Zika Lab Test Scores 91% Effective

Zika virus test based on a nonstructural protein 1 (NS1) human monoclonal antibody
Travel (Zika News)

A new lab test is a cost-effective way to determine if a person's infection is from the Zika virus or another virus of the same family, such as dengue or West Nile viruses.

This antibody-based assay has very high sensitivity (91.8 percent) and specificity (95.9 percent) for identifying Zika virus infections.

The antibody test is based on a nonstructural protein 1 (NS1) human monoclonal antibody.

Assays already exist to detect Zika virus infection, but they either work only shortly after infection or are poor at differentiating Zika from other flaviviruses.

The limited ability of assays to detect Zika virus has led to difficulty in determining the prevalence of Zika virus infections, the incidence of congenital Zika syndrome and the frequency of neurological complications associated with Zika virus infections.

"The whole world has been in urgent need of a serological method to distinguish dengue virus from Zika virus infections, and this is the first to have such high sensitivity and specificity in dengue-endemic regions," said Eva Harris, study co-author and UC Berkeley professor in the Division of Infectious Diseases and Vaccinology at the School of Public Health.

The assay is based on a well-established approach to detecting viral infections, but the new antibody and protocol give the assay superior sensitivity and specificity, two key assay metrics.

When the assay was run on patients infected with Zika virus and also on a control group of patients infected by other flaviviruses or other viruses, plus healthy donors, the specificity was 95.9 percent.

Davide Corti, senior vice president and chief scientific officer of Humabs BioMed said, "This novel assay has the potential to become an effective, simple and low-cost solution for Zika surveillance programs, prevalence studies and clinical intervention trials in flavivirus-endemic areas."

Zika virus (ZIKV), a mosquito-borne flavivirus with homology to dengue virus (DENV), has become a public health threat, particularly because of its association with severe congenital birth defects. The high level of cross-reactivity among flaviviruses and their co-circulation has complicated serological approaches to detect ZIKV infections.

The assay, developed by researchers at UC Berkeley and Humabs BioMed, and is currently in the licensing process.  Researchers hope it will be available to the medical community soon. Pricing for the lab test was not disclosed.

The research was supported, in part, by grants from National Institutes of Health. Conflict of interest statement: K.S, S.J., E.C., X.J., and D. Corti are employees of Humabs Biomed:  Angel Balmasedaa, Karin Stettlerc,Raquel Medialdea-Carrerad, Damaris Colladob, Xia Jinc, José Victor Zambranab, Stefano Jaconic, Elisabetta Cameronic, Saira Saborioa,b, Francesca Rovidae, Elena Percivallee, Samreen Ijazf, Steve Dicksf, Ines Ushiro-Lumbg, Luisa Barzonh, Patricia Siqueirai, David W. G. Browni, Fausto Baldantie, Richard Tedderf, Maria Zambonf, A. M. Bispo de Filippisi, Eva Harrisk,and Davide Cortic