The epidemiology of children hospitalized with herpes zoster in Canada: Immunization Monitoring Program, Active (IMPACT), 1991-2005

Annual pattern and clinical characteristics of herpes zoster in immunocompetent children in a rural area

This study aims to investigate the clinical signs, symptoms, complications and seasonal distribution of herpes zoster for otherwise healthy children and to demonstrate the outcome of varicella vaccinations on the herpes zoster incidence in a pediatric population. A retrospective study was conducted by using the data of the pediatric patients who were referred to two rural cities of Turkey, clinically diagnosed as Herpes Zoster (HZ). All participants were evaluated for clinical-epidemiological factors, signs, symptoms, complications and varicella vaccination status for HZ. This study was comprised of 69 pediatric patients (29 [42%] female and 40 [58%] male) who were diagnosed with HZ. The mean age was 10.57 (6 months-17) years old. The rash of HZ mostly appeared on the thoracic dermatome as seen in 29 patients. The findings revealed that among 56 unvaccinated patients of all, 25 (44.6%) had a painful rash, in comparison among vaccinated patients none reported pain as the characterization of shingles (P = .001). Annual distribution of cases showed two peaks (March and September), whereas in August no cases were detected. Of all participants, one patient had postherpetic neuralgia, who also had ophthalmic dermatomal involvement, and this was the only complication observed in this study cohort. In immunocompetent children, the most common involvement site was the thoracic dermatome. Our findings show that varicella vaccination has a protective role in the herpes zoster clinic, both by decreasing the prevalence and by making the infection course less severe.

A clinico-epidemiological multicenter study of herpes zoster in immunocompetent and immunocompromised hospitalized children

Purpose

There are limited population-based data regarding herpes zoster in children. Thus we conducted a multi-institutional epidemiological analysis of herpes zoster in children and comparative analysis according to their immune status.

Materials and Methods

The study included 126 children under the age of 18 years who were hospitalized for herpes zoster at 8 hospitals in South Korea, between July 2009 and June 2015. The subjects were divided into 2 groups according to their immune status, and medical records were reviewed.

Results

There were 61 cases (48.4%) in the immunocompetent group and 65 cases (51.6%) in the immunocompromised group. Median age was older in immunocompromised group (11.4 vs. 8.6) (p<0.001). The mean duration of hospitalization was longer in immunocompromised group (11.0 vs. 6.6) (p<0.001). Patients were treated with oral or intravenous antiviral agents. A total of 12 in immunocompetent group were cured only by oral acyclovir. No treatment failure was found in both groups. Six immunocompromised patients had postherpetic neuralgia and 1 case was in immunocompetent group. In immunocompetent children, herpes zoster was likely caused by early varicella infection. There was no increase in progression of severity in both groups due to appropriate treatment.

Conclusion

Early initiation of therapy is necessary for those in immunocompromised conditions. And inactivated herpes zoster vaccination may be considered in immunocompromised adolescents in the future.

Vaccine-preventable disease-related hospitalization among immigrants and refugees to Canada: Study of linked population-based databases

While immigrants tend to be healthier especially when they first arrived, this healthy immigrant effect may not apply to vaccine-preventable diseases (VPD) especially among immigrants from countries without vaccination programs. There is therefore an important information gap regarding differential health outcome and hospitalization usage by immigrant status, landing cohort, world region and immigrant category. This study focused on acute-care hospitalization, and used two recently linked population-based databases in Canada, namely, the 2006 Census linked to the Hospital Discharge Abstract (DAD), and the Immigrant Landing File linked to the DAD (ILF-DAD) to estimate crude and age-standardized VPD-related hospitalization rates (ASHR) by the above-mentioned immigrant characteristics to be compared with that for overall Canadian-born reference population. Based on the 2006 Census-DAD linked database, VPD-specific ASHR for overall immigrants was significantly higher than that for the Canadian-born population (1.6, 95% CI, 1.5, 1.6 vs 1.2, 95% CI, 1.1, 1.2, respectively). VPD-specific ASHRs by landing cohorts also increased with years in Canada (e.g. 1.4, 95% CI, 1.3, 1.5 for the 1990-2006 cohort, and 1.6, 95% CI, 1.5, 1.7 for the pre-1980 cohort). Based on the 1980-2006 ILF-DAD, the VPD-specific ASHRs were highest among Southeast and East Asians (e.g. 2.1, 95% CI, 1.9, 2.3 for East Asia). Compared with the Canadian-born, economic class immigrants overall had significantly lower ASHR (1.4, 95% CI 1.2, 1.6), but the low rate was mainly due to the dependants (spouse or children) within this class (0.8, 95% CI 0.6, 1.1). Both family and refugee categories had significantly higher ASHRs (1.3, 95% CI, 1.2, 1.5 and 1.7, 95% CI, 1.4, 2.1, respectively), especially among those refugees assisted by government (2.0, 95% CI, 1.4, 2.6). With increasing immigration, changing source countries and emerging needs for refugee settlements in Canada, these newly linked datasets help to monitor VPD-related hospitalization pattern among Canadian immigrants.

