A new blood test called ZIKV-NS2B-concat ELISA is faster, less expensive, and extends the window of accurate detection from weeks to months after the onset of infection, giving clinicians a powerful new tool to screen for Zika throughout pregnancy. The test, developed by a team including Columbia professor Nischay Mishra, improves on existing options, providing an accurate and cost-effective means to determine whether a patient was infected, days or months after exposure. The new test is detailed in the scientific journal mBio.
“Many people infected by Zika have only mild illness, or are unable to see a clinician in the early, acute phase of infection,” Mishra, an associate research scientist at the Center for Infection and Immunity at Columbia, and lead author of the study, is quoted saying in a press release. “Our new test greatly extends the window during which an individual can be assessed with accuracy.”
Diagnosis of Zika infection is complex. Molecular tests for exposure are only reliable in the first two to three weeks after infection while the virus is circulating in the bloodstream. Antibody tests are confounded by cross-reactivity of antibodies to Zika with dengue, yellow fever, and Japanese encephalitis viruses following infection or vaccination, notes the press release.
The new test was developed by scientists at the Center for Infection and Immunity (CII) at Columbia University’s Mailman School of Public Health and their colleagues at the University of California, Berkeley; Ministry of Health of Nicaragua; Walter Reed Army Institute of Research; Erasmus University Medical Centre; New York City Department of Health and Mental Hygiene; New York State Department of Health; and Roche Diagnostics.
Infection with Zika virus during pregnancy raises risk for neurodevelopmental problems in newborns, and in adults, can trigger Guillain-Barré syndrome which causes the immune system to attack the nerves. Since the emergence of Zika virus in the Americas in 2015, 583,144 cases have been reported to World Health Organization, with costs estimated as high as $18 billion between 2015 and 2017. However, long-term costs will likely be much higher given the additional, as-yet-unknown complications from congenital infections.