The consistency of shingles and its significance for health monitoring

Investigating regional variation of respiratory infections in a general practice syndromic surveillance system

BACKGROUND

Established surveillance systems can follow trends in community disease and illness over many years. However, within England there are known regional differences in healthcare utilisation, which can affect interpretation of trends. Here, we explore regional differences for a range of respiratory conditions using general practitioner (GP) consultation data.

METHODS

Daily data for respiratory conditions were extracted from a national GP surveillance system. Average daily GP consultation rates per 100 000 registered patient population were calculated by each region of England and for each study year (2013-17). Consultation rates and incidence rate ratios were also calculated for each condition by deprivation quintile and by rural, urban, and conurbation groups.

RESULTS

Upper and lower respiratory tract infections and asthma were higher in the North and the Midlands than in London and the South, were highest in the most deprived groups and tended to be higher in more urban areas. Influenza-like illness was highest in the least deprived and rural areas.

CONCLUSIONS

There are consistent differences in GP consultation rates across the English regions. This work has improved our understanding and interpretation of GP surveillance data at regional level and will guide more accurate public health messages.

A systematic literature review of herpes zoster incidence worldwide

We conducted a systematic review to characterize the incidence rate of herpes zoster (HZ) in the general population, specifically in individuals ≥50 years of age. A total of 69 publications were included in the review. We found a cumulative incidence of HZ ranging from 2.9–19.5 cases per 1,000 population and an incidence rate of HZ ranging from 5.23–10.9 cases per 1,000 person-years. The cumulative incidence (3.22–11.2 versus 2.44–8.0 cases per 1,000 population) and incidence rates (6.05–12.8 versus 4.30–8.5 cases per 1,000 person-years) were higher in females than males. Studies revealed a trend of increasing incidence of HZ with increasing age and over time. Variations in incidence estimates can be attributed to the various study designs, case ascertainments, age distributions of the population and year of the study. HZ is associated with a substantial disease burden and is expected to increase due to population aging.

Increasing trends of herpes zoster in Australia

Background

Increasing trends in incidence of herpes zoster (HZ) have been reported in Australia and internationally. This may reflect the impact of childhood VZV vaccination programs introduced universally in Australia in late 2005. The objective of this study was to evaluate changes in incidence of HZ and PHN in Australia over time, and associated healthcare resource utilisation.

Methods

Australian data on general practice (GP) encounters for HZ, specific antiviral prescribing data from the pharmaceutical benefits scheme, emergency department presentations from the states of NSW and Victoria and national hospitalisation data for HZ were analysed for time trends using regression models. Two time periods (2000-2006 and 2006-2013) were compared which correspond broadly with the pre- and post- universal VZV vaccination period.

Results

All data sources showed increasing rates of HZ with age and over time. The GP database showed a significant annual increase in encounters for HZ of 2.5 per 100,000 between 1998 and 2013, and the rates of prescriptions for HZ increased by 4.2% per year between 2002 and 2012. In the 60+ population HZ incidence was estimated to increase from 11.9 to 15.4 per 1,000 persons using GP data or from 12.8 to 14.2 per 1,000 persons using prescription data (p<0.05, between the two periods). Hospitalisation data did not show the same increasing trend over time, except for the age group ≥80 years. Most emergency visits for HZ were not admitted, and showed significant increases over time.

Discussion

The burden of HZ in Australia is substantial, and continues to increase over time. This increase is seen both pre- and post-universal VZV vaccination in 2005, and is most prominent in the older population. The substantial burden of HZ, along with ageing of the Australian population and the importance of healthy ageing, warrants consideration of HZ vaccination for the elderly.

Prevention of shingles by varicella zoster virus vaccination

Herpes zoster is caused by reactivation from previous varicella zoster virus (VZV) infection, and affects millions of people worldwide. It primarily affects older adults and those with immune system dysfunction, most likely as a result of reduced or lost VZV-specific cell-mediated immunity. Complications include post-herpetic neuralgia, a potentially debilitating and chronic pain syndrome. Current treatment of herpes zoster and post-herpetic neuralgia involves antiviral agents and analgesics, and is associated with significant economic cost. Results from several clinical trials have determined that a live, attenuated VZV vaccine using the Oka/Merck strain (Zostavax) is safe, elevates VZV-specific cell-mediated immunity, and significantly reduces the incidence of herpes zoster and post-herpetic neuralgia in people over 60 years of age. Regulatory approval has recently been obtained and once launched, it is expected that this vaccine will significantly reduce the morbidity and financial costs associated with herpes zoster. Durability of vaccine response and possible booster vaccination will still need to be determined.

Examination of links between herpes zoster incidence and childhood varicella vaccination

BACKGROUND

Introduction of a universal varicella vaccine program for U.S. children in 1996 sparked concern that less-frequent exposure to varicella would decrease external boosting of immunity to varicella zoster virus and thereby increase incidence of herpes zoster (HZ).

