Article

Decline in influenza-associated mortality among Dutch elderly following the introduction of a nationwide vaccination program.

Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands.
Vaccine (Impact Factor: 3.49). 09/2008; 26(44):5567-74. DOI: 10.1016/j.vaccine.2008.08.003
Source: PubMed

ABSTRACT With a retrospective nationwide cohort study in the Netherlands over 1992-2003, using mortality and viral surveillance data, the aim was to assess by means of rate difference methods the influenza-associated mortality in the elderly before and after the introduction of a nationwide influenza vaccination program in 1996 (vaccination coverage raised from below 50 to 80%). The average annual influenza-associated mortality declined in the years before and after the introduction from 131 to 105 per 100,000 persons (relative risk 0.80). The decline was largest in the age group 65-69 years (relative risk 0.54) and less in those aged 75 years and older. Validation by Serfling-type regression analysis revealed similar results. In conclusion, routine influenza vaccination among Dutch elderly was associated with a significant decrease in influenza-associated mortality, notably in those aged 65-69 years.

Full-text

Available from: Eelko Hak, Apr 17, 2015
0 Followers
 · 
73 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Influenza affects 5-15% of the population during an epidemic. In Western Europe, vaccination of at-risk groups forms the cornerstone of influenza prevention. However, vaccination coverage of the elderly (> 65 y) is often low in Central and Eastern Europe (CEE); potentially because a paucity of country-specific data limits evidence-based policy making. Therefore the medical and economic burden of influenza were estimated in elderly populations in the Czech Republic, Hungary, Kazakhstan, Poland, Romania, and Ukraine. Data covering national influenza vaccination policies, surveillance and reporting, healthcare costs, populations, and epidemiology were obtained via literature review, open-access websites and databases, and interviews with experts. A simplified model of patient treatment flow incorporating cost, population, and incidence/prevalence data was used to calculate the influenza burden per country. In the elderly, influenza represented a large burden on the assessed healthcare systems, with yearly excess hospitalization rates of ~30/100 000. Burden varied between countries and was likely influenced by population size, surveillance system, healthcare provision, and vaccine coverage. The greatest burden was found in Poland, where direct costs were over EUR 5 million. Substantial differences in data availability and quality were identified, and to fully quantify the burden of influenza in CEE, influenza reporting systems should be standardized. This study most probably underestimates the real burden of influenza, however the public health problem is recognized worldwide, and will further increase with population aging. Extending influenza vaccination of the elderly may be a cost-effective way to reduce the burden of influenza in CEE.
    Human Vaccines & Immunotherapeutics 10/2013; 10(2). DOI:10.4161/hv.26886 · 3.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the impact on mortality due to pneumonia or influenza of the change from risk-based to age group-based targeting of the elderly for yearly influenza vaccination in England and Wales. Excess mortality estimated using time series of deaths registered to pneumonia or influenza, accounting for seasonality, trend and artefacts. Non-excess mortality plotted as proxy for long-term trend in mortality. England and Wales. Persons aged 65-74 and 75+ years whose deaths were registered to underlying pneumonia or influenza between 1975/1976 and 2004/2005. Multiplicative effect on average excess pneumonia and influenza deaths each winter in the 4-6 winters since age group-based targeting of vaccination was introduced (in persons aged 75+ years from 1998/1999; in persons aged 65+ years from 2000/2001), estimated using multivariable regression adjusted for temperature, antigenic drift and vaccine mismatch, and stratified by dominant circulating influenza subtype. Trend in baseline weekly pneumonia and influenza death rates. There is a suggestion of lower average excess mortality in the six winters after age group-based targeting began compared to before, but the CI for the 65-74 years age group includes no difference. Trend in baseline pneumonia and influenza mortality shows an apparent downward turning point around 2000 for the 65-74 years age group and from the mid-1990s in the 75+ years age group. There is weakly supportive evidence that the marked increases in vaccine coverage accompanying the switch from risk-based to age group-based targeting of the elderly for yearly influenza vaccination in England and Wales were associated with lower levels of pneumonia and influenza mortality in older people in the first 6 years after age group-based targeting began. The possible impact of these policy changes is observed as weak evidence for lower average excess mortality as well as a turning point in baseline mortality coincident with the changes.
    BMJ Open 08/2013; 3(8). DOI:10.1136/bmjopen-2013-002743 · 2.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Determine the burden of illness associated with respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) in adults, especially young adults. Prospective surveillance study using RT-PCR for the diagnosis of RSV and HMPV. One academic Emergency Department (ED), one academic hospital and three middle Tennessee community hospitals. We prospectively enrolled Middle Tennessee residents ≥18 years old evaluated in the emergency department (ED) or hospitalized for respiratory symptoms May 2009 through April 2010. We collected nose/throat specimens for RSV and HMPV reverse-transcriptase polymerase chain reaction (RT-PCR) testing and obtained demographic and clinical data. Rates of ED visits and hospitalizations were calculated using the proportion of enrolled patients positive for each virus multiplied by the number of Middle Tennessee residents evaluated in EDs and/or hospitalized in Tennessee for acute respiratory illness during the study period. Three thousand two hundred and fifty six patients were eligible; 1477 (45·4%) were enrolled; 1248 (84·5%) of these consented to additional testing and had adequate samples. RT-PCR identified 32 (2·6%) patients with RSV and 33 (2·6%) with HMPV. The median duration of symptoms before ED presentation was 3·3 days with RSV and 2·8 days with HMPV, and before hospital admission was 4·5 days with RSV and 3·5 days with HMPV. The annual hospitalization and ED visit rates were similar for RSV and HMPV. The hospitalization rate associated with each virus was about 10 per 10 000 persons aged ≥50 years; ED rates were approximately 2 times higher. Hospitalization rates were about 2 per 10 000 persons aged 18-49 years, with ED rates 5-6 times higher. RSV and MPV are associated with substantial disease in adults, with hospitalization and ED visits rates increasing with age.
    Influenza and Other Respiratory Viruses 02/2014; 8(3). DOI:10.1111/irv.12234 · 1.90 Impact Factor