Epidemiology of severe varicella-zoster virus infection in Spain

Data of hospitalizations for varicella and herpes zoster in Spain during the 1999-2000 period were obtained from the national surveillance system for hospital data. A total of 3083 hospitalizations for varicella and 6324 for herpes zoster were identified, representing an annual incidence of 4.1 and 8.4 per 100,000 persons per year, respectively. Almost half of patients hospitalized for varicella were children under 5 years of age. In contrast, 78% of hospitalizations for zoster occurred in adults >50 years of age. Hospitalizations for varicella and herpes zoster resulted annually in 11,141 and 40,090 days of hospitalization and a cost of 3.2 and 7.0 million, respectively.     

某高校一起带状疱疹病例引起水痘疫情的调查报告

目的 了解苏州某高校一起带状疱疹病例引起水痘疫情的调查处置情况,分析疫情发生原因及控制效果,为高校传染病疫情防控提供参考经验。方法 建立带状疱疹及水痘病例定义,查看学校缺课记录、医院就诊记录、传染病疫情报告网络系统等进行病例搜索,并逐一进行个案调查。采用描述性流行病学方法分析疫情流行病学特征及传播过程。结果 本次疫情共发生1名带状疱疹病例和4名水痘病例,班级罹患率分别为1.33 %（1/75）和5.33 %（4/75）,该班级的水痘-带状疱症病毒感染罹患率为6.67%(5/75)。疫情持续33 d,控制在一个班级内。病例均为男性,病例年龄在18～20岁之间,居住在同一个宿舍楼的两个房间。1名患者有明确水痘疫苗免疫史,水痘突破发病时间与免疫接种间隔18年。结论 该高校水痘疫情为由1名带状疱疹病例传播水痘-带状疱疹病毒引起。建议高校今后加强带状疱疹和水痘疾病监测和管理,提前采取干预措施,避免疫情扩散。     

Healthcare costs associated with varicella and herpes zoster in Norway

BackgroundNorway does not implement routine vaccination against varicella or herpes zoster. Despite substantial health burden associated with both diseases, their economic impact is not well described. The aim of the present study was to document the healthcare costs associated with both conditions in a Norwegian setting.MethodsWe used registry data about patients’ contacts with primary and specialized healthcare services from 2008 to 2014 to estimate the costs associated with varicella and herpes zoster in the primary and hospital care sector. We calculated the individual costs by treatment facility (general practitioner and emergency primary care clinic) in primary care and by treatment level (inpatient, outpatient or ambulatory treatment) at hospitals.ResultsWe estimate that the annual healthcare cost of patients with varicella and herpes zoster are NOK 85 million (approximately € 9 million). Of the annual costs, 73% are associated with herpes zoster and 27% are due to varicella. The majority (54%) of the total annual cost is represented by patients with herpes zoster treated in hospital.ConclusionVaricella and herpes zoster impose a substantial financial burden on the national healthcare services in Norway. Most of the costs are incurred by herpes zoster, which could be prevented by vaccination.     

The burden and cost of hospitalised varicella and zoster in Australian children

BACKGROUND: Economic analyses of varicella-zoster virus (VZV) immunisation are sensitive to the costs of hospitalised cases, so there is a need to validate VZV hospitalisation data. AIMS: To assess the accuracy of hospital VZV coding data and to apply these parameters to a population-based sample to estimate incidence and costs. METHODS: A 3-year retrospective chart review from one hospital to document clinical features and validate coding data. A separate 9-year analysis of discharge data from two hospitals draining a defined region of suburban Melbourne, with adjustment for miscoding and estimates of direct hospital costs. RESULTS: After correction for miscoding, 224 patients were admitted to one hospital over 3 years, 79% with varicella and 21% with zoster. Miscoding resulted in a 15% underestimate of zoster cases and a 4% overestimate of varicella cases. Thirty-six percent of varicella admissions compared to 80% of zoster admissions were immunocompromised and/or had chronic disease. Compared to otherwise-healthy patients, immunocompromised patients were admitted earlier in their illness and had lower complication rates. Forty-two percent of immunocompromised/chronic disease patients with varicella had a known exposure, usually from a family member. The incidence of hospitalised varicella and zoster in under 15-year olds was 15.7 and 1.8 per 100,000 per year, respectively. This suggests that there are 615 varicella hospitalisations and 72 zoster hospitalisations in this age group each year in Australia, at a total direct cost of over 2.2 million AU dollars. CONCLUSION: These results highlight the considerable burden of hospitalised zoster and the importance of immunising non-immune contacts of immunocompromised individuals. They also support previous estimates of the incidence of hospitalised varicella in Australian children and adolescents, although direct medical costs may be higher than those previously estimated.     

