Varicella-zoster Virus Seroprevalence Research Articles

The association between antibodies to neurotropic pathogens and schizophrenia: a case-control study.

Background:Exposure to neurotropic pathogens has been proposed as an environmental risk factor for schizophrenia and can be evaluated by measuring pathogen-specific immunoglobulin G (IgG). Seroprevalence of pathogen-specific IgG reflects prior exposure, whereas IgG levels are associated with reactivity or reinfection. Several studies have examined these parameters in schizophrenia. However, results still remain inconclusive, as several previous studies did not correct for important confounding factors.Aims:To investigate whether schizophrenia is associated with prior exposure to neurotropic pathogens, or with their reactivation.Methods:We examined the seroprevalence and titer of IgG antibodies against herpes simplex virus-1 and -2 (HSV-1/HSV-2), varicella zoster virus (VZV), Epstein–Barr virus (EBV), cytomegalovirus (CMV), and Toxoplasma gondii (TG) in plasma of 368 adult patients with a schizophrenia spectrum disorder and 282 controls using ELISA.Results:We did not find evidence for an increased exposure to HSV-1, HSV-2, EBV, and TG in patients. There was a significantly higher seroprevalence of VZV (98.9% vs. 95.6%, P<0.05) and CMV (40.4% vs. 27.7%, P<0.001) in controls as compared with patients, which did not remain statistically significant after adjustment for various potential confounders. We did not find significant differences in antibody titers of seropositive patients and controls for any of the six pathogens.Conclusions:Our results do not support the hypothesis that increased exposure to neurotropic pathogens after birth is associated with schizophrenia.

Seroepidemiology of varicella-zoster virus in Korean adolescents and adults using fluorescent antibody to membrane antigen test

We conducted a cross-sectional seroepidemiological study in 2012-2013 to determine the seroprevalence of varicella-zoster virus (VZV) in adolescents and adults living in Korea, where varicella vaccination has been recommended universally at age 12-15 months since 2005. Residual serum samples were collected from 1196 healthy adults and adolescents aged ⩾10 years between November 2012 and March 2013. The fluorescent antibody to membrane antigen (FAMA) test and enzyme-linked immunosorbent assay (ELISA) were performed to determine the seroprevalence of VZV. The seroprevalences of VZV were compared between six age groups: 10-19, 20-29, 30-39, 40-49, 50-59, and ⩾60 years. The seroprevalence of VZV in the entire study cohort was 99·1% according to the FAMA test and 93·1% as determined by ELISA. The seroprevalences of the six age groups were as follows: 96·0%, 99·5%, 99·5%, 99·5%, 100%, and 100%, respectively, by the FAMA test, and 83·3%, 93·0%, 93·0%, 97·5%, 94·5%, and 97·5%, respectively, by ELISA. Seroprevalence increased significantly with age (P < 0·001); moreover, the seroprevalence in subjects aged 10-19 years was significantly lower than in other age groups (P < 0·001), as measured by both the FAMA test and ELISA. Thus, strategies to increase protective immunity against VZV in teenagers are necessary.

Seroepidemiology of Varicella and value of self-reported history of Varicella infection in Iranian medical students

We conducted this study to assess the seroprevalence of Varicella zoster virus (VZV) antibodies in a group of Iranian medical sciences students that were at risk of Varicella and the value of self-reported history as a predictor of immunity. 255 medical, nursing and obstetrics students who had not entered as a student or worked in a hospital from 3 different schools were enrolled in the study in 2012 (Qazvin province, Iran). Demographics and other information as well as the history of Varicella were obtained through a self-administered questionnaire. Blood samples were collected to determine the Varicella IgG levels via an enzyme-linked immunosorbent assay. A statistical analysis was performed by calculating prevalences and their 95% confidence intervals. Sensitivity, specificity, positive and negative predictive values, Cohen's kappa and positive and negative likelihood ratios of recalled history were determined. p < 0.05 was considered statistically significant. The mean age of participants was 21.3 ± 4.3 years. Seropositivity rate was 74.5%. The relationships between marital status, number of family members, and acquired VZV history with immunity against the virus were statistically significant. The overall rate of reported history was 57%. The positive and negative predictive values of self-reported history of Varicella were 91% and 47.3%, respectively. Immunization of students of Iranian medical sciences seems logical in the near future. Also, they should be tested for Varicella immunity regardless of the history of previous infection.

