Lyme disease was caused by Borrelia burgdorferi which was transmitted through the bite of infected blacklegged ticks. In 1977, the disease was first described as “Lyme Arthritis” after a few cases was reported in Old Lyme, Connecticut. The disease was reported from every U.S. state, commonly in Northeast and upper Midwest. In 1981, Willy Burgdorfer, a scientist who was studying Rocky Mountain Spotted Fever (RMSF), started to study Lyme disease. The connection between the deer tick and the disease was detected as he discovered that the Lyme disease was carried by ticks, caused by a bacterium called a spirochete (Borrelia burgdorferi). Later, in 1982 Dr. Burgdorfer’s discovery was honoured by the medical community by naming the spirochete Borrelia burgdorferi.
Each year, about 20,000 new cases were reported, while the true incidence may be three times higher or more, stated by the experts. The number of cases of Lyme disease ranked 7th on a list of the leading nationally notifiable diseases in 2014, outlined to the Centers for Disease Control and Prevention (CDC), regardless of more than 90% of cases being detected in only 10 states.
Today, one of the fastest-growing vector-borne infections in the United States (US) is Lyme disease. Each year, there are over 329,000 new cases of Lyme disease estimated by Centers for Disease Control and Prevention (CDC) in the US. There is no definitive cure yet for those with late-stage Lyme as the diagnostic tools are still unreliable.
Borrelia burgdorferi is a Gram-negative spirochete bacteria. Borrelia burgdorferi has a helical shape. Due to its shape, the protoplasm is long and cylindrical. Borrelia burgdorferi have a unique structural characteristic. Between the inner and outer cell membranes, the cell’s flagella are located inside the periplasm. The cell is able to travel through highly viscous fluids and materials (Charon) because of the interactions between the flagella and cell cylinder. The ability of Borrelia burgdorferi to be able to travel through the tissue of its infected host or vector is due to this adaptation, causing it to be highly invasive.
Borrelia burgdorferi is a bacteria that is responsible for the infection of Lyme disease. Because of its symptoms which is imitate many other diseases, lyme also known as “The Great Imitator”. The disease can influence the heart, brain and nervous system, muscles and joints and any organ of the body. Patients with Lyme disease were usually misdiagnosed with other diseases such as chronic fatigue syndrome, fibromyalgia, multiple sclerosis, and various psychiatric illnesses, including depression.
The infected tick transmitted the bacteria (Borrelia burgdorferi) to human through the bites. The size of the tick was so small that human may not noticed it. The bite may be painless because the tick’s saliva contained an anesthetic-like that numbs human skin. There was a thought that nymphs infected more human than adult ticks because of their small size.
The Western blacklegged tick (Ixodes pacificus), was responsible for spreading the disease on the West Coast of the United States. Meanwhile the Eastern blacklegged tick, also known as the “deer tick” (Ixodes scapularis) was responsible for spreading the disease on the East Coast and in several mid-western states.
During its larval, nymph, and adult stages, a tick emerged from an egg and feeds on different hosts or animals. With a handful of blood meals, a tick can live for several years. The bacteria infected the tick most during its larval or nymph stage. Later, the small animals like squirrels, mice, or birds will ate the infected tick which will automatically carry the bacteria. The infected tick now passed on the bacteria to humans or another animals during its next feeding cycle.
Hostcycle image courtesy of Emily M. Eng
The tick may feed for several days if it was undisturbed, once it had attached to the host (animals or humans). The tick will transmit more Lyme and pathogens into the bloodstream if it stays attached for a longer time. Sometimes, for the infected pregnant women, the disease can be passed to their unborn children.
Depending on the stage of infection, untreated Lyme disease will produced a wide range of symptoms such as fever, rash, facial paralysis, and arthritis. An early signs and simptoms can be detected after 3 to 30 days after tick bite. These include chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes. Erythema migrans (EM) rash referred to a rash often seen in the early stage of Lyme disease. Approximately 70% to 80% of infected person will be facing EM. It began at the site of a tick bite after a delay of 3 to 30 days after infection. EM rash will expand gradually over a period of days (up to 12 inches or more). It was rarely itchy or painful but it may felt warm to touch. Sometimes it will result in a target or “bull’s-eye” appearance as it enlarged and may appeared on any area of the body.
After days to months after tick bite, later signs and simptoms started to occur. The infected person will be having severe headaches and neck stiffness. Worser, an additional EM rashes appeared on other areas of the body. The disease also caused facial palsy, the condition where loss of muscle tone or droop on one or both sides of the face. Intermittent pain can be felt by the infected person in tendons, muscles, joints, and bones. Some of them experienced heart palpitations or an irregular heartbeat, also known as Lyme carditis. Other symptoms were episodes of dizziness, inflammation of the brain, nerve pain, shooting pains, numbness, or tingling in the hands or feet and short-term memory problems.