Incident Cases Of Herpes Zoster Research Articles

Risk of herpes zoster in adults with SARS-CoV-2 infection in Spain: A population-based, retrospective cohort study

ObjectivesWe aimed to compare the risk of herpes zoster (HZ) in adults with and without laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. MethodsThis retrospective dynamic cohort study analyzed data from a public healthcare database in Spain between November 2020 and October 2021. The main outcome was incident cases of HZ in individuals ≥18-year-old. Relative risk (RR) of HZ in SARS-CoV-2-confirmed versus SARS-CoV-2-free individuals was estimated by a multivariable negative binomial regression adjusted by age, sex, and comorbidities. ResultsData from 4,085,590 adults were analyzed. The overall HZ incidence rate in adults was 5.76 (95% confidence interval [CI], 5.66-5.85) cases per 1000 person-years. Individuals ≥18-year-old with SARS-CoV-2-confirmed infection had a 19% higher risk of developing HZ versus SARS-CoV-2-free ≥18-year-olds (adjusted RR = 1.19; 95% CI, 1.09-1.29); this percentage was 16% (adjusted RR = 1.16; 95% CI, 1.05-1.29) in ≥50-year-olds. Severe (hospitalized) cases of SARS-CoV-2 infection had a 64% (if ≥18 years old) or 44% (if ≥50 years old) higher risk of HZ versus nonhospitalized cases. ConclusionThese results support an association between SARS-CoV-2 infection and HZ, with a greater HZ risk in severe cases of SARS-CoV-2 infection.

Risk of herpes zoster following mRNA COVID-19 vaccine administration

ABSTRACTBackgroundAdverse events following mRNA COVID-19 vaccines, including herpes zoster (HZ), have been reported. We conducted a cohort study to evaluate the association between mRNA COVID-19 vaccination and subsequent HZ at Kaiser Permanente Southern California (KPSC).Research design and methodsThe vaccinated cohort consisted of KPSC members who received their first dose of mRNA COVID-19 vaccine (mRNA-1273 and BNT162b2) during 12/2020–05/2021 and were matched to unvaccinated individuals on age and sex. Incident HZ cases occurring within 90 days of follow-up were identified by diagnosis codes and antiviral medications. Cox proportional hazards models estimated adjusted hazard ratios (aHR), comparing HZ incidence between the vaccinated and unvaccinated cohorts.ResultsCohort included 1,052,362 mRNA-1273 recipients, 1,055,461 BNT162b2 recipients, and 1,020,334 comparators. Compared to unvaccinated individuals, aHR for HZ up to 90 days after the second dose of mRNA-1273 and BNT162b2 was 1.14 (1.05–1.24) and 1.12 (1.03–1.22), respectively. In those aged ≥50 years not vaccinated with zoster vaccine, aHR was also increased after the second dose of mRNA-1273 (1.18 [1.06–1.33]) and BNT162b2 (1.15 [1.02–1.29]) vaccine vs. unvaccinated individuals.ConclusionsOur findings suggest a potential increased risk of HZ after a second dose of mRNA vaccines, potentially driven by the increased risk in individuals aged ≥50 years without history of zoster vaccination.

Cigarette smoking and risk of herpes zoster: a population-based cohort study in Taiwan.

The effects of cigarette smoking on the risk of herpes zoster (HZ) infection remain unclear. This study aimed to examine the association between cigarette smoking and HZ. Participants were collected from four rounds (2001, 2005, 2009 and 2013) of the Taiwan National Health Interview Survey. Incident cases of HZ were identified from the Taiwanese National Health Insurance database. Of the 57641 participants, 3346 developed HZ during the observation period. After controlling for confounders, current smokers had a lower risk of incident HZ than never-smokers (adjusted hazard ratio 0.69; 95% CI 0.62-0.77). There was a trend toward a decreased risk of HZ with increasing numbers of cigarettes per day, years of smoking and cumulative pack-years of smoking among current smokers (Ptrend <0.001). Former smoking was not associated with risk of HZ. In conclusion, current smoking was significantly associated with a decreased risk of developing HZ.

