One thing that has become very clear over the last decade is how thirsty we all have become. It seems like everyone has a bottle of water or some type of drink with them all the time. Which is a good thing as the benefits of drinking water are well known.
But all the bottles of water floating around can lead to a lot of sharing of drinks with others, probably because it's easy to do.
So is sharing drinks healthy? What can you catch from sharing drinks?
Well you can catch some diseases/sicknesses. Since there's almost certain to be saliva involved in any sharing of drinks, salivary transfer of germs/viruses etc is going to happen. The most common are the one's you'd expect. We're talking strep throat, the common cold and mumps. There's also the rarer meningitis.
These are the main ones that can be transmitted via saliva, but there are a few others as well like herpes simplex (cold sores) and also mononueleosis (kissing disease).
So it gets down to any saliva transfer can cause any of the above to happen so probably best you don't share and water/drink bottles with anyone you wouldn't kiss on the lips, so if your willing to kiss this person on the lips, then by all means feel free to share your water bottle or any other drink with them.