Zika virus: symptoms and complications
Guidance on symptoms of Zika virus infection and complications of the disease.
Symptoms
Most people infected with Zika virus will have no symptoms. Those who do develop symptoms tend to have a mild, short-lived (2 to 7 days) illness that starts 3 to 14 days after an infected mosquito bite.
The most common symptoms of Zika virus infection are:
- rash
- itching
- fever
- headache
- arthralgia or arthritis
- myalgia
- conjunctivitis
- lower back pain
- retro-orbital pain
The symptoms of Zika virus infection are similar to dengue (caused by a related flavivirus) or chikungunya (an alphavirus), which are often co-circulating in areas where Zika virus is present. Laboratory testing is essential for the correct diagnosis.
Treatment
There is no specific antiviral treatment for Zika virus infection. Supportive nursing care and relief of symptoms are the standard treatment.
Complications
Zika virus infection is generally mild, and severe disease requiring hospitalisation is uncommon and the case fatality rate is very low.
However, infection in pregnancy is a cause of congenital brain abnormalities, including microcephaly. Further information on Zika virus infection in pregnancy can be found here.
Zika virus infection is also associated with neurological conditions such as Guillain-Barre syndrome (GBS).
GBS is an acute autoimmune condition in which the individual’s immune system inappropriately attacks components of their peripheral nerves. This results in muscle weakness in the legs and/or arms, which can spread to other parts of the body. Severe weakness or paralysis of the chest muscles occurs in 20 to 30% of GBS patients, making breathing difficult.
GBS can be triggered after infections with a number of different pathogens, most commonly Campylobacter jejuni. Why certain people develop GBS, and others do not, is unknown.
Although Zika virus is known to trigger GBS, it is a very rare complication. GBS may also be triggered by certain other arboviral infections such as dengue and chikungunya, that may be co-circulating with Zika virus.
Less frequently reported neurological complications include encephalitis and meningoencephalitis, myelitis, encephalopathy, sensory neuropathy and seizures.
Updates to this page
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Updated information and removed details not relevant anymore.
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Updated to reflect changes in travel and sexual transmission advice and revised Zika virus risk ratings.
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First published.