一起护理带状疱疹患者所致医务人员水痘暴发的调查与处理

目的 明确一起护理带状疱疹患者所致医务人员水痘暴发事件的流行病学特征，为水痘和带状疱疹的医院感染防控提供依据。方法 对山东省烟台市某三级医院2018年12月重症监护病房（ICU）内临床诊断为水痘的医务人员进行流行病学调查，分析流行病学特征及发病原因。结果 2018年12月17-19日，该院ICU共报告4名医务人员罹患水痘，其中有3名护士、1名护工，潜伏期内均看护过2床的带状疱疹患者，且距发病最长潜伏期内未接触过其他水痘和（或）发热出疹病例，判断为一起护理带状疱疹引起的医务人员医院感染暴发事件，通过积极采取隔离、接种疫苗、培训等措施，处置及时，未出现后续病例。结论 带状疱疹患者作为水痘的传染源不容忽视，治疗护理时严格执行空气隔离、接触隔离、标准预防等措施，可有效防控水痘-带状疱疹病毒医院感染的发生。     

The epidemiology of varicella and herpes zoster in The Netherlands: implications for varicella zoster virus vaccination

We studied the epidemiology of varicella (chickenpox) and herpes zoster (shingles) in The Netherlands to assess the desirability to implement routine varicella zoster virus vaccination in The Netherlands. Data on seroprevalence of varicella zoster virus in the general population (1995-1996), consultations of general practitioners for varicella (2000-2002) and herpes zoster (1998-2001) and hospital admissions due to varicella (1994-2001) and herpes zoster (1994-2001) in The Netherlands were analysed. The seropositivity increased sharply with age from 18.4% for both 0- and 1-year-olds, to 48.9%, 59.0%, 75.7% and 93.0% for 2-, 3-, 4- and 5-year-olds, respectively, and varied between 97.5% and 100% for older age groups. The average annual incidence of GP-consultations amounted to 253.5 and 325.0 per 100,000 for varicella and herpes zoster, respectively. The incidence of hospital admission due to varicella and herpes zoster was 1.3 (2.3 including side diagnosis) and 2.7 (5.8) per 100,000, respectively. Whilst for varicella, the incidence of GP-consultations and hospital admissions were highest in childhood, for herpes zoster, these were highest in elderly. Insight into epidemiology of varicella zoster is needed for the assessment of the desirability of introduction of routine varicella zoster vaccination.     

Descriptive epidemiology of varicella based on national surveillance data before and after the introduction of routine varicella vaccination with two doses in Japan, 2000–2017

Routine childhood immunization using two doses of the varicella vaccine was introduced in Japan in October 2014. In this study, we analyzed the data extracted from national varicella surveillance, including pediatric sentinel surveillance from 2000 to 2017 and hospitalized varicella surveillance from the 38th week of 2014 to the 37th week of 2017. Compared with the 2000–2011 baseline data, the number of varicella cases per sentinel decreased substantially by 76.6% overall and by 88.2% among children aged 1–4 years in 2017. Of 997 hospitalized patients, we found a decreasing trend in the number of cases among children aged <5 years. We also found a decreasing trend in the number of cases with complications among children aged 1–4 years. Data on the self-reported transmission sites in 35.5% (354/997) of the hospitalized varicella patients showed that transmission of varicella zoster virus (VZV) occurred frequently in household, at school for young children, in the workplace for adults, and at hospital for all age groups. Data from 29.0% (289/997) of the hospitalized patients with a self-reported source of infection showed that transmission of VZV occurred from a patient with herpes zoster (HZ) in 30.4% (88/289) of cases. Our data demonstrate a substantial decrease in the number of varicella cases in young children following introduction of routine childhood vaccination program with two-dose varicella vaccination in Japan. These data highlight the unique aspects of transmission sites across age groups and the important role of HZ cases in disease circulation.     

