Ticks | Ticks | Ticks

(1) Tick-borne diseases are relatively recent … and rising.

Ticks have been around for 300 million years, but they haven’t been known carriers of disease for nearly as long. Lyme disease, for example, was first discovered as recently as the late 1970s. Further back in time, Babesia, one of the first pathogens known to be carried by ticks, was discovered by veterinarians in the 1890s in cows that were dying by the thousands, but it was not until 1957 that the first case of Babesiosis, which has similar symptoms to Lyme disease, was recorded in humans.

Tick-borne disease is now a rising problem worldwide. In the United States alone the reported incidence of tick-borne disease doubled between 2004 and 2016. In addition, the geographic range of ticks has expanded, and researchers have discovered seven new tickborne pathogens that infect people. Cases of Lyme disease, anaplasmosis/ehrlichiosis, spotted fever rickettsiosis (including Rocky Mountain spotted fever), babesiosis, tularemia, and Powassan virus disease have all increased—from 48,610 cases in 2016 to 59,349 cases in 2017 alone. Since under-reporting of tick-borne diseases is known to be extremely common, the number of people actually infected is assumed to be much higher.

A number of factors may be contributing to the dramatic rise of tick-borne disease, including  the reforestation of suburban areas, increased human travel, a lack of vaccines to treat tick-borne diseases in people and the migration of ticks into areas that were once considered too cold for them to survive.

(2) Ticks are not born carrying diseases, like Lyme. Blame the white-footed mouse for infecting them.

Because ticks need to feed on blood in order to survive, it is only if and when they feed on the blood of a host infected with bacteria like Borrelia burgdorferi which causes Lyme disease that they become carriers. White-footed mice are often the blood hosts that infect ticks with Lyme disease.

As ticks move through their two-year life cycle, growing from eggs to six-legged larvae to eight-legged nymphs to adults, the blood hosts they feed on vary. At the larva and nymph stages, for example, ticks tend to feed on mice, small birds and other rodents, all of which are natural reservoirs of bacteria like Borrelia burgdorferi.

White-footed mice, in particular, are a problem in many areas of the country. Not only are they the most common rodent species in North America, but forty to ninety percent of them are also known to carry Borrelia burgdorferi, as well as other diseases including Babesiosis, Anaplasmosis, Powassan encephalitis and Hantavirus. It’s highly likely that tick larvae or nymphs feeding on white-footed mice will become infected. Tick nymphs infected with Lyme bacteria pose the biggest threat to humans; the numbers of infected tick nymphs are linked with the size of mouse populations.

(3) Connecticut is home to four types of ticks. Not all of them carry disease.

Approximately 878 species of ticks, including hard and soft ticks, have been found worldwide. The most common ticks to prey on people and pets are hard ticks. In CT, the black-legged tick is the most likely to transmit disease.

CT’s four varieties of ticks include:

The Black-Legged (Deer) Tick – the most likely tick to infect people & pets in CT with Lyme disease, Babesiosis and/or Anaplasmosis. Co-infections are not uncommon.

The American Dog (Wood) Tick – much bigger than the black-legged tick, can carry Rocky Mountain Spotted Fever but rarely in CT.

The Brown Dog Tick – feed on dogs, but rarely people.

The Lone Star Tick (rare in CT, found most recently along the southern coast) – can infect people and pets with Erlichiosis.

(4) The hosts that ticks feed on tend to vary as they move through their two-year life cycle.

Eggs. Female ticks need a blood meal before reproducing. They tend to breed in early spring (April/May) on a large host animal, such as the white-tailed deer, then drop to the ground once engorged with blood to lay their eggs, typically in leaf litter. It is not uncommon for a single tick to lay a few thousand eggs (anywhere from 1,500 to > 5,000). In order to develop from eggs to larvae to nymphs to adults, ticks must find blood hosts to feed on at each stage.

