A client with shingles is admitted to the hospital. When the client asks about the cause of shingles, which response by the nurse is correct?

A. You've been bitten by a vector insect such as a tick: Vector insects such as ticks are responsible for transmitting certain infections like Lyme disease or Rocky Mountain spotted fever. Shingles is not transmitted through insect bites and does not involve a vector in its pathogenesis. The condition results from reactivation of a virus already present in the body. B. The toxins from a bacterial infection are making you ill: Shingles is not caused by bacteria or bacterial toxins. It is a viral condition related to the varicella-zoster virus, which initially causes chickenpox. Bacterial toxins typically produce systemic toxic responses in illnesses such as food poisoning or certain severe bacterial infections, which is not the mechanism involved in shingles. C. You're having an antibody response to a disease: Antibody production is part of the immune system’s normal defense against infections, but it does not explain the underlying cause of shingles. The disease occurs when the virus that previously caused chickenpox remains dormant in nerve ganglia and later becomes reactivated. D. A dormant virus has been reactivated within your body: Shingles results from reactivation of the varicella-zoster virus that remains dormant in sensory nerve ganglia after a previous chickenpox infection. Factors such as aging, stress, or weakened immunity can allow the virus to reactivate and travel along nerve pathways to the skin. This leads to the characteristic painful vesicular rash distributed along a dermatome.