After a bite of tick - carrier it's a few percent chance to get the bacterium. Few percent - it's not much. Now - only few percent of ticks are carriers and moreover - only the one species of tick can spread the disease. Chances of an infection are then around 1 to 1000, most likely lower.

After infection there are few screenplays. It might be drastically bad, with a heavy joint, pain, fever, sometimes neural disorder. Sometimes a rash can appear, but it's not a rule. Some say that there's even a bigger chance not to do see any rash when you get Lyme. Anyway, rash is one of few symptoms that can't be misdiagnosed and always should be treated with antibiotics (even if it don't always mean Lyme). It can appear everywhere, anytime, even after months.

Another scenario - our white blood cells can terrorize Borella, yet do not destroy it completely. It's some kind of equilibrum.

Borella is master of evading our immune system. It changes a shape all the time, like a chameleon. Sometimes it can even invade a white blood cell, destroy it and dress in our own antigens - and become immortal, at least for a few days. Yet our guards fight with Lyme. Now the only question is - who is faster? Spirochaetes, and in such case the infection grows, or our defence?

It's some kind of a race - our "police" try to find Borella spirochetes, learn them, Borella changes the shape, creates cysts, tries to hide in hard places like joints or inside our cells. Now everything depend on our resistance and virulence of our local Lyme species.

Now, three possibilites. Death is one. Completely healing in just a few days another. And third....

Yes, stage 2 of Lyme, and again three scenarios:

First, after some time our defence can completely destroy the disease, even after years.

Second scenario - the infection is not destroyed completely, but cannot spread. Some spirochetes survived, but they cannot harm us anymore - once they start to dance, white blood cells joins the party. Still, when our immune system is weakened, things can go nasty...

Worst case scenario, luckily rare. We are fighting, but losing. Slowly borella invades joint after joint, organ after organ, spreads inside our brain. It's chronic Lyme, hard to diagnose, hard to treat sucessfully.