While Lyme disease is the best known and the most widespread tick-borne disease in Connecticut, it is not the only disease that can be transmitted by the bite of a tick.  Babesiosis, Ehrlichiosis and Rocky Mountain Spotted Fever (“RMSF”) also are emerging as public health threats in Connecticut. A total of 6,243 ticks feeding on humans were submitted for identification in 2003. Of these, 5,721 were tested for the presence of Borrelia burgdorferi, the causative organism of Lyme disease, and in 1,738 (30%) were found to carry this organism. Most of the ticks received were the “black-legged” or “deer tick.” http://www.caes.state.ct.us/FactSheetFiles/Entomology/TickSummary/TickSum2003.htm

Lyme Disease

Lyme disease is caused by the spirochete bacterium Borrelia burgdorferi and transmitted by the bite of the black-legged or deer tick, Ixodes scapularis.  Lyme disease is the most common vector-borne disease in the United States.  Most cases occur in the late spring and early summer when the nymphal stage of the tick is most active.   The highest incidence of Lyme disease in Connecticut appears in young children, as their play activities often place them at risk.  Certain occupational and recreational activities increase the risk in adults as well. 

Lyme Disease Signs and Symptoms

Lyme disease commonly begins in humans with the appearance of a red rash, called erythema  migrans (EM), within 3-21 days of a tick bite.  The painless rash gradually expands, often reaching five centimeters or more in diameter, which then disappears without treatment.  (The presence of an EM rash larger than the size of a quarter usually confirms a diagnosis of Lyme disease.)   This expansion is commonly accompanied by flu-like symptoms, including fatigue, muscle and joint pain, fever, headache, chills and stiff neck.  The fever is usually low-grade.

A year or more after the tick bite, symptoms of persisting infection may include numbness or tingling in the extremities, disturbances in memory, mood or sleep and chronic arthritis, typically in the large joints (especially the knees).

How Widespread Is Lyme Disease?

Lyme disease accounts for 90% of vector-borne infections in the United States.  From 1980 to 1998 about 112,000 cases have been reported from 49 states. 

How Is Lyme Disease Diagnosed?

There is no test that can determine if a patient is infected with the LD bacterium and then demonstrate that the patient has become bacterium-free. Therefore, LD is a clinical diagnosis, based on signs and symptoms, with the patient’s travel history to endemic areas and test results being additional pieces of information in the complete picture. No test can "rule-out" Lyme disease.

How is Lyme Disease Transmitted

Lyme disease is transmitted by the bite of an infected tick.  Ticks go through four life stages egg, larva, nymph and adult.  They evolve from one life stage to another by molting.  Each of these last three stages requires blood meal from a host.  If the tick feeds on an infected host animal, the tick becomes infected.  Ticks that transmit Lyme disease can retain the infection throughout their life and are able to transmit the infection to subsequent hosts.  This ability to pass the infection on to other hosts makes the tick “infective”.  These ticks can be anywhere, in the woods, by the seashore and even in your own backyard.  While ticks can bite year round, peak tick season in the Northeast is April through September. 

OTHER TICK-BORNE ILLNESSES

Ehrlichiosisis a bacterial infection caused by several types of rickettsiae, which invade and kill white blood cells. The American dog, brown dog, lone star, black-legged, and probably the Western black-legged ticks transmit the pathogens. There are two types of the human ehrlichiosis, human granulocytic ehrlichiosis (HGE) and human monocytic ehrlichiosis (HME).

Signs/Symptoms:

Fever, malaise, headache, chills, severe muscle aches or pain, vomiting, anemia, lung infection, decrease in white blood cells, elevated liver enzymes. A rash occurs in a small percentage of people. Neurologic manifestations include seizures, meningitis, confusion, ataxia, cranial nerve palsy and change in mental status. Delayed treatment can result in death.

Babesiosis is a malaria-like infection caused by several strains of parasites called Babesia (B.).  There is one species in the East (B. microti) and newly described species from the Midwest and West Coast. The black­-legged tick and probably the Western black-­legged tick transmit the parasites.

Signs/Symptoms:

Fever, chills, fatigue, headache, muscle pain, and anemia. A blood test may reveal the parasite in red blood cells. Chronic mild infection occurs. Babesiosis is more severe and sometimes fatal, in elderly people or in those who have had their spleens removed.  Immunosuppression may occur.

Rocky Mountain Spotted Fever (“RMSF”)one type of spotted fever, is caused by Rickettsia rickettsii and is reported from across North America, but is most prevalent in the eastern United States.  The Rocky Mountain wood, American dog and Pacific Coast ticks transmit the disease. The lone star ticks also transmit a spotted fever Rickettsia that causes similar symptoms.

Signs/Symptoms:

Flu-like aches and pains, headache, chills, confusion, light sensitivity and high fever. A reddish-to-black rash (resembling measles) starts on the extremities (e.g. wrists and ankles) and may spread to the entire body.  Death can occur. 

Reported Lyme disease cases in Connecticut

* In 2003, due to cut backs by the state of Connecticut, labs stopped reporting new cases.