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 15, 2016
Number of Submissions
Positive Test Results for Zika or Flavivirus, unspecified (likely Zika)
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.
There have been recent reports that Zika virus is spread through blood transfusion and sexual contact. Rarely, the virus may spread from mother to child around the time of birth. It also may be possible to spread the virus from a mother to her baby during pregnancy. Specific recommendations provided by the Centers for Disease Control and Prevention (CDC) include the following:
- Pregnant women should not travel to Zika-affected areas
- Men who have traveled to Zika-affected areas and have pregnant partners should abstain from sex or consistently and correctly use condoms for the duration of the pregnancy for all forms of sexual activity.
- Men who have traveled to Zika-affected areas and have non-pregnant partners should consider abstaining from sexual activity or consistently and correctly use condoms.
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 contact the ADPH Infectious Diseases & Outbreaks Division at 1-800-338-8374 if they have patients with a travel history and signs and symptoms consistent with Zika virus infection or pregnant women with a travel history whether symptomatic or not. Providers reporting patients with suspect Zika virus or pregnant women with a travel history to Zika endemic areas should call and request the Zika Virus Consultation Form. All specimens submitted for testing must be approved by ADPH prior to submission.
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See also: Bite Prevention and Vector Control