Do you have any of the following with your back pain?
Persistent or recurrent fever (not found to be from other causes)
Persistent night sweats even after changing mattress/ blanket
Recent infection
recreational drug use through veins
Increased risk of infection
This means immunocompromised, for eg, from use of any treatments for cancer, certain drugs like steroids, or drugs for cancer, rheumatoid arthritis (or similar inflammatory arthritis / conditions), lupus, Crohns/ Ulcerative colitis etc; or medical conditions such as HIV, absence of spleen, any transplant, certain genetic diseases. If you are not sure, or want to know more, ask your Doctor.
I do not have any of these