VDH Brochure

Preventing Tick Borne Diseases in Virginia- VDH Brochure

Spring and summer bring warm temperatures, just right for

walking in the woods or other outdoor activities. Warm

weather also means that ticks become more active and this

can increase the risk of a tick-borne disease.

The tick-borne diseases that occur most often in Virginia are

Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis.

Lyme Disease

Lyme disease is caused by infection with a spiral-shaped

bacterium called Borrelia burgdorferi. Although Lyme dis-

ease most often occurs in the Northeastern and upper

Midwestern states, people can get Lyme disease in Virginia.

The number of cases reported in Virginia has increased sub-

stantially in recent years.

The Tick

The blacklegged tick (Ixodes scapularis), formerly known

as the deer tick, is the only carrier of Lyme disease in the

Eastern U.S. The blacklegged tick's name comes from it

being the only tick in the Eastern U.S. that bites humans and

has legs that are black (or dark chocolate brown) in color.

Lyme disease transmission to humans usually occurs during

the late spring and early summer when young (nymph

stage) ticks are active and feeding. Tick nymphs normally

feed on small and medium sized animals, but will also feed on

people. Tick nymphs typically become infected with the

Lyme disease agent by feeding on certain rodent species

while in thier larval stage.

In the fall, the nymphs become adults and infected nymphs

will become infected adults. Adult blacklegged ticks prefer to

feed on deer. However, adult ticks will occasionally bite

people on warm days of the fall and winter and can transmit

Lyme disease at that time.

Transmission of Lyme disease by the nymph or adult ticks

usually does not occur until the tick has been attached and

feeding on a human or animal host for at least 36 hours.

The Symptoms

Between three days to several weeks after being bitten by an

infected tick, 70-90% of people develop a circular or oval

rash, called erythema migrans (or EM), at the site of the bite.

To qualify as an EM, the rash must be at least two inches in

diameter. That is because bites by some tick species can cause

local inflammation and redness around the bite that could be

mistaken for an EM. Unlike localized inflamation, an EM

rash will increase in size and may become more than 12 inch-

es across. As it enlarges, the area around the center of the rash

clears giving it a “bull's eye” appearance. The EM rash does

not itch or hurt so if it is not seen, it may not be noticed.

In addition to an EM rash, Lyme disease may cause

headache, fever, muscle and joint aches, and a feeling of

tiredness. If left untreated, Lyme disease may progress to

affect the joints, nervous system, or heart several weeks to

months after the tick bite. In a small percentage of infected

people, late symptoms may occur months to years later and

cause long-term nervous system problems or arthritis.

Unfortunately, blacklegged tick nymphs are small (about

the size of a pinhead), difficult to see, and cause no itch or

irritation at the site of the bite, so many people are not aware

they have been bitten. If you have been in an area that might

contain ticks and you experience any symptoms of Lyme

disease, contact your doctor.

The Treatment

When Lyme disease is detected early, its effects can be mild

and it is easily treated with antibiotics. In the late stages,

Lyme disease can be treated successfully with antibiotics,

but the treatment lasts longer and is more involved.

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever (RMSF) is caused by infec-

tion with a bacterium called Rickettsia rickettsii. The dis-

ease is characterized by a sudden onset of symptoms and

can be fatal if not treated. Nearly all cases occur in the

spring and summer months.

The Tick

In Virginia, the American dog tick (Dermacentor variabilis)

is the species known to carry the agent of Rocky Mountain

spotted fever. The tick needs to feed on a host/person for

only about four hours to transmit the bacteria. Fortunately,

less than 1% of American dog ticks carry the agent of RMSF.

The Symptoms

Symptoms of Rocky Mountain spotted fever begin 2-14 days

after the tick bite, and may include fever, deep muscle pain,

severe headache, chills, and upset stomach or vomiting.

From the third to fifth day of illness a red, spotted rash may

appear, beginning on the wrists and ankles. The rash spreads

quickly to the palms of the hands and soles of the feet and

then to the rest of the body. However, only about half of

RMSF patients develop a rash.

The Treatment

Antibiotic treatment for RMSF is effective, and suspected

RMSF should be treated as soon as possible based on symp-

toms and a history of tick exposure. The risk of death from

RMSF increases by the fifth day of illness - but the rash often

does not occur until that time. Therefore, do not wait for

RMSF blood test results, or the appearance of a rash, before

starting treatment. Treatment is important; almost one-third

of those who do not get treated die from this disease.

