- About 1 in 5 people infected with Zika virus become ill (i.e., develop Zika).
- The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headache.
- The illness is usually mild with symptoms lasting for several days to a week.
- Severe disease requiring hospitalization is uncommon.
- Deaths are rare.
- The symptoms of Zika are similar to those of dengue and chikungunya, which are diseases caused by other viruses spread by the same type of mosquitoes.
- See your healthcare provider if you develop the symptoms described above and have visited an area where Zika is present.
- If you have recently traveled, tell your healthcare provider when and where you traveled.
- Your healthcare provider may order blood tests to look for Zika or other similar viruses like dengue or chikungunya.
- No vaccine or medications are available to prevent or treat Zika infections.
- Treat the symptoms:
- Get plenty of rest
- Drink fluids to prevent dehydration
- Take medicines, such as acetaminophen or paracetamol, to relieve fever and pain
- Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen, should be avoided until dengue can be ruled out to reduce the risk of hemorrhage. If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.
- If you have Zika, avoid mosquito bites for the first week of your illness.
- During the first week of infection, Zika virus can be found in the blood and passed from an infected person to another mosquito through mosquito bites.
- An infected mosquito can then spread the virus to other people.
Zika virus is transmitted by daytime-active mosquitoes and has been isolated from a number of species in the genus Aedes, such as Aedes aegypti, and arboreal mosquitoes such as Aedes africanus, Aedes apicoargenteus, Aedes furcifer, Aedes hensilli, Aedes luteocephalus, and Aedes vitattus. Studies show that the extrinsic incubation period in mosquitoes is about 10 days. The vertebrate hosts of the virus are primarily monkeys and humans. Before the current pandemic, which began in 2007, Zika virus "rarely caused recognized 'spillover' infections in humans, even in highly enzootic areas".
In 2009, it was suggested that Zika virus can be sexually transmitted between humans. Brian Foy, a biologist from the Arthropod-borne and Infectious Diseases Laboratory at Colorado State University, visited Senegal to study mosquitoes and was bitten on a number of occasions. A few days after returning to the United States, he fell ill with Zika, but not before having had unprotected intercourse with his wife. She subsequently showed symptoms of Zika infection with extreme sensitivity to light. Foy is the first person known to have passed on an insect-borne virus to another human by sexual contact.
In 2015, Zika virus RNA was detected in the amniotic fluid of two fetuses, which indicates that it crossed the placenta and that fetal infection is possible