Ultraviolet Radiation Exposure and the Risk of Herpes Zoster in Three Prospective Cohort Studies

ObjectiveTo examine the association between ultraviolet radiation (UVR) exposure and the risk of herpes zoster (HZ) in 3 prospective cohorts. Patients and MethodsWe included 205,756 participants from the Health Professionals Follow-up Study (HPFS; 1986-2008), Nurses’ Health Study (NHS; 1996-2012), and Nurses’ Health Study II (NHS II; 1991-2013). Ambient UVR exposure was based on updated geocoded address histories linked with a high-resolution spatiotemporal ultraviolet model. Incident HZ cases were identified by self-reported clinician diagnosis. Sunburn history and medical, lifestyle, and dietary factors were assessed using biennial questionnaires. Multivariable Cox proportional hazards models were used. ResultsA total of 24,201 cases of HZ occurred during 3,626,131 person-years. Ambient UVR exposure was associated with a higher risk of HZ in men (HPFS: multivariable-adjusted hazard ratio [MVHR] comparing highest vs lowest quintiles, 1.14; 95% CI, 1.02-1.29; P=.03 for trend) but not in women (NHS: MVHR, 0.99; 95% CI, 0.93-1.05; NHS II: MVHR, 0.96; 95% CI, 0.90-1.03). A higher lifetime number of severe sunburns was associated with a higher risk of HZ in all cohorts (HPFS: MVHR for ≥10 sunburns vs none, 1.08; 95% CI, 0.96-1.20; P=.02 for trend; NHS: MVHR, 1.14; 95% CI, 1.05-1.22; P=.01 for trend; NHS II: MVHR, 1.13; 95% CI, 1.00-1.28; P<.001 for trend). ConclusionAmbient UVR exposure was associated with a higher risk of HZ in men but not in women. A history of severe sunburn was associated with a modest increased risk of HZ in men and women, possibly because of immunosuppression from overexposure to the sun.

2300. Incidence, Complications, and Recurrence of Herpes Zoster in Unvaccinated Adults ≥50 Years of Age

BackgroundMore recent baseline epidemiological data for Herpes Zoster (HZ) in adults ≥ 50 years of age, obtained before the introduction of the adjuvanted Recombinant Zoster Vaccine (RZV), are needed for future evaluations of the impact of RZV on HZ epidemiology.MethodsThe study comprised five elements: (1) The incidence of HZ was estimated from immunocompetent adults ≥ 50 years of age not vaccinated with Zoster Vaccine Live who had incident HZ between 2011–2015. HZ was identified by International Classification of Diseases (ICD) codes from electronic health records (EHR) of 4.6 million Kaiser Permanente Southern California members; (2) Postherpetic neuralgia (PHN) was identified by validated survey and medical record review of laboratory-confirmed incident HZ cases recruited during 2012–2015 for HZ-related pain ≥ 90 days after initial HZ diagnosis; (3) HZ Ophthalmicus (HZO) with ocular complications was identified by ICD codes and keyword search in EHR among patients identified with HZO using a validated natural language processing algorithm; (4) The proportion of HZ-related non-PHN and non-HZO cutaneous, neurological or other complications was assessed by double abstraction of EHRs from a sample of 600 incident HZ cases; (5) Recurrent HZ was identified by having an HZ diagnosis with HZ antiviral medication ≥ 6 months after the most recent HZ diagnosis with HZ antiviral medication in a cohort initially diagnosed with HZ between 2007 and 2008 and followed through 2016.ResultsWe identified 40,893 incident HZ cases with an overall incidence of 9.92 (95% confidence interval [CI]: 9.82–10.01) per 1000 person-years. The proportion of incident HZ cases with PHN and HZO with ocular involvement was 18.37% (95% CI: 14.90–21.84%) and 8.06% (95% CI: 7.80–8.32%), respectively. The proportion of cutaneous, neurological, and other complications was 7.20% (95% CI: 5.44–8.96%), 0.87% (95% CI: 0.79–0.95%), and 1.24% (95% CI: 1.15–1.33%), respectively. The incidence of recurrent HZ was 10.96/1000 person-years (95% CI: 10.18–11.79).ConclusionHZ is common among unvaccinated US adults ≥ 50 years of age, with PHN and HZO occurring most frequently among incident HZ cases.FundingGlaxoSmithKline Biologicals SA, GSK study identifier: HO-17-18378.Disclosures All authors: No reported disclosures.

