title: Herpes zoster recurrences more frequent than previously reported.
abstract: OBJECTIVE
  To present population-based estimates of herpes zoster (HZ) recurrence rates among adults.
  
  
  METHODS
  To identify recurrent cases of HZ, we reviewed the medical records (through December 31, 2007) of all Olmsted County, Minnesota, residents aged 22 years or older who had an incident case of HZ between January 1, 1996, and December 31, 2001. Kaplan-Meier curves and Cox regression models were used to describe recurrences by age, immune status, and presence of prolonged pain at the time of the incident HZ episode.
  
  
  RESULTS
  Of the 1669 persons with a medically documented episode of HZ, 95 had 105 recurrences (8 persons with >1 recurrence) by December 31, 2007, an average follow-up of 7.3 years. The Kaplan-Meier estimate of the recurrence rate at 8 years was 6.2%. With a maximum follow-up of 12 years, the time between HZ episodes in the same person varied from 96 days to 10 years. Recurrences were significantly more likely in persons with zoster-associated pain of 30 days or longer at the initial episode (hazard ratio, 2.80; 95% confidence interval, 1.84-4.27; P<.001) and in immunocompromised individuals (hazard ratio, 2.35; 95% confidence interval, 1.35-4.08; P=.006). Women and anyone aged 50 years or older at the index episode also had a greater likelihood of recurrence.
  
  
  CONCLUSIONS
  Rates of HZ recurrence appear to be comparable to rates of first HZ occurrence in immunocompetent individuals, suggesting that recurrence is sufficiently common to warrant investigation of vaccine prevention in this group.
authors.affiliation: Department of Research, Olmsted Medical Center, 210 9th Street SE, Rochester, MN 55904, USA. byawn@olmmed.org
authors.forename: Barbara P
authors.initials: BP
authors.lastname: Yawn
authors.forename: Peter C
authors.initials: PC
authors.lastname: Wollan
authors.forename: Marge J
authors.initials: MJ
authors.lastname: Kurland
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: St Sauver
authors.forename: Patricia
authors.initials: P
authors.lastname: Saddier
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006562:Herpes Zoster / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D016016:Proportional Hazards Models; D012008:Recurrence; D017678:Sex Distribution