Speleofish said:
There are numerous species (increasing all the time) and over 300 serovars
When I was at medical school I did want to do a testing programme on freshers as we observed that most people seemed to get a bit ill after their first few couple of trips and then would get better. They then seemed to get ill each time they were caving in different regions and we thought it might be due to regional serovars of lepto. Then again it might just be 'exer-stress'
The logistics, ethics and the implication of a health risk associated with caving put paid to that. Some years later I got pleurisy in death's head and ended up getting a very panicked phone call from my GP when they grew a previously unrecorded haemophilus species (I was fine and suffered no long term effects). So who knows what else is in the water.
I'd happily run a trial of the vaccine in cavers if it meant we could go caving again. I'd even swim in the most fetid holes in mendip open mouthed and all.