Zika virus

Key points about Zika virus

  • Zika virus is spread by mosquito bites. The mosquitoes that spread Zika virus are not normally found in Aotearoa New Zealand, but there have been outbreaks in other countries.
  • While the symptoms of Zika are generally mild, pregnant women can pass the infection to their unborn child, which is linked to birth defects.
  • There are also concerns that for some people, Zika may lead to Guillain-Barré syndrome.
  • There is currently no vaccine to protect against Zika virus.
  • Get immediate medical attention if you are unwell after travel to Zika-affected areas OR call Healthline (free in New Zealand) on 0800 611 116 for advice.
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Zika is a disease caused by the Zika virus. A person becomes infected by the bite of an infected mosquito and in rare instances by having unprotected sex with an infected person (mainly from a male sexual partner).

  • The mosquitoes that spread Zika virus are not normally found in Aotearoa New Zealand, but they are found in many countries around the world.
  • Specific areas where Zika virus is spreading are often difficult to determine and are likely to change over time.
  • New Zealand and world health authorities are continuing to monitor the spread of Zika virus(external link).
  • Infection during pregnancy has been shown to be linked to birth defects in babies and there are also concerns that Zika sometimes leads to Guillain-Barré syndrome, a serious neurological disorder caused by the immune system reacting to Zika infection.
  • There is ongoing research about how Zika can affect people. Find out more about what we do and don’t know about Zika virus(external link).

Most people who are infected with Zika don’t have any symptoms. For those who do have symptoms, they are often mild.

  • low-grade fever (between 38°C and 38.9°C)
  • joints pains, particularly those of hands and feet, with possible swelling
  • muscle pain
  • headache
  • red eyes (conjunctivitis)
  • rash – which could be confused with other diseases, eg, measles or dengue.

Symptoms are likely to occur within a few days to a week after being infected, but they may take up to 12 days to appear. They usually last from 4 to 7 days.

Get immediate medical attention if you have the above symptoms or you're unwell after travel to Zika-affected areas OR call Healthline (free in New Zealand) on 0800 611 116 for advice.

Diagnosis

If you feel unwell after travelling to another country see your doctor. Your doctor will ask about your symptoms and travel history to rule out more serious diseases such as measles, rubella and dengue.

Treatment

There are no specific medicines used to treat a Zika infection.

  • Symptoms can be treated with rest and paracetamol for pain and fever.
  • Don't use aspirin and other non-steroidal anti-inflammatory drugs like ibuprofen until a healthcare provider has ruled out dengue as a potential cause of illness.
  • Drink plenty of fluids to prevent dehydration.

If you're pregnant or planning a pregnancy

  • If you are pregnant or plan to become pregnant and you've recently travelled to an area with Zika, it’s recommended that you speak with your healthcare provider or lead maternity carer (LMC), even if you don't feel sick.
  • It's especially important to see a healthcare provider if you develop a fever, rash, joint pain, or red eyes during your trip or within 2 weeks after travelling to a country where Zika has been reported.

If you have been to a Zika-affected area but have no symptoms, there is no need to be tested. 

There's no vaccine to protect against Zika infection. The best way to avoid infection in areas where there are Zika-carrying mosquitoes is to protect yourself against being bitten. All people in Zika-affected areas, should take precautions to prevent being bitten.

Video: Fight the bite, day and night

In this video, Dr Laupepa Va'a from the Ministry of Health talks about how people travelling overseas can avoid being bitten by mosquitoes that might carry diseases such as dengue fever, malaria, yellow fever and Zika virus. This video may take a few moments to load.

(Ministry of Health,  NZ, 2018)

Protect against mosquito bites indoors

  • Use screens on doors and windows.
  • Use insect sprays.
  • Use mosquito coils.
  • Use a mosquito net over your bed at night. New bed nets often have insecticide already on the net but, if not, you can spray the net with insecticide.
  • Turn on air conditioning if you have it and close all windows and doors – this is very effective at keeping mosquitoes out of the room.

Protect against mosquito bites outdoors

  • Wear an insect repellent cream or spray containing no more than 50% diethyltoluamide (DEET) or 30% DEET for children. Higher concentrations are no more effective and can be harmful. Products containing 20–25% picaridin (also known as icaridin) or 30% lemon eucalyptus oil (also known as PMD) can also be used. Read more about insect repellents(external link) and how to use them safely.
  • When using sunscreen, apply repellent over the sunscreen. 
  • Wear light-coloured protective clothing such as long-sleeved shirts, long pants and hats.
  • Wear clothing treated with an insecticide such as permethrin. Clothing can be bought pre-treated, or you can buy permethrin and treat your own clothes. Permethrin-treated clothing can be washed several times and still provide protection against insects. Regular insect repellent applied to clothes can also provide temporary protection, but must be reapplied at regular intervals.
  • Wear shoes rather than sandals. 
  • Use zip-up screens on tents.
  • Avoid areas where mosquitoes are most active.

If you are pregnant or planning to become pregnant in the near term

Anyone who is pregnant or plans to become pregnant in the near term should avoid travel to a Zika-affected area. Women travelling in Zika-affected areas should protect themselves against mosquito bites and, if needed, use an appropriate contraception to prevent pregnancy. Women returning from Zika-affected areas should avoid getting pregnant for 8 weeks after leaving the affected country.

Very little is known about the risk of passing the Zika virus on through sexual activity. The risk from sexual activity is thought to be low compared to that associated with mosquito bites,. However, due to the potentially serious implications of transmitting Zika to a pregnant woman, the Ministry of Health advises that:

Ministry of Health advice regarding the sexual transmission of Zika virus

Though Zika virus is mainly transmitted by mosquitoes, there is scientific evidence to suggest that the Zika virus can be transmitted through sexual contact. The best way to reduce the possibility of sexual transmission of the virus, or the possibility of becoming pregnant while infected with Zika virus, is to avoid sex or use condoms.

  • All men who have travelled to a Zika-affected area and have a pregnant partner should not engage in sexual activity (oral, vaginal, and anal) or should use condoms for the duration of the pregnancy, whether they have symptoms or not.
  • All men who have travelled to a Zika-affected area and have a partner who is at risk of becoming pregnant should abstain from sexual activity (oral, vaginal, and anal) or use condoms, whether they have symptoms or not, for at least 6 months after leaving a Zika-affected area.

See also: Zika and sexual transmission(external link) Centres for Disease Control, US

Zika virus(external link) World Health Organization
Zika virus disease – questions and answers(external link) World Health Organization
Zika virus – what we do and don’t know(external link) Ministry of Health, NZ

References

  1. Zika virus(external link) Ministry of Health, NZ, 2023
  2. Zika virus(external link) Centre for Disease Control and Prevention (CDC), US, 2022

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Healthify editorial team.

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