Varicella Immunization Research Articles

IN4 Economic Impact of Routine Childhood Immunization in the 2017 United States Birth Cohort

This study evaluated the economic impact of routine childhood immunization in the United States (US), which should be reassessed periodically as uptake, disease epidemiology, and recommendations change. Previous estimates did not include annual influenza immunization and impact of immunization on quality-adjusted life years (QALYs). Separate decision trees were used to model each of the 14 vaccine-preventable diseases covered by routine childhood immunizations (i.e., DTaP, Haemophilus influenzae type b, hepatitis A, hepatitis B, inactivated poliovirus, influenza, MMR, pneumococcal conjugate, rotavirus, and varicella immunizations). The 2017 US birth cohort was followed for their remaining lifetime, with the model calculating direct medical costs associated with routine immunization and cases of illness for a scenario with and without immunization (based on current and pre-vaccine era disease incidence estimates, respectively). For the societal perspective, the model also includes productivity losses associated with immunization (influenza only), cases of disease, and disease-related mortality. The model estimates discounted incremental cases, disease-related deaths, life years (LYs) lost, quality-adjusted life years (QALYs) lost, costs (2018 USD), and an overall benefit-cost ratio (BCR). Across all vaccine-preventable diseases, routine childhood immunization resulted in the prevention of more than 18 million cases of disease, 12,000 deaths, 200,000 LYs lost, and 300,000 QALYs lost. Although the childhood vaccination program was associated with vaccination costs of nearly $8 billion from the direct medical cost perspective and over $9 billion from the societal perspective, these costs were fully offset by disease-related costs averted. Childhood immunization was associated with over $10 billion in averted direct medical costs (BCR > 2) and over $20 billion in averted societal perspective costs (BCR > 3). Results from the current economic evaluation highlight the value of the childhood immunization program in preventing disease-related morbidity, mortality, QALY loss, and associated costs.

Adherence to guidelines across different specialties to prevent infections in patients undergoing immunosuppressive therapies

BackgroundSubstantial numbers of patients are now receiving either immunosuppressive therapies or chemotherapy. There are significant risks in such patients of developing opportunistic infections or re-activation of latent infections, with higher associated morbidity and mortality. The aim of this quality improvement project was to determine how effective 5 different specialties were in assessing and mitigating risks of developing opportunistic infections or re-activation of latent infections in patients undergoing immunosuppressive therapies.MethodsThis was a single centre audit where records of patients attending clinics providing immunosuppressive therapies were reviewed for the following: evidence of screening for blood-borne virus [BBV] infections, varicella and measles immunity, latent/active TB or hypogammaglobulinaemia, and whether appropriate vaccines had been advised or various infection risks discussed. These assessments were audited against both national and international guidelines, or a cross-specialty consensus guideline where specific recommendations were lacking. Two sub-populations were also analysed separately: patients receiving more potent immunosuppression and black and minority ethnic [BME] patients,.ResultsFor the 204 patients fulfilling the inclusion criteria, BBV, varicella/measles and latent TB screening was inconsistent, as was advice for vaccinations, with few areas complying with specialty or consensus guidelines. Less than 10% of patients in one specialty were tested for HIV. In BME patients screening for HIV [60%], measles [0%] and varicella [40%] immunity and latent [30%] or active [20%] TB was low. Only 38% of patients receiving potent immunosuppression received Pneumocystis prophylaxis, with 3 of 4 specialties providing less than 15% of patients in this category with prophylaxis.ConclusionsCompliance with guidelines to mitigate risks of infection from immunosuppressive therapies was either inconsistent or poor for most specialties. New approaches to highlight such risks and assist appropriate pre-immunosuppression screening are needed.

Evaluation of Varicella Immunity during Pregnancy in Apulia Region, Southern Italy.

