Lyme disease or Lyme borreliosis (LB) is the most common vector born bacterial infection in the temperate northern hemisphere.
- the infection is caused by the bacterium, Borrelia burgdorferi sensu lato
- B. afzelii, B. garinii and other related species may also be responsible for Lyme disease in Europe and in Asia
- the infection is spread through the bite of an infected tick of the genus Ixodes
- the Ixodes ricinus tick is responsible for the transmission of the infection in the UK and Europe while in the USA, Ixodes scapularis (on the west coast Ixodes pacificus predominates) spreads the disease
- ticks are often found in hard-to-see areas such as the groin, armpits, and scalp (but may attach to any part of the human body)
- in most cases, the tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted.
- transmission from person to person or directly from other animals do not occur (1,2,3)
The disease was first recognised in Lyme, Connecticut when a large cluster of children developed arthritis.
Lyme borreliosis is more commonly diagnosed during the summer season, coinciding with tick activity, but cases are reported throughout the year (4).
Public Health England (PHE) reports that there are approximately 1,000 serologically confirmed cases of Lyme disease each year in England and Wales (5)
- many diagnoses will also be made clinically without laboratory testing
- true number of cases is currently unknown. In England and Wales, cases of laboratory-confirmed Lyme disease have increased
- not certain how much of the rise is due to increased awareness and how much to the spread of the disease
A subset of individuals reports persistent symptoms after antibiotic treatment, including fatigue, pain, arthralgia, and neurocognitive symptoms, which in some people are severe enough to fulfil the criteria for post-treatment Lyme disease syndrome (6):
- reported prevalence of such persistent symptoms following antimicrobial treatment varies considerably, and its pathophysiology is unclear
- persistent active infection in humans has not been identified as a cause of this syndrome
- randomized treatment trials have invariably failed to show any benefit of prolonged antibiotic treatment
Key points (6):
- treat erythema migrans empirically; serology is often negative early in infection
- for other suspected Lyme disease such as neuroborreliosis (CN palsy, radiculopathy) seek advice.