The straw filters and the sports bottles and the camelbacks with the built-in filters use the same type of filter and its limited to ghiardia and crypto. I've used them with stream water, etc, but the flow rate is very slow. If you're worried about beaver fever, typhoid, or any other waterborne disease I'd get a pump with a better filter ... if you're on the move. If you stay at home, get a biosand filter.
Keep in mind that straws, bottles and pumps are for short-term limited use. Iodine, water purification tablets can cause kidney problems and should not be used for anything other than emergency. Long term will require different solutions. If you are going to be away from your usual water source for the long term, plan on diarrhea - you can't filter everything, but you have to hydrate or die. I've had several of the waterborne illnesses and despite the accelerated weight loss, they all passed eventually.
Waterborne illness is the 2nd highest killer of children in the world; estimated 4,200 a day die. Most water sources in North America are pretty well protected from the types of things that those children are exposed to, but after a hurricane, natural disaster, plaque, it could get pretty nasty quick. We had folks get sick in Tombstone, where I used to live, when illegal immigrants were using the town water source as a toilet/bathtub.