1759. Incidence of Hospitalizations and Emergency Department Visits for Herpes Zoster in Immunocompromised and Immunocompetent Adults in Ontario, Canada, 2002–2016

BackgroundAdults with immunocompromising conditions are at increased risk of herpes zoster (HZ) infection and related complications. We aimed to assess the incidence of HZ seen in hospital or emergency department in immunocompromised populations and compare it to that of immunocompetent populations.MethodsUsing healthcare administrative data, we calculated incidence rates (IR) of HZ in Ontario, Canada between April 1, 2002 and August 31, 2016 in adults ≥18 years categorized as immunocompromised or immunocompetent. We repeated these analyses by type of immunocompromising condition and provided incidence rate ratios (IRR) comparing to immunocompetent adults. We also calculated IRs and IRRs of HZ complications by immunocompromised status.ResultsThere were 120,654 incident cases of HZ seen in hospital or emergency department during the study period. Immunocompromised adults accounted for 13% of these cases despite representing only 3% of the population. The risk of HZ was higher for immunocompromised adults compared with immunocompetent (IRR = 2.8, 95% CI 2.8–2.9) and ranged across type of immunocompromising condition (from 2.4 [95% CI 2.3–2.5] in those with a solid tumor malignancy to 11.0 [95% CI 10.0–12.0] in those who had undergone a hematopoietic stem cell transplant). The risk of any HZ complication was also higher in immunocompromised adults (IRR = 3.5, 95% CI 3.4–3.6) and was highest for disseminated zoster (IRR = 31.5, 95% CI 26.3–37.5).ConclusionThe risk of HZ and related complications was higher in immunocompromised populations compared with immunocompetent. Our findings underscore the high-risk nature of this population and the potential benefits that may be realized through HZ vaccination of this group.Disclosures All authors: No reported disclosures.

2303. Chronic Hepatitis B Virus Infection and Risk of Herpes Zoster: A Cohort Study

BackgroundNo cohort studies have evaluated the effect of hepatitis B virus (HBV) infection on the risk of herpes zoster. We investigated the association of HBV infection with the development of herpes zoster.MethodsWe performed a cohort study of 224,691 non-cirrhotic adult men and women free of herpes zoster at baseline who underwent serologic testing for hepatitis B surface antigen (HBsAg) and were followed annually or biennially for a median of 4.2 years. Incident cases of herpes zoster were ascertained using the Korean Health Insurance and Review Agency (HIRA) database. A Cox proportional hazard model was used to estimate the adjusted hazard ratio (aHR) with 95% confidence interval (CI) for incident herpes zoster according to HBsAg seropositivity status.ResultsDuring 830,073.4 person-years of follow-up, 11,061 cases of incident herpes zoster were identified. HBsAg seropositivity was inversely associated with the development of herpes zoster. After adjustment for possible confounders, the multivariable-adjusted hazard ratios (95% CI) for herpes zoster comparing HBsAg-positive to HBsAg-negative participants was 0.83 (0.75–0.93).ConclusionIn a large cohort of Korean adults, HBsAg seropositivity was associated with lower risk of herpes zoster, suggesting that HBV seems to inhibit the reactivation of varicella-zoster virus.Disclosures All authors: No reported disclosures.

Impact of Antiretroviral Therapy on the Risk of Herpes Zoster among Human Immunodeficiency Virus-Infected Individuals in Tanzania.

We examined the incidence of herpes zoster (HZ) before and after the initiation of antiretroviral therapy (ART), and risk factors for HZ among human immunodeficiency virus (HIV)-infected individuals in Tanzania. A cohort study was conducted among HIV-positive individuals enrolled in HIV care and treatment clinics in Dar es Salaam, Tanzania. A Cox proportional hazard model was used to examine the effect of ART on the risk of HZ after adjusting for sociodemographics and time-varying clinical and nutritional factors. Among 72,670 HIV-positive individuals, 2,312 incident cases of HZ (3.2%) occurred during the median follow-up of 15 months (interquartile range: 3-35). The incidence rate of HZ significantly declined from 48.9 (95% confidence interval [CI] = 46.7-51.0) per 1,000 person-years before ART to 3.7 (95% CI = 3.3-4.1) per 1,000 person-years after the initiation of ART (P < 0.001). The risk of HZ declined with longer duration on ART. Low CD4 cell count, older age, female sex, district of Dar es Salaam, and year of enrollment were independently associated with the risk of HZ in the multivariate analysis. Low body mass index and anemia were not associated with the risk of HZ. The risk of HZ substantially declined after ART initiation in this large cohort of HIV-infected individuals. Earlier initiation of ART could reduce the risk of HZ and other opportunistic infections among HIV-infected individuals in sub-Saharan Africa.