Seroprevalence of Cytomegalovirus, Epstein Barr Virus and Varicella Zoster Virus among Pregnant Women in Bradford: A Cohort Study

ObjectiveTo estimate the seroprevalence of cytomegalovirus (CMV), Epstein Barr virus (EBV) and varicella zoster virus (VZV) among pregnant women in Bradford by ethnic group and country of birth.MethodsA stratified random sample of 949 pregnant women enrolled in the Born in Bradford birth cohort was selected to ensure sufficient numbers of White UK born women, Asian UK born women and Asian women born in Asia. Serum samples taken at 24-28 weeks’ gestation were tested for CMV IgG, EBV IgG and VZV IgG. Each woman completed a questionnaire which included socio-demographic information.ResultsCMV seroprevalence was 49% among the White British women, 89% among South Asian UK born women and 98% among South Asian women born in South Asia. These differences remained after adjusting for socio-demographic factors. In contrast, VZV seroprevalence was 95% among women born in the UK but significantly lower at 90% among South Asian women born in Asia. EBV seroprevalence was 94% overall and did not vary by ethnic group/country of birth. ConclusionsAlthough about half of White British women are at risk of primary CMV infection in pregnancy and the associated increased risk of congenital infection, most congenital CMV infections are likely to be in children born to South Asian women with non-primary infection during pregnancy. South Asian women born in South Asia are at risk of VZV infection during pregnancy which could produce congenital varicella syndrome or perinatal chickenpox. Differences in CMV and VZV seroprevalence by ethnic group and country of birth must be taken into account when universal immunisation against these viruses is contemplated.

Seroprevalence of Varicella-Zoster Virus in Five US-Bound Refugee Populations

Little is known about varicella-zoster virus (VZV) susceptibility in US-bound refugee populations, although published data suggest that VZV seroprevalence in these refugee populations may be lower than US populations. We describe VZV seroprevalence in five US-bound refugee groups: (1) Bhutanese in Nepal, (2) Burmese on the Thailand-Burma (Myanmar) border, (3) Burmese in Malaysia, (4) Iraqi in Jordan, and (5) Somali in Kenya. Sera were tested for presence of VZV IgG antibodies among adults aged 18-45 years. Overall VZV seroprevalence was 97% across all refugee groups. VZV seroprevalence was also high across all age groups, with seroprevalence ranging from 92-100% for 18-26 year-olds depending on refugee group and 93-100% for 27-45 year-olds. VZV seroprevalence was unexpectedly high in these five US-bound refugee groups, though may not reflect seroprevalence in other refugee groups. Additional studies are needed to better understand VZV seroprevalence in refugee populations over time and by region.

Seroprevalences of varicella-zoster virus, herpes simplex virus and cytomegalovirus in a cross-sectional study in Mexico

We estimated the seroprevalences of varicella-zoster virus (VZV), herpes simplex virus (HSV) and cytomegalovirus (CMV) in this cross-sectional database study. Serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1–70 years between January and October 2010. Serological assays for the determination of antibodies against VZV, HSV and CMV were performed. The overall seroprevalences of VZV, HSV-1, HSV-2 and CMV were 85.8%, 80.9%, 9.9% and 89.2%, respectively. Seroprevalences of VZV, HSV-1 and CMV were comparable between males and females. For HSV-2, although the seroprevalence rate was higher in females when compared to males, this difference in seroprevalence was not statistically significant. Seroprevalence rates for VZV, HSV-1, HSV-2 and CMV increased with age (p-value<.0001). Differences in seroprevalence rate for VZV by socioeconomic status (SES) were significant (p-value<0001). Results of the serological analyses reported high VZV seroprevalence, indicating high transmission in the Mexican population with children and adolescents at risk of acquiring VZV. Global HSV-1 seroprevalence was high, especially in adults. HSV-1 and HSV-2 seroprevalences were consistently higher in women than men, particularly for HSV-2. CMV seroprevalence was higher in Mexico when compared to developed countries. Seroepidemiological data on VZV supports the fact that varicella vaccination may serve as an alternative effective solution to reduce transmission in the Mexican population. For CMV and HSV, since no vaccines are available, activities to reduce transmission are important to reduce the risk of complications and therefore need to be considered.

