Similar Herpes Zoster Incidence Across Europe
Similar Herpes Zoster Incidence Across Europe
The Medline search identified 1 644 articles, of which 1 563 were immediately excluded based on their abstracts. A review of the reference lists of the 81 remaining articles identified 23 additional articles, making a total of 104. Of these, 77 were excluded due to the inclusion and exclusion criteria: four hospital-based studies, six cost-effectiveness studies (some epidemiological data, but obtained or derived from several community-based studies), 34 general reviews, 18 studies in countries not included in this review, and 15 with no exploitable incidence data or that lacked information on the quality criteria necessary to score the publication.
The 27 remaining articles that corresponded to the inclusion criteria were scored using the reading grid. After the reading grid was applied, six of the 27 studies were further excluded as they did not meet the threshold for inclusion (i.e., 15 points). Therefore, 21 articles were finally included in this review (Figure 1).
(Enlarge Image)
Figure 1.
Flowchart representing the selection process. PC, prostate cancer; RR, relative risk.
The 21 reports of HZ incidence from European countries included one from Belgium, four from France, two from Germany, two from Iceland, two from Italy, three from the Netherlands, two from Spain, one from Switzerland, and four from the UK (Table 1). No relevant data were found for the other 21 countries considered in this review (Austria, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Ireland, Latvia, Lithuania, Luxembourg, Malta, Poland, Portugal, Romania, Slovenia, Slovakia, Sweden and Norway).
Table 1 shows the main features of the included studies and HZ incidence by country. Annual HZ incidence varied by country from 2.0 to 4.57 per 1 000 person-years (PY). The HZ incidence rates in the studies with a score inferior to 15 were in the same range (from 3.2 and 4.14 per 1000 person-years). The overall incidence was lower in Iceland, Germany and Switzerland (around 2/1 000 PY), medium in the UK, the Netherlands and France (around 3/1 000 PY), and higher in Belgium, Spain and Italy (around 4/1 000 PY) (Table 1). However, no geographic trend of overall incidence was clearly observed (Figure 2).
(Enlarge Image)
Figure 2.
Overall annual herpes zoster (HZ) incidence rates in Europe (/1 000 person-years). Notes: The confidence interval is presented when available in the original publication. In case of several publications per country, the publication with the most recent data and that reported the overall HZ incidence rate is depicted.
It was estimated that in England and Wales alone there are approximately 225 000 new cases of HZ each year. In 2009, the French sentinel network estimated that there were around 350 000 cases of HZ across all age groups. Another study performed in France reported around 182 500 incident cases among immunocompetent people aged 50 years or over.
Using the nine most recent studies, which had the highest quality score for their country and were performed without age criteria, we estimated an average HZ incidence rate of 3.4 ± 0.2/1 000 for all age groups combined. If this is applied to the total European population of 512 million inhabitants, a rough estimate of 1.7 ± 0.1 million new HZ cases can be expected each year in Europe.
Eleven publications from seven countries presented both overall and specific incidence rates by sex and/or by age group (See Additional file 1). In spite of the age groups, which differed from one study to another, age-specific HZ incidence rates appeared to hold steady during the review period at around 1/1 000 children <10 years, around 2/1 000 adults aged < 40 years, around 1–4/1 000 adults aged 40–50 years, and then increased rapidly after 50 years to around 7–8/1 000, up to 10/1 000 at 80 years of age and older (Figure 3). Figure 3 illustrates that in many countries in Europe, HZ incidence increases with age, and quite steeply so after 50 years of age. In all studies included in this review, incidence rates were consistently higher among women than men (male/female ratio range: 1.13–1.56), and this difference also increased with age.
(Enlarge Image)
Figure 3.
Herpes zoster incidence by age in Europe. Note: These studies were the most recent with available HZ incidence data by age group per country.
Studies performed among immunocompetent people and among the general population (including both immunocompetent and immunocompromised people), showed that the risk of HZ was higher in the general population (9.80/1 000 in Germany and 4.31/1 000 in Italy) than among immunocompetent people (9.50/1 000 (Germany) and 4.07/1 000 (Italy)).
