The disease is treatable with antibiotics. In November 1998 leptospirosis killed eight people and hospitalized one hundred in China. Another disease passed on through rat urine is hantavirus. It is transmitted to humans through breathing in particles of an infected rodent's urine, droppings or saliva. The virus becomes airborne when excrement dries.
Early symptoms mimic the flu and can progress to respiratory failure.
In general, urine-encrusted soda cans are not the most likely purveyors of these diseases. Most cans of soda are packaged into cardboard boxes while still on the production line and thus aren't at any risk of contamination. Additionally, once bottlers have mixed soft drink syrup is with soda water and sweetener, they try to get the finished product to the consumer as expeditiously as possible. Moreover, any rats living in bottling plants are going to be hanging out where they find can food, and the best place for them to find food is where the product ingredients are mixed. There's little or nothing for a rat to dine on in the finished product area.