“Mosquito season is approaching, and the number of travel-related cases continues to inch up for Texas. It’s only a matter of time before Zika virus is locally transmitted here by mosquitoes,” said Dr. John Hellerstedt, DSHS commissioner.
While there is no evidence of local transmission by Texas mosquitoes now, state health officials have quickly implemented Zika virus prevention plans in anticipation of increased mosquito activity and the potential for local mosquito transmission.
Zika virus is spread to people primarily through the bite of an infected “Aedes aegypti” mosquito. “Aedes aegypti” mosquitoes can be found in Texas, particularly urban areas in the south and southeast portions of the state, but can live anywhere humans are present.
Texas has confirmed 18 cases of Zika virus disease. Seventeen of those are related to travel abroad to areas with active Zika transmission. One case, from Dallas County, was likely the result of sexual contact with someone who acquired the Zika infection while traveling abroad.
Texas is now testing for Zika virus at its public health lab in Austin.
Current state lab capacity is up to 135 human specimens per week, and capacity across the state is increasing as local labs add testing capability in anticipation of a possible surge in demand. This testing, called polymerase chain reaction or “PCR” testing, is used to detect Zika virus in human specimens collected less than seven days after illness onset. The PCR test is considered confirmatory for the presence of Zika virus. Specific testing guidance is available at www.TexasZika.org.
Texas is also adding the more complex serologic testing for Zika virus. The benefit of serologic testing is that it can detect Zika infection in people who may not have had symptoms, and the test can be conducted up to 12 weeks after a person is infected. A positive serologic test result requires confirmatory testing to definitively pinpoint Zika because it can cross-react with other viruses, such as dengue.
Texas is working with local officials in the Rio Grande Valley area to monitor mosquito activity and conducted spot trapping in the area in February, which yielded no “Aedes aegypti” mosquitoes. The Rio Grande Valley is considered to be a potential area of increased risk of Zika virus transmission. DSHS is urging communities to consider expanding their surveillance in coordination with local mosquito control efforts.
The agency’s Birth Defects Epidemiology and Surveillance Branch is analyzing historical microcephaly data to better understand patterns, trends and causes of microcephaly in Texas. Microcephaly is a birth defect that may be linked to Zika virus infection in other parts of the world.
Texas also is implementing the “rapid ascertainment” of microcephaly, which means the condition will be closely monitored going forward for Zika virus and other causes.
The Governor’s 31-member Task Force on Infectious Disease Preparedness and Response, directed by Dr. Hellerstedt, will meet in Austin March 9 to discuss infectious disease prevention, and Zika will be part of that discussion.
Texas is urging health care providers to be aware of and consider Zika virus as they see patients. State health officials are actively coordinating with the Centers for Disease Control and Prevention and local officials about surveillance, testing and mosquito control. Texas is educating the general public about Zika in English and Spanish through its new website www.TexasZika.org.
“We’re focusing on urging people to strictly follow the guidance to prevent the disease,” Dr. Hellerstedt said. “We need everyone on board, helping to cut down mosquito populations and avoid mosquito bites as we head into spring.”
Take Action in Communities
DSHS sent a letter to local leaders asking for help in protecting people from the Zika virus and outlining steps to prevent or delay Zika virus transmission by local mosquitoes. Eliminating potential mosquito breeding areas, especially near homes and communities, is an effective way to protect against all mosquito-borne diseases including Zika. These are the recommended actions local leaders can take to help protect communities from Zika virus:
* Initiate or enhance monitoring and surveillance of mosquito activity.
* Accelerate mosquito abatement efforts.
* Develop a local contingency plan for mosquito abatement and surveillance; plan for additional control measures if needed.
* Encourage people to report illegal dumpsites and standing water, and respond quickly to these complaints.
* Implement efforts to clean up illegal dumpsites and collect heavy trash.
* Keep public drains and ditches clear of weeds and trash so water will not collect.
* Treat standing water with larvicide (such as mosquito “dunks”) when it cannot be drained and the water will be present for more than seven days.
* Conduct neighborhood outreach about precautions people can take to protect themselves and their families from mosquito bites.
Take Action Around Homes
DSHS suggests the following steps people can take in and around their own homes to help reduce potential mosquito breeding habitats:
* At least weekly, empty or get rid of cans, buckets, old tires, pots, plant saucers and other containers that hold water.
* Keep gutters clear of debris and standing water.
* Remove standing water around structures and from flat roofs.
* Change water in pet dishes daily.
* Rinse and scrub vases and other indoor water containers weekly.
* Change water in wading pools and bird baths several times a week.
* Maintain backyard pools or hot tubs.
* Cover trash containers.
* Water lawns and gardens carefully so water does not stand for several days.
* Screen rain barrels and openings to water tanks or cisterns.
* Treat front and back door areas of homes with residual insecticides if mosquitoes are abundant nearby.
* If mosquito problems persist, consider pesticide applications for vegetation around the home.
Avoid Mosquito Bites
People living or traveling to areas with active transmission should carefully follow steps to avoid mosquito bites while there and for at least seven days after leaving the area. Precautions include:
* Wear insect repellent.
* Cover up with long-sleeved shirts and long pants.
* Keep mosquitoes out with air conditioning or intact window screens.
* Limit outdoor activities during peak mosquito times.
Zika virus is primarily spread to people through mosquito bites. The virus also can be spread from mother to unborn child or to her newborn around the time of birth. Spread of the virus through blood transfusion and sexual contact also has been reported.
The disease can cause fever, rash, muscle and joint aches and red eyes but also has been linked to the birth defect microcephaly and other poor birth outcomes in some women infected during their pregnancy. The illness is usually mild with symptoms lasting for several days to a week, and hospitalizations are rare. A small number of cases of Guillain-Barré syndrome, a paralysis disorder, also have been linked to Zika virus infection.
Most people exposed to Zika virus won’t develop any symptoms at all. There is currently no vaccine or treatment for the virus.