-based ELISA and virus neutralization, and negative for neutralizing antibodies against West-Nile and Dengue serotype 1 to 4 viruses [5]. All attempts for virus isolation and detection of the ZIKV genome by RT-PCR (RealStar Zika Virus RT-PCR kit, Altona Diagnostics, Germany [6]) in serum, urine and semen were negative, even in early samples collected less than two days after onset.…”