Guidelines for Zika Testing and Safety Issued

By Kelly A. Briganti, Editorial Director, G2 Intelligence

The Zika virus is getting increased attention from U.S. media and the Centers for Disease Control and Prevention (CDC) now that the first case of the infection has been detected in a “non-traveler” in the continental U.S. The CDC has updated guidelines and resources for diagnosing and preventing transmission of the Zika virus.

The CDC’s Jan. 29 issue of Morbidity and Mortality Weekly Report (MMWR) indicated that by Jan. 20, 2016, “locally-transmitted cases had been reported to the Pan American Health Organization from Puerto Rico and 19 other countries or territories in the Americas” and infections had been reported in U.S. for returning travelers. Feb. 5, the CDC reported that “in collaboration with the Dallas County Health and Human Services” it has confirmed the first case of the infection in the continental US involving an individual who hadn’t traveled to a country experiencing an outbreak of the virus. In that case, the infection was sexually transmitted. The CDC indicates that other documented means of transmission for the Zika virus have included intrauterine transmission, intrapartum transmission from mother to newborn, blood transfusion, and laboratory exposure.

The CDC’s Feb. 5 guidelines address when testing is recommended for pregnant women, indicating Zika testing can be offered to pregnant women 2-12 weeks after returning from outbreak locations, regardless of whether they have symptoms. New York State has promised free testing for symptomatic individuals and symptomatic or asymptomatic pregnant women, who have traveled to a country in which there is a Zika outbreak. The New York Times reported last week that as of Feb. 4, 11 Zika infections have been found in New York State (3 in New York City). Testing for the Zika virus is currently being performed at the CDC and four state health department laboratories—including one in New York state—and the CDC says it is working to expand laboratory diagnostic testing to additional states. Testing can be complicated by the fact that cross-reacting antibodies for other viruses such as dengue and yellow fever viruses may lead to false positive results for Zika.

As to lab safety, the CDC advised in a Jan. 13 memo that the virus is classified as a biological safety level 2 pathogen and “should be handled in accordance with Biosafety in Microbiological and Biomedical Laboratories (BMBL) guidelines and a risk assessment performed for each laboratory for the specific procedures utilized.”