一起医务人员水痘暴发调查分析——一种少见的空气传播方式

 目的 调查分析一起医务人员医院感染水痘暴发事件,分析水痘-带状疱疹病毒医院传播的原因。方法 通过实地访谈、电话问询调查2020年10月5日—12月23日某院重症监护病房（ICU）医务人员人口统计学资料、水痘、带状疱疹相关流行病学史和疫苗接种史,并了解所有ICU住院患者水痘、带状疱疹发生情况及转归,分析其流行病学特征及传播途径。结果 2020年10月26日—12月2日,ICU共报告4例医务人员感染水痘,暴发持续时间为38 d。罹患者均为ICU护理人员,其中本科室护士2例,实习学生1例,轮转护士1例;一代病例1例,二代病例2例,三代病例1例,所有病例均否认其共同居住人员及近期生活中接触水痘或带状疱疹病例。ICU于9月28日—10月20日曾收治1例64岁老年女性带状疱疹后神经痛患者,收治时患者右腰部散在带状疱疹已结痂;首发病例曾在未佩戴手套情况下护理过该患者。在感染病例出疹前72 h使用休息室1的易感者水痘感染率为66.7%,使用休息室2的易感者均未发生感染。此次水痘暴发事件共造成直接经济损失2 725元。结论 首发病例可能是由于未佩戴手套情况下护理1例免疫功能不全的带状疱疹病例引起,续发病例可能是吸入感染病例使用休息室后呼吸道分泌物在室内形成较高浓度的病毒颗粒气溶胶引起的水痘暴发事件。     

一起护理带状疱疹患者所致医务人员水痘暴发的调查与处理

目的明确一起护理带状疱疹患者所致医务人员水痘暴发事件的流行病学特征,为水痘和带状疱疹的医院感染防控提供依据。方法对山东省烟台市某三级医院2018年12月重症监护病房(ICU)内临床诊断为水痘的医务人员进行流行病学调查,分析流行病学特征及发病原因。结果 2018年12月17—19日,该院ICU共报告4名医务人员罹患水痘,其中有3名护士、1名护工,潜伏期内均看护过2床的带状疱疹患者,且距发病最长潜伏期内未接触过其他水痘和(或)发热出疹病例,判断为一起护理带状疱疹引起的医务人员医院感染暴发事件,通过积极采取隔离、接种疫苗、培训等措施,处置及时,未出现后续病例。结论带状疱疹患者作为水痘的传染源不容忽视,治疗护理时严格执行空气隔离、接触隔离、标准预防等措施,可有效防控水痘-带状疱疹病毒医院感染的发生。     

Varicella and herpes zoster incidence prior to the introduction of systematic child vaccination in Navarre, 2005-2006

Varicella is an acute and highly contagious disease produced by the varicella-zoster virus, which leaves lasting immunity. Herpes zoster is produced by reactivation of a latent infection of the same virus. The introduction of systematic and free vaccination against varicella in children of 15 months in Navarre from 2007 onwards can be expected to produce important epidemiological changes. For this reason we describe the previous epidemiological situation in the period from 2005 to 2006. We analysed all cases of varicella and herpes zoster registered in the electronic clinical files of primary care, in the database of hospital discharges and in the mortality register. Between 2005 and 2006, 9,908 cases of varicella were diagnosed (8.29 annually per 1,000 inhabitants), with 90% in children under 15 years old. There were 80 hospital admissions (8 for every 1,000 cases), complications in 2.5 out of every 1,000 cases, and there was one death due to this cause (0.1 per 1,000 cases). In the same period, 4,959 cases of herpes zoster were diagnosed (4.15 cases per 1,000 inhabitants), half in people over 55 years old. There were 179 hospital admissions (36 per 1,000 cases), whose average age was 77, and 83 presented complications (16.7 per 1,000 cases). This epidemiological pattern is similar to that found in other places before the introduction of the vaccine.     

