A.
Its name comes from the Ziika Forest of Uganda, where the virus was first isolated in 1947. Zika virus is related to the dengue, yellow fever, Japanese encephalitis, and West Nile viruses. Since the 1950s, it has been known to occur within a narrow equatorial belt from Africa to Asia. From 2007 to 2016, the virus spread eastward, across the Pacific Ocean to the Americas, leading to the 2015–16 Zika virus epidemic.
B.
Zika is spread mostly by the bite of an infected Aedes mosquito. Many people infected with Zika virus won’t have symptoms or will only have mild symptoms lasting for several days to a week. The most common symptoms of Zika are: fever, rash, headache, joint pain, conjunctivitis (red eyes), & muscle pain. Zika can be passed from a pregnant woman to her fetus. This can result in microcephaly, severe brain malformations, and other birth defects. Zika infections in adults may result rarely in Guillain–Barré syndrome.
C.
It was estimated that 1.5 million people were infected by Zika in Brazil, with over 3,500 cases of microcephaly reported between Oct 2015 and Jan 2016. In Nov 2016, WHO declared that the Zika virus was no longer a global emergency while noting that the virus still represents "a highly significant and a long-term problem". In 2018 and 2019, no local mosquito-borne Zika virus transmission has been reported in the continental United States.
D.
In January 2016, the US CDC issued travel guidance on affected countries, including the use of enhanced precautions, & guidelines for pregnant women including considering postponing travel. There is no vaccine or medicine for Zika.