PDF printable version of Zika Virus Factsheet - The Basics (PDF 486 KB)
Zika is a mosquito borne virus that is closely related to dengue. Zika virus can be found in animals in many parts of Asia and Africa without any outbreaks in humans.
Between 2013 and 2015 there were large outbreaks of Zika virus in a number of Pacific countries, and in 2015 and 2016, large outbreaks have occurred and are ongoing in the Americas.
If someone has caught Zika virus, it can take typically take up to 3 to 12 days for symptoms to appear.
Approximately one person in five who catches Zika virus is likely to feel sick, and if they do, the disease is generally not severe and lasts only a few days. People who do get sick may have:
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- A fever.
- Pain in the joints, especially in the hands and feet possibly with swelling.
- Muscle pain.
- Headache, especially with pain behind the eyes.
- A skin rash that may be flat in some areas and bumpy in others.
- Weakness or lack of energy.
Recent outbreaks of Zika virus in the Pacific and the Americas and subsequent published studies show that the virus may be passed to the baby if the woman is infected while pregnant, and this can cause certain severe birth defects. Further studies are ongoing to provide further understanding of the likelihood of this occurring.
There is also strong scientific consensus that Zika virus can cause a rare paralysing condition called Guillain-Barré Syndrome, noting that Zika is one of a number of possible causes. This condition has been found in areas where Zika virus outbreaks are occurring and in cases of individual travellers returning from affected areas.
How it spreads
Zika virus is spread by the bite of a mosquito that is carrying the virus, but not all types of mosquitoes can spread it. Some types of of Aedes mosquito can spread Zika virus,particularly Aedes aegypti but also possibly Aedes albopictus. Aedes aegypti mosquitoes often live around buildings in urban areas whereas Aedes albopictus live in outdoor sites. Both are daytime biting mosquitoes, with increased activity around sunrise and sunset.
Most areas of Australia do not have the Aedes aegypti mosquito that can carry the virus. This mosquito is currently limited to parts of Northern, Central and Southwest Queensland. Aedes albopictus is confined to the Torres Strait Islands. Therefore, in most parts of Australia, there is no risk of Zika virus being spread by mosquitoes. Currently, all cases of Zika virus diagnosed in Australia were caught overseas.
Zika virus can also spread through sexual activity (vaginal, oral, or anal). However, the main way that Zika virus spreads is still by mosquitoes.
People at risk
People living in or visiting areas where there are current active outbreaks of Zika virus may be at increased risk of infection.
For a list of countries where outbreaks are currently being reported refer to the Department of Health webpage.
There is no vaccine for Zika virus infection. Prevention relies on avoiding mosquito bites in areas where Zika virus occurs.
Due to the concerns about the possibility of severe outcomes for unborn babies, women who are pregnant or seeking to become pregnant should consider delaying their travel to countries with current or recent local Zika virus transmission. If they do travel or reside in these areas, they should strictly follow mosquito bite avoidance advice, and discuss their travel plans and mosquito bite avoidance with their doctor.
Travellers should follow recommendations to avoid mosquito bites at all times when travelling in overseas countries where there is a risk of mosquito-borne diseases. This is particularly important if you are or could be pregnant and there are a range of mosquito-borne diseases such as malaria that are serious for pregnant women.
All travellers are advised to take the following mosquito bite prevention measures. It is important to be aware that these precautions are necessary in the daytime as well as night time:
- Cover as much exposed skin as possible, including wearing light coloured long-sleeved shirts and long pants.
- Use insect repellents, applied according to the product label.
- The most effective mosquito repellents contain Diethyl Toluamide (DEET) or Picaridin. Repellents containing oil of lemon eucalyptus (OLE) (also known as Extract of Lemon Eucalyptus) or para menthane diol (PMD) also provide adequate protection.
- Note that insect repellents containing DEET or picaridin, are safe for pregnant and breastfeeding women and children older than 2 months when used according to the product label.