Varicella paediatric hospitalizations in Spain

Varicella is a very common childhood disease responsible for an important number of hospitalizations every year in Spain. The aim of this study was to assess the burden of chickenpox hospitalizations in Spain in the 7-year period between 1999 and 2005. Data of hospital discharges relating to varicella were obtained from the Conjunto Mínimo Básico de Datos (CMBD), the Spanish surveillance system for hospital data. All paediatric hospitalizations for primary varicella that occurred between 1 January 1999 and 31 December 2005 were selected. The hospitalization rate for the 7-year study period was 23.06 hospitalizations/100 000 population. The highest incidences of hospitalizations were observed in the youngest groups (60.79 and 55.65/100 000 population for ages 0-12 months and 1-2 years respectively). Nineteen deaths were reported during the study period. The median length of stay in hospital was 4 days (interquartile range 3-7 days). Despite the availability of effective varicella vaccines, chickenpox remains an important cause of hospitalizations in Spain.     

Development of varicella vaccine in Japan and future prospects

In Japan, Dr. Michiaki Takahashi (1928–2013) successfully developed the first live attenuated varicella vaccine in the world. The virus used for this vaccine was varicella-zoster virus isolated from the vesicular fluid of a child with typical varicella and it was named the Oka strain after the family name of the child. In 1974, a patient with nephrosis developed varicella in the Pediatric Ward, and uninfected pediatric patients received varicella vaccine immediately. As a result, there were no cases of varicella in the other children and all of the vaccinated children acquired immunity to the disease. These results were published in the Lancet, demonstrating the safety and efficacy of varicella Oka strain vaccine for the first time. When clinical studies were conducted at the start of vaccine development, most of the subjects were pediatric patients with a high risk of contracting severe varicella. Therefore, the development process was different from that for other vaccines, since clinical studies are generally performed in healthy individuals.This vaccine was approved in Japan in 1986, and voluntary single-dose vaccination for children aged 1 year or older was started in 1987. However, the vaccination coverage rate remained low and the number of patients with varicella did not decrease significantly. Due to its voluntary status, the cost of vaccination was borne by the child's family and this was considered to be a reason for the low coverage rate. Moreover, although the vaccine achieved a good antibody response, the number of cases of breakthrough varicella (BV) was relatively high and showed an increasing trend that was also a concern. In order to increase the coverage rate and reduce BV, the Japanese government changed the varicella vaccination policy from voluntary to routine vaccination in October 2014. At the same time, a two-dose schedule was introduced that involved administration of the vaccine twice at an interval of at least 3 months up to the age of 3 years.At present, cases of varicella are only monitored at the pediatric sentinel clinics in Japan. Therefore, we need to establish a system to survey all patients, in order to demonstrate the efficacy of varicella vaccine based on detailed surveillance data. We also need to investigate the optimum timing of the second dose of the vaccine and the necessity for further booster vaccination. A combined live vaccine containing varicella vaccine has not yet been approved in Japan. Because of the greater convenience of combined vaccines, development and introduction of such a vaccine in the future would be desirable. Routine varicella vaccination is also expected to eventually reduce the occurrence of herpes zoster, although there are no supporting epidemiological data. The prevalence of herpes zoster has attracted attention, but it is necessary to develop a surveillance system for this disease. In March 2016, use of varicella vaccine to prevent herpes zoster in adults aged 50 years or older was approved in Japan, and the results of this policy change need to be assessed.     

Population-based incidence of herpes zoster after introduction of a publicly funded varicella vaccination program

Background

Past varicella infection (chicken pox) may reactivate into herpes zoster (shingles). Varicella vaccination leads to a reduction in cases of varicella that may in turn increase herpes zoster rates due to reduction in the immune boosting effect of exposure to varicella zoster virus against varicella reactivation. We assessed the impact of childhood varicella vaccination in Ontario, Canada on zoster incidence and healthcare visits, and established baseline zoster rates prior to zoster vaccine introduction.

Methods

We used population-based, administrative databases to identify zoster incidence and healthcare use from April 1992 to March 2010.

Results

After routine varicella vaccination, zoster incidence rates decreased 29% for children aged 0-9 and changed minimally for other ages. Age-standardized rates of hospitalizations during the study period declined by 53%, while outpatient rates declined by 9%. The annual zoster incidence for those 60 or older was 740 per 100,000.

