Assessment of varicella underreporting in Italy (original) (raw)

A Study of Varicella Seroprevalence in a Pediatric and Adolescent Population in Florence (Italy). Natural Infection and Vaccination-Acquired Immunization

Vaccines

Background: Varicella is a well-known infectious disease that can have severe complications, also in young children. The Universal Varicella Vaccination (UVV) program was introduced in Tuscany (Italy) in 2003, with a two-dose vaccine schedule given to children between their 13th and 15th month, and at 5–6 years old, as a monovalent for varicella (V) or tetravalent (measles, mumps, rubella and varicella (MMRV)) formulation. Although varicella notifications have dramatically fallen in the last two decades, varicella disease underreporting remains a challenge. Methods: A qualitative immunoenzymatic test (ELISA) was used to measure the presence of anti-varicella antibodies in 165 sera of subjects aged 1–18 years residing in the province of Florence (Italy). Information regarding the anamnestic and vaccination status (including disease notification) was also collected. Results: Our study showed an overall varicella seropositivity of 75.8% (reaching the maximum at 96.3% in the 15–18 years...

Varicella: epidemiological aspects and vaccination coverage in the Veneto Region

BMC Infectious Diseases, 2009

Background: With the control of many infections through national vaccination programmes, varicella is currently the most widespread preventable childhood disease in industrialized nations. In 2005 varicella vaccination was added to the Veneto Region routine immunization schedule for all children at 14 months of age and 12 year-old susceptible adolescents through an active and a free of charge offer. To evaluate parameters at the start of the programme, we conducted a study to describe the epidemiology of varicella infection and coverage rates for varicella vaccine in the Veneto Region (North-East Italy).

Universal varicella vaccination in the Sicilian paediatric population: rapid uptake of the vaccination programme and morbidity trends over five years

Eurosurveillance, 2009

Following the licensure of the Oka/Merck varicella vaccine in Italy in January 2003, the Sicilian health authorities launched a universal vaccination programme in all nine Local Health Units. A two-cohort vaccination strategy was adopted to minimise the shift of the mean age of varicella occurrence to older age groups, with the goal of vaccinating with one dose at least 80% of children in their second year of life and 50% of susceptible adolescents in their 12th year of life. Two studies were implemented in parallel to closely monitor vaccination coverage as well as varicella incidence. Overall, the programme achieved its target, with 87.5% vaccine coverage for the birth cohort 2005 and 90.2% for adolescents born in 1995 and 1996. Varicella surveillance data obtained from a total of 28,188 children (0-14 years-old) monitored by family paediatricians showed a decline in incidence rates from 95.7 (95% confidence interval (CI): 72.2-126.8) for 1,000 person-years (PY) in 2004 to 9.0 (95...

Assessment of the effectiveness of the universal varicella vaccination program in Toscana (Italy), in the period 2010-2013

Epidemiologia e prevenzione

To assess the effectiveness of the varicella vaccination program in Toscana after one dose of vaccine, in the birth cohorts 2008-2011. Varicella vaccine effectiveness (VE) was calculated using the "screening method", based on vaccine coverage (VC) at 24 months and proportion of vaccinated subjects among varicella notified cases (PVC), verified through the Local Health Units' (LHUs) immunization registries. Breakthrough varicella (BV) was defined as a case of varicella occurring in a child vaccinated ≥42 days before the date of disease onset. The study was conducted in the 12 Tuscan LHUs and included all varicella cases notified in 2010-2013 in children of the birth cohorts 2008-2011. BV cases; VE after one dose of varicella vaccine; time interval between varicella vaccination and symptom onset. VC was 79.8%, VE reached 90.8%(95%CI 89.5%-92.0%) and the proportion of BV among notified cases was 26.6%. The median time interval between vaccination and symptom onset was 25 ...

Estimation of the burden of varicella in Europe before the introduction of universal childhood immunization

BMC infectious diseases, 2017

Varicella is generally considered a mild disease. Disease burden is not well known and country-level estimation is challenging. As varicella disease is not notifiable, notification criteria and rates vary between countries. In general, existing surveillance systems do not capture cases that do not seek medical care, and most are affected by underreporting and underascertainment. We aimed to estimate the overall varicella disease burden in Europe to provide critical information to support decision-making regarding varicella vaccination. We conducted a systematic literature review to identify all available epidemiological data on varicella IgG antibody seroprevalence, primary care and hospitalisation incidence, and mortality. We then developed methods to estimate age-specific varicella incidence and annual number of cases by different levels of severity (cases in the community, health care seekers in primary care and hospitals, and deaths) for all countries belonging to the European M...

The Epidemiology of Varicella Zoster Virus Infection in Italy

BMC Public Health, 2008

The epidemiological importance of varicella and zoster and the availability of an efficacious and safe vaccine have led to an important international debate regarding the suitability of mass vaccination. The objective of the study was to describe the epidemiology of varicella and zoster in Italy and to determine whether there have been changes with respect to observations provided by an analogous study conducted 8 years ago, in order to define the most appropriate vaccination strategy.

Analysis of the cost-effectiveness of varicella vaccine programmes based on an observational survey in the Latium region of Italy

Herpes : the journal of the IHMF, 2005

Varicella is the most widespread childhood disease in Italy. However, as in many parts of the world, the country does not yet have a unified approach to the management of the disease. A cost-effectiveness analysis of varicella vaccination strategies, using the Latium region in Italy as a case study, was undertaken. Mass vaccination is only recommended if the immunization programme can achieve coverage of over 85% in a short time. However, experience in Italy with non-compulsory vaccinations has shown this is difficult to achieve. Consequently, eradication of the disease is not seen as an attainable short-term goal. For mass varicella vaccination to be successful, it must be run at a national as well as regional level in combination with education programmes, and a reliable surveillance system. The interaction between varicella and herpes zoster must also be taken into account when considering vaccination strategies, as zoster vaccination strategies may have an impact on varicella co...