Which viral infection causes shingles?

Shingles is caused by the varicella-zoster virus, which is the same virus responsible for chickenpox. After a person has chickenpox, the virus can remain dormant in the nerve tissues and can be reactivated later in life, leading to shingles. This reactivation often occurs when the immune system is weakened, causing a painful rash and blisters that typically appear on one side of the body.

Other viruses listed do not cause shingles. The human papillomavirus primarily causes warts and is unrelated to the varicella-zoster virus. Herpes simplex virus is associated with oral and genital herpes but not with shingles. The HIV virus attacks the immune system and can predispose individuals to opportunistic infections but does not cause shingles directly. Understanding the specific nature of these viruses helps clarify why varicella-zoster is the correct answer regarding shingles.