Negative History Of Varicella Research Articles

Varicella seroprevalence in individuals with a negative or unknown varicella history - results from a large travel clinic in Switzerland between 2008 and 2015.

In Switzerland, vaccination against varicella is not recommended in the basic immunisation schedule. However, for individuals aged 11-40 years who do not have a reliable varicella history the Swiss Federal Office of Public Health recommends either (i) a vaccination or (ii) a serology test and vaccination of those with a negative result. In the Travel Clinic of the University of Zurich, the second strategy is followed. In this study we retrospectively assessed the overall percentage of individuals with varicella-specific antibodies despite a negative history and we examined the influence of age, number of siblings, order of siblings, age difference to siblings and nationality on varicella seropositivity. Between December 2008 and August 2015, the sera of 1757 individuals with a negative varicella history were tested for varicella antibodies. A total of 1593 individuals (91%) had a positive result. We found an increasing trend for varicella seropositivity with increasing age. Those aged less than 40 years were significantly more often seronegative (9.5%) than those aged 40 years and above (6.0%, p = 0.049). Seropositivity was associated with nationality. The percentage of seropositives increased with the number of siblings. Our results indicate that, despite the significant varicella seropositivity differences between those aged below and above, the age of 40 may not be an ideal threshold for performing a varicella serology in individuals with a negative or unknown varicella history. In the age groups above 40, testing for varicella antibodies may be especially reasonable in individuals with no or a small number of siblings and in those of specific nationalities.

Chickenpox and shingles: one virus, two diseases and current vaccination recommendations in Switzerland

Adults, pregnant women, premature babies and immunocompromised persons are at increased risk for varicella complications. Therefore the current Swiss vaccination recommendations against varicella include a general recommendation for 11 to 15 year old adolescents with a negative varicella history, as well as a specific recommendation for risk groups. The goal of both recommendations is to reduce varicella complications in persons most at risk. The vaccine is not universally recommended for all toddlers in Switzerland, while this is the case in some countries such as the United States. Pros and cons of different vaccination strategies, as well as possible short- and long-term effects on herpes zoster incidence are taken into account. In the United States, there was a marked decline in incidence and hospitalisations, but an increased herpes zoster incidence in the short term. Finally, public health aspects of herpes zoster, post-herpetic neuralgia and possible vaccination strategies are outlined.

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.

Seroepidemiology of varicella‐zoster virus and reliability of varicella history in Turkish children, adolescents and adults

This study aimed to assess the age specific varicella-zoster virus (VZV) seroprevalence in Izmir, Turkey and to determine the reliability of a history of varicella to detect susceptible children, adolescents and adults. A questionnaire, including previous history of varicella, was completed for each participant and, in 590 of them, VZV-specific IgG was measured using an ELISA test. Overall, 28.5% of individuals were seronegative for VZV. By 5 years of age, only 25.5% of children were seropositive for VZV. Among adolescents and young adults, 18.8% and 11.7% were seronegative, respectively. The negative predictive value was 57.8%, decreasing with age (81.9% in children, 34.5% in adolescents and 8.3% in adults). In conclusion, a negative history of varicella is not a reliable predictor of varicella antibody status in adolescents and young adults. Serological testing before immunisation will be logical, rather than presumptive vaccination, for adolescents and adults with negative history of varicella.

Presumptive varicella vaccination is warranted in Greek adolescents lacking a history of disease or household exposure

Current practice favors serotesting adolescents with a negative history of chickenpox rather than offering presumptive vaccination. Recent epidemiologic data from Greece indicate that a high proportion of adolescents (21.5%) are susceptible to chickenpox. We assessed the reliability of negative varicella history in relation to type of exposure in 311 children and 283 adolescents. In children with social or unknown exposure to varicella, a negative history had a high negative predictive value (NPV = 73.5), supporting the clinical practice of presumptive vaccination. Conversely, children with a negative history and household exposure had a low NPV (13.8), suggesting that pre-vaccination serologic testing is warranted. In conclusion, based on our local epidemiologic data, presumptive varicella vaccination should be offered to all adolescents with the exception of the subgroup of adolescents with household exposure.

Varicella vaccination in Europe: are we ready for a universal childhood programme?

Safe and effective vaccines against varicella zoster virus (VZV), the aetiological agent of varicella and shingles, have been available in Europe for the last 5-10 years. The USA has had a universal childhood vaccination policy since 1995 and this has resulted in a dramatic decrease in the incidence, morbidity and mortality related to varicella. The economic and medical burden of VZV has led to discussions regarding both the desirability and feasibility of a similar routine immunisation policy for all European children. This article examines the epidemiology of varicella in Europe and how the data emerging from the USA can be used to achieve adequate prevention of the disease. It looks into the current evidence of the health economic evaluation of universal varicella vaccination and explores the concerns surrounding such a policy, including the postulated impact on the incidence of zoster. In conclusion, the Society of Independent European Vaccination Experts (SIEVE) recommends that the immunisation of susceptible adolescents needs to be urgently implemented, in addition to the current recommendations targeting high-risk patients, their close contacts with a negative history of varicella and seronegative health-care workers. A universal policy, optimally incorporating a two-dose schedule, will be needed to finally reduce the burden of disease of varicella from a societal point of view. The SIEVE recommends the implementation of such a policy as soon as financially and practically possible.

Varicella Among Immigrants from the Tropics, a Health Problem

The incidence of varicella in Tamil refugees in Denmark was evaluated. Of 256 Tamils, 44% developed varicella infection in the first few months after arrival, representing 38% of the adults, and 68% of the children. During approximately four months' observation in Denmark, 75% of the refugees with no history of varicella developed a typical infection whereas only 2% of those with a history of varicella developed the disease. Tropical refugees with a negative history of varicella must therefore be considered nonimmune. Nine of 44 fertile women were pregnant. Two acquired the varicella infection during the first-trimester, none in relation to delivery. By organizing a health-check on arrival, prophylactic measures can reduce the health hazard of varicella infection in refugees from the tropics.