Newb warning....

I recently purchased a Sawyer squeeze after reading a ton of reviews. This weekend is the first hike long enough where I will have a legitimate need for it. I'll be using it on the AT near the rollercoaster (NoVa).

Should I be concerned that it doesn't filter out viruses and consider using chemical as well ot is the Sawyer enough. I really don't know as much about this as I should...other then I know I am not interested in drinking from the source....