Varicella is a highly contagious, infectious disease caused by the varicella-zoster virus. Those at higher risk of severe complications are immunocompromised individuals, adults, non-immune pregnant women, and newborns. According to the gestational time, when varicella-zoster virus infection is acquired during pregnancy, serious complications can potentially occur for both the woman and the fetus. The present study was conducted to assess the profile of varicella susceptibility in pregnant women in Apulia, a large region in Southern Italy, from 2016 to 2019. The data showed that pregnant women between the age of 15–24 and 40–49 years, the youngest and the oldest, respectively, are the most protected against varicella-zoster virus infection, exceeding the prevalence rate of 90%. Conversely, pregnant women between the age of 25 and 34 years seem to be the most vulnerable and the most at risk for acquiring varicella-zoster virus infection during pregnancy. Analysis of the immunity status against varicella should be introduced as a screening test before pregnancy, together with a strategic vaccination campaign targeting non-immune women of childbearing age, in order to reduce the risk of congenital and perinatal varicella.

Varicella seroepidemiology and immunization in a cohort of future healthcare workers in the pre-vaccination era

ObjectivesThe goal of this study was to establish the seroprevalence of positive antibodies against varicella and compliance with varicella vaccination in the pre-vaccination era. MethodsA cohort of 10 683 Italian students from Padua University Medical School (from 2004 to 2019) were enrolled and classified as unvaccinated, vaccinated once, or vaccinated twice against varicella, according to their vaccination certificate. The antibody titre was measured and the seroprevalence of positive subjects was determined. Subjects with negative or equivocal antibodies were invited for vaccination, and then the antibody titre was retested. ResultsUnvaccinated students were mostly seropositive (95.6%), compared with vaccinated students who were less seropositive (68.0% after one dose and 78.6% after two doses) and had significantly lower antibody titres (p < 0.0001). The post-test vaccination had a positive response rate of 85.4%: 67.4% after one dose and 91.4% after two doses. ConclusionsIn the pre-vaccination era, only 3.3% of future healthcare workers were vaccinated against varicella (1.1% once and 2.2% twice). Vaccination or revaccination of negative and equivocal individuals could reduce the number of susceptible people. Implementation of varicella vaccine (two doses) in healthcare workers is of primary importance to reduce the risk of transmission.

Characteristics of breakthrough varicella cases with different doses of varicella vaccine immunization history in Tongzhou District of Beijing during 2013 to 2017

Objective To analyze the epidemiological characteristics of breakthrough varicella cases with different doses of varicella vaccine immunization history in Beijing Tongzhou from 2013 to 2017. Methods Data about varicella incidence and immunization history were obtained through spot investigation and consulting the information systems of Chinese Disease Control and Prevention and Beijing′s Immunization Programme. Descriptive epidemiological method was used for statistical analysis. Results From 2013 to 2017, Tongzhou District reported 2 102 cases of varicella in primary and middle schools and kindergartens, which included 989 cases of primary varicella, 966 breakthrough varicella cases with one-dose vaccine immunization history, and 147 breakthrough varicella cases with two-dose vaccine immunization history. There were significant differences in gender, age, and occupation among the three groups. Among the primary cases, the incidence of fever and moderate and severe rash was 46.71% and 34.68%; among the breakthrough cases with one-dose immunization history, the incidence of fever and moderate and severe rash was 41.20% and 17.39%; among the breakthrough cases with two-dose immunization history, the incidence of fever and moderate and severe rash was 26.53% and 7.48%. There were significant differences in the incidence of fever and rash among the three groups. The median number of varicella morbidity interval was 5.11 years in one-dose immunization history group and 2.44 years in two-dose immunization history group, and the difference between them was statistically significant. Conclusions The symptoms of fever and rash in breakthrough varicella cases become less atypical as the dose of vaccination increases. Because the clinical symptoms are relatively mild, breakthrough cases as a source of infection in collective units are more likely to be neglected. Key words: Varicella; Breakthrough case; Characteristics

Assessment of pre-specified adverse events following varicella vaccine: A population-based self-controlled risk interval study

