The reason that the Lyme bacteria are only transmitted by ticks after prolonged feeding times (my most recent source says 36 hrs) is that they needs to change their cell surface proteins in order to become infectious. They reside in the tick's stomach. When the tick begins to feed, and ingests warm blood, it triggers a change in the bacteria and causes them to manufacture new proteins and swap them for some of the existing ones on their surfaces. This is a process that takes some time, and when they're ready, they migrate to the tick's salivary glands, from which they can be injected into their new victim. Without this protein change, they're not infectious, which is why, for instance, you can't get Lyme disease by eating an infected tick. I know that deer and horse flies feed on deer, and probably ingest Lyme-containing blood, but I'm not sure if they can transmit it effectively, because they feed so very briefly (ticks stay attached for several days). Don't forget--it's not always the tick you see that gives you Lyme disease, and the bullseye rash doesn't always appear at the bite site--it can develop elsewhere. As for white-footed mice, they are the definitive hosts for Lyme disease, and are fed upon by first stage ticks (larvae). Deer ticks can transmit the disease in both the nymph and adult stages, but more effectively by the latter. @IpmMan: The reason doctors use antibiotics prophylactically in cases of known or suspected tick exposure is because the Lyme bacteria can be eradicated from the body only in the first few weeks after exposure. After that, they hole up in the lymph nodes and become permanent residents and cause a variety of disease syndromes. In fact, the best time to treat Lyme disease is BEFORE the blood test is positive, in those early weeks. The disease is responsive to antibiotics at any stage, but can only be eradicated early on. Once it reaches the more chronic form, bacterial numbers can be decreased with treatment, but not wiped out. I hope this answers a few questions.

Oh, please don't feel bad! It makes me feel good to know someone "gets" it. The whole situation is such a mess. Yes, the Yale man expressed the academic viewpoint. Maybe I'm deluding myself, but I think he might be open to considering data that contradicts it. The consumer groups trying to educate the public sabotage themselves sometimes, I think. After hanging out on their message boards for some time I backed off because it's hard to know what to believe. They often blame everything on ticks. They may be right, but it sounds like lunacy at times. Also, they place a lot of importance on going to Lyme-literate doctors (LLMDs). Unfortunately, anyone can call himself--or herself--an LLMD. I discovered that the ones in my area (within 100 miles, none close) don't take insurance, and all charge big bucks. And I didn't see anyone posting about being cured. Post after post talked about switching meds, adding meds, trying a new med, going for IV meds, adding supplements, giving up certain foods, exercising, reacting to meds, feeling better, feeling worse, noticing no changes, etc. It was dizzying. My own doctor is a good guy. He admits he doesn't know much about tick-borne illness, but he reads what I give him and trusts my judgment. So I learn all I can (which is how I found myself talking to the Yale researcher), but there are no clear answers. I was on Doxycycline a total of 5 months. Doxy is the least risky of the recommended antibiotics. I'm sure I'll be on it again this spring or summer. It helps, but it's not a cure. The best book I read on the subject is Cure Unknown: Inside the Lyme Epidemic. The author, Pamela Weintraub, is an experienced medical journalist whose family was severely affected by Lyme and its co-infections. She goes on antibiotics periodically as symptoms return.

Sjerin, thank you so much!! Believe me, I don't know everything about Lyme and its co-infections. I'm always learning, or trying to. There's so little definitive information out there. Your link looks fascinating; I'll check it out tomorrow when I'm (hopefully) not tired. This year's tick bites (six that I know of, so far) have taken a bit of a toll. I'm looking forward to my first appointment with a family-practice MD who has dealt with his own case of Lyme. I'm told he's very good. He's kind of a long drive away, but I hope it'll be well worth it. Thank you for thinking of me!

Even if the Lyme test is negative, unless another cause is conclusively determined, he should probably keep taking the dox, since as Alisande mentions, the test they perform for Lyme is notorious for false negatives. Another possibility that occurs to me is that is could be some sub-cutaneous infection of a nasty bacteria. Does he live in an area that have been affected by the flooding? Or has he visited and helped out in such an area? Lastly if it starts looking much worse, and the doctors say "It must be a Brown Recluse Spider bite", that in all likelihood is a guess on their part, and most likely a wrong one since the Brown Recluse's range doesn't extend into West Virginia.