Project description:We screened plasma samples (minipools of 96 samples, corresponding to 53,234 blood donations) from France that had been processed with solvent-detergent for hepatitis E virus RNA. The detection rate was 1 HEV-positive sample/2,218 blood donations. Most samples (22/24) from viremic donors were negative for IgG and IgM against HEV.
Project description:BackgroundHepatitis E virus (HEV) is an emerging zoonotic pathogen and an important cause of acute viral hepatitis in European countries. Corsica Island has been previously identified as a hyperendemic area for HEV.AimOur aim was to characterise the prevalence and titres of IgG antibodies to HEV among blood donors on Corsica and establish a model of the annual force of infection.MethodsBetween September 2017 and January 2018, 2,705 blood donations were tested for anti-HEV IgG using the Wantai HEV IgG enzyme immunoassay.ResultsThe overall seroprevalence was 56.1%. In multivariate analysis, seroprevalence was higher in men than in women (60.0% vs 52.2%; p?<?0.01), increased with age and was significantly higher among donors born on Corsica (60.6% vs 53.2%; p?<?0.01). No significant difference was observed between the five districts of the island. IgG anti-HEV titres were mostly low (70% of positive donors had titres?<?3 IU/mL). In Corsican natives, increasing seroprevalence by age could be explained by models capturing a loss of immunity (annual probability of infection:?4.5%; duration of immunity: 55 years) or by age-specific probabilities of infection (3.8% for children, 1.3% for adults).ConclusionWe confirmed the high HEV seroprevalence on Corsica and identified three aspects that should be further explored: (i) the epidemiology in those younger than 18 years, (ii) common sources of contamination, in particular drinking water, that may explain the wide exposure of the population, and (iii) the actual protection afforded by the low IgG titres observed and the potential susceptibility to secondary HEV infection.
Project description:The genotype distribution of hepatitis C virus (HCV) in blood donors from southeast France was tracked for a period of 13 years (1991 to 2003). Virus genomes from 321 samples were analyzed by amplification and sequencing of the NS5b and E1 regions. The most frequent genotypes were 1b (30.2%), 1a (27.7%), and 3a (22.4%). Although it was less common, genotype 2 was characterized by the presence of strains belonging to 11 different subtypes, including 5 that had never been characterized. Genotypes 1a, 1b, 3a, and 4a presented typical "epidemic" profiles, with a large number of isolates per subtype and short mean genetic distances between isolates. Type 2 isolates displayed a typical "endemic" profile, with a large number of subtypes and very few isolates in each subtype. The epidemiology of HCV infection in southeast France changed radically during the study period in relation to modifications in the etiology of infection. We observed the emergence of new epidemic subtypes (subtypes 1a and 3) linked to intravenous drug use and a decrease in the types linked to blood transfusion and nosocomial infection (epidemic subtype 1b and endemic type 2). Comparison of strains from blood donors with strains from a cohort of inpatients in the same region during 2001 and 2002 demonstrated for the first time that the monitoring of blood donors is a generally valid indicator of HCV epidemiology in terms of genotype distribution.
Project description:BackgroundSyphilis in blood donors (BD) has increased in many countries.AimWe aimed to describe trends in syphilis seroposivity in BD in France, to identify risk factors and assess if a non-treponemic test (NTT) could define BD having recovered from syphilis for more than 1 year.MethodsThe analysis covered the period 2007 to 2022 and 45,875,939 donations. Of the 474 BD syphilis-positive in 2022, 429 underwent additional investigations with an NTT. History of syphilis was obtained at the post-donation interview or based on serology results for repeat donors.ResultsUntil 2021, positivity rates remained stable (mean: 1.18/10,000 donations, range: 1.01-1.38). An increased rate was observed in 2022 (1.74/10,000; p = 0.02). Over the whole study period, prevalence was 2.2 times higher in male than in female BD (4.1 times higher in 2022). The proportion of males with an identified risk factor who have sex with men increased from 16.7% in 2007 to 64.9% in 2022. Based on NTT, 79 (18%) of the donors who were seropositive in 2022 were classified as having been infected in the previous year. History of syphilis was available for 30 of them. All had an infection within the previous 3 years. Among seven donors with a syphilis < 12 months before testing, one had an NTT titre ≥ 8, three a titre between 1 and 4, three were negative.ConclusionSyphilis seropositivity increased considerably in BDs in 2022, mostly in males, notably MSM. Available data did not allow appropriate evaluation of the NTT to distinguish recent from past infection.