Conclusions

In the early post-varicella vaccination period, incidence rates of medically attended herpes zoster did not increase for the overall population and decreased moderately for children 9 years and younger, the age group targeted for varicella vaccination.     

Early impact of universal varicella vaccination on childhood varicella and herpes zoster hospitalizations in Brazil

IntroductionThe Brazilian childhood National Immunization Program (NIP) introduced live and attenuated varicella vaccination in a single dose, combined as tetraviral vaccine, at 15 months of age in the whole country, during September to December of 2013. The aim of this study was to report trends in incidence of childhood hospital admissions related to varicella and zoster in Brazil from 2003 to 2016, including the first three years after vaccine introduction.MethodsThe number and incidence of hospital admission in patients aged less than 20 years in Brazilian public health system with an admission diagnosis of varicella and zoster from 2003 to 2016 were analyzed and pre (2003–2013) and post-vaccination periods (2014–2016) were compared. The data were obtained from DATASUS, a Brazilian government’s open-access public health database system, and analyzed adjusting for secular trend and seasonality if a statistically significant change was found.ResultsDuring the study period, 69,791 admissions due to varicella and herpes zoster occurred in the children younger than 20 years. After adjusting for seasonality, the incidence of hospitalizations decreased from 27.33 to 14.33 per 100000 per year, which corresponds to a reduction of 47.6% (95% confidence interval 18.19–77.04%, p < 0.001) in the vaccinated age group (1–4 years) in 2014–2016 compared to pre-vaccination period. The changes were not significant in the unvaccinated age groups.ConclusionThe hospitalizations due to varicella and herpes zoster were decreased by half early after the introduction of a single dose of tetraviral vaccine in NIP in the vaccinated children. Further studies may assess duration and intensity of this effect, as well as the indirect effect in the unvaccinated age groups.     

Herpes zoster in the context of varicella vaccination – An equation with several variables

BackgroundVaricella and herpes zoster (HZ), diseases both caused by the varicella zoster virus (VZV), are vaccine-preventable. However, the hypothesis that childhood varicella vaccination may increase the incidence of HZ hinders varicella universal routine vaccination (URV) implementation in many countries.MethodsThis non-systematic and narrative review of the literature considers the burden of varicella and HZ, and the effectiveness of the respective vaccines. We present the factors involved in the interplay between varicella vaccination and HZ incidence, including the roles of exogenous and endogenous boosting. We review HZ incidence model predictions, and compare these with real-world evidence, which has accumulated since varicella URV was introduced.ConclusionAlthough more research and longer surveillance are needed, available real-world evidence has not confirmed the model-predicted increase in HZ incidence, associated with childhood varicella URV. Although there is a rising incidence of HZ globally, this trend appears to be predominantly the result of an aging population. Vaccination against varicella in childhood provides significant benefits with respect to the medical, societal and economic burdens of the disease. Therefore, a theoretical concern of an increased burden of HZ with varicella vaccination programs should not prevent children from being protected against the disease.     

Die Varizellenimpfung in Deutschland

In 2004, a general varicella immunization was introduced in Germany for infants from the age of 11 months, followed by the subsequent recommendation in 2009 of a second vaccine dose. The vaccination is carried out at the same time as the immunization against measles, mumps, and rubella (MMR). Results of the nationwide sentinel surveillance of varicella and herpes zoster implemented by the Varicella Working Group (Arbeitsgemeinschaft Varizellen, AGV) show that the defined goals for varicella immunization (reduction of varicella-related morbidity, complications and hospitalizations) have been reached within a few years owing to the advances in vaccine coverage. Although coverage rates for varicella have not yet reached the same levels as for MMR, varicella immunization seems to have benefited from the established MMR immunization schedule. Moreover, there is no evidence for an adverse effect on the use and acceptance of the MMR vaccine. Lessons learnt in measles epidemiology (such as trends in the incidence of the disease in adolescents and infants), as well as in the history of MMR recommendations, may be useful for the evaluation of future epidemiological changes with respect to varicella and herpes zoster. In view of a rapidly waning immunity against the varicella zoster virus after vaccination with one dose and the lifelong persistence of the virus, achieving a robust and sustainable immunity in the general population seems to be an ambitious goal. However, this accomplishment will be indispensable in preventing breakthrough infections and a shift of varicella to older ages and in avoiding an increase in herpes zoster incidence.     

