Zika virus infection

Last updated: July 25, 2023

Summarytoggle arrow icon

Zika virus is an arbovirus transmitted by the mosquito Aedes aegypti. The infection can also be transmitted transplacentally and sexually. Since 2015, epidemic outbreaks of Zika virus infection have occurred in South America, US territories, and in certain southern US states. The infection is typically asymptomatic or results in mild flu-like symptoms. However, this infection has received a lot of attention because it can result in fetal microcephaly when the virus infects pregnant women. Much about this disease is still unknown and it is currently the subject of much study and research. The diagnosis is usually confirmed by PCR and/or serology. Currently, neither a definitive therapy nor a clinically-approved vaccine exist.

Epidemiologytoggle arrow icon

  • Worldwide geographical distribution
    • Outbreaks most commonly occur in tropical and subtropical regions.
    • Before 2015, a few cases were reported in Africa, southeast Asia, and in the Pacific islands
    • Since 2015, epidemic outbreaks have been reported in South America (especially Brazil).
  • Epidemiology in the US
    • The overwhelming majority of cases (> 25,000) are reported in US territories, most of which occurred in Puerto Rico.
    • Approx. 4000 cases were reported in the continental US, most of which occur in New York, Florida, California, and Texas.


Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon


Clinical featurestoggle arrow icon

The symptoms of Zika virus infection in adults are usually mild and non-specific, but its complications may be devastating (see “Complications” below).


Diagnosticstoggle arrow icon

A Zika virus infection should be considered in any patient that recently traveled to a region with an outbreak.


Treatmenttoggle arrow icon

To prevent bleeding, NSAIDs and aspirin should be avoided until dengue has been excluded as a diagnosis.


Complicationstoggle arrow icon


We list the most important complications. The selection is not exhaustive.

Preventiontoggle arrow icon

  • A vaccine against Zika virus does not exist yet.
  • Vector control and safer sexual practices are the most important public health measures in endemic regions.
  • Individuals traveling to endemic regions should be told to use insect repellents, mosquito nets, and long-sleeved clothing.
  • In the case of travel to an endemic region and/or a positive Zika test, couples planning to conceive should use a condom or abstain for the following time periods (even if asymptomatic!):
    • : at least 2 months
    • : at least 3 months
  • During pregnancy
    • Avoid visiting endemic regions.
    • Abstain from unprotected intercourse until the end of the pregnancy if a partner has recently traveled to an endemic region.

Zika virus infection is a notifiable disease!


Referencestoggle arrow icon

  1. Barzon L, Lavezzo E, Palù G. Zika virus infection in semen: effect on human reproduction. Lancet Infect Dis. 2017; 17 (11): p.1107-1109.doi: 10.1016/s1473-3099(17)30495-4 . | Open in Read by QxMD
  2. Saiz J-C, Vázquez-Calvo Á, Blázquez AB, Merino-Ramos T, Escribano-Romero E, Martín-Acebes MA. Zika virus: the latest newcomer. Front Microbiol. 2016; 7: p.496.doi: 10.3389/fmicb.2016.00496 . | Open in Read by QxMD
  3. The History of Zika Virus. Updated: March 27, 2017. Accessed: March 27, 2017.
  4. Case Counts in the US. Updated: March 23, 2017. Accessed: March 27, 2017.
  5. A Desiree LaBeaud. Zika virus infection: An overview. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: January 27, 2020. Accessed: March 2, 2020.
  6. LaBeaud AD. Zika Virus Infection: An Overview. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: March 21, 2017. Accessed: March 27, 2017.
  7. $Zika Virus Information and recommendations of the Swiss Expert Committee of Travel Medicine (ECTM).
  8. Nielsen-Saines K. Congenital Zika Virus Infection: Clinical Features, Evaluation, and Management of the Neonate. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: March 15, 2018. Accessed: March 29, 2018.
  9. Zika and Pregnancy - Women & Their Partners Trying to Become Pregnant. Updated: March 23, 2017. Accessed: March 27, 2017.
  10. Zika and pregnancy: Women and Their Partners Trying to Become Pregnant. Updated: April 23, 2020. Accessed: July 14, 2020.
  11. Lockwood CJ, Ros ST, and Nielsen-Saines K. Zika virus infection: Evaluation and management of pregnant women. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: May 18, 2020. Accessed: July 14, 2020.

Icon of a lock3 free articles remaining

You have 3 free member-only articles left this month. Sign up and get unlimited access.
 Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer