Maybe it's coincidence but my brother started having back pain over the weekend. since then I have as well (live in a different state) I have encountered 6 other people since then that are experiencing the same thing starting around the same time.
Might be nothing but might be something. Just seems strange.
The flu will sometimes do that. Also a sign of kidney issues (stones, infection, etc).
....I knew a lot of people who had kidney stones last year....including myself. Apparently apple cider vinegar is a good remedy......