The Nature of Herpes Zoster: A Long-term Study and a New Hypothesis

Dr Hope-Simpson presents a study of all cases of herpes zoster occurring in his general practice during a sixteen-year period. The rate was 3·4 per thousand per annum, rising with age, and the distribution of lesions reflected that of the varicella rash.

It was found that severity increased with age, but that the condition did not occur in epidemics, and that there was no characteristic seasonal variation. A low prevalence of varicella was usually associated with a high incidence of zoster.

Dr Hope-Simpson suggests that herpes zoster is a spontaneous manifestation of varicella infection. Following the primary infection (chickenpox), virus becomes latent in the sensory ganglia, where it can be reactivated from time to time (herpes zoster). Herpes zoster then represents an adaptation enabling varicella virus to survive for long periods, even without a continuous supply of persons susceptible to chickenpox.

     

Trends in U.S. Community hospitalizations due to herpes zoster: 2001–2015

Background

In 2007, based on decisions by the U.S. Advisory Committee on Immunization Practices, the CDC recommended a booster dose at 4–6?years in the varicella vaccine schedule. In 2008, a herpes zoster vaccine was recommended for use in persons age ≥60?years. The purpose of this study was to examine trends in herpes zoster hospitalization rates and assess the impact of both policy recommendations using U.S. hospital discharge data.

Epidemiology of primary varicella hospitalizations in Spain.

An approach to the burden of varicella can be obtained from information on the hospitalizations. Data were obtained from the national surveillance system for hospital data. All hospital discharges for varicella were analyzed for the 1995-1998 period. A total of 3632 primary varicella-related discharges were identified, representing an annual incidence of 2.8 per 100,000 population. A total of 58% of cases were <10 years of age and 33% were 21-50 years old. Each year primary varicella will be responsible for 6174 days of hospitalization, representing an annual cost of 1.6 million euros. There is substantial severe morbidity each year from varicella that, to reduce, would require vaccination of infants and susceptible adults.     

Impacts of routine varicella vaccination program and COVID-19 pandemic on varicella and herpes zoster incidence and health resource use among children in Japan

PurposeTo determine the epidemiological trends in pediatric varicella and herpes zoster incidence and changes in healthcare resource use from 2005 to 2022 using a nationally representative database in Japan.Materials and methodsWe conducted a retrospective observational study consisting of 3.5 million children with 177 million person-months during 2005–2022 using Japan Medical Data Center (JMDC) claims database in Japan. We investigated trends in incidence rates of varicella and herpes zoster and changes in healthcare resource use (e.g., antiviral use, office visits, and healthcare costs) over 18 years. Interrupted time-series analyses were used to investigate the impact of the routine varicella vaccination program in 2014 and infection prevention measures against COVID-19 on incidence rates of varicella and herpes zoster and related healthcare utilization.ResultsAfter the introduction of the routine immunization program in 2014, we observed level changes in incidence rates (45.6 % reduction [95 %CI, 32.9–56.0] of varicella cases, antiviral use (40.9 % reduction [95 %CI, 25.1–53.3]), and relevant healthcare costs (48.7 % reduction [95 %CI, 38.2–57.3]). Furthermore, infection prevention measures against COVID-19 were associated with additional level changes in varicella rates (57.2 % reduction [95 %CI, 44.5–67.1]), antiviral use (65.7 % reduction [59.7–70.8]), and healthcare costs (49.1 % [95 %CI, 32.7–61.6]). In contrast, the changes in incidence and healthcare costs for herpes zoster were relatively small, which showed 9.4 % elevated level change with a decreasing trend and 8.7 % reduced level change with a decreasing trend after the vaccine program and the COVID-19 pandemic. The cumulative incidence of herpes zoster in children born after 2014 was lower than that before 2014.ConclusionsVaricella incidence and healthcare resource use were largely affected by the routine immunization program and infection prevention measures against COVID-19, while these impacts on herpes zoster were relatively small. Our study indicates that immunization and infection prevention measures largely changed pediatric infectious disease practices.