The same site states that any mammal can carry a particular strain of
the bacterium *but* that different mammals are only susceptible to
some strains. It gives an example that humans can contract it from
rats and dogs but there is no transfer between rats and dogs.

The strain carried by rats actually started on farms. It is carried by farm
animals. The rat carries it into towns and cities and, as this presents a
risk to a larger number of people, the rat has born the blame.

The thing to remember about leptospirosis is that it has fluelike symptoms.
It is normally curable (with antibiotics) but, if left untreated, it can
kill (through kidney and/or liver failure).

It can be easily identified from a simple blood test. If you may have been
contaminated (this is usually by contaminated water entering the body though
a cut in the skin or by being ingested) and develop flue like symptoms,
speak to your doctor. The real danger is to ignore it.

Regards

Howard Neil