Zika Virus & Mosquitoes

Zika is a virus that spreads to humans through Aedes mosquito bites. Prior to 2015, known Zika cases were limited parts of Africa and Asia, but more than one million cases have been reported in Brazil since 2015 and the World Health Organization (WHO) has noted the virus is spreading to many countries.

How is Zika Transmitted?

Zika virus is transmitted to humans through a bite from infected Aedes-species mosquitoes (such as the Asian tiger mosquito). Aedes mosquitoes are also known to spread yellow and dengue fevers and chikungunya viruses.

According to the CDC, the Zika virus can be transmitted in four ways:

1. Through mosquito bites

  • Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito.
  • 2. From mother to child

  • A pregnant woman, who is infected with Zika virus, can pass it to her fetus during pregnancy or around the time of birth. To date, there are no reports of infants getting Zika virus through breastfeeding.
  • 3. Through sexual intimacy

  • Zika can be passed from a person who has Zika, to another person, via sexual relations — even if the infected person shows no symptoms. Studies are underway to find out how long Zika remains in the bodily fluids of infected people.
  • 4. Through blood transfusion

  • As of February 1, 2016, there have been no confirmed blood transfusion transmission cases in the United States.
  • Zika Virus Symptoms

    In most cases, symptoms associated with Zika are mild, and cases requiring hospitalization are uncommon. According to the Centers for Disease Control and Prevention (CDC), common Zika symptoms include headache, fever, skin rash, conjunctivitis and joint and muscle pain. These symptoms can last up to seven days from the time of the bite, but sometimes dissipate earlier.

    While most cases are relatively mild, health officials also are examining links between Zika and long-term health outcomes. After the first confirmed Zika virus case in Brazil, reports surfaced of Guillain-Barre syndrome, a rare immune system disorder, and birth defects such as microcephaly in newborn babies. According to the Pan American Health Organization (PAHO), evidence supports a link between Zika virus and microcephaly.

    Is Zika in the United States?

    As of July 2016, the Centers for Disease Control and Prevention (CDC) has confirmed several locally transmitted Zika virus cases in the United States’ southeastern region. In some cases, travelers have become infected abroad and carried the virus upon their return. Visit the Centers for Disease Control site for the latest information on known Zika-affected areas and updated travel alerts.

    Zika Virus Treatment

    Approximately one in five people infected with Zika virus actually become ill. No vaccine or medications for Zika infections currently exist, so combat the symptoms with rest and hydration. If you develop symptoms connected to Zika and recently have visited a Zika-affected area, contact your healthcare provider right away.

    Zika Virus Prevention

    Since no Zika vaccine exists, the best way to help reduce the risk of Zika virus is to avoid mosquito bites. To help protect yourself and your home against bites, use these tips:

    Prevent Your Exposure

    • Tuck shirts into pants and pants into socks to cover gaps in clothing.
    • Use EPA-registered mosquito repellents when necessary.

    Eliminate Entry Points

    • Close gaps in windows, walls, doors and screens to help prevent entry.

    Remove Their Habitat

    • Remove standing water from gutters, buckets and other containers, as mosquitoes can breed in just a few inches of standing water.
    • Change water regularly in bird baths, fountains and potted plants.
    • Keep pool water treated and circulating.

    For more information and prevention tips, visit our Mosquitoes page or view our Mosquito 101 infographic.

    Additional Resources:

    • CDC: http://www.cdc.gov/zika/symptoms/
    • Pan American Health Organization / World Health Organization: http://www.paho.org/hq/index.php?option=com_topics&view=article&id=427&Itemid=41484