Horror story time:

As a child, my cousin liked to play in a small, wooded area close to his garden and one day, a long time ago, he must have had a tick. He didn't notice it, nobody noticed anything strange and years (10+ years) later he got problems with rheumatic attacks and arthritis. Doctors were stumped as an adolescent shouldn't present with this. They checked genetic factors which were negative and treated the symptoms. It got worse and worse over the years, many visits to many doctors and specialists, they all had no idea what the cause of his problems were.

2 years ago (he is 38 now), he got a new knee joint and this year, he had to get a hip replacement because the arthritis. On a whim, a doctor did some tests and found that he has long-term Lyme borreliosis, likely from a tick, but never presented with the more common symptoms and had an unusually long onset time for the long-term effects of the untreated disease.

All of his problems could have been prevented with a few doses of antibiotics.