Zika Virus Infection: Overview and Status Update

26 Feb 2016

What is Zika virus infection?

Zika virus infection is a mosquito-borne viral illness caused by the Zika virus. This virus was first identified in 1947 in a rhesus monkey in Uganda. It was identified in humans in 1952 in Uganda and Tanzania. The Zika virus is in the Flavivirus family, the same family of viruses that cause Dengue, Japanese encephalitis, West Nile fever and Yellow Fever. Outbreaks of Zika virus infection have occurred in Africa, Southeast Asia, and the Pacific Islands. There is currently an ongoing Zika virus outbreak in the Americas

How is Zika virus infection transmitted?

Zika virus is transmitted to humans through the bite of an infected Aedes mosquito. Aedes mosquitoes breed in stagnant pools of water and usually bite during the daytime hours. Their peak biting times are dawn and dusk. Infected pregnant women can transmit the virus to the fetus. There are no reports of transmission from mother to baby through breast feeding.

What are the symptoms?

People who are infected with Zika virus typically experience acute onset of the following symptoms:

  • Fever, lethargy
  • Skin rashes
  • Conjunctivitis (eye redness)
  • Muscle and joint pain
  • Headache

Zika virus infection during pregnancy has also been associated with pregnancy loss and congenital microcephaly (type of brain development abnormality) in babies. However, a definite causal link has not been established. Further investigation is ongoing.

How long after being exposed will I exhibit symptoms?

Most infected people do not exhibit symptoms. Symptoms develop in 20 – 25% of people who become infected with Zika virus and typically occur 2 - 12 days after the infected mosquito bites. The symptoms last 2-7 days and are usually mild. Severe disease needing hospitalization is uncommon and the mortality rate from this disease is low.

Is there a treatment?

Currently there is no specific treatment for Zika virus. Protecting yourself is the best course of action. If you think you have been infected, seek treatment from your healthcare provider. Your provider may order blood tests to look for the virus and exclude other diseases with similar symptoms. Infected pregnant women may need additional tests to monitor fetal wellbeing and growth. Treatment will focus on managing your symptoms. Do not take aspirin or non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, without consulting your doctor. This is because they can cause bleeding in people who have a disease that is similar to Zika, called dengue fever.