The WHO Director-General, Margaret Chan, issued a statement in February 2016 "declaring that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern." The declaration allowed the WHO to coordinate international response to the virus as well as gave its guidance the force of international law under the International Health Regulations. The declaration was ended in November 2016. Vaccine
As of 2016 there was no available vaccine. Development was a priority of the US National Institutes of Health (NIH), but officials stated that development of a vaccine could take years. To speed new drug development regulatory strategies were proposed by the WHO and NIH. Animal and early human studies were underway as of September 2016. As of December 2019, there were several vaccine candidates in various stages of development. Mosquito control
Disease control in the affected countries currently centres around mosquito control. Several approaches are available for the management of Aedes aegypti mosquito populations, including the destruction of larval breeding sites (the aquatic pools in which eggs are laid and larvae hatch prior to mosquito development into flying adults); and, insecticides targeting either the larval stages, adult mosquitoes or both.
Serological cross-reactions with closely related flaviviruses such as dengue and West Nile virus as well as vaccines to flaviviruses are possible. As of 2019, the FDA has authorized two tests to detect Zika virus antibodies. Screening in pregnancy
The CDC recommends screening some pregnant women even if they do not have symptoms of infection. Pregnant women who have traveled to affected areas should be tested between two and twelve weeks after their return from travel. Due to the difficulties with ordering and interpreting tests for Zika virus, the CDC also recommends that healthcare providers contact their local health department for assistance. For women living in affected areas, the CDC has recommended testing at the first prenatal visit with a doctor as well as in the mid-second trimester, though this may be adjusted based on local resources and the local burden of Zika virus. Additional testing should be done if there are any signs of Zika virus disease. Women with positive test results for Zika virus infection should have their fetus monitored by ultrasound every three to four weeks to monitor fetal anatomy and growth. Infant testing
For infants with suspected congenital Zika virus disease, the CDC recommends testing with both serologic and molecular assays such as RT-PCR, IgM ELISA and plaque reduction neutralization test (PRNT). RT-PCR of the infants serum and urine should be performed in the first two days of life.