II. Lyme’s disease
Lyme’s disease is an infection caused by bacteria known as Borrelia bugdorferi. These are transmitted by deer tick and western black-legged tick bites. Though mice and deer are major reservoirs of infection, it can also affect dogs, cattle. This disease not only causes skin symptoms but also involves joints, the nervous system and the heart.
Individuals who live or work in areas surrounded by woods or overgrown bush
Persons who participate in recreational activities such as camping, fishing and hunting in tick habitat
Persons with outdoor occupations such as landscaping, bush clearing, forestry.
Signs and symptoms
The disease progresses in three stages.
- Stage one starting as a rash at the site of bite which gradually increases in size. The central area is cleared up as it expands, giving it a Bull’s eye appearance (Erythema chronicum migrans). The patient has headache, fever and chills (flu like symptoms).
- Stage two develops in a few weeks with heart and nervous system involvement in about two thirds of the patients. This manifests as meningitis, facial muscle paralysis, abnormal sensations (neuropathies) and impulse conduction blocks in the heart.
- Eventually in stage three the joints are involved over a period of months to years. Usually a single large joint is involved, with swelling and pain. The commonly affected joints are knee, shoulder, ankle and elbow.
The following investigations may be advised to support the diagnosis:
- Blood tests: Show increased antibody levels by ELISA and Western blot tests (confirmatory test)
- Synovial fluid examination: The bacterial DNA can be detected by polymerase chain reaction.
The disease is treated by Ceftriaxone, doxycycline or amoxycillin antibiotics therapy. Joint rehabilitation is essential to maintain mobility and limit disability.