Sprenger, M.J.W.

Mortality benefits of influenza vaccination in elderly people (Article)

2008-08-01T00:00:00Z

Prevalence and risk factors for hepatitis B virus infections among visitors to an STD clinic (Article)

1997-12-01T00:00:00Z

Objective: To determine the prevalence and risk factors for hepatitis B virus (HBV) infections among individuals attending an STD clinic in a low endemic region. Study design: A total of 1228 women and 1648 men attending the STD clinic at the University Hospital Rotterdam, Netherlands, were examined for HBV infection by determination of hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B core antigen (anti-HBc). Demographic characteristics, information on sexual behaviour, and intravenous drug use were recorded. Results: The seroprevalence of HBsAg was 1.4% in women and 2.1% in men (0% in homosexual men). The seroprevalence of anti-HBc was 13% in women and 20% in men (36% in homosexual men). Native country, intravenous drug use, a history of STD, and the number of partners in the past half year (inversely) were independent risk factors for HBsAg positivity in women and heterosexual men. For anti-HBc independent associations were observed for native country, age, intravenous drug use, commercial sex, number of lifetime partners, homosexual contacts, orogenital contact (inverse), and a history of STD. Conclusion: The HBV prevalence in the STD clinic attendants was high, exceeding the national estimate, and indicates that the STD clinic population may be considered a high risk group. Our data confirmed an increased risk for HBV infections among established risk groups. Therefore, these risk groups should be routinely screened to identify HBV cases for counselling and contact tracing.

Impact of influenza on mortality in relation to age and underlying disease, 1967-1989 (Article)

1993-04-01T00:00:00Z

Based on data from the Dutch Central Bureau of Statistics, the impact of influenza on mortality in The Netherlands was estimated for a 22.5-year period (1967-1989) in four age groups and three entities of disease, using Poisson regression techniques. Our analysis suggests that, on average, more than 2000 people died from influenza in The Netherlands each year, but in only a fraction of these deaths was influenza recognized as the cause of death. For each case of death registered as caused by influenza (registered influenza mortality), 2.6 additional cases of death registered as due to causes other than influenza, nevertheless, were influenza-related (non-registered influenza mortality). Therefore, the overall impact of influenza on mortality is estimated to be greater than registered influenza mortality by a factor of 3.6. Those under 60 years of age accounted for 5% of all non-registered influenza deaths, whereas people aged 60-69, 70-79 years and > 80 years accounted for 12%, 29% and 54% of such deaths, respectively. When extrapolating the figures for the Dutch population of 1989, we could attribute, on average per season-year, 82 deaths per 100,000 people > 60 years, 143 in people > 70 years, and 280 in people > 80 years. Of all non-registered influenza cases of death, 47% were estimated to occur in people with heart disease as a primarily reported cause of death, 23% in those with lung disease, and 30% in those with other diseases. This study stresses the serious effects of influenza, mainly in the elderly (95% of non-registered influenza mortality)...

Antibody response after influenza immunization with various vaccine doses (Article)

1993-03-19T00:00:00Z

The dose effect (0, 10, 20 and 60 micrograms) of influenza subunit vaccine on the antibody response was investigated in nursing-home residents and young controls. The vaccine antigens were: A/Taiwan/1/86 (H1N1), A/Sichuan/2/87 (H3N2) and B/Beijing/1/87. For the influenza B antigen, the post-GMT and the 'percentage protective titre' increased significantly both in the young controls and nursing-home residents. No dose effect was observed for the A/Taiwan, and a minor dose effect for A/Sichuan. All vaccine doses were well tolerated by both groups. We conclude from our data that higher vaccine doses may result in a better antibody response against some antigens but not against others. Therefore, in general, increasing the vaccine dose is no adequate method to improve the antibody response.

Influenza vaccines: the effect of vaccine dose on antibody response in primed populations during the ongoing interpandemic period. A review of the literature. (Article)

1993-01-01T00:00:00Z

Health authorities tend to favour an increase of the antigen dose in inactivated influenza vaccines from < or = 10 micrograms haemagglutinin (HA) per vaccine strain to 15 micrograms HA/strain. The increased dose is expected to yield a meaningful increase in the number of subjects to be protected after vaccination. To verify this expectation, we have reviewed 20 published reports (1978-1991) of serological studies in which anti-HA-IgG antibody after different doses was measured. In the review, stratification groups of previously primed subjects were formed and the antibody response was estimated for doses of 10 and 15 micrograms HA by linear k*2-chi 2 model. Despite a considerable heterogenicity of study populations, study designs, vaccine types and strains, and antibody assays, the results were consistent in revealing high protection rates (> or = 75%) for a 10 micrograms HA dose of influenza A vaccine components. For both response and protection rates, an increase of the antigenic load from 10 to 15 micrograms HA was not associated with a meaningful increase of seroresponse: in 38 out of 39 stratification groups, the increase of response and/or protection rate varied between -9% and +8%, with a median of 1.5%. These results do not justify the expectation that a vaccine dose of 15 micrograms HA per strain would be clinically superior to a dose of 10 micrograms HA. Only in a group of immune-compromised patients on chronic intermittent haemodialysis were results in favour of a higher dose found, which may justify further evaluation in this special population.

Influenza-related excess mortality in The Netherlands 1989/90 (Letter To Editor)

1990-08-01T00:00:00Z