It's regional.
In California, the grey squirrel is the biggest culprit. For example, studies have shown that 86% of tick larvae carrying Borrelia burgdorferi (Bb) were infected by the western grey squirrel. (Salkeld et al, 2008)
On the East Coast, the white-footed mouse is the primary host.
Birds and many small mammals can also harbor Lyme bacteria. Notably, the white-tailed deer supports the tick, but not the spirochete. These hosts provide the ticks with a bountiful supply of food (i.e., blood meals), enabling the ticks to live, reproduce, and/or infect a human.
Interestingly, research by Dr. Robert Lane and others at the University of California at Berkeley, has documented that when ticks feed off a Western Fence lizard, the Bb bacteria inside them is destroyed. These lizards use the complement pathway of their immune system to destroy the Bb bacteria with proteins that burst the bacterial cells. Understanding this phenomenon may provide insights into treatments for humans.
From Bayarealyme.org
Post Edited (jrpsf) : 9/24/2015 11:52:20 AM (GMT-6)