BackgroundClinical trials and spontaneous reporting systems have revealed rare but biologically plausible adverse events following varicella immunization. Few post-marketing controlled studies have been conducted to assess the relationship between the varicella vaccine and these outcomes. ObjectivesTo evaluate the risk of pneumonia, idiopathic thrombocytopenic purpura (ITP), meningitis, encephalitis and ischemic stroke following varicella immunization. Materials and methodsThis nationwide observational study was based on Taiwan National Health Insurance data and National Immunization Information System from 2004 through 2014. Primary analysis included children aged 12–35 months who received the single varicella vaccine on the date of administration. The self-controlled risk interval design compared the incidence of pre-specified outcomes during a risk interval of 1–42 days post-vaccination and a control interval of 43–84 days. The outcomes of interest were defined as admitted pneumonia, ITP, meningitis, encephalitis, and ischemic stroke, as well as fracture as a negative control. Conditional Poisson regression was used to assess the incidence rate ratio (aIRR) with adjustments for age and seasonal effects. ResultsAmong 1,194,189 children, who receiving the varicella vaccine, there was no observed increase in the risk for ITP (aIRR 1.00; 95% CI, 0.76–1.33), meningitis (aIRR 1.21; 95% CI, 0.49–2.95), encephalitis (aIRR 1.00; 95% CI, 0.62–1.60), or ischemic stroke (aIRR 1.24; 95% CI, 0.31–4.95). A clustering feature with pneumonia occurred during days 36–42 post-vaccination (aIRR 1.10; 95% CI, 1.02–1.18). An increase in the risk for ITP was observed in children receiving the varicella and MMR vaccines concomitantly (aIRR 1.70; 95% CI, 1.19–2.43), but not among those receiving the varicella vaccine only. ConclusionsWe detected a small risk of incidental pneumonia associated with varicella vaccine in the 6th week after immunization. There was no increase in the risk of other pre-specified adverse events.

Assessment of the Clinical and Economic Impact of Different Immunization Protocols of Measles, Mumps, Rubella and Varicella in Internationally Adopted Children.

The appropriate immunization of internationally adopted children (IAC) is currently under debate and different approaches have been suggested. The aim of this study is to evaluate the clinical and economic impact of different strategies of measles, mumps, rubella, and varicella (MMRV) immunization in IAC in Italy. A decision analysis model was developed to compare three strategies: presumptive immunization, pre-vaccination serotesting and vaccination based on documentation of previous immunization. Main outcomes were the cost of strategy, number of protected IAC, and cost per child protected against MMRV. Moreover, the incremental cost-effectiveness ratio (ICER) was calculated. The strategy currently recommended in Italy (immunize based on documentation) is less expensive. On the other hand, the pre-vaccination serotesting strategy against MMRV together, improves outcomes with a minimum cost increase, compared with the presumptive immunization strategy and compared with the comparator strategy. From a cost-effectiveness point of view, vaccination based on serotesting results in being the most advantageous strategy compared to presumptive vaccination. By applying a chemiluminescent immunoassay test, the serology strategy resulted to be clinically and economically advantageous. Similar results were obtained excluding children aged <1 year for both serology methods. In conclusion, based on our analyses, considering MMRV vaccine, serotesting strategy appears to be the preferred option in IAC.

Risk of herpes zoster after exposure to varicella to explore the exogenous boosting hypothesis: self controlled case series study using UK electronic healthcare data

ObjectiveTo assess the magnitude and duration of any hypothesised protective effect of household exposure to a child with varicella on the relative incidence of herpes zoster in adults.DesignSelf controlled case...

Measles, Mumps, Rubella, and Varicella Immunity among Nursing Staff in a Major Hospital, Riyadh, Saudi Arabia.

