Tick Types and the diseases they carry
There are nearly 900 species of ticks found around the globe, and close to 100 of those reside in North America. Knowing how to identify ticks in your area can be critical.
TICK TYPES - IDENTIFICATION IS KEY TO PREVENTION
Ticks are certainly not the only insects looking to gain a blood meal from unsuspecting hosts, so it’s important to know how to spot a tick, and how to differentiate it from other biting insects.
Through the four life stages, (egg, larvae, nymph and adult) an unfed tick can vary in size from that of the tip of a pinhead, to a poppy seed, to a sesame seed. When engorged with blood the tick is more noticeable, at an average length of 10 mm. A significant change in appearance also occurs between the larvae and nymph stages, as larvae have only 6 legs while nymph and adult ticks have 8. All adult ticks share a common body structure consisting of 8 legs, a single, flat, oval-shaped body unit, and a mouthpiece, often mistaken for its head.
Knowing which type of tick you’ve encountered can help you and your physician to identify the potential pathogens it may be carrying - really important information to consider when determining an appropriate treatment plan. The following is a list of the most commonly found ticks in North America that are known to spread disease to humans and other animals:
- engorged black-legged tick vs non-engorged black-legged tick
Blacklegged Tick (Ixodes scapularis)
Also known as the deer tick, this species transmits borrelia burgdorferi and B. mayonii (both of which cause Lyme disease), anaplasmosis, b. miyamotoi disease, ehrlichiosis, babesiosis, tularemia, tick paralysis disease and Powassan virus disease. Though these ticks can be found virtually anywhere throughout North America, they are most prevalent throughout Nova Scotia, New Brunswick, Ontario, Quebec, Manitoba, and the north-eastern and mid-western United States.
Western Blacklegged Tick (Ixodes pacificus)
Transmits anaplasmosis, borrelia burgdorferi , and b. miyamotoi. Prevalent throughout British Columbia, Alberta, the Pacific Coast states, parts of Nevada, Arizona and Utah.
American Dog tick (Dermacentor variabilis)
Transmits anaplasmosis, feline cytauxzoonosis, Rocky Mountain spotted fever, tick paralysis disease, and tularemia. Found in some parts of the Pacific Coast, with widespread prevalence east of the Rocky Mountains.
Brown Dog Tick (Rhipicephalus sanguineus)
Transmits Rocky Mountain spotted fever, canine babesiosis, canine haemobartonellosis, canine ehrlichiosis and tick paralysis disease. Widespread prevalence throughout North America.
Rocky Mountain Wood Tick (Dermacentor andersoni)
Transmits Rocky Mountain spotted fever, Colorado tick fever, anaplasmosis, tick paralysis disease and tularemia. Prevalent throughout the Rocky Mountain provinces and states.
Pacific Coast Tick (Dermacentor occidentalis)
Transmits 364D Rickettsiosis, otherwise known as rickettsia philipii or Pacific Coast tick fever, Rocky Mountain spotted fever, tularemia, bovine anaplasmosis and tick paralysis disease. The Pacific Coast tick can be found in most of California, southern Oregon, northern Baja California, and Mexico.
Groundhog Tick (Ixodes cookei)
Otherwise known as the woodchuck tick, this arthropod transmits Powassan virus disease, and is prevalent throughout Ontario, Quebec, Manitoba and the Atlantic provinces, as well as eastern and central United States.
Soft Shelled Tick (Argasidae, Ornithodoros)
There are numerous physical and behavioural differences between hard and soft shelled tick species. Soft shelled ticks feed several times per life cycle stage, often for only a few minutes, with females producing a multitude of smaller egg deposits throughout their potential 10-20 year lifespan. They are less capable of spreading diseases that require longer attachment times for transmission, but easily spread tick borne relapsing fever and other pathogens during their extensive lives. Prevalent in southern British Columbia, Arizona, California, Colorado, Florida, Idaho, Kansas, Montana, Nevada, New Mexico, Oklahoma, Oregon, Texas, Utah, Washington, and Wyoming.
Lone Star Tick (Amblyomma americanum)
Transmits alpha-gal allergy (red meat allergy), canine ehrlichiosis, human ehrlichiosis, tularemia, Heartland virus disease, Bourbon virus disease, southern tick-associated rash illness (STARI), Q fever, and cervid theileriosis. Prevalent in the eastern and southern United States, and emerging in Ontario, Quebec, and New Brunswick.
Asian Longhorned Tick (Haemaphysalis longicornis)
Though known to cause a potentially deadly hemorrhagic illness in China, South Korea and Japan, this tick species has yet to transmit a recorded infection since it’s first noted appearance in North America in 2017. It has, however, spread through several states rapidly and has been known to swarm livestock in the thousands, killing animals by sheer bloodloss alone. By the end of 2018 this species had been recorded in New Jersey, Arkansas, Connecticut, Maryland, New York, North Carolina, Pennsylvania, Virginia and West Virginia. Due to its’ appearance in border states, experts suggest it won’t be long before it shows up in Canada as well. The Asian longhorned tick is a particularly adaptable species, and is capable of asexual reproduction.