Photo Credit: Muhammad Mahdi Karim Licensed under GNU Free Documentation License 1.2

Zika virus infection

The Zika virus is a mosquito-borne flavivirus transmitted primarily by Aedes species mosquito (Aedes aegypti and Aedes Albopictus). These mosquitoes that are aggressive biters during the day but also bite at night.  An estimated 80% of persons infected with Zika virus have no symptoms.

Symptoms are usually mild and include acute onset of fever, and maculopapular rash, arthralgia, or conjunctivitis for several days to a week. Severe disease requiring hospitalization is uncommon and fatalities are rare. Currently, no vaccine or medication is available to prevent or treat Zika virus infection.

Outbreaks, cases and transmission

Zika outbreaks are occurring in multiple countries. In 2015, the first local Zika virus transmission in the Americas was reported in Brazil and local transmission has now been in several countries or territories in the Americas. (See world map and list of countries.)

Cases in the United States:

In US Territories, there have been more than 30,000 cases of Zika- the majority were locally acquired from mosquitos. In the US States, there have been 4,000 cases of Zika – the majority were travel-associated cases and 139 cases were locally acquired from mosquitos.

The Florida Department of Health (FL DOH) has identified the area with local mosquito-borne Zika virus transmission (active Zika virus transmission) in Miami (http://www.cdc.gov/zika/intheus/florida-update.html). As of November 1, 2016, total of 139 cases have been identified from this area in FL. The investigation is ongoing and CDC released a Health Advisory Alert, with guidance for travel and testing of pregnant women and women of reproductive age for Zika Virus infection related to investigation for local mosquito-born Zika virus transmission in Miami-Dade and Broward counties, Florida.

Travelers

Travelers to areas with ongoing Zika virus transmission and outbreaks are at risk of becoming infected and spreading the virus to new areas.  The recent cases in Florida were not unexpected because imported cases may result in local spread of the virus in some areas where there are Aedes species mosquito. This happens when people infected with Zika virus infect mosquitoes that bite them and the mosquitos transmit the virus to others.

Clinicians- reporting, lab testing

A blood or urine test can confirm a Zika infection.  Healthcare providers are encouraged to report suspected Zika virus disease cases to their state health department to facilitate diagnosis and to mitigate the risk of local transmission.  CDC has provided guidance and training materials for clinicians and healthcare providers for evaluation, testing and clinical care of pregnant women, women of childbearing age, infants/children; guidance to prevent sexual transmission; and guidance for diagnostic testing.

Pregnant women

CDC is recommending that pregnant women consider postponing travel to any area where Zika virus transmission is ongoing. Pregnant women who do travel to these areas should talk to their doctors or other healthcare providers first and strictly follow steps to avoid mosquito bites during the trip. Women trying to become pregnant should consult with their healthcare providers before traveling to these areas and strictly follow steps to avoid mosquito bites during the trip and throughout the day, as the Aedes mosquitoes bite mostly during the daytime.

Key resources

Webinars

CDC Health Advisories-Alerts

Communication

Location of Zika infections

Traveler health precautions

Prevention

Pregnant women

About Zika virus

Prevention of sexual transmission: men and their partners

Mosquito control

Hospital – clinic care settings

Testing (blood, urine) and Diagnosis

Clinicians – healthcare providers

Transmission

Response to Local Transmission

Resources

State and local public health laboratories

Blood Supply