How do ticks transmit Lyme disease? - briefly
During a blood meal, an infected tick inserts its mouthparts into the host’s skin and injects saliva that carries the bacterium Borrelia burgdorferi. Transmission typically requires the tick to remain attached for 24–48 hours before the pathogen can enter the bloodstream.
How do ticks transmit Lyme disease? - in detail
Ticks act as vectors for the bacterium Borrelia burgdorferi, the causative agent of Lyme disease. The transmission process involves several distinct steps that occur during the tick’s blood meal.
When a larval or nymphal tick attaches to a vertebrate host, it inserts its mouthparts into the skin and begins to feed. During the first 24–48 hours, the tick’s salivary glands secrete a cocktail of proteins that suppress host immune responses and facilitate blood ingestion. If the tick previously fed on an infected reservoir—commonly the white‑footed mouse—it harbors B. burgdorferi in its midgut. The spirochetes multiply and migrate from the midgut to the salivary glands, a movement triggered by the onset of feeding.
The bacterium is released into the host through the tick’s saliva. Transmission typically requires at least 36 hours of attachment; shorter feeding periods usually do not allow sufficient migration of the pathogen to the salivary glands. Once introduced, B. burgdorferi disseminates via the bloodstream, reaching peripheral tissues and establishing infection.
Key factors influencing the efficiency of pathogen transfer include:
- Tick developmental stage – Nymphs are most responsible for human cases because they are small and feed for extended periods.
- Duration of attachment – Longer feeding increases the likelihood of spirochete migration.
- Host immune status – Immunocompromised individuals may experience faster disease progression.
- Environmental conditions – Warm, humid climates favor higher tick activity and infection rates in reservoir hosts.
Preventive measures target interruption of these steps: prompt removal of attached ticks within 24 hours, use of repellents, and avoidance of high‑risk habitats during peak activity seasons. Early antibiotic therapy after confirmed exposure can halt bacterial spread and reduce long‑term complications.