Once suspect water had been in my bottle I would not be drinking from it until the bottle was sanitised.
Yes, I misunderstood!
No, I would not drink from the water bottle / container until I sterilised it, preferably with boiling water.
I used the water bottle only with drinking / clean water, never suspect. If that principle is adhered to religiously you do not risk getting sick.
Similar to the Jewish Kosher laws in the kitchen.
Natural water in Northern Europe does not contain viruses, can just be full of bacteria, toxic stuff and so on.
In Scandinavia most streams away from human habitation is safe to drink if you follow some simple rules.
I was taught to investigate upstream for about 100 meters, both sides and the water, checking for dead animals. Use the nose too. Only drink running water.
Never used purification tablets, and never got sick.
In UK I would treat all water as dirty.
I used to live on a farmhouse outside Mayfield in East Sussex. Cesspit was about 100 meters downhill from the house, and a stream was maybe 20 meters beyond that. Downhill.