The book was brand-new from the manufacturer and arrived in plastic.
But I did spend two days mostly sitting on my porch because my child was having a yard sale - maybe the outdoor furniture cushions are moldy. They're new-ish, but it probably doesn't take long. As I know you understand as well as anyone, I do not want to believe that it's mold.... But I will keep it in mind.
I don't think I have started doing anything that would have an antimicrobial effect.
I did drink the Traditional Medicinals Detox tea that day, but I would be surprised if that would create such a strong effect. (I use one tea bag for a liter of tea, steeped for an hour, and then chill it and drink throughout the day.) I've had it before with no ill effects, but it has been a while.