Introduction:Measles, mumps, rubella, and varicella (MMRV) represent risk to HCWs. Checking on antibodies against MMRV is an important part of infection control among nursing staff for their own health, their colleagues and for the health of patients. Screening for immunity against MMRV is an initial step before vaccination of nursing staff. This study is to describe immunity status against MMRV by screening nursing staff in a tertiary care hospital in Riyadh.Methods:A cross sectional survey among nursing staff was conducted from July to August 2019 at Prince Sultan Military Medical City. A convenience sampling was used to screen 1534 nursing staff working at several high-risk departments. Record for their immune status and antibody titer for MMRV were reviewed using a data collection form.Results:Screening for immunity among nursing staff found that; 79.3% were immune against measles; 75.5% to be immune against mumps; 95.8% were immune against rubella; and 67% were immune against varicella. The highest proportion of immune nursing staff against measles (96.3%) and varicella (93.5%) was found in Intensive care department while the highest proportion of immune staff against mumps (89.4%) was found in Long Stay department, and against rubella (97.5%) in Hemodialysis department. On the other hand, It was found that Hemodialysis Department had the Highest proportion of non-immune staff against measles (35.6%), mumps (39%), and varicella (56.3%), while Emergency Department had the lowest proportion of immune staff (6%) against rubella.Conclusion:Despite that immunity among nurses screened was good on some departments; however, such results need improvement in these critical areas. These finding emphasize the importance of the currently mandatory screening for MMRV before employment. We suggest conducting comprehensive programs to increase awareness and vaccination coverage in areas with low rates of immunity.

Optimising immunisation in children with 22q11 microdeletion

Background:The condition known as 22q11 microdeletion syndrome has a broad phenotypic spectrum, with many affected individuals experiencing mild-to-moderate immunodeficiency. Currently, there are significant variations in live vaccine practices and immunological testing prior to live vaccine administration due to safety concerns and limited established guidelines.Methods:Queensland Children’s Hospital (QCH) Child Development Unit, offers a state-wide 22q11 microdeletion clinic. This is a retrospective single-centre review, capturing the majority of children with 22q11 microdeletion in Queensland, Australia. We describe the live vaccination status of 134 children, age 0 to 18 years under our care between 2000 and 2018, adverse events following immunisation (AEFI) and the proportion of children who received additional pneumococcal coverage. An immunological investigation pathway prior to live vaccine administration is proposed.Results:Of the 134 children, 124 were eligible for live vaccinations as per the Australian National Immunisation Program: 82% had received dose one of measles, mumps and rubella (MMR) vaccine, 77% had completed MMR dose two and 66% had completed varicella immunisation. There were no AEFI notifications reported. Of the total sample of children, 18% received a fourth dose of conjugate pneumococcal vaccine (Prevenar 7 or 13) and 16% received a dose of Pneumovax 23 from 4 years of age. Immunology workup practices were demonstrated to vary widely prior to live vaccine administration. Most patients’ immune profiles were consistent with mild-to-moderate immunodeficiency.Conclusion:We propose an immunological investigation and vaccination pathway with the aim of providing guidance and consistency to clinicians caring for children with 22q11 microdeletion.

A Decade of Varicella Screening Within a Paediatric Inflammatory Bowel Disease Population.