Clinical Presentation of Herpes Zoster in Immunocompetent and Immunocompromised Hospitalized Children Treated With Acyclovir

Herpes zoster, defined as the reactivation of a latent varicella-zoster virus (VZV) infection, used to be a serious disease in immunocompromised children until recently. The aim of this study was to describe the clinical presentation of herpes zoster in hospitalized immunocompromised children compared with hospitalized immunocompetent counterparts. We reviewed the hospital charts of 72 children aged 6 months to 18 years diagnosed with herpes zoster and treated with acyclovir in our department covering a 19-year period. Forty-six of the children were immunocompromised which was mainly due to hematologic diseases. There were no differences in the age at which herpes zoster occurred, length of hospitalization, and the location or extent of the skin eruption. General symptoms were observed more frequently in the hospitalized immunocompetent patients compared with the hospitalized immunocompromised children (80% vs. 56%). The average age at which primary VZV infection occurred was higher among the immunocompromised children than the immunocompetent children with the latter group suffering from significantly more primary VZV infections during infancy. The presentation of herpes zoster in immunocompromised children is similar to that of herpes zoster in hospitalized immunocompetent children.

Epidemiology of pediatric herpes zoster after varicella infection: a population-based study

BACKGROUND

There are limited population-based data regarding pediatric herpes zoster (HZ).

METHODS

Children aged <12 years with varicella infections between 2000 and 2006 were identified from a national population-based database and followed-up for a diagnosis of HZ until December 2008. Since a routine varicella vaccination program was started in 2004, vaccinated children without medically attended varicella were identified between 2004 and 2006, and followed-up for a diagnosis of HZ until December 2008.

RESULTS

Of 27 517 children with medically attended varicella, 428 developed HZ. The incidence of HZ was 262.1 per 100 000 person-years. Of 25 132 vaccinated children without medically attended varicella, 106 developed HZ. The incidence of HZ was 93.3 per 100 000 person-years. The mean duration from varicella to HZ was 4.12 years. Children diagnosed with varicella at aged <2 years had a higher incidence (P < .001) and shorter duration (P = .04) than those diagnosed aged ≧2 years. Children diagnosed with varicella aged ≥2 but <8 years had a significantly increased incidence of HZ after than before the vaccination program (relative risk = 1.85 at 3 years of follow-up, P = .03). Children with varicella infections had a significantly greater risk of HZ than vaccinated children without a history of varicella (relative risk = 2.31 at 4 years of follow-up, P < .001).

CONCLUSIONS

This study demonstrates the population-based epidemiologic characteristics of pediatric HZ among those who contracted varicella. In the early postvaricella vaccination period, an increased HZ incidence was observed among children with varicella infection aged ≥2 years.

The effect of funded varicella immunization programs on varicella-related hospitalizations in IMPACT centers, Canada, 2000-2008

BACKGROUND

The 12 Immunization Monitoring Program, Active (IMPACT) centers that represent 90% of pediatric tertiary care beds in Canada conducted active surveillance for varicella-related hospitalizations and complications from 1999 onward, after varicella vaccine was authorized. Publicly funded routine immunization programs at 12 or 15 months of age were introduced by 5 provinces and territories (prov/terr) in 2000 to 2002 (earlier programs, EP) and by 8 prov/terr in 2004 to 2007 (later programs, LP).

OBJECTIVE

To determine whether the number of varicella-related hospitalized cases had declined by 2008 at 12 IMPACT centers after the sequential introduction of publicly funded varicella immunization programs in Canada.

METHODS

Varicella-related hospitalizations from 2000 to 2008 in the prov/terr with EP were under surveillance by 3 IMPACT centers (Halifax, Edmonton, Calgary), whereas the prov/terr with LP were under surveillance by the remaining 9 centers. The age, gender, underlying health status, varicella complications, and length of stay in hospital and the pediatric intensive care unit were documented. Breakthrough cases were identified and their clinical characteristics described.

