Evaluating diagnostics for ZIKV infection in pregnancy and childhood

A major activity of ZIKA-VID was a comprehensive comparative analysis of the accuracy of second generation ZIKV diagnostic assays for use in LAC populations in pregnancy and childhood, which informed a theoretical model to address uncertainty in diagnosis that could prove useful not only in ZIKV but also in future emerging infections.  

Results

• The challenge of ZIKV virus diagnosis following acute infection – A systematic evaluation of IgM and IgG antibody-based assays and the plaque reduction neutralisation test, Raquel Medialdea-Carrera et al., Journal of Clinical Microbiology

This paper highlights the low sensitivity of ZIKV IgM testing in DENV endemic populations, the poor specificity of first generation ZIKV IgG and IgM assays and the value of the plaque neutralization test (PRNT), the most accurate reference assay for underpinning testing strategies in these studies. 

Among the 3 novel IgG assays evaluated, BNITM / Hamburg Blackbox EIA IgG assay showed best sensitivity and specificity is also in use and was therefore introduced into three consortium sites (Rio, Haiti, and Jamaica) because of its good performance, excellent accuracy, and availability.  

• Accurate detection of ZIKV virus IgG using a novel ZIKV immune complex ELISA suitable for use in dengue-endemic countries. C. Ehmen et al., Tropical Medicine and International health
• Modulated Zika virus NS1 conjugate offers advantages for accurate detection of Zika virus specific antibody in double antigen binding and Ig capture enzyme immunoassays

Additional work on optimization of diagnostic PCR assay was performed which has the potential to enhance future surveillance of ZIKV infections, particularly in communities underserved by laboratory services where cases in these communities often present late to clinical services.  

• Field  diagnosis  and  genotyping  of  chikungunya  virus  using  a  dried  reverse  transcription  loop-mediated  isothermal  amplification  (LAMP)  assay  and  MinION  sequencing
• Zika Virus in Rectal Swab Samples 
• Genomic and Epidemiological Surveillance of Zika Virusin the Amazon Region
• Minor groove binder modification of widely used Taq Man hydrolysis probe for detection of dengue virus reduces risk of false-negative real-time PCR results for serotype
• A Systematic Evaluation of IgM and IgG Antibody Assay Accuracy in Diagnosing Acute Zika Virus Infection in Brazil: Lessons Relevant to Emerging Infections