Zika Virus

Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito. These are the same mosquitoes that spread dengue and chikungunya viruses.

  • These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They are aggressive daytime biters, prefer to bite people, and live indoors and outdoors near people.
  • Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.

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 incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week. The illness is usually mild with symptoms lasting for several days to a week. Zika virus usually remains in the blood of an infected person for a few days but it can be found longer in some people. Severe disease requiring hospitalization is uncommon and deaths are rare.

Outbreaks of Zika have been reported in tropical Africa, Southeast Asia, the Pacific Islands, and most recently in the Americas. Because the mosquitoes that spread Zika virus are found throughout the world, it is likely that outbreaks will continue to spread.

Zika is in a family of viruses called flaviviruses that includes dengue, and both share similar clinical presentations and geographic spread. When exposed individuals test preliminarily positive for both of these flaviviruses and the confirmatory test (plaque reduction neutralization test (PRNT)) is not able to distinguish which flavivirus is causing the current infection, the test is interpreted as recent flavivirus, unspecified. Based on the epidemiological evidence, individuals with unspecified flaviviruses, positive by PRNT for dengue and Zika, are classified as Zika cases for surveillance purposes, if compatible clinical features and/or exposure(s) are present.

Zika Virus Disease - Current Situation

Alabama Residents Tested for Zika Virus as of August 9, 2018


Number of Investigations

Positive Test Results*




Since Jan 2016



*Positive test results include Zika virus or Flavivirus unspecified.  

Zika can be passed through sex from a person who has Zika to his or her sex partners. There is a strong possibility that Zika virus can be spread through blood transfusions. A pregnant woman can pass Zika virus to her fetus during pregnancy or around the time of birth.

The Alabama Department of Public Health advises pregnant women to consider postponing travel to areas where the Zika virus is being transmitted, including areas in South and Central America, as well as the American territories, including Puerto Rico. Infection with the Zika virus causes only mild symptoms in the majority of the cases, but an apparent link to birth defects and other pregnancy-related poor outcomes has been associated with infection during pregnancy. Out of an abundance of precaution, the ADPH is recommending that health care providers advise their patients who are pregnant about the risk of travel to these areas.

Zika can be passed through sex, even if the infected person does not have symptoms. Both males and females can pass it to sex partners. Sex includes vaginal, anal, and oral sex, and the sharing of sex toys. Couples with a partner who lives in or has traveled to an area with active Zika transmission should use condoms (or other barrier methods to protect against infection).

These are the current recommendations for couples who have returned from an area with active Zika transmission, whether or not symptoms of Zika infection were present:

  • If partner traveling was female, use barrier methods or abstain from sex for at least 8 weeks after returning.
  • If the partner traveling was male, use barrier methods or abstain from sex for at least 6 months after returning.
  • If the partner who traveled has a pregnant partner, barrier protection should be used or abstain from sex for the duration of the pregnancy.

Detect, Test, and Report

Testing should be performed on anyone who has a travel history to an infected area and is symptomatic. In addition, providers are asked to evaluate all pregnant women with a history of travel to countries with Zika virus transmission during pregnancy regardless of whether symptomatic or not. Because of the similar geographic distribution and clinical presentation of Zika, patients with symptoms consistent with Zika virus disease should also be evaluated for dengue and chikungunya virus infection.

Alabama physicians are asked to complete an online consultation form for ALL suspect Zika patients to request approval for Zika virus testing. Go to our Healthcare Providers page for more information and guidance. The submitted consultation form will be reviewed and answered within 24 hours or the next business day. All specimens submitted for testing must be approved by ADPH prior to submission. Any provider with a suspect Zika patient suffering a fetal loss or with a suspect Zika patient giving birth are asked to call the Infectious Diseases & Outbreaks Division at 1-800-338-8374 prior to submitting the online consultation form.

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See also: Bite Prevention and Vector Control

Page last updated: September 13, 2018