OBJECTIVE

To determine whether the varicella vaccination program has influenced trends in HZ incidence in the U.S. population older than 65 years.

DESIGN

Retrospective study of Medicare claims.

SETTING

Medicare, 1992 through 2010.

PARTICIPANTS

2 848 765 beneficiaries older than 65 years.

MEASUREMENTS

Annual HZ incidence from 1992 through 2010; rate ratios (RRs) for HZ incidence by age, sex, and race or ethnicity; and state-level varicella vaccination coverage.

RESULTS

281 317 incident cases of HZ occurred. Age- and sex-standardized HZ incidence increased 39% from 10.0 per 1000 person-years in 1992 to 13.9 per 1000 person-years in 2010 with no evidence of a statistically significant change in the rate of increase after introduction of the varicella vaccination program. Before introduction of this program, HZ incidence was higher in women (RR, 1.21 [95% CI, 1.19 to 1.24]) than men and was lower in black persons (RR, 0.51 [CI, 0.48 to 0.53]) and Hispanic persons (RR, 0.76 [CI, 0.72 to 0.81]) than white persons. In a model adjusted for sex, age, and calendar year from 1997 to 2010, HZ incidence did not vary by state varicella vaccination coverage (RR, 0.9998 [CI, 0.9993 to 1.0003]).

LIMITATION

Uncertain level and consistency of health-seeking behavior and access and uncertain accuracy of disease coding.

CONCLUSION

Age-specific HZ incidence increased in the U.S. population older than 65 years even before implementation of the childhood varicella vaccination program. Introduction and widespread use of the vaccine did not seem to affect this increase. This information is reassuring for countries considering universal varicella vaccination.

PRIMARY FUNDING SOURCE

None.

Measuring the burden of herpes zoster and post herpetic neuralgia within primary care in rural Crete, Greece

Background

Research has indicated that general practitioners (GPs) have good clinical judgment in regards to diagnosing and managing herpes zoster (HZ) within clinical practice in a country with limited resources for primary care and general practice. The objective of the current study was to assess the burden of HZ and post herpetic neuralgia (PHN) within rural general practices in Crete, Greece.

Methods

The current study took place within a rural setting in Crete, Greece during the period of November 2007 to November 2009 within the catchment area in which the Cretan Rural Practice-based Research Network is operating. In total 19 GP's from 14 health care units in rural Crete were invited to participate, covering a total turnover patient population of approximately 25, 000 subjects. For the purpose of this study an electronic record database was constructed and used as the main tool for monitoring HZ and PHN incidence. Stress related data was also collected with the use of the Short Anxiety Screening Test (SAST).

Results

The crude incidence rate of HZ was 1.4/1000 patients/year throughout the entire network of health centers and satellite practices, while among satellite practices alone it was calculated at 1.3/1000 patients/year. Additionally, the standardised incidence density within satellite practices was calculated at 1.6/1000 patients/year. In regards to the stress associated with HZ and PHN, the latter were found to have lower levels of anxiety, as assessed through the SAST score (17.4 ± 3.9 vs. 21.1 ± 5.7; p = 0.029).

Conclusions

The implementation of an electronic surveillance system was feasible so as to measure the burden of HZ and PHN within the rural general practice setting in Crete.

The influence of population characteristics on variation in general practice based morbidity estimations

Background

General practice based registration networks (GPRNs) provide information on morbidity rates in the population. Morbidity rate estimates from different GPRNs, however, reveal considerable, unexplained differences. We studied the range and variation in morbidity estimates, as well as the extent to which the differences in morbidity rates between general practices and networks change if socio-demographic characteristics of the listed patient populations are taken into account.

Methods

The variation in incidence and prevalence rates of thirteen diseases among six Dutch GPRNs and the influence of age, gender, socio economic status (SES), urbanization level, and ethnicity are analyzed using multilevel logistic regression analysis. Results are expressed in median odds ratios (MOR).

Results

We observed large differences in morbidity rate estimates both on the level of general practices as on the level of networks. The differences in SES, urbanization level and ethnicity distribution among the networks' practice populations are substantial. The variation in morbidity rate estimates among networks did not decrease after adjusting for these socio-demographic characteristics.

Conclusion

Socio-demographic characteristics of populations do not explain the differences in morbidity estimations among GPRNs.

Comparing shingles incidence and complication rates from medical record review and administrative database estimates: how close are they?

Accurate rates of herpes zoster incidence and complication have become of greater interest as studies have suggested an increasing temporal trend in incidence rates across all age groups and long-term follow-up studies of vaccine effectiveness are required by the Food and Drug Administration. This study compares the results obtained from the most commonly used method to obtain herpes zoster data (rates obtained from administrative data) with results obtained when administrative data are supplemented by medical record review. Administrative billing code data identified 1,959 cases of herpes zoster in Olmsted County, Minnesota, adults between January 1, 1996, and December 31, 2001. Of those 1,959 cases, 1,669 (85.2%) could be confirmed by medical record review, a decrease in incidence rate of 14.8%, resulting in a decrease of 0.61/1,000 person-years when adjusted to the US adult population. Complication rates were also significantly different between the 2 methods. It is not clear if the 15% decrease in incidence rates would be seen in every administrative data set or if the lack of confirmation of cases may be variable in both validity and reproducibility between data sets, making estimations in temporal trends and pre/post-vaccine rates difficult to compare across data resources.

