Everyone that has had chicken pox can get shingles although most do not.
Shingles is caused byt the reactivation of the Varicella Virus
After primary infection, VZV remains dormant in sensory nerve roots for life. Upon reactivation, the virus migrates down the sensory nerve to the skin, causing the characteristic painful dermatomal rash. After resolution, many individuals continue to experience pain in the distribution of the rash (postherpetic neuralgia). In addition, reactivation of VZV infection can cause a spectrum of atypical presentations ranging from self-limited radicular pain without rash to spinal cord disease with weakness.
Pathophysiology: The host immunologic mechanisms suppress replication of the virus. Reactivation can occur if host immune mechanisms are compromised. This can occur from medications, illness, malnutrition, or from the natural decline in immune function with aging. Upon reactivation, the virus migrates along sensory nerves and produces sensory loss, pain, and other neurologic complications. If motor nerve roots also are involved, then weakness can occur in addition to sensory changes. Leptomeningeal involvement can occur rarely when the ophthalmic branch of the trigeminal nerve is involved.
Stress can aslo cause a reactivation.
I hope he is feeling better.
You can not catch shingles form someone that has shingles.
If you have had chicken pox already there is no need to fear "catching"shingles. the only thing that can happen is is you have never had chicken pox ther eis a slight chance of "catching"them.