Effectiveness of Live Zoster Vaccine in Preventing Herpes Zoster Ophthalmicus (HZO)

BackgroundHerpes zoster ophthalmicus (HZO), caused by reactivation of varicella-zoster virus in or around the eye, can be severe and often results in care-seeking that may be less discretionary than for uncomplicated herpes zoster (HZ). We compared the vaccine effectiveness (VE) of live zoster vaccine against HZO with the VE against HZ overall.MethodsKaiser Permanente Northern California (KPNC) members enter the ongoing cohort study when age-eligible for zoster vaccine starting in 2007. Incident HZ was defined as a new diagnosis of HZ with an antiviral prescription or a positive varicella viral test. Among those, an HZO case was defined as having an HZO diagnosis during an ophthalmology visit within 30 days of the initial HZ diagnosis. VE by age at vaccination and time since vaccination was estimated using Cox regression adjusted for age, race, sex and time-varying measures of healthcare use, comorbidities and immunocompromise status. Average VE over the first 5 years following vaccination was calculated as a weighted average of annual VE estimates.ResultsDuring 2007–2014, ~1.3 million individuals ≥50 years of age entered the study population and 29% were vaccinated. Among 48,889 incident HZ cases, 2,858 (6%) had HZO, 87% of whom were unvaccinated. For all ages combined, VE against HZO was 72% (95% CI, 64%-79%) in year 1, similar to 68% (95% CI, 65%-70%) against HZ. VE fell in years 2, 3, 4, and 5 to 47%, 45%, 42% and 27% for HZO and to 47%, 39%, 41% and 37% for HZ. For age groups 60 – 69 and 70 – 79, where we have the most data, initial VE and waning were similar for HZO and HZ. Numbers of HZO cases for 50–59 year olds were too small to evaluate at this time. Average VE against HZO over the first 5 years following vaccination was 52% (95% CI, 42%–60%) for ages 60–69, 51% (95% CI, 39%–61%) for ages 70-79, and 39% (95% CI, 14%-57%) for ages 80+; similarly, 5-year average VE against HZ was 49%, 46%, and 44% for these 3 age groups.ConclusionVE against HZO was similar to VE against HZ regardless of age at vaccination or time since vaccination. Effectiveness of live zoster vaccine in preventing HZO was highest in year one with subsequent waning.Disclosures E. Earley, Merck & Co.: Research Contractor, Salary; M. Marks, Merck and Co. Inc.: Employee, Restricted Stock and Salary; P. Saddier, Merck & Co., Inc.: Employee, Salary; N. P. Klein, GSK: Investigator, Grant recipient; sanofi pasteur: Investigator, Grant recipient; Merck & Co.: Investigator, Grant recipient; MedImmune: Investigator, Grant recipient; Protein Science: Investigator, Grant recipient Pfizer: Investigator, Grant recipient

Incidence and risk factors of herpes zoster among adult renal transplant recipients receiving universal antiviral prophylaxis.

BackgroundHerpes zoster (HZ) is a significant cause of morbidity and complications in adult renal transplant recipients. We determined the incidence, complications and risk factors for the development of HZ after renal transplantation in a setting using universal antiviral prophylaxis.MethodsThe medical files of all adult renal transplants, performed between 2004 and 2008, were retrospectively reviewed to assess the clinical characteristics and risk factors of HZ. Incident cases of HZ were determined and the probability of developing post-transplant HZ for all subjects was calculated using the Kaplan Meier method. A multivariable Cox proportional hazards model was applied to assess the risk factors associated with the development of HZ.ResultsA total of 450 patients were eligible with a median follow up of 38 months. Twenty nine subjects (6.4 %) developed HZ, the median time to onset was 18 months, only three of them (10.3 %) required hospitalization, and none developed disseminated or visceral disease and death directly attributed to zoster. However, high rates of post-herpetic neuralgia (48.7 %) were observed. Overall incidence was calculated at 20.6 cases per 1000 patient-years of follow-up. Following multivariate analysis, increased age ≥ 60 years old, positive pre-transplant history of varicella related disease and administration of rejection treatment conferred an increased risk of 4.00-fold (CI: 1.79- 8.92), 16.00-fold (CI: 4.62- 55.52), and 5.57-fold (CI: 1.56- 19.84) respectively, for the development of post-transplant zoster.ConclusionsHZ remains a common complication after renal transplantation in adults under current immunosuppession protocols and universal antiviral prophylaxis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-015-1038-1) contains supplementary material, which is available to authorized users.

Vaccination against zoster remains effective in older adults who later undergo chemotherapy.

