Spillover: Zika, Ebola & Beyond

Click and drag or use the buttons below to move the model.

The proteins embedded in the viral envelope are shown. The ones colored red are involved in binding to and entering the host cell. The icosahedral virus core is not visible.

Zika Cross Section

A. Envelope protein; B. Membrane protein; C. Lipid envelope; D. RNA genome; E. Capsid protein

Zika Virus

  • Flaviviridae family, which includes yellow fever virus, West Nile virus, and dengue virus
  • ~50-nm enveloped particles with an icosahedral core
  • Linear, ss + RNA genome of ~10,800 bp
  • Infects humans and other primates
  • Carried and transmitted by mosquitoes of the genus Aedes
  • No vaccine is currently available

Show Relative Size

Zika virus is one of several mosquito-borne flaviviruses. The virus was of limited concern until 2015, when in South America scientists discovered an association between Zika infection in pregnant women and an increase in the number of babies born with smaller-than-normal head sizes, a condition known as microcephaly. Scientists have since agreed that Zika virus infection in pregnant women may lead to microcephaly and other neurological defects in their child. The virus is spread primarily through the bite of Aedes aegypti and related species of mosquitoes.

Historical Timeline of Zika Virus Spread

world map

Zika virus date of first appearance

  1. 1947–1952
  2. 1954
  3. 1969–1983
  4. 2012–2014
  5. Feb 2015
  6. Oct 2015
  7. Nov 2015
  8. Dec 2015
  9. Jan 2016
  10. May 2016

Relative Sizes

Chart showing size comparison of different viruses.

The white line represents 100 nanometers (nm). For comparison, the width of a human hair is about 75,000 nm, so it would be 750 times as long!