HOSTS AND TRANSMISSION

Transmission can be prevented by preventing contact with the deer ticks. Contact with the animal can be prevented by covering all areas of the body to limit surface area for the tick to bite. Additionally, there are tick repellents, though they are often harsh and have a level of toxicity associated with overuse.

Ticks are removed from tick-infested deer while feeding at a deer treatment area. (Link)

Contact can also be prevented by limiting contact to the animals carrying the ticks. It is typically the deer, more than the mice and small animals, which transmit to humans. If ticks are removed from the deer at treatment centers such as the ‘4-Poster' Deer Treatment Bait Station then they can not access the human and pass along the disease [2].

When ticks bite, the tick saliva contains many protective elements that help spirochete invasion. Tick saliva reduces efficacy of host PMN (Polymorphonuclear Leukocytes) which are the first immune cells to respond to a tick bite [3]. It decreases the ability of PMN binding to the Borrelia burgdorferi and decreases spirochete killing. The down regulation of PMN ß2-intergrins causes a decreased adhesion of the PMNs, and so lower host defense abilities. Tick saliva also inhibits T-cells by using a protein to bind IL-2, thus suppressing T-cell proliferation [4].

In order to invade the salivary glands to enter the host, the spirochetes must leave the midgut of the tick. To do this, the b. burgdorferi requires a protein, OSP-C (outer surface protein C) in order to adhere to the tissue of the salivary gland [5]. Without this protein, the spirochetes would not enter the saliva, and so could not be transmitted during a tick bite.

These imply that there are many elements of the tick saliva which could be targeted by vaccines or medications.