- If you use both sunscreen and insect repellent, apply the sunscreen first and then the repellent.
- Use insecticide-treated (such as permethrin) clothing and gear (such as boots, pants, socks, and tents).
- Stay and sleep in screened-in or air-conditioned rooms.
- Use bed nets as necessary.
- Seek medical advice, as soon as practicable, if unwell during or soon after travel.
Men who have travelled to a country with current or recent local Zika virus transmission and who have a pregnant partner should avoid all sexual activity (vaginal, oral, or anal) or always use a condom for the duration of the pregnancy.
Men who have had a confirmed Zika virus infection and have a partner who is not pregnant should avoid all sexual activity (vaginal, oral or anal), or always use a condom, and also avoid donating sperm, for 6 months after being diagnosed.
Men who have travelled to a country where there is current or recent local Zika virus transmission and have no symptoms should avoid all sexual activity (vaginal, oral or anal), or always use a condom and avoid donating sperm, for at least 8 weeks following the last day in a Zika virus affected country.
How Zika virus infection is diagnosed
A blood test can diagnose Zika virus infection.
For further information on testing, please refer to Information of testing for Zika.
How Zika virus infection is treated
At the moment there is no specific treatment for Zika virus infection, but supportive medical care can be provided if required (e.g. rest, fluids).
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How health authorities will prevent its spread in Australia
Health authorities prevent the spread of Zika virus in Australia by:
- Continuing to monitor international ports of entry to prevent the mosquitoes that can transmit Zika virus from entering or spreading to new areas;
- Ensuring the safety of the blood supply through restrictions on whole blood donation for travellers coming to Australia from areas where mosquito-borne diseases are occurring;
- In areas of Queensland where the mosquitoes Aedes aegypti and/or Aedes albopictus are present, health authorities will respond urgently to cases to prevent it from spreading in Australia, as they do for cases of dengue. This will include advising people on avoiding mosquito bites during their illness and may include controlling mosquitoes around the person’s home.
What should I do if I think I might have Zika virus?
If you have returned within the last two weeks from travel to countries where there is current or recent local Zika virus transmission and become unwell, you should see a doctor and mention your overseas travel.
Pregnant women who have travelled to countries where there is current or recent local Zika virus transmission should see their healthcare professional for assessment. Testing for Zika virus can be discussed.
What should I do if I think I may have been exposed to Zika virus?
If you have recently travelled to a country with current or recent local Zika virus transmission, please see your doctor for further advice.
If you are pregnant and you have recently travelled to a country where there is current or recent local Zika virus transmission, or where Zika virus transmission occurred at the time of your travel, you should discuss this with your doctor.
Women who have travelled to a country where there is current or recent local Zika virus transmission should defer pregnancy for at least 8 weeks following the last day they were in a country with ongoing transmission of Zika virus. If any symptoms occur, please see your health care professional for advice.
Men who have travelled to a country where there is current or recent local Zika virus transmission who have a pregnant partner should avoid all sexual activity (vaginal, oral, or anal), or always use a condom for the duration of the pregnancy.
Men returning from countries where there is current or recent local Zika virus transmission should avoid all sexual activity (vaginal, oral, or anal), or always use a condom for at least 8 weeks upon return. This includes those with male or female partners.
Men who have had a confirmed Zika virus infection and have a partner who is not pregnant should avoid all sexual activity (vaginal, oral, or anal) or always use a condom for 6 months after diagnosis.
Please see your doctor for further advice.
Can I still donate blood?
People who have been to an area with current or recent local Zika virus transmission should defer donation of whole blood for 4 weeks after they have returned. If someone is confirmed to have Zika virus infection, they should defer donation for 4 weeks after symptoms have disappeared. A person who is a sexual contact of someone who has been diagnosed with Zika virus infection at any time in the last 3 months should defer donations for 4 weeks at the time of the last sexual contact with the person who had a Zika virus infection.
For more information, refer to:
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