Zika Virus: Frequently Asked Questions for the General Public
What is Zika?
Zika is a viral infection that usually causes a mild illness that typically lasts between 2 and 7 days. 80% of people who become infected by Zika virus have no symptoms. Zika virus is spread through the bite of a mosquito that is in certain countries.
Infection with Zika virus has been strongly linked with a serious birth condition called microcephaly. Microcephaly means a baby born with an unusually small head. In these cases, the baby’s brain may not have formed properly during pregnancy. Cases of a neurological illness (called Guillain Barre Syndrome) possibly caused by Zika virus infection are also being studied.
Recently, the World Health Organization and the Centers for Disease Control and Prevention (CDC) in the US have reviewed the evidence of this association and now consider that the relationship between Zika virus disease and microcephaly to be causal i.e. that the cases of microcephaly seen in the Americas have been directly caused by Zika virus disease infection. The CDC team who undertook the review of evidence relating to Zika virus disease and microcephaly have published their findings in the New England Journal of Medicine.
A number of cases of person to person spread have been reported, through sex.
What are the symptoms of Zika?
An estimated three out of four people infected with Zika virus do not have symptoms at all.
For those who have symptoms, Zika virus generally causes a mild illness that lasts for between 2 and 7 days.
The most common symptoms include:
- mild fever
- muscle or joint pains
- headache
- itchy rash
- conjunctivitis (sore eye)
The time between being infected by a mosquito bite and developing symptoms is usually between 3 and 12 days.
Elderly people and those with weakened immune systems, e.g. people living with cancer, may have more severe symptoms, but full recovery is usually the rule.
How is Zika spread?
Zika virus is spread when an infected mosquito bites a person.
Other less common possible forms of transmission include:
- From mother to baby during pregnancy or childbirth
- From an infected partner during unprotected sex (without a condom)
- From a blood transfusion
Zika virus is not spread by the following:
- regular social contact
- usage of communal household utensils
- caring for someone with Zika virus
How is Zika spread from mother to baby?
Zika virus may be transmitted from mother to baby from their shared blood supply during pregnancy. For more information on Zika virus and pregnancy please see HPSC Factsheet on Zika Virus and Pregnancy.
How is Zika spread through sexual contact?
Zika virus can be passed between sexual partners. This is more likely if the man had symptoms of Zika virus infection. For this reason, it is important to practice safe sex (by wearing a condom) with a partner who has recently returned from, or is living in, an affected area.
Research has shown that Zika virus can be found in a man's semen for up to 6 months after symptoms have started.
For advice on how to prevent sexual transmission see information in the graphic here.
This is a precaution and may be revised as more information becomes available.
Can Zika be spread through blood?
Zika virus can be transmitted through blood, but it is not common. People who have travelled to affected areas should not give blood (http://www.giveblood.ie).
How is Zika treated?
There is no vaccine or specific drug for Zika virus. Treatment consists of relieving pain, fever and any other symptom that inconveniences the patient. To prevent dehydration, patients should control the fever, rest and drink plenty of water.
How is Zika diagnosed?
Zika virus infection can be diagnosed in a patient who has Zika symptoms and a relevant travel history to an affected area. Laboratory tests are currently available for blood and urine for symptomatic patients recently returned from an affected area.
People with no symptoms who have returned from an affected area do not need to be tested for Zika virus but should follow the advice for preventing sexual transmission.
Have cases of Zika been diagnosed in Ireland?
Zika virus infection has been diagnosed in a small number of travellers returning from affected area. All have recovered fully.
Are people in Ireland at risk of Zika?
Zika virus infection can be imported into Ireland in a traveller returning from an affected area. The virus is mainly spread through the bite of an infected Aedes mosquito, which is not present in Ireland. This type of mosquito is unlikely to establish in Ireland in the near future as the Irish temperature is not consistently high enough for it to breed.
What countries are affected by Zika?
Currently, outbreaks of Zika virus are occurring in some countries in South and Central America, South-East Asia, the Caribbean and Pacific Islands and Africa. It is likely that Zika virus will spread to other countries where the Aedes mosquito which transmits the infection is found. For an up to date list of countries affected by Zika virus please refer to Zika Travel Information | Travelers' Health | CDC. Of note, when a country is classified as an affected country, the risk is considered to be the same for any part of the country.
What is the current travel advice?
The Department of Foreign Affairs and Trade (DFA) provides guidance to travellers that is updated regularly. Please consult the DFA website and click on the relevant country. It is important to check this information prior to any trips, as the situation could change rapidly.
How can I protect myself from being bitten by mosquitoes?
- Protect skin from exposure to mosquitoes by wearing long sleeves, long trousers and hats
- Use mosquito repellent as indicated by health authorities and according to instructions on the label
- A suitable mosquito repellent (such as DEET) can be obtained from your local pharmacy
- DEET is safe to use during pregnancy and while breastfeeding but only in concentrations less than 50%
- DEET is only safe for babies aged 2 months and older
- If using sunscreen, mosquito repellent should be applied after sunscreen
- If you sleep during the day, protect yourself with insecticide-treated mosquito netting
- Identify and eliminate possible mosquito breeding sites, such as standing collections of water
For further information on preventing mosquito bites is available from the HPSC website.
What do I do if I am travelling to an area where Zika virus is circulating?
- All travellers going to an area affected by Zika virus should take measures to prevent mosquito bites. For example using mosquito repellent, wearing long-sleeved shirts and long trousers and using mosquito nets for sleeping.
- Travellers should prevent sexual transmission by using condoms for the duration of their stay in an affected area
- Women who are pregnant or are trying to become pregnant should consult their doctor or seek advice from a travel clinic before travelling to a country affected by Zika virus. They should consider postponing their travel to affected area. Further information on advice for women who are pregnant or trying to become pregnant, is available in the Zika and Pregnancy FAQ
- Travellers that have weakened immune system or severe chronic illnesses should consult their doctor or seek advice from a travel clinic before travelling to an affected area.
- Irish citizens who live in an affected area should also take measures to prevent mosquito bites and sexual transmission. This applies particularly for pregnant women and women who are trying to become pregnant.
- People showing symptoms suggestive of Zika virus infection within 10 days after returning from an affected area should contact their healthcare provider.
Please see travel advice on HPSC website.
What do I do if I’m returning to Ireland from an area where Zika virus is circulating?
If you become ill upon your return to Ireland, you should contact your doctor for assessment and let him/her know of your recent travel history to an affected area.
What do I do if I’m living / working in an area where Zika virus is circulating?
If you become ill you should contact your local health care provider who will be able to advise on your individual circumstances.
What activities are not a risk?
Zika virus is not spread by regular social contact or caring for someone with Zika virus.
Last reviewed: 01/11/2019