I contracted leptospirosis almost twenty years ago, on Cape York, FNQ, Australia, in grass contaminated with rat's piss.
I was in hospital for a month, off work for a year. I went back to work briefly and then was off for another three months. I have not worked full time since. A Dutch study (uncontrolled so not scientific literature) indicated 5% of people with the disease have chronic issues. It has been very costly, marriage, job, money etc but you learn to live with things and life is OK.
Pigs will give it to you too, and cows. I think you should not indulge in obsessive behaviour trying to avoid it. Just don't swim or paddle in dirty still water. If you are worried about getting it you will have to be terrified of crossing the road as the odds are much worse there.
In parts of the 3rd world it is endemic, ie. Jamaica. I read of an outbreak about 15 years ago in Central America where thousands died, mostly because they did not have good access to health care. It belongs to a group of ailments which were largely cured by penicillin and therefore seen as solved. There are no great rewards, prizes or fortunes for solving it. Most GPs will not see a single case in a lifetime. My expert said more is known about it in horses because they are are valuable and usually are post-mortemed after death.
Cheers
Chris