Zika virus infection

At a glance

No vaccine available – read more about prevention
Nationally notifiable disease

About Zika virus

Zika virus mainly spreads to people through the bites of infected mosquitoes.

Most infections are mild, but it can have serious consequences for unborn babies.

There is no vaccine against Zika virus.

Why it matters to public health

Most cases of Zika virus infection are mild or asymptomatic. But if a pregnant person is infected, it can have serious consequences for the baby, including fetal loss or microcephaly – where the baby is born with a smaller head than expected and an intellectual disability.

Zika virus is found in:

parts of Africa
the Asia-Pacific
Central and South America
the Caribbean.

Zika virus has not been detected in mosquitoes in Australia. But the type of mosquito that can spread it is found in parts of Queensland. This means a local outbreak is possible if a person with Zika virus infection enters Australia.

Symptoms

If you’re looking for advice about your own health or treatment options, see healthdirect or speak with a qualified healthcare professional. Our role is to provide public health advice – information and guidance that helps prevent disease, protect communities and improve wellbeing at a population level.

Most people with Zika virus infection have no or very mild symptoms. Symptoms can include:

Most people recover within a week.

A small proportion of people with Zika virus infection experience severe illness. This can include:

inflammation of the brain (encephalitis)
inflammation of the tissues around the brain (meningitis) or spinal cord (myelitis)
a blood disorder that can cause bleeding, bruising or slow blood clotting.

Rarely, Zika virus infection can cause Guillain-Barré syndrome.

Zika virus infection rarely causes death. But infection during pregnancy can have serious consequences for the baby, such as:

fetal loss
microcephaly
problems with brain development
hearing and vision problems
seizures
stiff muscles and joints
problems with feeding and swallowing.

Read more about the symptoms, diagnosis and treatment of Zika virus.

healthdirect’s symptom checker can help you decide whether to see a health professional. If you become unwell with fever, rash or headache during or soon after travelling to an area at risk for Zika virus, speak to your healthcare professional as soon as possible.

Check your symptoms

Onset of symptoms

Symptoms usually start between 3 and 12 days after getting infected.

How it spreads

Mosquitoes become infected when they bite someone with Zika virus infection. Mosquitoes can then pass on the virus when they bite another person.

It can also spread:

to unborn babies during pregnancy
through unprotected sexual contact with an infected person
through exposure to the virus in a laboratory
through blood and blood products.

Infectious period

People with Zika virus infection can spread the virus to mosquitoes for up to 7 days after their symptoms begin.

The virus can be present in semen for months after infection

Prevention

There is no vaccine against Zika virus infection.

Protect yourself

The best ways to protect against Zika virus infection are to:

prevent mosquito bites
practise safe sex – do not have unprotected vaginal, anal or oral sex with anybody who has
- Zika virus infection
- recently travelled to an area at risk for Zika virus.

Before travelling to an area at risk for Zika virus, talk to a healthcare professional.

People who are:

pregnant should not travel to an area at risk for Zika virus
planning pregnancy and their partners might be advised to delay pregnancy or travel.

People who are pregnant, or their partners, who have travelled to an area at risk for Zika virus infection should:

speak with a healthcare professional as soon as possible
not have unprotected vaginal, anal or oral sex until told by their healthcare professional it safe to do so.

Protect others

People with Zika virus infection should follow the advice of their healthcare professional to reduce the risk of the virus spreading to other people and mosquitoes while they are infectious.

This might include advice to:

prevent mosquito bites
avoid travelling to areas of Queensland where the type of mosquito that can spread Zika virus is found
practise safe sex (including using a condom or dental dam) until told it’s safe not to
not donate sperm for at least 6 months
not donate blood for at least 4 months.

People who have had Zika virus infection should speak with their healthcare professional if they are planning a pregnancy.

Priority groups and settings

Some people are at greater risk of Zika virus infection or of getting very sick from it.

People at greater risk of severe disease

Zika virus infection poses a greater risk of severe illness for unborn babies.

People at greater risk of exposure

People might be at greater risk of being exposed to Zika virus if they:

travel to places overseas at risk for Zika virus
have unprotected vaginal, anal or oral sex with someone who
- has recently had Zika virus infection
- has recently travelled to an area at risk for Zika virus.

Read more about how to prevent infectious diseases while travelling.

Diagnosis and treatment

Zika virus infection is usually diagnosed through a blood or urine test.

You can use healthdirect’s directory to find a health service near you.

Find a health service

There is no specific treatment for Zika virus.

Read more about how to manage or treat Zika virus.

Surveillance and reporting

Zika virus is a nationally notifiable disease – these are diseases that present a risk to public health.

Health authorities in each state and territory report new laboratory confirmed cases or probable cases to us through the National Notifiable Diseases Surveillance System.

This is part of our national surveillance activities, to monitor case numbers around the country and understand disease patterns.

We analyse the data and report on case numbers and other data through our data visualisation tool, where you can filter and search the latest information.

Outbreaks

Control measures for Zika virus infection outbreaks focus on humans, animals and the environment, and might include:

identifying people with Zika virus infection and providing them with advice about how to reduce the risk of spread to other people or mosquitoes
mosquito control activities
providing advice to the community about mosquito bite prevention and other prevention steps
providing information and advice about pregnancy and pregnancy planning.

Read more about how the Australian Government defines and plans for outbreaks.

Support

For information about Zika virus in your state or territory, see:

If you need mental health support, see a list of organisations, websites and services that offer support, counselling and information.

For travel advice, see Smartraveller.