The effect of giving influenza vaccination to general practitioners: a controlled trial [NCT00221676]

BACKGROUND: No efficacy studies of influenza vaccination given to GPs have yet been published. Therefore, our purpose was to assess the effect of an inactivated influenza vaccine given to GPs on the rate of clinical respiratory tract infections (RTIs) and proven influenza cases (influenza positive nose and throat swabs and a 4-fold titre rise), while adjusting for important covariates. METHODS: In a controlled trial during two consecutive winter periods (2002–2003 and 2003–2004) we compared (77 and 100) vaccinated with (45 and 40) unvaccinated GPs working in Flanders, Belgium. Influenza antibodies were measured immediately prior to and 3–5 weeks after vaccination, as well as after the influenza epidemic. During the influenza epidemic, GPs had to record their contact with influenza cases and their own RTI symptoms every day. If they became ill, the GPs had to take nose and throat swabs during the first 4 days. We performed a multivariate regression analysis for covariates using Generalized Estimating Equations. RESULTS: One half of the GPs (vaccinated or not) developed an RTI during the 2 influenza epidemics. During the two influenza periods, 8.6% of the vaccinated and 14.7% of the unvaccinated GPs had positive swabs for influenza (RR: 0.59; 95%CI: 0.28 – 1.24). Multivariate analysis revealed that influenza vaccination prevented RTIs and swab-positive influenza only among young GPs (ORadj: 0.35; 95%CI: 0.13 – 0.96 and 0.1; 0.01 – 0.75 respectively for 30-year-old GPs). Independent of vaccination, a low basic antibody titre against influenza (ORadj 0.57; 95%CI: 0.37 – 0.89) and the presence of influenza cases in the family (ORadj 9.24; 95%CI: 2.91 – 29) were highly predictive of an episode of swab-positive influenza. CONCLUSION: Influenza vaccination was shown to protect against proven influenza among young GPs. GPs, vaccinated or not, who are very vulnerable to influenza are those who have a low basic immunity against influenza and, in particular, those who have family members who develop influenza

Computerized general practice based networks yield comparable performance with sentinel data in monitoring epidemiological time-course of influenza-like illness and acute respiratory illness

<p>Abstract</p> <p>Background</p> <p>Computerized morbidity registration networks might serve as early warning systems in a time where natural epidemics such as the H₁N₁flu can easily spread from one region to another.</p> <p>Methods</p> <p>In this contribution we examine whether general practice based broad-spectrum computerized morbidity registration networks have the potential to act as a valid surveillance instrument of frequently occurring diseases. We compare general practice based computerized data assessing the frequency of influenza-like illness (ILI) and acute respiratory infections (ARI) with data from a well established case-specific sentinel network, the European Influenza Surveillance Scheme (EISS). The overall frequency and trends of weekly ILI and ARI data are compared using both networks.</p> <p>Results</p> <p>Detection of influenza-like illness and acute respiratory illness occurs equally fast in EISS and the computerized network. The overall frequency data for ARI are the same for both networks, the overall trends are similar, but the increases and decreases in frequency do not occur in exactly the same weeks. For ILI, the overall rate was slightly higher for the computerized network population, especially before the increase of ILI, the overall trend was almost identical and the increases and decreases occur in the same weeks for both networks.</p> <p>Conclusions</p> <p>Computerized morbidity registration networks are a valid tool for monitoring frequent occurring respiratory diseases and the detection of sudden outbreaks.</p

Expression of retrovirus-related antigen in pregnancy. II. Cytotoxic and blocking specificities of immunoglobulins eluted from the placenta

Immunoglobulins, mostly of the IgG class, were detected in eluates of the placenta of 75% of 50 healthy women in their first or second pregnancy, 92% of 30 women with more than two pregnancies, and 87% of 23 pre-eclamptic patients. The immunoglobulins were assayed for complement-dependent cytotoxicity on human and monkey cell-lines, as well as on the same cells chronically infected with either Mason-Pfizer Virus (M-P V) or Baboon Endogenous Virus (BeV). The frequency of cytotoxic reactions was very low, except with immunoglobulins from the pre-eclamptic placentae, where one third of the samples lysed virus-infected cells with occasional killing of virus-free cells. All placental immunoglobulins which were not cytotoxic were then assayed for blocking activity by testing whether they could compete with the action of anticellular sera on virus-free cells, or with the toxic effect of antiviral sera on virus producing cells. 64% of the immunoglobulins from normal placentae competed with antiviral antibodies while only 17% blocked the action of anticellular sera. The frequency of blocking immunoglobulins was no greater in eluates from pre-eclamptic placentae. The data indicate that the placenta possesses retrovirus antigen sites which bind blocking antibodies in normal pregnancy and complement-dependent cytotoxic antibodies in pre-eclampsia. © 1981.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The effect of giving influenza vaccination to general practitioners: a controlled trial [NCT00221676]

Abstract Background No efficacy studies of influenza vaccination given to GPs have yet been published. Therefore, our purpose was to assess the effect of an inactivated influenza vaccine given to GPs on the rate of clinical respiratory tract infections (RTIs) and proven influenza cases (influenza positive nose and throat swabs and a 4-fold titre rise), while adjusting for important covariates. Methods In a controlled trial during two consecutive winter periods (2002–2003 and 2003–2004) we compared (77 and 100) vaccinated with (45 and 40) unvaccinated GPs working in Flanders, Belgium. Influenza antibodies were measured immediately prior to and 3–5 weeks after vaccination, as well as after the influenza epidemic. During the influenza epidemic, GPs had to record their contact with influenza cases and their own RTI symptoms every day. If they became ill, the GPs had to take nose and throat swabs during the first 4 days. We performed a multivariate regression analysis for covariates using Generalized Estimating Equations. Results One half of the GPs (vaccinated or not) developed an RTI during the 2 influenza epidemics. During the two influenza periods, 8.6% of the vaccinated and 14.7% of the unvaccinated GPs had positive swabs for influenza (RR: 0.59; 95%CI: 0.28 – 1.24). Multivariate analysis revealed that influenza vaccination prevented RTIs and swab-positive influenza only among young GPs (ORadj: 0.35; 95%CI: 0.13 – 0.96 and 0.1; 0.01 – 0.75 respectively for 30-year-old GPs). Independent of vaccination, a low basic antibody titre against influenza (ORadj 0.57; 95%CI: 0.37 – 0.89) and the presence of influenza cases in the family (ORadj 9.24; 95%CI: 2.91 – 29) were highly predictive of an episode of swab-positive influenza. Conclusion Influenza vaccination was shown to protect against proven influenza among young GPs. GPs, vaccinated or not, who are very vulnerable to influenza are those who have a low basic immunity against influenza and, in particular, those who have family members who develop influenza.</p