Results
The Medline search identified 1 644 articles, of which 1 563 were immediately excluded based on their abstracts. A review of the reference lists of the 81 remaining articles identified 23 additional articles, making a total of 104. Of these, 77 were excluded due to the inclusion and exclusion criteria: four hospital-based studies, six cost-effectiveness studies (some epidemiological data, but obtained or derived from several community-based studies), 34 general reviews, 18 studies in countries not included in this review, and 15 with no exploitable incidence data or that lacked information on the quality criteria necessary to score the publication.
The 27 remaining articles that corresponded to the inclusion criteria were scored using the reading grid. After the reading grid was applied, six of the 27 studies were further excluded as they did not meet the threshold for inclusion (i.e., 15 points). Therefore, 21 articles were finally included in this review (Figure 1).
(Enlarge Image)
Figure 1.
Flowchart representing the selection process. PC, prostate cancer; RR, relative risk.
The 21 reports of HZ incidence from European countries included one from Belgium, four from France, two from Germany, two from Iceland, two from Italy, three from the Netherlands, two from Spain, one from Switzerland, and four from the UK (Table 1). No relevant data were found for the other 21 countries considered in this review (Austria, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Ireland, Latvia, Lithuania, Luxembourg, Malta, Poland, Portugal, Romania, Slovenia, Slovakia, Sweden and Norway).
Table 1 shows the main features of the included studies and HZ incidence by country. Annual HZ incidence varied by country from 2.0 to 4.57 per 1 000 person-years (PY). The HZ incidence rates in the studies with a score inferior to 15 were in the same range (from 3.2 and 4.14 per 1000 person-years). The overall incidence was lower in Iceland, Germany and Switzerland (around 2/1 000 PY), medium in the UK, the Netherlands and France (around 3/1 000 PY), and higher in Belgium, Spain and Italy (around 4/1 000 PY) (Table 1). However, no geographic trend of overall incidence was clearly observed (Figure 2).
(Enlarge Image)
Figure 2.
Overall annual herpes zoster (HZ) incidence rates in Europe (/1 000 person-years). Notes: The confidence interval is presented when available in the original publication. In case of several publications per country, the publication with the most recent data and that reported the overall HZ incidence rate is depicted.
It was estimated that in England and Wales alone there are approximately 225 000 new cases of HZ each year. In 2009, the French sentinel network estimated that there were around 350 000 cases of HZ across all age groups. Another study performed in France reported around 182 500 incident cases among immunocompetent people aged 50 years or over.
Using the nine most recent studies, which had the highest quality score for their country and were performed without age criteria, we estimated an average HZ incidence rate of 3.4 ± 0.2/1 000 for all age groups combined. If this is applied to the total European population of 512 million inhabitants, a rough estimate of 1.7 ± 0.1 million new HZ cases can be expected each year in Europe.
Eleven publications from seven countries presented both overall and specific incidence rates by sex and/or by age group (See Additional file 1). In spite of the age groups, which differed from one study to another, age-specific HZ incidence rates appeared to hold steady during the review period at around 1/1 000 children <10 years, around 2/1 000 adults aged < 40 years, around 1–4/1 000 adults aged 40–50 years, and then increased rapidly after 50 years to around 7–8/1 000, up to 10/1 000 at 80 years of age and older (Figure 3). Figure 3 illustrates that in many countries in Europe, HZ incidence increases with age, and quite steeply so after 50 years of age. In all studies included in this review, incidence rates were consistently higher among women than men (male/female ratio range: 1.13–1.56), and this difference also increased with age.
(Enlarge Image)
Figure 3.
Herpes zoster incidence by age in Europe. Note: These studies were the most recent with available HZ incidence data by age group per country.
Studies performed among immunocompetent people and among the general population (including both immunocompetent and immunocompromised people), showed that the risk of HZ was higher in the general population (9.80/1 000 in Germany and 4.31/1 000 in Italy) than among immunocompetent people (9.50/1 000 (Germany) and 4.07/1 000 (Italy)).
