Evaluation of Zika Diagnostics for Epidemic Preparedness

Abstract

Background: Development and evaluation of diagnostics for diseases of epidemic potential are often funded during epidemics and left unfinished once the epidemic is over, leaving countries ill-prepared to combat the next epidemic. UNICEF partnered with USAID to address this important gap by investing in an advance purchase commitment (APC) mechanism to accelerate the development and availability of Zika diagnostics. A central pillar of this initiative was a process for rigorous test evaluations. Methods: A network of EU-funded ZikaPLAN sites in Africa, Asia, Latin America with access to well-characterized clinical specimens were selected to evaluate rapid diagnostic tests (RDTs) for the detection of antibodies against Zika virus (ZIKV), chikungunya virus (CHIKV), yellow fever virus (YFV), and dengue virus (DENV) using a standardised protocol. Evaluation panels included Zika specimens collected during acute and convalescent stages of ZIKV outbreaks and specimens that assess potential cross-reactive antibody responses. Findings: Of five Zika RDTs evaluated, three were found to meet criteria for UNICEF procurement. The sensitivity/specificity for ChemBio ZCD system for anti-ZIKV IgM was 79.0%/97.1%, anti-DENV IgM was 90.0%/89.2%, anti-CHIKV IgM was 90.6%/97.2%. The sensitivity and specificity of the test for anti-ZIKV IgM and IgG antibodies was 86.4% and 92.7%, and 82.8% and 59.6%, respectively. The sensitivity/specificity for the SD Biosensor anti-ZIKV IgM was 96.8%/90.8%, anti-DENV IgM was 71.8%/80.7%, the DENV NS1 glycoprotein was 90.0%/90.2%, anti-YFV IgM was 84.6%/98.6%, anti-CHIKV IgM was 86.3%/92.0%. Interpretation: Biobanking networks provide access to specimens that were used to rapidly evaluate diagnostic tests for diseases of epidemic potential and facilitated procurement of tests eligible for procurement by funders. Funding: This work was supported by the USAID grant GHA-G-00-07-00007 and ZikaPLAN (European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 734584). Declaration of Interest: We declare that we have no conflicts of interest. Ethical Approval: All sites have institutional and ethics committee approval for the use of archived left over clinical or surveillance specimens for this evaluation.