Shingles, an an infection that precipitated Sen. Diana Feinstein, who was hospitalized in February, affected a 3rd of People. However the comorbidities that the 89-year-old senator confronted — encephalitis and Ramsay Hunt syndrome — are much less frequent and may be severe.

Feinstein, Calif., returned to Washington final week after a months-long absence and recovered from encephalitis, an irritation of the mind, her spokesman stated.