Zika virus disease is a disease caused by the Zika virus transmitted primarily through the bite of infected Aedes species mosquitoes. The most common symptoms of Zika are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting for several days to a week after being bitten by an infected mosquito. People usually don't get sick enough to go to the hospital, and they very rarely die of Zika. For this reason, many people might not realize they have been infected. However, Zika virus infection during pregnancy can cause a serious birth defect called microcephaly, as well as other severe fetal brain defects. Once a person has been infected, he or she is likely to be protected from future infections.
In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infection in Brazil. On February 1, 2016, the World Health Organization (WHO) declared Zika virus a Public Health Emergency of International Concern (PHEIC). Local transmission has been reported in many other countries and territories. Zika virus will likely continue to spread to new areas.
What We Know
- No vaccine exists to prevent Zika.
- Prevent Zika by avoiding mosquito bites (see below).
- Mosquitoes that spread Zika virus bite mostly during the daytime.
- Mosquitoes that spread Zika virus also spread dengue and chikungunya viruses.
- Prevent sexual transmission of Zika by using condoms or not having sex.
Steps to prevent mosquito bites
- Wear long-sleeved shirts and long pants.
- Stay in places with air conditioning and window and door screens to keep mosquitoes outside.
- Sleep under a mosquito net to protect yourself while you are asleep.
- Use insect repellents to keep mosquitoes away.
- Treat clothing with permethrin or purchase permethrin-treated items.
Protect those infected
- During the first week of infection, Zika virus can be found in the blood and passed from an infected person to another mosquito through mosquito bites. An infected mosquito can then spread the virus to other people.
- Zika virus can be spread during sex by a man infected with Zika to his sex partners.
- To help prevent spreading Zika from sex, you can use condoms, correctly from start to finish, every time you have sex. This includes vaginal, anal, and oral (mouth-to-penis) sex. Not having sex is the only way to be sure that someone does not get sexually transmitted Zika virus.
- Avoid getting pregnant while you have Zika as it is known to have adverse affects on newborns.
Control Breeding Grounds
An efficient way to control mosquitoes is to find and eliminate their larval habitat. Eliminating large larval development sites (source reduction) such as swamps or sluggishly moving streams or ditches may require community-wide effort. This is usually a task for your organized mosquito control program. They might impound an area of water, establish ditches or canals or control the aquatic weeds (cattails, water lettuce, etc) on a body of water. The second method used by organized mosquito control agencies is larviciding. This utilizes the application of insecticides targeted at the immature mosquitoes - the larvae or pupae. These are applied to bodies of water harboring the larvae. However, since larvae do not usually occupy the entire body of water, larvicides are applied where the larvae are, usually the areas near the shoreline of the lake, stream or ditch.
Homeowners can take the following steps to prevent mosquito breeding on their own property :
- Destroy or dispose of tin cans, old tires, buckets, unused plastic swimming pools or other containers that collect and hold water. Do not allow water to accumulate in the saucers of flowerpots, cemetery urns or in pet dishes for more than 2 days.
- Clean debris from rain gutters and remove any standing water under or around structures, or on flat roofs. Check around faucets and air conditioner units and repair leaks or eliminate puddles that remain for several days.
- Change the water in birdbaths and wading pools at least once a week and stock ornamental pools with top feeding predacious minnows. Known as mosquito fish, these minnows are about 1 - 1-1/2 inches in length and can be purchased from pet stores.
- Fill or drain puddles, ditches and swampy areas, and either remove, drain or fill tree holes and stumps with mortar. These areas may be treated with Bti or methoprene products also.
- Eliminate seepage from cisterns, cesspools, and septic tanks.
- Eliminate standing water around animal watering troughs. Flush livestock water troughs twice a week.
- Check for trapped water in plastic or canvas tarps used to cover boats, pools, etc. Arrange the tarp to drain the water.
- Check around construction sites or do-it-yourself improvements to ensure that proper backfilling and grading prevent drainage problems.
- Irrigate lawns and gardens carefully to prevent water from standing for several days.
- If ditches do not flow and contain stagnant water for one week or longer, they can produce large numbers of mosquitoes. Report such conditions to a Mosquito Control or Public Health Office.
Sources: Center for Disease Control Mosquito Control Association