Ehrlichiosis and Anaplasmosis

Although several diseases can be caused by bacteria in the

Ehrlichia and Anaplasma genera, the most common in

Virginia are human monocytic ehrlichiosis (HME) and

human granulocytic anaplasmosis (HGA). HME is transmit-

ted only by the lone star tick (Amblyomma americanum).

Disease transmission occurs most commonly by bites from

the adult ticks. Lone star ticks are very common and are the

species causing the most tick bites to people in Virginia.

HGA is transmitted only by the blacklegged tick (most com-

monly by bites from nymphal stage ticks). The bacteria caus-

ing HME or HGA will not be transmitted unless the infected

tick has been attached and feeding for at least 24 hours.

The Symptoms

Symptoms for both HME and HGA can include fever, head-

ache, muscle pain, vomiting, and general discomfort. Illness

can be severe - up to 3% of patients may die if not treated.

The Treatment

HME and HGA respond rapidly to treatment with antibi-

otics. Treatment should be based on symptoms (including

platelet and liver enzyme tests) and history of tick exposure -

treatment should not be delayed while waiting for ehrli-

chiosis or anaplasmosis-specific test results.

Other Diseases

Ticks can transmit other diseases, such as tularemia (rabbit

fever) and babesiosis. Neither of these illnesses is common in

Virginia. Tularemia is a bacterial disease that has a sudden onset

of fever and chills. Typically, an ulcer develops at the site of

the tick bite and surrounding lymph nodes become enlarged.

Tularemia can be transmitted by the American dog tick, the

lone star tick and the blacklegged tick.

Babesiosis is caused by a parasite that infects red blood

cells. The babesiosis agent is transmitted only by infected

blacklegged ticks. Symptoms include fever, chills, muscle

aches, fatigue, and jaundice.

Tick Identification Chart


Ticks do not jump or fly; they wait on the forest floor, leaf

litter, or low vegetation and attach to the feet, shoes or legs

of people and animals that pass by. The ticks then crawl

upward. The following steps can reduce your risk of tick-

borne diseases:

• Avoid potential tick-infested areas such as tall grass and

dense vegetation in shaded areas and along forest edges.

• Walk in the center of mowed trails to avoid brushing

against vegetation.

• Keep grass cut and underbrush thinned in yards. If chem-

icals are used for tick control, follow directions carefully

or hire a professional to apply the chemicals.

• Eliminate the living places of small rodents around your


• Wear light-colored clothing so that ticks are easier to see

and remove.

• Tuck pant legs into socks and boots. Wear long-sleeved

shirts buttoned at the wrist.

• Conduct tick checks on yourself, your children, and your

pets every four to six hours while in tick habitat.

• Apply tick repellent to areas of the body and clothing that

may come in contact with grass and brush. Repellents

include those containing up to 50% DEET for adults or

less than 30% for children. An aerosol repellent/insecti-

cide containing 0.5% permethrin may be applied to shoes,

socks, and other clothing, but should not be used on skin.

Follow directions carefully and do not overuse. Some tick

repellents can cause toxic or allergic reactions.

• Ask your veterinarian to recommend tick control meth-

ods for your pets. Animals can get Lyme disease, Rocky

Mountain spotted fever, and ehrlichiosis, but they do not

transmit these diseases to humans.

Tick Removal

Because ticks do not transmit disease until they have been

attached to the host for several hours to several days, it is

very important to remove ticks as soon as they are found.

The following is the best way to remove a tick:

• Grasp the tick with tweezers as close to the skin as possi-

ble and gently, but firmly, pull it straight out. Avoid any

twisting or jerking motion that may break off the mouth

parts in the skin. Mouth parts left in the wound will not

transmit the disease, but may cause irritation or infection

similar to a reaction from a splinter.

• If tweezers are not available, protect your fingers with

gloves, tissue, or a paper towel; do not touch the tick

with bare fingers. Do not squeeze or rupture the tick's

swollen abdomen. This may cause an infectious agent to be

injected into the skin and cause disease.

• After the tick has been removed, wash hands with soap

and water. Apply a topical antiseptic to the bite site.

• You can dispose of the tick by drowning it in alcohol or

flushing it down a drain or toilet. However, it may be

useful to save the tick in alcohol for several weeks and

have it identified by an expert in case you become ill.

Knowing what kind of tick bit you might help your doc-

tor diagnose the illness.

• Tick removal using nail polish, petroleum jelly, alcohol

or a hot match is not safe. These methods could cause

the tick to regurgitate an infectious agent into the site of

the bite.

If you get sick, and you have been exposed to ticks, be sure to tell your doctor about your tick exposure.

For more information, visit our website at:



August 2008