Increased risk of opportunistic infection-e.g., varicella zoster infection-secondary to therapies is a cause of morbidity in inflammatory bowel disease [IBD] patients. The UK vaccination schedule does not include varicella immunisation. We aimed to evaluate the varicella screening and immunisation programme in a paediatric IBD population. Data regarding IBD diagnosis, varicella status, and consequent immunisations/treatment interventions were collected retrospectively from the records of patients diagnosed with IBD over a 10-year period [2009-2018]. In all, 520 IBD patients were diagnosed; 505/520 [97%] had varicella testing; 46/505 [9%] were naïve. Of 501 patients, 391[78%] were tested before or within 7 days of diagnosis; this increased in the second 5-year period compared with the first (229/268 [85%] versus 162/233 [70%]; p <0.00001). Median diagnosis age of naïve patients was lower [8.3 years versus 12.8 years; p <0.00001]. Where vaccination was feasible, 21/31 [68%] had two and 7/31 [23%] one immunisation. Prednisolone induction led to lower rates of vaccination (5/13 [39%] versus 23/33 [70%] for other induction therapies; p =0.02). Of 28 vaccinated patients, 5 [18%] had suspected breakthrough varicella; and 6/18 [33%] unimmunised patients required post-exposure prophylaxis or treatment for varicella. Immunisation was associated with a decrease in patients requiring post-exposure prophylaxis (0/28 [0%] versus 5/18 [28%]; p =0.0006) and varicella-related hospital admission (1/28 [4%] versus 4/18 [22%]; p =0.01). High rates of varicella screening and immunisation within a PIBD population are possible, resulting in a reduction in hospital admissions for varicella treatment. Varicella immunisation may be of increasing importance within the PIBD population with the emergence of novel therapeutic strategies.

P18 Audit on pre-methotrexate screening in a paediatric rheumatology centre

Abstract Background The BSPAR section council consensus-based guidance is the most widely used guideline on the use of methotrexate. This recommends that varicella immunity status is checked prior to commencing methotrexate and to consider immunisation if the child is non-immune. It also suggests considering checking measles status and testing for TB in high risk patients. We aim to evaluate our practice of screening paediatric rheumatological patients prior to commencing them on methotrexate. All patients in our centre have methotrexate teaching with a clinical nurse specialist prior to commencing treatment. Methods This study included paediatric patients who were prescribed methotrexate in all forms (subcutaneous, intravenous and orally) for rheumatological conditions and uveitis during a 2-year period (2016 – 2018) regardless of when it was first commenced. Digital health records were accessed to obtain the data retrospectively. Patients were excluded if they had been started on methotrexate prior to joining our centre, or were lost to follow up during the study period or if the required data was unavailable. Results 123 patients were identified to have been prescribed methotrexate during the 2-year study period and 102 patients were included in the study. 28 patients were commenced on methotrexate during 2016 /17 and others were commenced anytime between 2008 -2015. 91 (89%) patients had their varicella status checked prior to commencing methotrexate and 7 patients were checked after treatment was commenced. It was not checked in 4 patients (1 sample rejected and not repeated). Of those checked 20 patients were non-immune and 16 were vaccinated. 57 patients had had measles serology checked, 31 of these prior to commencing methotrexate. 35 patients had TB Quantiferon checked prior to methotrexate being started and 39 after. There were no positive results and 6 (8%) indeterminate of which 5 were repeated and 4 were negative. Of the indeterminate results 4 samples were taken prior to commencing methotrexate and 2 after. Conclusion This study shows that local adherence to checking varicella status prior to commencing methotrexate and vaccinating non-immune patients is good. Routine practice for checking measles, hepatitis and TB is varied. The data was captured over a 2-year period but actually included practice of methotrexate commencement over 9 years and thus time span and change in doctors will have contributed to the variation in practice. We believe some results from outreach clinics were not captured. All four tests are often carried out if it is felt the patient is likely to go on to require biologics. An updated guideline would help streamline the pre-DMARD screening and may limit the number of unnecessary investigations. Conflicts of Interest The authors declare no conflicts of interest.

Varicella vaccination in children with acute lymphoblastic leukemia: Experience from a pediatric cancer centre in India