Approximately 40% of adults develop invasive cancer during their lifetimes, many of whom require chemotherapy. Herpes zoster (HZ) is common and often severe in patients undergoing chemotherapy, yet there are no data regarding whether these patients retain specific protection against HZ if they had previously received zoster vaccine. We conducted a study to determine whether zoster vaccine was effective in patients who subsequently underwent chemotherapy. The cohort study consisted of Kaiser Permanente Southern California members aged ≥60 years treated with chemotherapy. The exposure variable was receipt of zoster vaccine prior to initiation of chemotherapy. Incident HZ cases were identified using International Classification of Diseases, Ninth Revision diagnostic codes. HZ incidence rates were calculated; hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models. There were 91 and 583 HZ cases in the vaccinated and unvaccinated cohorts, respectively, yielding an incidence rate of 12.87 (95% CI, 10.48-15.80) vs 22.05 (95% CI, 20.33-23.92) per 1000 person-years. Thirty-month cumulative incidence was 3.28% in the vaccinated group and 5.34% in the unvaccinated group (P < .05). The adjusted HR for HZ was 0.58 (95% CI, .46-.73) and showed no significant variation by age, sex, or race. HZ incidence rates remained increased in the small subgroup of persons receiving zoster vaccine within 60 days before chemotherapy, but this was the only group affected by indication bias. No vaccinated patients underwent hospitalization for HZ, compared with 6 unvaccinated patients. Zoster vaccine continues to protect against HZ if recipients later undergo chemotherapy. Our findings provide an additional rationale for offering zoster vaccine to indicated adults while they are immunocompetent.

Herpes Zoster Among Persons Living With HIV in the Current Antiretroviral Therapy Era

Previously, herpes zoster (HZ) was found to occur at a higher rate in the HIV population than the general population. However, there are limited data about the incidence, risk factors, and clinical outcomes of HZ in the current antiretroviral therapy (ART) era. We identified HZ episodes in an urban HIV clinic cohort between 2002 and 2009. Three controls were matched to each case, and conditional logistic regression was used to assess for risk factors associated with incident HZ cases. Logistic regression was used to assess for factors associated with complicated HZ. One hundred eighty-three new HZ cases were identified in 4353 patients with 19,752 person-years (PY) of follow-up--an incidence rate 9.3/1000 PY. Cases were majority men (62%) and African American (75%), with a mean age of 39 years (interquartile range, 32-44 years). Fifty patients (28%) had complicated HZ with 12% developing postherpetic neuralgia. In multivariate regression, factors associated with the increased risk of HZ were having started ART within 90 days of the episode [adjusted odds ratio (AOR), 4.02; 95% confidence interval (CI), 1.31 to 12.41], having a viral load of >400 copies per milliliter (AOR, 1.49; 95% CI, 1.00 to 2.24), and having a CD4 <350 cells per cubic millimeter (AOR, 2.46; 95% CI, 1.42 to 4.23) or 350 to 500 cells per cubic millimeter (AOR, 2.02; 95% CI, 1.14 to 3.57) as compared with CD4 >500 cells per cubic millimeter. The incidence of HZ is lower than previously reported in HIV cohorts but remains higher than the general population. Over one fourth of patients developed complicated HZ, which is remarkable given the young age of our population. Risk factors for HZ include markers of poor immune function, suggesting that appropriate ART may reduce the burden of HZ in this population.

Health Care Utilization and Cost Burden of Herpes Zoster in a Community Population

To conduct a population-based study to assess health care utilization (HCU) and costs associated with herpes zoster (HZ) and its complications, including postherpetic neuralgia (PHN) and nonpain complications, in adults aged 22 years and older. Medical record data on HCU were abstracted for all confirmed new cases of HZ from January 1, 1996, through December 31, 2001, among residents of Olmsted County, Minnesota. Herpes zoster-related costs were estimated by applying the Medicare Payment Fee Schedule to health care encounters and mean wholesale prices to medications. All costs were adjusted to 2006 US dollars using the medical care component of the Consumer Price Index. The HCU and cost of the 1669 incident HZ cases varied, depending on the complications involved. From 3 weeks before to 1 year after initial diagnosis, there were a mean of 1.8 outpatient visits and 3.1 prescribed medications at a cost of $720 for cases without PHN or nonpain complications compared with 7.5 outpatient visits and 14.7 prescribed medications at a cost of $3998 when complications, PHN, or nonpain complications were present. The annual medical care cost of treating incident HZ cases in the United States, extrapolated from the results of this study in Olmsted County, is estimated at $1.1 billion. Most of the costs are for the care of immunocompetent adults with HZ, especially among those 50 years and older.