Varicella zoster virus infection occurs at a relatively young age in the Netherlands

IntroductionTo date, there is no universal varicella vaccination in the Netherlands. We studied the seroprevalence of varicella zoster virus (VZV) specific antibodies and determinants for seropositivity among participants of a serosurveillance study, conducted in 2006/2007 among Dutch inhabitants 0–79 years of age. Materials and methodsSerological testing of 6386 blood samples for VZV was performed with a fluorescent bead-based multiplex immunoassay. Seroprevalence and geometric mean concentration (GMC) were weighted for age, sex, ethnicity, and urbanization rate to the total Dutch population. Determinants for VZV seropositivity were identified among children younger than 6 years of age using a logistic regression model. ResultsThe overall seroprevalence of VZV specific antibodies in the Dutch population was 94.6% (95% CI: 93.2–96.0%). This seroprevalence increased rapidly with age: at 6 years of age, more than 95% were seropositive. Determinants associated with lower VZV seropositivity were: young age, first-generation non-Dutch ethnicity, and low frequency of attendance at a day care center or nursery school. The GMC increased with age and was lower for women than for men from the age of 20 years onwards. ConclusionsThis study confirmed that VZV infection occurs at a younger age in the Netherlands compared to other countries, which might explain the low disease burden due to varicella. Introduction of universal varicella vaccination is not a foregone conclusion in the Netherlands. Changes in migration and day care usage will influence the age-specific risk on varicella and should therefore be monitored. Further research might elucidate the sex differences in VZV specific GMC.

Varicella zoster virus in American Samoa: seroprevalence and predictive value of varicella disease history in elementary and college students

The epidemiology of varicella is believed to differ between temperate and tropical countries. We conducted a varicella seroprevalence study in elementary and college students in the US territory of American Samoa before introduction of a routine varicella vaccination programme. Sera from 515 elementary and 208 college students were tested for the presence of varicella-zoster virus (VZV) IgG antibodies. VZV seroprevalence increased with age from 76·0% in the 4-6 years group to 97·7% in those aged ⩾23 years. Reported history of varicella disease for elementary students was significantly associated with VZV seropositivity. The positive and negative predictive values of varicella disease history were 93·4% and 36·4%, respectively, in elementary students and 97·6% and 3·0%, respectively, in college students. VZV seroprevalence in this Pacific island appears to be similar to that in temperate countries and suggests endemic VZV circulation.

Seroprevalence and Risk Factors of Varicella-Zoster Among Children of Kashan- Center of Iran

Background: Varicella, the primary infection of varicella-zoster virus(VZV), is a highly contagious and vaccine preventable infectious disease. It can cause severe complications in neonates and adults. Herpes zoster results from VZV reactivation later in life. Objectives: This study was performed to determine the seroprevalence of VZV by evaluating the specific IgG antibody in 1-15 year-old children in Kashan. Patients and Methods: This cross-sectional study was carried out on 558, one through fifteen year-old children among health-care centers in Kashan city during 2011. IgG antibodies against VZV were measured in sera by enzyme-linked immunosorbent assay (ELISA). Results: In total, 27.6% of children were seropositive. The seroprevalence of varicella zoster antibodies increased by age (12.7% in 1-5 year-old, 34.4% in 6-10 year-old and 39.6% in 11-15 year-old children). There was no difference in seroprevalence of VZV according to sex and habitation zone. By using multivariate analysis, independent factors associated with seropositivity were the family size being greater than 4 (OR = 2.01, 95% CI 1.35 - 3.29 P = 0.001) and history of varicella (OR = 39.31, 95% CI 22.79-67.79 P < 0.001). The Negative predictive value of varicella history was 91.1% and slightly decreased by age. Conclusions: In this region, a significant proportion of children are susceptible to VZV, severe varicella and its complications at older ages. It is recommended for varicella vaccine to be added to routine childhood vaccination programs and also to be injected to susceptible adolescents. Negative history of varicella would be a predictor of varicella antibody status in children and young adults.

Seroprevalence of varicella-zoster virus in the prevaccine era: A population-based study in Izmir, Turkey

To determine the population-based seroprevalence of varicella zoster virus (VZV) and related risk factors in Izmir. A population-based household survey was conducted. A representative sample of the population older than 15 years of age was selected using multistage random sampling. A total of 2136 healthy persons participated in this cross-sectional study. The participants completed a questionnaire designed to collect data related to socio-demographic characteristics and risk factors. Blood samples were collected, and VZV-specific IgG was measured using an ELISA. In total, 94.3% of individuals were seropositive for VZV. The difference between VZV seroprevalence in urban and rural populations was significant (OR: 2.6 (95% CI, 1.7-3.8)). No statistically significant differences in seropositivity were observed with respect to other sociodemographic characteristics. A large proportion of the participants were found to be immune to VZV.

