Herpes zoster vaccine effectiveness and manifestations of herpes zoster and associated pain by vaccination status

Options for managing herpes zoster (HZ)-related pain and complications have limited effectiveness, making HZ prevention through vaccination an important strategy. Limited data are available on HZ vaccine effectiveness against confirmed HZ and manifestations of HZ among vaccinated persons. We conducted a matched case-control study to assess HZ vaccine effectiveness for prevention of HZ and other HZ-related outcomes and a cohort study of persons with HZ to compare HZ-related outcomes by vaccination status. Cases were identified through active surveillance among persons age ≥ 60 years with HZ onset and health-care encounters during 2010-2011 in Southeastern Minnesota. Controls were age- and sex-matched to cases. Data were collected by medical record review and from participants via interviews and daily pain diaries. 266 HZ case-patients and 362 matched controls were enrolled in the vaccine effectiveness studies and 303 case-patients in the cohort study of HZ characteristics by vaccination status. Vaccination was associated with 54% (95% CI:32%-69%) reduction in HZ incidence, 58% (95% CI:31%-75%) reduction in HZ prodromal symptoms, and 70% (95% CI:33%-87%) reduction in medically-attended prodrome. HZ vaccine was statistically significant effective at preventing postherpetic neuralgia (PHN) measured at 30 d after rash onset, 61% (95% CI: 22%-80%). Among persons who developed HZ, no differences were found by vaccination status in severity or duration of HZ pain after rash onset. In this population-based study, HZ vaccination was associated with >50% reduction in HZ, HZ prodrome, and medically-attended prodrome.

Herpes zoster recurrences more frequent than previously reported

OBJECTIVE

To present population-based estimates of herpes zoster (HZ) recurrence rates among adults.

PATIENTS AND 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.

CONCLUSION

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.

A population-based study of the incidence and complication rates of herpes zoster before zoster vaccine introduction

OBJECTIVE

To establish accurate, up-to-date, baseline epidemiological data for herpes zoster (HZ) before the introduction of the recently licensed HZ vaccine.

METHODS

Using data from January 1, 1996, to October 15, 2005, we conducted a population-based study of adult residents (Greater than or equal to 22 years) of Olmsted County, MN, to determine (by medical record review) the incidence of HZ and the rate of HZ-related complications. Incidence rates were determined by age and sex and adjusted to the US population.

RESULTS

A total of 1669 adult residents with a confirmed diagnosis of HZ were identified between January 1, 1996, and December 31, 2001. Most (92%) of these patients were immunocompetent and 60% were women. When adjusted to the US adult population, the incidence of HZ was 3.6 per 1000 person-years (95% confidence interval, 3.4-3.7), with a temporal increase from 3.2 to 4.1 per 1000 person-years from 1996 to 2001. The incidence of HZ and the rate of HZ-associated complications increased with age, with 68% of cases occurring in those aged 50 years and older. Postherpetic neuralgia occurred in 18% of adult patients with HZ and in 33% of those aged 79 years and older. Overall, 10% of all patients with HZ experienced 1 or more nonpain complications.

CONCLUSIONS

Our population-based data suggest that HZ primarily affects immunocompetent adults older than 50 years; 1 in 4 experiences some type of HZ-related complication.

Diagnosis and care of irritable bowel syndrome in a community-based population

OBJECTIVE

To identify the healthcare utilization and evaluation in a community-based population with an incident diagnosis of irritable bowel syndrome (IBS).

STUDY DESIGN

Retrospective cohort.

PATIENTS

A randomly selected cohort of 149 Olmsted County, MN, adults with an incident diagnosis of IBS between June 1, 1992, and December 31, 1994.

METHODS

Retrospective medical record review of each medical encounter for the 10 years before and the 3 years after the incident IBS diagnosis. Specific attention was given to healthcare visits, tests, and treatment associated with documented gastrointestinal (GI) tract symptoms and diagnosis of IBS.

RESULTS

Of 149 patients, 98 (66%) were women, and the mean patient age was 46.6 years. Patients averaged 4.7 healthcare visits annually, including 0.5 related to GI tract symptoms. Two thirds of patients had GI tract symptom-related visits at least 2 years before IBS diagnosis. Only 5% of IBS diagnoses were made by a gastroenterologist. Colon examinations (colonoscopy or barium enema) were performed on 47% of patients and were more common in those aged > or = 55 years (58% vs 36%; P = .02). One third of patients had no GI tract testing proximal to the IBS diagnosis. Following the IBS diagnosis, only about half the patients made any IBS or GI tract symptom-related visits per year.

CONCLUSION

The path to diagnosis of IBS is through the primary care physician and includes minimal testing and limited follow-up care.