Zika virus is a vector-borne flavivirus in the same family as yellow fever, dengue, West Nile, and Japanese encephalitis viruses, and is transmitted by the Aedes aegypti mosquito. It is a member of the Flaviviridae virus family and the Flavivirus genus.
In humans, it causes a mild illness known as Zika fever, Zika, or Zika disease, which since the 1950s has been known to occur within a narrow equatorial belt from Africa to Asia.
Since April 2015, a large, ongoing outbreak of Zika virus that began in Brazil and has spread to other countries in South and Central America, and to the Caribbean.
Local authorities suspected the outbreak was due to an increased influx of foreign visitors attending the 2014 FIFA World Cup, coupled with the large population of Aedes aegypti and A. albopictus mosquitoes in the region. The virus had previously been present only in Africa, Asia and the Pacific.
French Polynesian researchers argued that none of the Pacific countries with circulating Zika virus participated in the soccer games and have suggested that the outbreak is more likely linked to the Va’a World Sprint Championship canoe race in August 2014.
In January 2016, the U.S. Centers for Disease Control and Prevention (CDC) issued travel guidance on affected countries, including the use of enhanced precautions and considering postponing travel, and guidelines for pregnant women.
Other governments or health agencies soon issued similar travel warnings, while Colombia, Ecuador, El Salvador, and Jamaica advised women to postpone getting pregnant until more is known about the risks.
