Health Advisory: Zika Virus

Updated 03/03/16

Modes of Transmission

Zika virus, a flavivirus, is transmitted to humans primarily through the bite of an infected Aedes species mosquito. The mosquito vectors typically breed in domestic water-holding containers; they are aggressive daytime biters and feed both indoors and outdoors near dwellings. Perinatal, in utero, transfusion and sexual transmission may also occur. Although not currently transmitted in the continental United States, infections have been diagnosed in travelers returning from endemic areas (see regularly updated map).

Letter from Texas Department of State Health Services on how to help prevent Zika and other mosquito-borne illnesses in our community. For more information about Zika virus visit DSHS Zika Website at

Clinical Signs & Symptoms

About 1 in 5 people infected with Zika virus become symptomatic. Characteristic clinical findings are acute onset of fever with maculopapular rash, arthralgia, or conjunctivitis. Because of similar geographic distribution and symptoms, patients with suspected Zika virus infections also should be evaluated and managed for possible dengue or chikungunya virus infection


Diagnosis, Reporting, & Testing

Preliminary diagnosis is based on the patient’s clinical features, places and dates of travel, and activities. Laboratory diagnosis is generally accomplished by testing serum or plasma to detect virus, viral nucleic acid, or virus-specific immunoglobulin M and neutralizing antibodies. Testing should occur for Zika, dengue and chikungunya simultaneously through the state laboratory. In Texas, dengue and chikungunya testing are available at the state laboratory and Zika through the Centers for Disease Control and Prevention (CDC).


Report ALL suspected cases of Zika virus infection as soon as possible to your local health department in order to coordinate specimen submission to CDC through the state laboratory:


  • Bexar County Residents: consult with San Antonio Metropolitan Health District (SAMHD)-Epidemiology via phone call at (210) 207-8876.


  • Residents outside of Bexar County: consult with Texas Department of State Health Services (DSHS), Health Service Region (HSR) 8 via phone call at (210) 949-2000 or (210) 949- 2121.


Criteria and Information needed for specimens to be tested:


Date of Birth

Onset Date of symptoms

Collection Date

Travel history (location AND dates) – travel within 2 weeks of onset of symptoms


Flavivirus vaccination history (Japanese Encephalitis Virus, Yellow Fever Virus and Tick-borne Encephalitis)

Pregnant (If yes, provide gestational week)



No specific antiviral treatment is available for Zika virus disease. Treatment is generally supportive and can include rest, fluids, and use of analgesics and antipyretics. Because of similar geographic distribution and symptoms, patients with suspected Zika virus infections also should be evaluated and managed for possible dengue or chikungunya virus infection. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) should be avoided until dengue can be ruled out to reduce the risk of hemorrhage. People infected with Zika, chikungunya, or dengue virus should avoid mosquito bites. Furthermore, since it is not yet known if people with Zika who do not have symptoms can transmit the virus to Texas mosquitoes, all travelers returning to Texas from areas affected by Zika avoid mosquito bites for one week following return from travel.