Communicable Diseases

Risk Management highlights the Zika virus

What is Zika virus disease (ZIKA)?

  • Disease spread primarily through the bite of an Aedes species mosquito infected with Zika virus.
  • Many people infected with Zika virus won’t have symptoms or will only have mild symptoms.


Where has Zika virus been found?

  • Before 2015, Zika outbreaks occurred in Africa, Southeast Asia, and the Pacific Islands.
  • Currently outbreaks are occurring in many countries and territories.


How is Zika transmitted?

  • Zika can be transmitted through:
    • Mosquito bites
    • From a pregnant woman to her fetus
    • Sexual contact
    • Blood transfusion


What are the symptoms?

  • The most common symptoms of Zika are:
    • Fever
    • Rash
    • Joint pain
    • Conjunctivitis (red eyes)


How does Zika virus affect people?

  • Anyone who lives in or travels to an area with Zika and has not already been infected with Zika virus can get it.
  • Many people infected with Zika virus won’t have symptoms or will only have mild symptoms.


How does Zika affect pregnant women?

  • Zika virus can pass from a pregnant woman to her fetus during pregnancy or around the time of birth.
  • Zika infection in pregnancy is a cause of microcephaly and other severe fetal brain defects.
    • Microcephaly: birth defect in which a baby’s head is smaller than expected when compared to babies of the same sex and age.
    • Previous infection will not affect future pregnancies.
  • Other problems have been detected in pregnancies among fetuses and infants infected with Zika virus before birth.
  • Scientists are studying the full range of other potential health problems that Zika virus infection during pregnancy may cause.
  • No reports of infants getting Zika through breastfeeding.


How is Zika diagnosed?

  • Diagnosis of Zika is based on a person’s recent travel history, symptoms, and results of blood tests.
  • A blood test is the only way to confirm a Zika infection.
  • Symptoms of Zika are similar to other illnesses spread through mosquito bites, like dengue and chikungunya.
  • Your doctor or other healthcare provider may order blood tests to look for several types of infections.


How is Zika treated?

  • There is no specific medicine or vaccine for Zika virus.
  • Treat symptoms
    • Rest
    • Drink fluids to prevent dehydration
    • Take acetaminophen (Tylenol®) to reduce fever and pain
  • Protect yourself from mosquito bites. During the first week of illness, Zika virus can be found in blood for about a week. If a mosquito bites the person, it becomes infected and can pass the infection to others.


Preventing Mosquito Bites

Zika is primarily transmitted through mosquito bites. Protect yourself.

STEP 1   Keep mosquitoes outside

Keep mosquitoes out of your home or hotel.
Stay in places with air conditioning and with window/door screens.
Do not leave doors propped open.

Keep mosquitoes out of your home or hotel.
Once a week, empty and scrub, turn over, cover, or throw out items that hold water. Mosquitos lay eggs near water.
Tightly cover water storage containers (buckets, cisterns, rain barrels) so that mosquitos cannot get inside to lay eggs
If you have a septic tank, repair cracks or gaps.

Keep mosquitoes out of your home or hotel.
When traveling, use a bed net if air conditioned or screened rooms are not available or if sleeping outdoors.



STEP 2   Create a barrier between you and mosquitoes

Cover up!
Wear long-sleeved shirts and long pants.

Treat clothing and gear

Use permethrin to treat clothing and gear or buy permethrin-treated clothing and gear. Read product information to find out how long the protection will last.

If treating items yourself, always follow the product instructions.

Do not use permethrin products directly on skin.


STEP 3 Wear insect repellent

Always follow the product label instructions.


STEP 4 Protect your family

For babies and children
Cover crib, stroller, and baby carrier with mosquito netting.


STEP 5    Protect your partner


STEP 6 Do your homework before traveling

If you are pregnant, do not travel to areas with Zika. If you must travel, talk to your doctor or other healthcare provider before your trip.
If you are trying to get pregnant, talk to your doctor or other healthcare provider before you travel.

If you choose to travel:
Strictly follow steps to prevent mosquito bites to protect yourself and your family.
Even if you do not feel sick, travelers returning to the United States from an area with Zika should take steps to prevent mosquito bites for 3 weeks so they do not spread Zika to uninfected mosquitos.

See the latest travel notices at:




What is CDC doing?

Activated Emergency Operations Center (EOC) to level 1

Providing on-the-ground support in affected areas

Educating healthcare providers and the public about Zika

Posting travel notices and other travel-related guidance

Providing laboratories with diagnostic tests

Creating and distributing Zika Prevention Kits for affected US territories

Conducting a study to evaluate the persistence of Zika virus in semen and urine among male residents of the United States

Working with partners to:

Monitor and report cases

Conduct studies to learn more about the potential link between Zika and Guillain-Barré syndrome

Create action plans for state and local health officials to improve Zika preparedness

Publish and disseminate guidelines to inform testing and treatment of people with suspected or confirmed Zika

Publish and disseminate conclusions on the causal association between Zika and microcephaly


For more information

Contact CDC 1-800-CDC-INFO (232-4636) TTY: 1-888-232-6348

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.