Mosquito management in and around your home and neighborhood can help prevent infection.

The relatively new and emerging Zika virus has caused a substantial amount of alarm in the United States and around the world. This virus is one of many in the family Flaviviridae, like those responsible for dengue and yellow fever.

Symptoms of Zika virus infection can include conjunctivitis, rash, flu-like symptoms and joint aches, and may last a few days to a week. However, up to 80 percent of those infected are asymptomatic and are often unaware they are infected (and infectious).

The most publicized symptom of infection is the birth defect, microcephaly, in which babies’ brains fail to develop normally and the baby is born with an abnormally small head. These babies are typically severely intellectually disabled, with many medical problems, and many do not reach adolescence. Additionally, there is strong evidence that Zika virus is linked to multiple other central nervous system disorders in adults. This is because the virus is thought to specifically target nerve cells in humans.

Zika virus is mostly transmitted by Aedes mosquitoes (although there are also a few dozen cases of sexual transmission). Unlike the mosquito vectors (vectors are small organisms, like mosquitoes or ticks, that carry infections from person to person) of West Nile virus, these mosquitoes are aggressive day-biting species specifically adapted to attacking humans. The yellow fever mosquito (Aedes aegypti) has so far been the primary vector of the virus in Latin America and the Caribbean, but it has a limited range in the United States. Although a few can be found in many parts of the U.S., it is only present in high enough numbers to maintain virus transmission in the extreme southern U.S.: Southern Florida, Gulf Coast, Mid-Atlantic states and along the Mexican border.

Another species that has vectored Zika in other parts of the world is the Asian tiger mosquito (Aedes albopictus). Since its introduction into the U.S. in 1985, it is now found throughout most of the temperate regions of the states, frequently outcompeting the yellow fever mosquito. The Asian tiger mosquito is an anthropophilic species which generally inhabits areas alongside humans. In the majority of metropolitan areas east of the Mississippi River, it is the most common mosquito biting people in mid-late summer. We worry that it will begin transmitting Zika in the Americas, but it has not yet been observed to do so in the wild.


Since there is no vaccine for Zika — the only way to minimize the human cases is to minimize mosquito bites. The first line of defense is personal protection. Use mosquito repellents when outdoors, especially in the late afternoon or dusk. Products containing DEET or Picaridin are highly effective against these mosquitoes.

The second line of defense is your personal space. Those with backyards, can purchase mosquito insecticides designed to exclude mosquitoes from backyards, but the commercial mosquito control services have access to more effective products. These services will reduce mosquitoes in a backyard by about 80 percent for a month or more from a single application. Eliminate any standing water on your property where mosquitoes can breed. Places were standing water can be found include bird baths, potted plant drain pans, dented/sagging gutters, tires, etc. These mosquitoes will develop from egg to adult in a week or so in as little as a tablespoon of water so examine your property carefully.

The next line of defense is your neighborhood. Church groups, neighborhood associations, scout/ school groups and the like, can all pitch in to eliminate any trash or other harborage for mosquitoes in the area. These mosquitoes only y 100 – 200 yards, so eliminating breeding sites in your neighborhood can be highly effective. Finally, cooperate with your local mosquito control authority. Pay attention to any public announcements that you may see and follow their suggestions, and please call, email or write your city leaders to support your local mosquito control organizations.

The news of the Zika virus spreading has raised awareness of mosquito-borne diseases and mosquito prevention. By following practical tips and taking simple steps this summer, you can minimize exposure to mosquitoes, reduce the potential risk of disease transmission and enjoy the warm weather.

Dr. Grayson Brown has been chief investigator of the Public Health Entomology Laboratory at the University of Kentucky for 40 years. He has led research involving mosquito control in suburban areas, sand flies and their public health impact in Kentucky, and mosquito flight behavior. He is a former President of the Entomological Society of America.

Kyndall Dye is the Senior Lab Technician and has completed her Master’s Degree in the program.

Glenn Skiles has recently joined the lab and will complete her Master’s Degree in May 2017.