BackgroundVaricella infection in children with Acute Lymphoblastic Leukemia (ALL) is associated with significant morbidity and mortality. Immunisation against varicella infection is not mandatory as per the national immunisation program in India and therefore the majority of children with ALL are unimmunised and are at an increased risk of infection. MethodsThe present study retrospectively analysed the case records of patients with ALL diagnosed between January 2013 and May 2017 and received the varicella vaccine. Patients with ALL who had no previous history of varicella infection or immunisation and were in remission were given a single dose of live attenuated varicella vaccine prior to the start of the maintenance phase of treatment. ResultsThe study included 125 patients with a median age of 6 years and 57% patients were males. Fifty-two patients (41%) developed vaccine-induced varicella. The median time to develop vaccine-induced varicella was 21 days (range: 10–35 days). The median duration of fever was 2 days (range; 1–8) and 5 patients developed febrile neutropenia. Maintenance chemotherapy was withheld in symptomatic patients for a median duration of 7 days (range: 3–15 days). Breakthrough varicella infection after vaccination was seen in 2 patients. There was no mortality due to vaccine-induced varicella. ConclusionVaricella immunisation is safe and efficacious in children with ALL and should be considered in countries where varicella immunisation is not routinely practiced. Vaccine-induced varicella is commonly seen; however, it is self-limiting.

Seroprevalence and molecular characteristics of varicella-zoster virus infection in Chinese children

BackgroundVaricella-zoster virus (VZV) infection in children is an important public health problem in China. We performed the current study to explore the seroprevalence of VZV infection in Chinese children in order to provide more information for improvement of varicella vaccination in China.MethodsThree thousand fourteen children were recruited from Chinese kindergarten students aged from four to six years. Anti-VZV IgG and IgM were assayed using enzyme-linked immunosorbent assay. Both ORF22 and ORF62 of VZV were amplified, sequenced, and analyzed by nested PCR.ResultsAmong 3014 children, 43.9% of boys and 46.3% of girls were vaccinated with varicella vaccine, respectively. The seroprevalence of anti-VZV IgG was 54.4% in the children with varicella vaccination, which was significantly higher than those in unvaccinated children (49.2%) (χ2 = 8.206, P = 0.004). Among of the vaccinated children, the detection rates of VZV IgG antibody increased with age, with 49.4, 50.9 and 58.9% in 4, 5 and 6-year groups, respectively (Trend χ2 = 17.202, P = 0.002). However, there was no difference in anti-VZV IgG detection rates among those unvaccinated children in different age groups (Trend χ2 = 8.681, P = 0.070). In addition, 13 boys and 13 girls were positive for anti-VZV IgM, respectively. Among of them, eight children (0.6%) have received varicella vaccination, which was similar to those in unvaccinated children (1.1%). However, only one ORF22 sequence was isolated from an unvaccinated 5-year boy. Compared to the reference VZV sequences, the nucleotide homology was estimated to be 99.7% with genotype J.ConclusionsOur study indicated that about half of Chinese children aged four to six years have a high risk of VZV infection. It should be helpful for the evaluation on the necessity of varicella immunization in China.

Measles, mumps, rubella (vaccine) and varicella vaccines in pediatric liver transplant: An initial analysis of post-transplant immunity.

Varicella and measles infection represents a significant source of morbidity and mortality for pediatric LT recipients. We evaluated the prevalence and correlates of post-transplant immunity in pediatric LT recipients previously immunized against measles (n=72) and varicella (n=67). Sixteen of seventy-two (22%) patients were measles non-immune, and 42/67 (63%) were varicella non-immune after LT. Median time from LT to titers for measles and varicella was 4.0 and 3.3years, respectively. In the measles cohort, non-immune patients received fewer pretransplant vaccine doses (P=0.026) and were younger at both time of vaccination (P=0.006) and LT (P=0.004) compared with immune patients. Upon multivariable analysis, weight>10kg at LT (OR 5.91, 95% CI 1.27-27.41) and technical variant graft (OR 0.07, 95% CI 0.01-0.37) were independently, significantly associated with measles immunity. In the varicella cohort, non-immune patients received fewer pretransplant vaccine doses (P=0.028), were younger at transplant (P=0.022), and had less time lapse between their last vaccine and transplant (P=0.012) compared with immune patients. Upon multivariate analysis, time>1year from last vaccine to LT was independently, significantly associated with varicella immunity (OR 3.78, CI 1.30-11.01). This study demonstrates that non-immunity to measles and varicella is a prevalent problem after liver transplantation in children and identifies 3 unique risk factors for non-immunity in this high-risk population.