Varicella zoster virus infection among healthcare workers in Taiwan: seroprevalence and predictive value of history of varicella infection

Varicella zoster infection can be spread by infected healthcare workers (HCWs) to coworkers and patients. A self-reported history of chickenpox infection is sometimes taken as proof of immunity. To establish the relationship between positive recall history and serological immunity against varicella zoster virus (VZV) amongst healthcare workers in a tertiary hospital in Taiwan. Between May 2008 and April 2009, all HCWs in a Taiwanese tertiary care hospital were tested for VZV immunoglobulin G (IgG), and completed a self-administered questionnaire to determine their history of varicella infection or vaccination. Those who were seronegative were vaccinated. All HCWs (N=3733) at the hospital participated in this study. Their mean age was 34.6 years, and the seroprevalence of VZV was 91.1%. Sensitivity, specificity, and positive and negative predictive values of a self-reported history of varicella infection were 82.3%, 48.6%, 96.3% and 14.4%, respectively. Corresponding figures for a history of varicella vaccination were 23.4%, 69.4%, 90.9% and 6.5%, respectively. The recall history of younger HCWs and medical professionals (doctors, nurses and paramedical staff) to varicella had higher sensitivity. However, only the recall history of medical professionals had a significantly higher positive predictive value. A positive recall history of varicella infection and vaccination did not ensure the presence of protective VZV IgG, and a negative history was not predictive of a lack of immunity. For effective prevention of nosocomial infection, VZV IgG status should be documented for all HCWs, and susceptible HCWs should be vaccinated.

Seroprevalence of varicella zoster virus among pregnant women in Hong Kong: Comparison with self-reported history

To compare seroprevalence (serum IgG titre) with self-reported history of varicella zoster virus (VZV) infection among pregnant women in Hong Kong. Pregnant women undergoing first trimester Down screening over a 3-months period were recruited for the study. Positive immunity was found in 477 (95.4%) of the 500 recruited women, and those with positive, negative, or uncertain history of infection had similarly high seroprevalence (96.4, 90.5, 95.9% respectively). The mean age of infection from self-recalled history was 8.61 (SD 4.69) years, and only 3% recalled infection after age 18. Insufficient knowledge on the disease and vaccination was demonstrated. Despite the absence of a routine vaccination programme, VZV immunity was high among pregnant women, the majority being infected during childhood and infection above age 18 was very rare. Hence, universal antenatal screening or vaccination for all women in the reproductive age would not be cost-effective in Hong Kong.

Seroprevalence of varicella‐zoster virus in Korea

Varicella-zoster virus (VZV) causes chickenpox and herpes zoster. Korea is assumed to have a high seroprevalence of VZV, although data are scant. A cross-sectional and age-stratified study was conducted to investigate the seroprevalence of VZV in different ages in the South Korean population. Four medical institutions were chosen in the southwestern area of Seoul in the vicinity of Gyeonggi-do. Serum samples were obtained at each institution from consenting patients during April-August, 2008. Anti-VZV IgG antibody was measured by an enzyme immunoassay. Of the 887 patients, 87.6% had anti-VZV IgG antibody. The prevalence of anti-VZV IgG antibody was 75% during the first 3 months after birth, but was only 13.6% 12 months after birth. Anti-VZV IgG antibody prevalence increased, first at 1-2 years of age, and then at 5-6 years of age. The seroprevalence rate exceeded 90% in subjects over 11 years of age. The results show that the seroprevalence of VZV is relatively high in the South Korean population. A study on the rate of varicella vaccination and the vaccine's efficacy in South Korea is warranted.

