How can you contract Lyme disease from a tick? - briefly
Transmission occurs when an infected nymph or adult tick attaches to the skin and remains attached for at least 24–48 hours, allowing the bacterium Borrelia burgdorferi to be injected via the tick’s saliva into the host’s bloodstream. Prompt removal of the tick reduces the risk of infection.
How can you contract Lyme disease from a tick? - in detail
Ticks acquire the bacterium Borrelia burgdorferi during a blood meal from an infected host, typically small mammals such as mice. The pathogen persists in the tick’s midgut and migrates to the salivary glands when the insect begins a subsequent feeding. During attachment, the tick inserts its hypostome into the skin, creates a feeding cavity, and secretes saliva that contains anticoagulants, immunomodulators, and the spirochetes. This saliva facilitates the transfer of the bacteria into the host’s bloodstream.
The likelihood of infection increases with several factors:
- Duration of attachment: transmission rarely occurs before 24 hours of continuous feeding; risk rises sharply after 48 hours.
- Tick developmental stage: nymphs are most often responsible for human infection because they are small and go unnoticed.
- Geographic prevalence: regions with established B. burgdorferi reservoirs, such as the northeastern United States and parts of Europe, present higher exposure.
- Host immune status: individuals with compromised immunity may develop disease more readily after exposure.
The biological steps of transmission are:
- Infected tick attaches to skin and begins feeding.
- Salivary glands become infected as spirochetes move from midgut.
- Saliva containing B. burgdorferi is injected into the host’s dermis.
- Bacteria disseminate via the bloodstream to peripheral tissues.
- Clinical manifestations appear days to weeks later, beginning with erythema migrans and potentially progressing to joint, cardiac, or neurological involvement.
Prevention focuses on minimizing tick contact and prompt removal. Strategies include wearing protective clothing, applying repellents containing DEET or picaridin, performing regular body checks after outdoor activity, and using fine‑tipped tweezers to grasp the tick close to the skin and pull steadily upward. Early removal, ideally within 24 hours, greatly reduces the probability of bacterial transmission.