Improving Assessment and Documentation of Routine Prenatal Care Using a Standardized Template [40L

INTRODUCTION: Routine prenatal care is a vital aspect of improving both maternal and infant morbidity. Standardizing clinical documentation, using templates and automatic alerts, can improve patient care by ensuring providers cover all aspects of routine prenatal care. The objective of this study was to evaluate improvement in the assessment and documentation of routine prenatal care after implementing a standardized electronic template. METHODS: This was a retrospective review of postpartum visits at a single obstetrical clinic affiliated with an obstetrics and gynecology residency program. A sample of fifty charts was reviewed before and after implementation of a standardized electronic prenatal care template. Charts were evaluated for provider counseling and documentation on the basic prenatal care recommended for all pregnant patients. Gestational age at the last prenatal visit and number of prenatal visits attended was collected. IRB committee approval was waived for this quality improvement project. RESULTS: Average gestational age at the last prenatal appointment and average number of prenatal visits was similar for both time periods. After implementing the template, there was an improvement in addressing and documenting the following topics: group prenatal classes (56%), genetics (10%), complete pregnancy ultrasound (4%), prenatal 2s (4%), early diabetes mellitus (10%), diabetes mellitus (88%), influenza (18%), GBS status (4%), contraception (24%), Varicella (72%), HPV vaccination (74%), breastfeeding (46%), safe sleep (76%), and Rh immunization (16%). CONCLUSION: Implementing a standardized template improved provider counseling and documentation of several key aspects of routine prenatal care, including improving discussion of important maternal health factors, vaccination, contraception, and intended postpartum care.

Susceptibility for varicella and factors associated with immunity among pregnant women in a tertiary care hospital in Sri Lanka- a cross-sectional study

BackgroundVaricella during pregnancy can lead to serious maternal and fetal consequences. Although an effective vaccine is available it is not incorporated in to the routine vaccination programs in most of the Asian countries. Objectives of the study were to determine the susceptibility to varicella and factors associated with immunity, among a group of pregnant women attending to a tertiary care hospital in Sri Lanka.MethodsA hospital based descriptive cross sectional study was carried out at De Soyza maternity Hospital, Colombo. A sample of 385 pregnant women was selected. Data were collected through an interviewer administered questionnaire; presence of varicella IgG in blood was assessed by a validated commercial ELISA (Enzyme Linked Immunosorbant Assay.ResultsThe sample had a mean age of 28.5 years and majority was educated beyond General Certificate of Education (GCE) Ordinary Level. We found that 34% of study population was susceptible for the infection. A past history of varicella had a 89.5% positive predictive value and 53.1% negative predictive value for varicella immunity. Varicella sero-positivity was only associated with a lower educational level and number of childhood household members more than four. There was no association of sero-positivity with age.ConclusionThis study demonstrates that a significant proportion of pregnant women of the study population are varicella-susceptible. Pre-pregnancy screening and preventive strategies including vaccination should be evaluated. History of past varicella infection could be a useful screening tool to exclude patients for vaccination.

