This incident apparently happened. It is not a joke.
A woman drank from a normal coke can which she had in her refrigerator. She later died from Leptospirosis a toxic deadly disease traced to the can. On the top of the can was found dried rat urine containing the Leptospirosis.
Studies have shown that the tops of cans can be contaminated with bacteria as they are typically stocked in warehouses and transported straight to the shops without being cleaned.
As a precaution it is recommended washing cans before putting them to your mouth. This applies to all cans, yes beer and juice cans too!!