Lyme disease

Lyme disease, also known as Lyme borreliosis, is a tick-borne disease caused by species of Borrelia bacteria, transmitted by blood-feeding ticks in the genus Ixodes.^[4][9][10] It is the most common disease spread by ticks in the Northern Hemisphere.^[11][8] Infections are most common in the spring and early summer.^[4]

The most common sign of infection is an expanding red rash, known as erythema migrans (EM), which appears at the site of the tick bite about a week afterwards.^[1] The rash is typically neither itchy nor painful.^[1] Approximately 70–80% of infected people develop a rash.^[1] Other early symptoms may include fever, headaches and tiredness.^[1] If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness or heart palpitations.^[1] Months to years later, repeated episodes of joint pain and swelling may occur.^[1] Occasionally, shooting pains or tingling in the arms and legs may develop.^[1]

Diagnosis is based on a combination of symptoms, history of tick exposure, and possibly testing for specific antibodies in the blood.^[5][12] If an infection develops, several antibiotics are effective, including doxycycline, amoxicillin and cefuroxime.^[4] Standard treatment usually lasts for two or three weeks.^[4] People with persistent symptoms after appropriate treatments are said to have Post-Treatment Lyme Disease Syndrome (PTLDS).^[13]

Prevention includes efforts to prevent tick bites by wearing clothing to cover the arms and legs and using DEET or picaridin-based insect repellents.^[4][9] As of 2023, clinical trials of proposed human vaccines for Lyme disease were being carried out, but no vaccine was available. A vaccine, LYMERix, was produced but discontinued in 2002 due to insufficient demand.^[14] There are several vaccines for the prevention of Lyme disease in dogs.