Larvae. After about two weeks, ticks hatch from eggs into tiny, six-legged larvae about the size of poppy seeds (less than 1/8^th inch). Due to the small size of larval ticks, hosts at this stage tend to be birds and rodents, such as white-footed mice. Larval ticks cannot jump, run or fly, but they can make their way from the ground up to the tops of tall grasses, shrubs and plants where they are in a good position to grab onto passing potential hosts. Signals such as elevated CO2 levels, breath, body odor, body heat, moisture, vibration, and even shadows alert ticks to the presence of potential hosts. Larval ticks are patient. They can survive for more than a year (up to 540 days) without feeding. After feeding on a host for several days, once full, larval ticks drop to the ground where they remain inactive over the winter until the following spring when they shed their skins and become eight-legged nymphs.

Nymphs. In late spring and early summer, new nymphs seek out blood hosts, which tend to be larger mammals, such as chipmunks, grey squirrels, raccoons, skunks, possums, household pets and people. After filling with blood from these hosts, the nymphs drop to the ground, shed their skins and finally emerge as adults.

Adults. In the fall, adult ticks (up to 5/8 of an inch in size) seek out even larger hosts, particularly deer and livestock, but also people and pets, for their blood meals. It’s interesting to note that deer do not infect ticks with Lyme disease. They also do not contract Lyme disease when an infected tick feeds on them. As long as the temperature remains above 35 degrees, ticks continue to feed. They do not die over the winter. Females drop to the ground where they lay their eggs the following spring.

(5) Ticks prefer specific habitats – beware of invasive tick magnet plants like Japanese Barberry!

Adult ticks can be found living in the grass along the edges of forests, near stone walls and wood piles, in shrubs and gardens, and anywhere with dense ground cover between ankle and waist height. A number of invasive plants, such as Japanese Barberry, Multiflora Rose and Jewelweed are known to be havens for ticks. One of the reasons for this is that small rodents, such as the white-footed mice which carry Borrelia burgdorferi, the cause of Lyme disease, are attracted to the warmth and humidity that exists in thickets of these dense, thorny shrubs. 

(6) Acorns can play a role in the cycle of deer, ticks, mice, and Lyme disease

 Acorns are an attractive food source to both white-footed mice and white-tailed deer. Adult ticks are sometimes carried to oak forests after latching onto white-tailed deer in search of acorns. Once there, the engorged ticks drop from the deer to the ground and end up spending the winter in the acorn and leaf debris under the oaks. In the spring, the female ticks lay their eggs which soon hatch into larval ticks. The tiny larval ticks in search of a blood meal then latch onto passing white-footed mice who are in search of their own meals – acorns. Typically, as mentioned above, ticks that feed on the blood of white-footed mice become infected with the bacteria the causes Lyme disease.

(7) Red Foxes and Guinea Fowl – Ticks have natural predators that can be used to keep their numbers in check

Since hosts like white-footed mice have the potential to infect ticks and ticks are known to infect people and pets, attempts to reduce the spread of tick-borne diseases by eliminating infected blood hosts have included the study of their natural predators.

Red foxes, for example, are known to feed on white-footed mice and thus reduce the white-footed mice populations wherever they live. When coyotes are present, however, they feed on red foxes and subsequently reduce the red fox population significantly. Because coyotes are not as likely to eat white-footed mice as red foxes and white-footed mice populations tend to grow when fewer red foxes around, researchers have found that places with more coyotes and fewer red foxes have more white-footed mice and also more Lyme disease.

Guinea Fowl and chickens provide a natural form of pest control, often eating incredible quantities of ticks, mosquitos and fleas. Guinea fowl have been known to eat as many as 4,000 ticks a day. Chickens, too, eat lots of ticks. One study of free-range chickens in a tick-infested cattle field found that they ate an average of more than 80 ticks within a 30 to 60-minute time frame.

(10) Common Symptoms and Treatment of Lyme Infection

Lyme disease is not always easy to detect. Symptoms may not appear for days or months. About 50% of infected people may get a rash. Only about 9% get the classic bulls-eye rash. Other symptoms include flu-like fever, headache, fatigue, joint pain, neck and back pain, and/or jaw pain. Oral antibiotics prescribed by a doctor are the standard treatment for early stage Lyme disease.