How Lyme Is Transmitted
The Transmission Process
Borrelia burgdorferi bacteria live inside certain ticks. When an infected tick attaches and begins feeding, it can transmit the bacteria through its saliva. The tick must remain attached and actively feeding for transmission to occur — and timing matters.
How Long Does Attachment Take?
Transmission of Lyme disease typically requires an attached tick to feed for at least 36–48 hours. This is because the bacteria must first multiply in the tick's midgut and then migrate to the salivary glands before transmission. Prompt removal — within 24 hours — dramatically reduces Lyme risk from an attached tick.
This Is Why Daily Tick Checks Matter
Checking for ticks daily after outdoor activities allows you to catch and remove them before they have been attached long enough to transmit Lyme. See our Tick Check guide.
The Reservoir Hosts
The Lyme disease cycle involves small mammals — primarily white-footed mice and shrews — as the main reservoir for Borrelia. Ticks pick up the bacteria by feeding on these animals during the larval stage, remain infected through their life cycle, and eventually transmit to humans. White-tailed deer are important for maintaining tick populations but are not themselves a reservoir for the bacteria.
Myths — Corrected
- Myth: You can get Lyme from another person. Fact: There is no evidence of person-to-person transmission through any route — sexual, casual, or maternal.
- Myth: Deer are the main carriers of the bacteria. Fact: Small rodents (especially white-footed mice) are the primary reservoir hosts, not deer.
- Myth: Pets can give you Lyme directly. Fact: Pets cannot directly transmit Lyme. However, they can carry infected ticks into your home.
- Myth: All black-legged ticks carry Lyme. Fact: Tick infection rates vary significantly by region. In high-prevalence areas, 20–50% of nymphal deer ticks may be infected.