Tick-bourne Diseases

The tick-borne diseases that are seen most often in Virginia are Lyme disease and Ehrlichiosis.

                                                     Lyme disease:
Lyme disease activity continues to expand its geographic range southwestward in Virginia. In 2016, public health identified 1,350 confirmed and probable cases of Lyme disease, Virginia’s second-highest annual count ever recorded.

Lyme Disease Lyme disease is caused by infection with a bacterium called Borrelia burgdorferi.

The black-legged tick, formerly known as the “deer tick”, is the only carrier of Lyme disease in the Eastern U.S.  The black-legged tick’s name comes from it being the only tick in the Eastern U.S. that bites people and has legs that are black (or dark chocolate brown) in color. 

Transmission:
Black-legged ticks are primarily found on forest leaf litter and vegetative ground cover in shady forest environments.

The nymphs are more likely to bite people than adult ticks. Nymphs typically become infected with the Lyme disease agent by feeding as larvae on certain rodent species.

Transmission of Lyme disease by the nymph or adult ticks generally does not occur until the tick has been attached and feeding on a human or animal host for at least 36 hours.

Symptoms:
Lyme disease symptoms commence from 3 to 30 days after an infectious tick bite. From 70-90% of people develop a circular or oval rash, called erythema migrans (or EM), at the site of the bite. 

Unlike localized inflammation, an EM rash will increase in size and may become more than 12 inches across. As it enlarges, the rash may remain a solid color or the area around the center of the rash may clear, giving it a “bull’s eye” appearance.

Lyme disease may cause a headache, fever, muscle and joint aches, swollen glands 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 initial illness.

Unfortunately, blacklegged tick nymphs are very small (as small as a poppy seed), difficult to see, and generally 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 blacklegged ticks and you experience any symptoms of Lyme disease, contact your doctor.

Treatment:
When Lyme disease is detected early, its effects can be mild and the illness is easily treated with antibiotics. In the late stages, Lyme disease can be treated successfully with antibiotics, but complete recovery from the after-effects of illness may take months to years.
                                                        Ehrlichiosis
Ehrlichia pathogens are transmitted only by the lone star tick which is by far, the most common cause of human tick-bites in Virginia.

Transmission:
Tick transmission of Ehrlichiosis occurs only after the infected ticks have been attached and feeding for at least 24 hours.

Symptoms:
Ehrlichiosis is characterized by a sudden onset of fever and symptoms that may include headache, muscle pain, nausea, vomiting, and mental confusion.

Severe illness may also result in difficulty breathing, or bleeding disorders. Persons who are asplenic (without a spleen or poorly functioning spleen) or immune-compromised are more likely to suffer a severe illness or fatal infection.

Treatment:
Ehrlichiosis both respond rapidly to treatment with antibiotics.