RESULTS

Between 2000 and 2008, the number of varicella-related hospitalized cases in IMPACT centers declined relatively sooner in prov/terr with EP (by 2002 to 2003), as compared to those with LP (only by 2007 to 2008). In 2008, varicella-related hospitalized cases declined by 88% in the EP centers, and by 81% in the LP centers. In all IMPACT centers, the greatest decline occurred in the 1-4 years age group (90% decline), with smaller declines in both <1 year and 5-9 years age groups (78% and 76% decline, respectively). Breakthrough disease accounted for 39 (2%) cases, with the proportion due to breakthrough increasing from 0.9% in 2000 to 2001, to 2% in 2003 to 2004 and 9.5% in 2007 to 2008. The majority (72%) of breakthrough cases were in immunocompromised children.

CONCLUSIONS

Publicly funded varicella vaccination programs have led to a significant decline in varicella-related hospitalizations in Canadian children, as a result of direct effects of the program beginning within 1 to 2 years after the start, as well as probable indirect protection of children outside the vaccinated cohort.

The health and economic burden of chickenpox and herpes zoster in Belgium

Varicella-zoster virus causes chickenpox (CP) and after reactivation herpes zoster (HZ). Vaccines are available against both diseases warranting an assessment of the pre-vaccination burden of disease. We collected data from relevant Belgian databases and performed five surveys of CP and HZ patients. The rates at which a general practitioner is visited at least once for CP and HZ are 346 and 378/100 000 person-years, respectively. The average CP and HZ hospitalization rates are 5·3 and 14·2/100 000 person-years respectively. The direct medical cost for HZ is about twice as large as the direct medical cost for CP. The quality-adjusted life years lost for ambulatory CP patients consulting a physician is more than double that of those not consulting a physician (0·010 vs. 0·004). In conclusion, both diseases cause a substantial burden in Belgium.

The controversy of varicella vaccination in children with acute lymphoblastic leukemia

BACKGROUND

The available guidelines for varicella vaccination of susceptible children with acute lymphoblastic leukemia (ALL) have become increasingly conservative. However, vaccination of those who have remained in continuous complete remission for 1 year and are receiving chemotherapy is still considered a reasonable option. There is little available data to allow a comparison of the risk versus benefit of vaccinating these patients.

PROCEDURE

We retrospectively reviewed mortality due to varicella in the records of 15 pediatric ALL study groups throughout Europe, Asia, and North America during the period 1984-2008.

RESULTS

We found that 20 of 35,128 children with ALL (0.057%; 95% confidence interval [CI], 0.037-0.088%) died of VZV infection. The mortality rate was lower in North America (3 of 11,558 children, 0.026%; 95% CI, 0.009-0.076%) than in the Asian countries (2 of 4,882 children, 0.041%; 95% CI, 0.011-0.149%) and in Europe (15 of 18,688 children, 0.080%; 95% CI, 0.049-0.132%) consistent with the generally higher rate of VZV vaccination in North America. Fourteen of the 20 patients (70%) died during the first year of treatment for ALL. One death was attributed to varicella vaccination.

CONCLUSIONS

The negligible rate of fatal varicella infection in children with ALL, the risk that accompanies vaccination, and the necessity of withholding chemotherapy for vaccination appear to outweigh the potential benefit of varicella vaccination for children during treatment of ALL.

Herpes zoster in healthy infants and toddlers after perinatal exposure to varicella-zoster virus: a case series and review of the literature

Exposure to varicella-zoster virus in utero or during the first months of life is the main risk factor for the development of herpes zoster (HZ) in healthy children. We report a case series of 16 infants and toddlers who presented with HZ after early exposure to varicella-zoster virus. Two patients had recurrences. Despite the severity of the rash in some cases, the benign course and the long-term good prognosis of HZ in healthy children is noteworthy.

Herpes zoster and meningitis resulting from reactivation of varicella vaccine virus in an immunocompetent child

Herpes zoster complicated by meningitis has been mainly reported in immunocompromised patients after reactivation of wild-type varicella-zoster virus. We present one of the first cases of aseptic meningitis after herpes zoster caused by reactivation of vaccine-type varicella-zoster virus in an immunocompetent child. We also highlight the increasing role of both wild-type and vaccine strains of varicella-zoster virus as a cause of viral meningoencephalitis and the use of appropriate laboratory tools to rapidly and accurately identify the virus in order to provide prompt patient care and management.