Declining rates of suicidal behavior among general practice patients in Belgium: results from sentinel surveillance between 1993 and 2008

The aim of this study was (1) to estimate the incidence of suicidal behavior, i.e., suicide and suicide attempts, among Belgian general practice patients in 2007-2008 and to estimate trends since previous surveillance periods, i.e., 1991-1993 and 2000-2001; and (2) to investigate characteristics of actors, acts, and first care delivery. Data were collected by the national network of sentinel general practitioners, recording all suicidal behavior they were confronted with in their daily practice in the three periods. In 2007-2008 incidence rates of both suicide and suicide attempts had declined compared to the previous periods while the use of violent versus non-violent suicidal methods remained unchanged. GP involvement in first care after suicidal behavior declined over time from 71% to 39% in the largest part of the population, i.e., younger and adult persons. The last surveillance of suicidal behavior by the Belgian sentinel network of GPs most likely resulted in an underestimation, probably as a result of a declining role of GPs in delivery of first care to patients following suicidal behavior.

A literature review regarding the management of varicella-zoster virus

Chickenpox and shingles (varicella-zoster virus [VZV]) pose a threat to individuals who are immunosuppressed and/or have rheumatoid arthritis or another inflammatory musculoskeletal condition. In this paper we present a literature review of the condition, management and prevention.

What factors explain the differences in morbidity estimations among general practice registration networks in the Netherlands? A first analysis

BACKGROUND

Information on the incidence and prevalence of diseases is a core indicator for public health. There are several ways to estimate morbidity in a population (e.g., surveys, healthcare registers). In this paper, we focus on one particular source: general practice based registers. Dutch general practice is a potentially valid source because nearly all non-institutionalized inhabitants are registered with a general practitioner (GP), and the GP fulfils the role as "gatekeeper". However, there are some unexplained differences among morbidity estimations calculated from the data of various general practice registration networks (GPRNs).

OBJECTIVE

To describe and categorize factors that may explain the differences in morbidity rates from different GPRNs, and to provide an overview of these factors in Dutch GPRNs.

RESULTS

Four categories of factors are distinguished: "healthcare system", "methodological characteristics", "general practitioner", and "patient". The overview of 11 Dutch GPRNs reveals considerable differences in factors.

CONCLUSION

Differences in morbidity estimation depend on factors in the four categories. Most attention is dedicated to the factors in the "methodology characteristics" category, mainly because these factors can be directly influenced by the GPRN.

Herpes zoster burden of illness and health care resource utilisation in the Australian population aged 50 years and older

Incidence of zoster and post-herpetic neuralgia (PHN) and associated health care resource utilisation were investigated in the Australian population aged > or =50 years, using general practice data from 2000 to 2006, and pharmaceutical prescribing, hospital morbidity and emergency department data from 1998 to 2005. Zoster and PHN incidence rates were estimated as approximately 10/1000 and 1.45/1000 persons, respectively, with antivirals prescribed for 73.5% of zoster cases. Estimated hospitalisation and emergency department visit rates were 0.67/1000 and 0.38/1000 persons, respectively. Management of zoster (including PHN) involved approximately 2.4 general practitioner consultations. Total costs to the health care system were estimated as approximately 32.8 million per year. The substantial burden of zoster and PHN highlights the potential benefit of zoster vaccination.

Gender as an independent risk factor for herpes zoster: a population-based prospective study

PURPOSE

Several studies reported a difference in herpes zoster (HZ) incidence between males and females, but limitations in design and analysis impeded the assessment of gender as an independent risk factor for HZ. This study examines the independent etiologic association between gender and HZ.

METHODS

A total of 335,714 persons were observed prospectively during 2001. We registered gender and HZ occurrence, as well as other risk factors for HZ. We calculated overall crude and adjusted odds ratios (ORs) and stratified to age.

RESULTS

The HZ incidence in females was 3.9/1000 patients/year (95% confidence interval [CI], 3.6-4.2), and in males, 2.5/1000 patients/year (95% CI, 2.3-2.8), with a crude OR of 1.53 (95% CI, 1.36-1.74). After adjustment for potential confounders, the adjusted OR was 1.38 (95% CI, 1.22-1.56). The incidence was greater in females in the middle-aged (age, 25 to 64 years; OR range, 1.36 to 1.83) and youngest group (OR, 1.31; 95% CI, 0.90-1.89). Gender effect was inverse in young adults (age, 15 to 24 years; OR, 0.64; 95% CI, 0.41-1.03).

CONCLUSION

Female gender is an independent risk factor for HZ in the 25- to 64-year-old age groups.