Zika is a mosquito-borne infection caused by Zika virus, a member of the genus flavivirus and family Flaviviridae. It was first isolated from a monkey in the Zika forest in Uganda in 1947.


Transmission is usually via the bite of an infected Aedes mosquito, although a small number of cases of sexual transmission have been reported. There is increasing evidence of transmission via the placenta from mother to fetus.

Clinical features

The majority of people infected with Zika virus have no symptoms. For those with symptoms, Zika virus tends to cause a mild, short-lived (2 to 7 days) febrile disease. Signs and symptoms suggestive of Zika virus infection may include a combination of the following:
  • fever
  • rash
  • arthralgia/arthritis
  • conjunctivitis
  • myalgia
  • headache
  • retro-orbital pain
  • pruritus


Serious complications in adults are not common, although the virus has been associated with Guillain-Barre syndrome. Scientific consensus however has linked Zika with microcephaly and other congenital abnormalities, which has led the World Health Organisation (WHO) to declare a Public Health Emergency of International Concern (PHEIC).

Screening and prevention

Advice for travellers

There is currently no vaccine or drug to prevent Zika infection. Prevention revolves around avoiding mosquito bites (Aedes mosquitoes usually bite during the day) by using mosquito repellent and cover-up clothing. Pregnant women are advised to avoid non-essential travel to Zika prevalent areas until after pregnancy.