2514. Pediatric Medically Attended Shingles in Alberta, Canada 2016; Preliminary Results

BackgroundHerpes zoster (shingles) is a reactivation of latent varicella virus. Shingles is uncommon in children and children vaccinated against varicella may be at a reduced risk of shingles. Alberta has a publicly funded healthcare system and added publicly funded varicella vaccine to the routine childhood vaccination schedule in 2001.MethodsWe used provincially held administrative health databases to examine the epidemiology of incident shingles cases in children under the age of 19. Incident shingles cases were defined as the earliest record of ICD-9-CM 053 OR ICD-10-CA B02 coded physician claims, hospital, or emergency room visits between 1985 and 2016, with incident cases in this cohort occurring between January 1, 2016 and December 31, 2016. Varicella immunization was identified through Alberta’s immunization repository and immunosuppressive comorbid conditions (neoplasms, HIV/AIDS, cystic fibrosis, and immune system disorders) were identified using ICD diagnostic codes from physician claims, hospital, or emergency room visits and Alberta’s Communicable Disease Control databases.Results1,003 incident shingles cases were identified in children under the age of 19 in 2016, a crude rate of 0.98/1,000 persons. Females comprised 54% of cases. The largest proportion of cases occurred among those aged 15–19 years. About 39% of cases were prescribed antiviral medication, most commonly those aged 15–19 years. The crude rate per 1,000 population increased with age: 0.5 for children under the age of 1, 1.2 for those 1–4 years, 1.25 for children 5–9 years, 2.19 for children 10–14 years, and 3.7 for children aged 15–19 years. Crude rates were similar among both males and females. Less than 3% of the cases had ever been immunized against varicella. Shingles diagnostic codes were not validated, which likely led to an overestimation of the true rates of disease.ConclusionAdditional studies are needed on pediatric shingles cases and factors that influence shingles in this group, as well as validation studies of ICD diagnostic coding in administrative data.Disclosures M. L. Russell, Novartis Pharmaceuticals Canada Inc.: Grant Investigator and Unconditional Research Grant, Grant recipient. Merck Frosst Canada Inc.: Grant Investigator and Unconditional Research Grant, Grant recipient.

Seroepidemiology of varicella zoster virus infection in Vojvodina, Serbia.

The present cross-sectional serosurvey constitutes the first effort to describe the varicella zoster virus (VZV) seroepidemiology in Serbia. An age-stratified serum bank of 3570 residual samples collected between 2015 and 2016 in each of the seven districts of the Vojvodina Province was tested for IgG anti-VZV antibodies with an enzyme immunoassay. Results were standardised into common units according to the European Sero-Epidemiology Network (ESEN2) methodology. Univariable and multivariable analyses were used to examine the relationships between standardised anti-VZV positivity or logarithmically transformed antibody titres and demographic features of study subjects. Seropositivity (85% overall) increased with age, in parallel with geometric mean titres. By the time of school entry, 68% of children were immune. The slower subsequent acquisition of immunity leaves epidemiologically relevant proportions of adolescents (7%), young adults (6%) and especially females of reproductive age (6%) prone to more severe forms of varicella. In the ongoing pre-vaccine era, natural infection provides a high level of collective immunity, with the highest VZV transmission in children of preschool age. The detected gaps in VZV immunity of the Serbian population support the adoption of the official recommendations for varicella immunisation of non-immune adolescents and young adults, including non-pregnant women of childbearing age.

Maritime varicella illness and death reporting, U.S., 2010-2015.

Ships destined for, or departing from, U.S. ports of entry must report certain signs and symptoms of potentially communicable diseases of public health interest among travelers to the Division of Global Migration and Quarantine (DGMQ) at the Centers for Disease Control and Prevention. We reviewed ships' varicella case and outbreak reports from January 2010 through December 2015. DGMQ received 967 reports of varicella and 13 reports of herpes zoster. Most varicella case-patients were 20-49 years of age (84.7%, 472/557) and were cruise ship crew members (78.4%, 758/967). Most often, cruise ship crew member case-patients were born in or held passports from Indonesia (21.7%, 80/369), Philippines (17.6%, 65/369), or India (17.3%, 64/369). Ninety-nine varicella outbreaks were reported, including 439 varicella cases and one herpes zoster case; 97 (98.0%) outbreaks occurred on cruise ships, and 90.2% of associated cases were among crew members (397/440). Most varicella cases were in crew members, who are adults often from tropical regions where varicella immunity is acquired later in childhood or young adulthood or without varicella vaccination programs. Varicella vaccination as appropriate for susceptible travelers, particularly crew members, before maritime travel may decrease risk of varicella infection and prevent outbreaks on ships.