Concerns in assessing risk factors for herpes zoster infection in multiple myeloma patients

TO THE EDITOR: Recent developments of new agents such as bortezomib and high-dose chemotherapy followed by stem cell transplantation for multiple have improved the outcome of patients. However, it has also been reported that these therapies have impacted predisposing patients to various opportunistic infections [1]. A recent report of risk factors for herpes zoster in bortezomib treatment in patients with multiple myeloma by Yi et al. has showed that the bortezomib itself might act as a risk factor for herpes zoster [2]. The authors additionally concluded that the patients with low absolute lymphocyte counts (ALCs) at the time of bortezomib treatment initiation were at greater risk of herpes zoster during bortezomib treatment. I would like to comment several viewpoints on this interesting article. Recent report of seroprevalence of Varicella-Zoster virus (VZV) in Korea showed that overall 87.6% had anti-VZV IgG antibody among the 887 patients [3]. And the seroprevalence rate exceeded 90% in subjects over 11 years of age. With consideration of VZV vaccine availability in Korea, adults over 20 years who were not vaccinated and were seropositive by nautral infection of varicella, were more likely to have been the source of herpes zoster. Even though Yi et al. looked through the history of herpes zoster, prior history of varicella or antibody for VZV would be needed to see the potential risk factors for herpes zoster more precisely during the bortezomib therapy. In addition, 91.7% of herpes zoster positive group and 90.8% of herpes zoster negative group were also treated with dexamethasone in this study. Only 8.3-9.3% of patients were treated with bortozomib for itself. Not only bortezomib but also corticosteroid could have a role for the development of herpes zoster. And Chanan-Khan et al demonstrated ALCs and absolute neutrophil counts (ANCs) were comparable between patients regardless of herpes zoster state [4]. Notably the median ALCs and ANCs measured at the closest time point before the herpes zoster were significantly lower in bortezomib-treated patients compared with dexamethasone-treated patients. Therefore, the correlation of lower ALCs at the time of bortozomib treatment initiation and the risk of herpes zoster in this study should be interpreted carefully. There are reports that overall incidence (7-13%) of herpes virus infections during the treatment of bortezomib appears to be similar to the incidence of those infections in myeloma, especially in the setting of advanced diseases and in patients treated with steroid [5]. Considering the high seroprevalence of VZV in Korea, 16.7% of incidence of herpes zoster in this study was not so surprisingly high. I hope the studies of infectious complications including herpes zoster during the new era of multiple treatment extend widely and these efforts could give the chance to find out the novel prophylactic strategy for the prevention of infection finally.

Incidence of herpes zoster and seroprevalence of varicella-zoster virus in young adults of South Korea

This study was performed to determine the incidence of herpes zoster and seroprevalence of varicella-zoster virus (VZV) in young adults of South Korea, where VZV seroprevalence remains relatively high. In South Korea, military service is compulsory for all healthy young men and hence those in military service might provide a reflection of the general population. The computerized database of the Armed Forces Medical Command was examined to identify the number of reported herpes zoster cases. In order to evaluate VZV seroprevalence, serum samples were obtained from randomly selected subjects among those who had been admitted to the Armed Forces Capital Hospital. A total of 705 cases of herpes zoster were reported between June 2004 and May 2005. The annual incidence rate of herpes zoster was 141 (95% CI 131.0-151.8) per 100000 population. A total of 192 subjects were enrolled for the analysis of VZV seroprevalence. All subjects were male and their median age was 21 (range 19-24) years. The overall anti-VZV IgG seropositivity prevalence was 92.7% (178/192, 95% CI 88.0-95.7%). We have described a population-based study of the epidemiology of VZV infections in the military personnel of South Korea.

Comparison of the dynamics and correlates of transmission of Herpes Simplex Virus-1 (HSV-1) and Varicella-Zoster Virus (VZV) in a sample of the Israeli population

Herpes simplex virus types-1 (HSV-1) and Varicella-zoster virus (VZV) are herpes viruses that share many characteristics. However, HSV-1 spreads by close contact while VZV spreads mainly by the airborne route. In this study we compared the dynamics and correlates of transmission of these viruses in the same population. In 2000-2001, 1555 sera from an age-stratified general population sample were tested using commercial ELISA kits to measure type-specific HSV-1 and varicella IgG antibodies. The VZV seroprevalence increased rapidly with age reaching 50% seropositivity by the age of 3 years, while HSV-1 reached 50% seropositivity at the age of 14 years. The highest VZV force of infection was in the 3.5-5.5-year age group followed by the 5.5-10.5 years age group, while for HSV-1 the age specific force of infection was substantially lower and stable over the various age groups. Multivariate analysis revealed that HSV-1 seroprevalence was significantly, independently associated with age, country of birth, country of origin, ethnicity, socio-economic status and VZV sero-status. Only age, country of origin and HSV-1 sero-status were found to be associated with VZV seropositivity. In developed countries such as Israel the transmission of VZV is much quicker and less dependent on socioeconomic status as compared with HSV-1.