Evaluation of the incidence of herpes zoster after concomitant administration of zoster vaccine and polysaccharide pneumococcal vaccine

In 2009, a revision to the zoster vaccine package insert was approved stating that the zoster vaccine and the pneumococcal vaccine should not be given concurrently because concomitant use resulted in reduced immunogenicity of the zoster vaccine. We conducted an observational study to evaluate if concomitant vaccination reduces the protective effect of the zoster vaccine. The study was conducted in Kaiser Permanente Southern California. Incidence of herpes zoster (HZ) after vaccination with a zoster vaccine in the population receiving both vaccines on the same day was compared to that in the population receiving a pneumococcal vaccine within one year to 30 days prior to zoster vaccine. Vaccinations and incident HZ cases were identified by electronic health records. The hazard ratio for incident HZ associated with concomitant vs. nonconcomitant vaccination was estimated using the Cox proportional hazard model. There were 56 incident HZ cases in the concomitant vaccination cohort and 58 in the nonconcomitant vaccination cohort, yielding a HZ incidence of 4.54 (95% confidence interval [CI], 3.43–5.89) and 4.51 (95% CI, 3.42–5.83) per 1000 person-years, respectively. The hazard ratio comparing the incidence rate of HZ in the two cohorts was 1.19 (95% CI, 0.81–1.74) in the adjusted analysis. In this study, we found no evidence of an increased risk of HZ in the population receiving zoster vaccine and pneumococcal vaccine concomitantly. The revision of the product information needs to be carefully assessed to avoid introducing barriers to patients and providers who are interested in these two important vaccines.

Health care utilization and cost burden of herpes zoster in a community population.

To conduct a population-based study to assess health care utilization (HCU) and costs associated with herpes zoster (HZ) and its complications, including postherpetic neuralgia (PHN) and nonpain complications, in adults aged 22 years and older. Medical record data on HCU were abstracted for all confirmed new cases of HZ from January 1, 1996, through December 31, 2001, among residents of Olmsted County, Minnesota. Herpes zoster-related costs were estimated by applying the Medicare Payment Fee Schedule to health care encounters and mean wholesale prices to medications. All costs were adjusted to 2006 US dollars using the medical care component of the Consumer Price Index. The HCU and cost of the 1669 incident HZ cases varied, depending on the complications involved. From 3 weeks before to 1 year after initial diagnosis, there were a mean of 1.8 outpatient visits and 3.1 prescribed medications at a cost of $720 for cases without PHN or nonpain complications compared with 7.5 outpatient visits and 14.7 prescribed medications at a cost of $3998 when complications, PHN, or nonpain complications were present. The annual medical care cost of treating incident HZ cases in the United States, extrapolated from the results of this study in Olmsted County, is estimated at $1.1 billion. Most of the costs are for the care of immunocompetent adults with HZ, especially among those 50 years and older.

The incidence of herpes zoster in a United States administrative database

Few recent studies have reported data on the incidence of herpes zoster (HZ) in U.S. general clinical practice. To estimate the age- and sex-specific incidence of HZ among U.S. health plan enrollees. Data for the years 2000 to 2001 were obtained from the Medstat MarketScan database, containing health insurance enrollment and claims data from over 4 million U.S. individuals. Incident HZ cases were identified through HZ diagnosis codes on health care claims. The burden of HZ among high-risk individuals with recent care for cancer, HIV, or transplantation was examined in sub-analyses. Overall incidence rates were age- and sex-adjusted to the 2000 U.S. population. MarketScan U.S. health plan enrollees of all ages. We identified 9,152 incident cases of HZ (3.2 per 1,000 person-years) (95% confidence interval [CI], 3.1 to 3.2 per 1,000). Annual HZ rates per 1,000 person-years were higher among females (3.8) than males (2.6) (P<.0001). HZ rates rose sharply with age, and were highest among individuals over age 80 (10.9 per 1,000 person-years) (95% CI, 10.2 to 11.6). The incidence of HZ per 1,000 person-years among patients with evidence of recent care for transplantation, HIV infection, or cancer (10.3) was greater than for individuals without recent care for these conditions (3.0) (P<.0001). The overall incidence of HZ reported in the present study was found to be similar to rates observed in U.S. analyses conducted 10 to 20 years earlier, after age- and sex-standardizing estimates from all studies to the 2000 U.S. population. The higher rate of HZ in females compared with males contrasts with prior U.S. studies.