Having trouble understanding which insect- and tick-borne illnesses you should be concerned about in your area? Some threats, like Lyme disease, Zika, and West Nile Virus, make national headlines all the time, while other serious illnesses to not. Further complicating matters is the fact that different states have different disease reporting requirements, resulting in biased media coverage. Thankfully, the Centers for Disease Control (CDC) provides the public with the latest news through its regional Centers of Excellence, giving you the latest scoop on insect and tick diseases by region. Here is more about those resources, and what applies to your region.
About the Centers of Excellence
The CDC established five regional Centers of Excellence in 2017 to fight insect- and tick-borne diseases in the U.S. Those different areas are at different risks for various diseases carried by mosquitoes, ticks, and related vectors (a vector is an organism that ferries disease microbes from one host to another). The goals of the Centers of Excellence include training public health department entomologists in vector recognition and control, conducting research to develop new tools for disease prevention and control, and researching how to anticipate potential disease outbreaks. Here are some general warnings by each region to help you keep your family safe this summer.
Insect & Tick Diseases by Region
New England, the Mid-Atlantic states, and the Upper Midwest (Great Lakes states) continue to be the epicenter for Lyme disease, transmitted by the Blacklegged Tick, Ixodes scapularis, also known as a “deer tick.” Many other illnesses vectored by ticks and mosquitoes are just as important, but do not make headlines. These include the tick-vectored illnesses Babesiosis, anaplasmosis, and Powassan Disease. Incidents of tick-borne diseases are far greater in this region than are cases of mosquito-borne diseases, but you should not overlook the risk of West Nile and other illnesses.
While the Northeast is tick-borne disease central, Florida continues to be the most vulnerable area for exposure to the Zika virus in the continental U.S. The virus is transmitted by the Yellow Fever Mosquito, Aedes aegypti, and the Asian Tiger Mosquito, Aedes albopictus.
Recently, another mosquito-borne virus, Keystone virus, turned up in a teenage boy in Florida. The virus is known mostly for afflicting other animals, and is rarely tested for in humans, so its impact and prevalence is still largely unknown.
The CDC defines the Midwest as Wisconsin, Minnesota, Michigan, Iowa, and Illinois. West Nile Virus, carried by Culex mosquitoes, and Lyme disease continue to make headlines in this region. Heavy rain and flooding increase breeding opportunities for mosquitoes, though this does not always translate to more disease cases.
Still, with over 50 species of mosquitoes in the Great Lakes states, it is possible to contract La Crosse Encephalitis, St. Louis Encephalitis, Western Equine Encephalitis, and other diseases. Ticks of this region can now be identified using The Tick App, a smart phone program available at the Apple App and Google Play stores. Beyond Lyme disease, the Black-legged Tick alone can also transmit anaplasmosis, babesiosis, and Powassan Disease.
Western Gulf (of Mexico)
This region includes Tennessee and Alabama, west through Arkansas, Mississippi, Louisiana, Texas, Oklahoma, New Mexico, and Colorado. The eastern two-thirds of this area is home to the Lone Star Tick, Amblyomma americanum, which transmits human ehrlichiosis, Heartland Virus, tularemia, and STARI (Southern Tick-associated Rash Illness).
Most cases of Rocky Mountain Spotted Fever cases occur in this region, chiefly in Oklahoma, Arkansas, and Tennessee (plus Missouri and North Carolina). Coastal areas are seen as vulnerable to Zika virus as well as chikungunya and dengue, but those diseases are not perceived as established threats.
This area covers California, Nevada, and Arizona. The principal mosquito-borne diseases of concern here are West Nile Virus, St. Louis Encephalitis, and Western Equine Encephalomyelitis. In addition, Zika, chikungunya, dengue fever, and malaria all have the potential for occurring as at least isolated cases, mostly among travelers returning from tropical countries. In California, Western Black-legged Tick, Ixodes pacificus, is a known carrier of Lyme disease. Other frequent tick-borne illnesses in California include spotted fever Rickettsia group bacteria, and tick-borne relapsing fever. Bubonic Plague, transmitted by fleas, is of concern especially in rural areas where human contact with ground squirrels and other rodents is not uncommon.
There is no Center of Excellence covering Oregon, Washington, Idaho, Montana, Utah, and Wyoming. These states are not populous, so there are fewer cases of arthropod-borne diseases than elsewhere. Colorado Tick Fever is a virus transmitted by Dermacentor andersoni “wood ticks,” chiefly at elevations between 4,000 and 10,000 feet.
Tickborne Relapsing Fever is caused by Borrelia bacteria delivered by Ornithodoros soft-bodied ticks. West Nile Virus is the most-reported mosquito borne illness in this area, but there have been periodic cases of Western Equine Encephalitis and St. Louis Encephalitis.
Prevention is Key Wherever You Are
Knowing the insect and tick diseases by region can help you prepare wherever you go. However, whether at home or on vacation in some other state, you can be fearless by taking simple precautions to prevent ticks and mosquitoes from biting. Wear pants and long sleeves. Try clothing and gear treated with permethrin. Apply repellents with DEET to exposed skin, following label instructions on the product. Shower soon after returning from tick habitat. Closely inspect yourself and family members and pets for wandering or attached ticks. Wash and dry your clothes in warm water and high heat. Explore our blog here for more tips on how to enjoy a painless outdoor experience.