Susceptibility to varicella in childbearing age women, Central Italy: Is there a need for vaccinating this population group?

We conducted a cross-sectional seroprevalence study of varicella-zoster virus (VZV) antibodies in childbearing age women aged 17-42 years. Sera were collected in Central Italy in years 2001-2002 and were tested by a commercial VZV IgG enzyme immunoassay. Overall VZV seroprevalence was 80.9% and it showed a significant increase by age, confirming a considerable circulation of VZV also in the older age groups not commonly considered at high risk. This study further supports the importance of vaccinating susceptible adolescents and women of childbearing age in order to reduce both maternal and foetal complications associated with varicella in pregnancy.

Varicella seroprevalence in Turkish population in Cyprus

This study was conducted to determine the age-specific seroprevalence of varicella zoster virus (VZV) infection in Turkish population in Cyprus. A total of 600 unvaccinated individuals aged 1-30 years were selected for the study with cluster sampling. Information on socio-demographic characteristics was gathered for each participant and, anti-VZV antibodies were assayed by using enzyme immune assay. Of the 578 assayed samples, 486 (84.1%) were seropositive. Varicella seroprevalence increased sharply with age from 25% for the 2-3 year olds to 55, 78 and 85% for 4-5, 6-7 and 8-9 year olds, respectively. More than 90% of individuals >16 years of age were seropositive. Varicella seroprevalence was higher in large families with five and more members (91.2%) than in small families with four or fewer members (80.2%). The majority of varicella-zoster virus infections occur during preschool period and at the first years of schooling. Therefore, routine varicella vaccination of children would be logical in Northern Cyprus, as is currently recommended by the European Working Group on Varicella.

Analysis of factors associated with varicella-zoster virus susceptibility among children 0–12 years old in Taiwan

Objectives Varicella is a highly infectious disease caused by varicella-zoster virus (VZV). The aim of this study was to explore the geographical difference of VZV antibody seroprevalence among children in private vaccination areas in Taiwan, controlling for potential factors relating to varicella susceptibility. Patients and method A cross-sectional survey of the seroprevalence of VZV antibodies among children 0–12 years of age was conducted in Taiwan between August and December 2003. Sera of children visiting the outpatient unit of the participating hospitals around the island were collected. Six hundred and fifty-six parents among those of the 931 children studied agreed to answer the self-administered questionnaire regarding the possible factors associated with varicella susceptibility. IgG antibodies to VZV were measured using an enzyme-linked immunosorbent assay kit, Enzygnost anti VZV/IgG. Results The susceptibility was the highest at age 1 year, and then decreased as the age increased. Children living in southern and eastern Taiwan showed higher susceptibility to varicella than those living in northern area (odds ratio (OR) = 2.71 and 2.10, respectively). Prior history of varicella infection, varicella vaccination, and contact with cases remained to be associated with the susceptibility after multivariate analysis. Conclusions Children who lived in tropical and rural regions and those who had no history of varicella infection, varicella vaccination, and contact with cases, might be more susceptible to varicella. Island-wide VZV seroprevalence surveillance is required to examine whether the geographical difference of susceptibility in Taiwan will become less significant or disappear after the mass varicella vaccination program initiated in 2004.

Seroepidemiology of Varicella zoster in Israel Prior to Large-scale Use of Varicella Vaccines

This large-scale study provides up-to-date estimates of Varicella zoster virus (VZV) age-specific seroprevalence and characteristics of VZV transmission in a representative sample of the Israeli population. In 2000-2001, 1,642 sera collected from an agestratified general population sample were tested for VZV antibodies using an indirect IgG ELISA system. The age-weighted VZV overall estimate was 90.2%. Seropositivity increased rapidly with age, from 68.9% at age 4 to 94.4% at age 7 and 96.6% at age 12 years. The highest force of infection was in the 4-5 years age group (0.548 per susceptible year) followed by the 6-9 years age group. Multivariate analysis revealed that VZV seroprevalence estimates were significantly associated with age and place of origin. The highest seroprevalence estimate was found among subjects of Eastern origin. The seroepidemiology of VZV in Israel shows a pattern corresponding to that described for developed European countries. This study indicates that the highest force of infection is in pre-school children. Knowledge of pre-vaccination seroepidemiology is important to evaluate the effect of vaccination programs on the epidemiology of the disease.