What Causes Zika?

Zika is caused by infection with Zika virus, spread mainly through bites from infected Aedes mosquitoes. These mosquitoes can bite during the day as well as at night. A person may also pass the virus through sexual contact, and an infection during pregnancy can pass to the developing baby. Transmission through blood is possible but uncommon.

Many people with Zika have no symptoms or only a mild illness. When symptoms occur, they may include an itchy rash, fever, red eyes, joint pain, muscle pain, or headache. Symptoms can overlap with other infections, so a symptom alone cannot identify Zika. The main reason Zika needs particular attention is its possible effect during pregnancy, including problems affecting fetal development. A recent stay in an area where Zika transmission occurs, or sexual exposure to someone who has travelled there, helps a clinician assess the possibility.

Tell a clinician about recent travel, mosquito exposure, symptoms, pregnancy or plans for pregnancy, and any relevant sexual exposure. Prevent further mosquito bites by using an appropriate repellent, wearing covering clothing, and reducing standing water around your home. If Zika is possible, use precautions during sex and discuss how long they should continue with a clinician. A Travel Health Consultation can help before travel or after returning from an affected area.

Arrange medical advice if you develop a rash, fever, red eyes, or joint pain after travel to an area where Zika may occur, especially if you are pregnant or could be pregnant. Contact a clinician promptly after possible exposure during pregnancy so appropriate assessment and follow-up can be discussed. Seek urgent care for severe weakness, trouble breathing, confusion, fainting, or new muscle weakness, because these symptoms need assessment even though they are not specific to Zika.

Ask whether your travel history and symptoms fit possible Zika exposure, whether testing is appropriate, what precautions to use during sex, and whether pregnancy-related monitoring is needed. A GP Consultation can help review symptoms, timing, travel details, and other possible causes.