Temporal trends in incidence rates of herpes zoster among patients treated in primary care centers in Madrid (Spain), 2005–2012
Introduction
Herpes zoster (HZ) results from the reactivation of latent varicella zoster virus (VZV). The triggers for reactivation of VZV have not been identified and probably involve multiple factors. However, specific components of cell-mediated immunity (CMI) have an important role in controlling the development of zoster by preventing reactivation within the neuron or the full clinical expression of reactivated VZV as zoster. The effectiveness of these protective components of CMI is well maintained in immunocompetent persons during childhood and early adulthood. These CMI components are believed to be partially or substantially maintained by periodic immunologic boosting.1
A recent literature review of population-based studies of HZ incidence in Europe published between 1960 and 2010, showed similar HZ incidence across the included countries for which data was available.2 Overall annual incidence varied from 2.0 to 4.6/1000 person-years depending on the country,2 which is consistent with previous published estimates.3 The lifetime risk of zoster is estimated to be 10–30% and incidence increases markedly with age, affecting up to 50% of people who live to 85 years.4, 5 The risk approximately doubles for each decade after 50 years of age.6 This age-related increase in HZ is due to a varicella zoster virus-specific decline in CMI with increasing age.7 About 5–18% of persons with HZ develop post-herpetic neuralgia, a disabling pain syndrome that can last months or even years with no consistently effective treatments.8, 9, 10 HZ imposes a significant burden of hospitalizations and results in large cost expenses, especially in population older than 50 years of age, with an annual hospitalization rate of 10.0 per 100,000 habitants and an average cost per hospitalization of more than 3500 €.11, 12
It has been speculated that a universal varicella vaccination program might alter the epidemiology of HZ due to the expected decline of the boosting of CMI caused by the reduced varicella circulation.13 The mechanism of exogenous boosting exists, although not for all persons, nor in all situations.14 Studies modeling the impact of a varicella vaccination program have predicted that cases of zoster may significantly increase in the first 50 years following vaccination.15, 16, 17 However, other model-based evaluations show that, after varicella immunization, an increase of HZ incidence is not a certainty. Rather, it depends on the presence or absence of factors promoting a strong boosting intensity, which may or may not be heavily affected by changes in varicella circulation due to mass immunization.18 In 2006 the Madrid Autonomous Region included universal varicella vaccination in its systematic vaccination schedule for children aged 15 months.19
The objectives of this study were to estimate total and age-specific incidence rates of herpes zoster on the basis of data drawn from electronic clinical records in primary care (ECRPC), and to analyze their temporal trends by sex and age.
Section snippets
Materials and methods
We performed a descriptive cross-sectional study covering all the HZ episodes registered in the ECRPC of the Madrid Regional Public Health System (MRPHS) for the period 2005–2012.
The target study population was defined as all persons included in the MRPHS, and therefore registered in the Individualized Health Card (IHC) database, from 1st January 2005 to 31st December 2012. IHC coverage was close to 95% of the population.
Health care data were drawn from ECRPC, implemented for 99% of primary
Results
Between 2005 and 2012, a total of 211,650 episodes of HZ were attended and registered in ECRPC in the Madrid Autonomous Region (Table 1). Of those, 60.6% were in women, and 52.2% were in patients older than 55 years old (n = 110,398). The mean age was higher in women (53.9 -SD 22.0- vs. 49.2 -SD 23.0-, p < 0.001). The distribution of these characteristics remained stable throughout the study period, with an increasing number of episodes over time.
The incidence rate of episodes of herpes zoster
Discussion
This study shows that HZ cases have been increasing, with a significant rise in annual incidence rates in Madrid from 2005 to 2012. This growing trend affected both sexes from age 14. This is the first study in our country to analyze temporal trends of herpes zoster attended in primary care using population-wide information. The large volume of data allows a detailed analysis of trends by age and sex.
More than a half of HZ episodes occurred in women and in people of 55 years and older.
Conclusions
The incidence of herpes zoster treated in primary care presents a clear upward trend in the period 2005–2012, especially in adults and the elderly. Women and the elderly are the most vulnerable to this disease. Data from ECRPC seem to be a valuable source of information for the surveillance of herpes zoster. Monitoring the incidence rates, and especially the age-specific rates, will help to detect future changes in HZ trends. It will be necessary to deepen the knowledge of other risk factors to
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Incidence of herpes zoster and its complications in ≥ 50-year-old Spanish adults: A prospective cohort study
2022, VacunasCitation Excerpt :In Spain, epidemiologic data on the incidence and burden of HZ (and PHN) are, until recently, quite limited. Existing data includes retrospective analyses of databases and case records from regional or municipal health systems.6,10–16 A comprehensive retrospective analysis of primary care records for the period 2009–2014 in the Valencia region, evaluating the risk of HZ in patients with/without chronic obstructive pulmonary disease (COPD) reported an IR of 7.2/1,000 PY in patients aged ≥ 50 years (without COPD).16
Ultraviolet Radiation Exposure and the Risk of Herpes Zoster in Three Prospective Cohort Studies
2020, Mayo Clinic ProceedingsPrevaccination epidemiology of herpes zoster in Denmark: Quantification of occurrence and risk factors
2017, VaccineCitation Excerpt :The rate was higher for women than men at all ages (Fig. S2). The age-specific HZ rate estimated by our algorithm is consistent with (although in the lower range of) rates reported by previous European studies (Fig. 3) [11–20]. The hospitalization rate is in the mid-range of the rates reported in other countries (Fig. S3) [14,16,21–28].
Zoster Vaccines
2017, Plotkin's VaccinesSeroprevalence of varicella-zoster virus antibodies after the recent introduction of the universal childhood immunisation schedule in the Community of Madrid
2016, Enfermedades Infecciosas y Microbiologia ClinicaCharacteristics of herpes zoster-associated hospitalizations in Madrid (SPAIN) before vaccine availability
2016, Journal of InfectionCitation Excerpt :Differences in rates could be related to different vaccination schedules against varicella as well as to the clinical and therapeutic management of the disease and the coding habits. Female gender has been identified as an independent risk factor for HZ,25 and in our region, the rates of HZ in primary care are higher among women.3,16 Nevertheless, the global rates of hospitalization were similar when considering to entire population and higher among men when considering episodes of HZ in primary care.