Zika virus infection - including symptoms, treatment and prevention

Zika virus infection is an infection in humans caused by the Zika virus.The first human cases were identified in 1952 in Uganda and Tanzania. The Australian Government Department of Health has a list of countries with current or recent active circulation of Zika virus.

Knowledge about Zika virus infection is evolving rapidly. Readers are encouraged to refer to the Australian Government Department of Health web page for the most up to date information.

Zika virus infection is a notifiable condition1

How Zika virus is spread

Zika virus is spread when a person is bitten by an Aedes mosquito infected with the virus. Spread is mainly through bites from infected Aedes aegypti mosquitoes but also through bites from infected Aedes albopticus mosquitoes.

Neither of these mosquitoes are naturally found in South Australia, but Aedes aegypti is found in North Queensland and Central Queensland.

Zika virus can be transmitted from mother to baby during pregnancy or delivery. Sexual transmission is also possible.

Signs and symptoms of Zika virus infection

Most people (80%) with Zika virus do not have any symptoms. If illness occurs, it usually lasts 4 to 7 days.

Symptoms include:

  • mild fever
  • rash (maculopapular)
  • sore joints and possibly swollen joints (usually small joints of the hands and feet)
  • muscle pain
  • conjunctivitis – inflamed (red) eyes, usually without any discharge
  • headache, usually behind the eyes.

Some people may experience fatigue and low energy levels after the initial symptoms resolve.

Zika virus has been linked to:

  • rare neurological diseases including Guillain-Barré syndrome
  • rare birth defects, including microcephaly (an underdeveloped brain), in babies born to mothers with Zika virus infection during pregnancy.

Diagnosis of Zika virus infection

Individuals who have returned to Australia within two weeks following travel to countries where there is current or recent local Zika virus transmission and become unwell, should see their doctor and mention their overseas travel. Zika virus infection is diagnosed with a blood test. Other infections, such as dengue fever and chikungunya,which occur in the same geographical areas and have similar symptoms, should be excluded. Pregnant women, women at risk of pregnancy, men with a pregnant partner and men who are part of a couple planning pregnancy who have travelled to a Zika virus affected area should see their doctor regarding prevention of transmission and testing.

Incubation period

(time between becoming infected and developing symptoms)

Usually 3 to 12 days.

Infectious period

Unknown

Treatment for Zika virus infection

There is no specific treatment available.

General recommendations include the use of supportive treatments such as rest, fluids and medications for pain relief.

Do not use aspirin or other non-steroidal anti-inflammatory medications until dengue fever is excluded. These medications can cause severe bleeding in people with dengue fever.

Aspirin should not be given to children under 12 years of age unless specifically recommended by a doctor.

Prevention of Zika virus infection

  • There is no vaccine to prevent human infection by this virus.
  • Protect yourself from mosquito bites at all times in Zika virus areas. For tips on how to protect yourself, see Fight the Bite.
  • Do not travel to Queensland whilst unwell with confirmed or suspected Zika virus infection. It is important to avoid introducing Zika virus into Aedes aegypti mosquitoes in Queensland.
  • People with Zika virus infection should avoid mosquito bites during the first week of the illness, particularly if travelling to Queensland.
  • Refer to the Australian Government Zika web page for information on preventing Zika in pregnancy and preventing sexual transmission.
  • Refer to the Australian Government Zika web page for advice on blood and sperm donation.

Useful links

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.