Zika Virus Symptoms

Quick Glance: Common Zika Virus Symptoms 

Most people with Zika virus infection do not develop symptoms. When symptoms occur, they are generally mild, usually beginning 3–14 days after infection and lasting for around 2–7 days.

Common Zika virus symptoms include:

• Mild fever

• Skin rash, which may be itchy

• Red or inflamed eyes (conjunctivitis)

• Joint pain

• Muscle pain

• Headache

• Feeling tired or unwell (malaise)

These symptoms can resemble dengue, chikungunya and other viral infections. Symptoms alone cannot confirm Zika virus infection, so medical assessment and appropriate testing may be needed.

Symptoms of Zika Virus That Should Not Be Ignored

Zika virus infection is usually mild, but rare neurological and other complications can occur. Progressive weakness, difficulty breathing or swallowing, confusion, seizures or unusual bleeding should be medically assessed promptly.

The following table explains symptoms that may indicate a complication of Zika virus infection and may require prompt medical evaluation:

Guillain-Barré syndrome is a rare neurological complication associated with Zika virus infection. It can cause progressive weakness and, in severe cases, paralysis or breathing difficulties.

Why Do Zika Virus Symptoms Occur?

Zika virus infection occurs when the virus enters the body, most commonly through the bite of an infected Aedes mosquito. The infection triggers an immune response, which contributes to symptoms such as fever, headache, tiredness and muscle pain.

The skin rash and conjunctivitis can occur as part of the body's response to infection. Joint pain, known medically as arthralgia, and muscle pain, or myalgia, are also characteristic symptoms of Zika virus disease.

Conjunctivitis causes red or inflamed eyes. Zika-associated conjunctivitis is generally non-purulent, meaning it does not usually produce pus-like discharge.

Most Zika virus infections remain mild. In rare cases, however, infection can be associated with neurological complications such as Guillain-Barré syndrome, neuropathy and myelitis.

Symptoms of Zika Virus That Require Immediate Medical Attention

Most Zika virus infections do not require hospitalisation. However, urgent medical care is important if symptoms suggest a serious neurological complication or significant bleeding.

Seek immediate medical attention for:

• Rapidly worsening muscle weakness

• Weakness that begins in the legs and spreads to the arms or other parts of the body

• Severe difficulty walking or moving the arms or legs

• Difficulty breathing or swallowing

• Severe numbness or loss of sensation

• Confusion, altered consciousness or seizures

• Severe neurological symptoms following possible Zika virus exposure

• Significant or unexplained bleeding

These symptoms may indicate rare but serious complications, such as Guillain-Barré syndrome or other neurological conditions, and require prompt medical assessment.

Symptoms of Zika Virus-Specific Conditions

The following table explains the symptoms and clinical features associated with specific Zika virus-related conditions or presentations:

Symptoms of Zika Virus in Children

Children with Zika virus infection may develop symptoms similar to those seen in adults, including fever, rash, conjunctivitis, joint pain, muscle pain, headache and feeling unwell. In infants and young children, joint pain can be difficult to recognise.

An infant may instead become unusually irritable, resist moving an arm or leg, or appear uncomfortable when a joint is touched or moved.

Children exposed to the Zika virus before birth may also develop congenital abnormalities affecting the brain, eyes, hearing or movement. Some affected babies may appear well initially, so appropriate clinical assessment is important after known exposure during pregnancy.

Can You Have Zika Virus Without Symptoms?

Yes. Most people infected with the Zika virus do not develop noticeable symptoms. When symptoms do occur, they are usually mild and last around 2–7 days.

Since Zika virus infection can be asymptomatic or cause only mild symptoms, a person may not realise they have been infected. This is particularly important during pregnancy because infection can affect the developing fetus even when the pregnant woman has no symptoms.

When Can Zika Virus Symptoms Become Life-Threatening?

Zika virus infection is rarely life-threatening. Serious complications mainly involve the nervous system and, more rarely, problems affecting blood clotting. The following table explains the rare complications of the Zika virus that can become serious or potentially life-threatening:

Zika virus infection during pregnancy can also cause serious fetal and pregnancy complications. These include congenital abnormalities, fetal loss, stillbirth and preterm birth, but they should be distinguished from emergencies that directly threaten the infected person's life.

How are Zika Virus Symptoms Diagnosed?

Zika virus symptoms can resemble dengue, chikungunya and other infections. A healthcare professional considers symptoms together with recent travel, mosquito exposure and other relevant exposure history before deciding whether testing is appropriate.

The following table explains the main investigations that may be used when evaluating suspected Zika virus infection:

The choice and timing of testing depend on factors such as when symptoms began, pregnancy status and exposure history. A healthcare professional may also consider testing for other infections with similar symptoms, including dengue and chikungunya.