FDA Grants Emergency Use Authorization for Zika Test as Local Zika Transmission Increases

*Updated 8/1/2016 4:54 PM EST

The US Food and Drug Administration approved the VERSANT Zika RNA 1.0 Assay (kPCR) Kit for Emergency Use Authorization, as the number of locally transmitted Zika cases rose to 14.

Manufactured by Siemens Healthcare Diagnostics Inc, the VERSANT kPCR can detect the Zika virus in plasma, serum and urine. The new test can detect the Zika virus earlier than anti-Zika antibodies. FDA clearance for kPCR use does not indicate FDA approval; according to a press release, the test “is only authorized for use for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of in vitro diagnostic tests for detection of Zika virus and/or diagnosis of Zika virus infection.”

Fernando Beils, vice president and head of Molecular Diagnostics at Siemens, stated, “The FDA’s emergency use authorization for the VERSANT Zika RNA 1.0 Assay (kPCR) Kit from Siemens can lead us one step closer to stopping the spread of the Zika virus… Being able to quickly diagnose patients will help physicians to more efficiently manage those affected.”

On Friday, July 29, 2016, the Florida Department of Health and the Centers for Disease Control and Prevention (CDC) confirmed that four cases of non—travel-related Zika infections in Florida are in fact due to active Zika transmission in the Miami area. Tom Frieden, MD, MPH, director of the CDC stated that active transmission is suspected to have started in early July. Prior to official confirmation of active transmission, and as a precaution, the FDA issued a statement urging all blood establishments to cease blood collection from areas where the non–travel-related infected individuals reside.

Today, Governor Rick Scott announced that ten new cases of locally acquired Zika infection have been identified, bringing the total of locally acquired Zika cases to 14. Zika is known to cause several neurological complications in developing fetuses of pregnant women infected with the virus. It is not known whether mode of infection is associated with severity of complications. Nonetheless, the CDC does not advise women of child-bearing age living in the infected area to postpone pregnancy. In response to the newly identified cases, the CDC issued a travel warning to the infected areas, advising pregnant women to avoid travel, or follow infection prevention methods. The CDC also noted that, “Pregnant women who live in or frequently travel to this area should be tested in the first and second trimester of pregnancy.”

Since only 20% of infected individuals present with symptoms, the CDC suspects that there may be more cases than currently identified. According to a press release, the Florida Department of Health tested 26 of the first two cases' close contacts, of whom one was tested positive while three are suspected of infection. From the community, 52 individuals were tested for Zika, six of whom have been identified to be infected but were asymptomatic.

On the other hand, a new study published in PLoS Biology is predicting that timing conception in relation to seasonal mosquito decline can reduce the risk of Zika infection during pregnancy. The study author suggests that mosquito populations decline with the rise of the ‘dry season,’ indicated by low rates of rainfall and normal evaporation, in tropical areas. Since this denies Aedes aegypti, the mosquito vector that transmits Zika, and other insects the standing water supplies needed for larvae to hatch, female mosquitos are less-likely to feed on humans since they will not need to produce eggs, and are therefore less likely to spread the Zika virus. The author of the PLoS study call this the ‘trough’ period.

According to the author, Micaela Martinez, PhD, a researcher at Princeton University, timing the first 20 weeks of pregnancy during this trough period can increase the chance of women having safe pregnancies, since this is considered the most dangerous time for the fetus to be infected with the Zika virus. In an effort to aid in identifying safe conception periods, Martinez created a computer software program that can identify weeks during which conception would be safest.

Commenting on her findings, Martinez stated in a press release, “All other animals time their reproduction to match favorable environmental conditions. Why couldn’t we? Mosquitos are seasonal, which most people are quite aware of, but we tend not to think about that in terms of preventing infections.”

According to the press release, local governments, healthcare workers as well as scientists can enter mosquito activity specific to their regions into the program, which would predict the ‘ideal’ time for women in the respective regions to conceive. However, before this measure can be used as a surefire way to prevent Zika-related congenital complications, more evidence of Zika seasonality is needed, according to Alex Perkins, PhD, assistant professor of biological sciences at the University of Notre Dame. He stated, "That said, the more recurrent that seasonal epidemics of Zika virus become, the more seriously people will start to consider strategies such as the one proposed here…. With additional research, the ideas proposed in this article could tell us quite a lot about the extent to which knowledge about the seasonality of transmission could be used to our advantage to minimize the risk of severe disease in vulnerable populations."