Project description:BACKGROUND: Knowledge of the age-specific prevalence of seroprotection and incidence of seroconversion infection is necessary to complement clinical surveillance data and statistical models. It provides the basis for estimating the future impact of influenza A (H1N1pdm09) and implementing appropriate prevention and response strategies. METHODS: Using a cross-sectional design, two-stage stratified sampling and paired plasma samples, we estimated the age-specific prevalence of a protective level of H1N1pdm09 antibodies in the French adult population before and after the 2009/10 pandemic, and the proportion of those susceptible that seroconverted due to infection, from a single sample of 1,936 blood donors aged 20-70 years in mainland France in June 2010. Samples with a haemagglutination inhibition (HI) titre ?1?40 were considered seropositive, and seroconversion due to infection was defined as a 4-fold increase in titre in the absence of H1N1pdm09 vaccination or pre-pandemic seropositivity. RESULTS: Out of the 1,936 donors, 1,708 were included in the analysis. Seroprevalence before the pandemic was 6.7% (95% CI 5.0, 8.9) with no significant differences by age-group (p?=?0.3). Seroprevalence afterwards was 23.0% (95% CI 17.7, 29.3) with 20-29 year olds having a higher level than older groups (p<0.001). Seroconversion due to infection was 12.2% (95% CI 6.9, 20.5). Younger age-group, vaccination against H1N1 and being seropositive before the pandemic were strongly associated with post-pandemic seropositivity. CONCLUSIONS: Before the 2009/2010 winter influenza season, only 6.7% of the French mainland population aged 20-70 had a level of antibodies usually considered protective. During the first pandemic wave, 12.2% of the population seroconverted due to infection and the seroprevalence after the wave rose to 23%, either due to prepandemic seropositivity, infection or vaccination. This relatively low latter figure contributed to an extension of target groups for influenza vaccination for the 2010/2011 season.
Project description:IntroductionWaiting rooms in general practitioners' (GP) surgeries are a potentially useful site for spreading educational messages about health behaviors. We aimed to evaluate the impact of posters displayed in GPs' waiting rooms on the number of donors attending the blood donation drives in the Aube Department of France. The secondary objective was to identify self-reported factors that incited people to give blood among donors who did and donors who did not see the posters.MethodsObservational, multicenter, prospective study, from 1 June to 31 December 2021. Six blood donation centers in the Aube Department were selected. All GPs located within a 15 km radius around each center were invited to participate by hanging posters advertising blood drives in their waiting rooms. The number of blood donations per hour was measured before and during the campaign. Factors prompting people to give blood were evaluated by questionnaires completed by persons attending the blood drives.Results33 GPs participated. The number of donations per hour was lower in the year in which the posters were displayed (2021) compared to the previous year (12 vs. 15). A total of 1,469 questionnaires were completed by blood donors: 729 reported having seen the posters, and 740 reported not having seen the posters. Those who claimed to have seen the posters were more likely than those who claimed not to have seen the posters to respond that in parallel, they had been prompted to give blood via online publicity (7.5 vs. 3.9%, adjusted Odds ratio [aOR] 1.75, 95% confidence interval [CI] 1.12-2.82, p = 0.02). They also more often reported that they had been prompted to donate by television advertisements (8.0 vs. 4.2%, aOR 1.74, 95%CI 1.10-2.76, p = 0.02). Overall, 68% of all respondents indicated that posters in the GP's waiting room would incite them to give blood more often.ConclusionThe number of blood donations per hour was lower during the year in which posters were displayed. Questionnaire data from donors suggests that promoting blood donation via posters in GPs' waiting rooms could have a positive effect: 68% of donors claimed that posters would incite them to give blood.
Project description:Hepatitis B virus (HBV) infection is the most frequent viral infection found in blood donors (BDs) in France. We analyzed the epidemiological and sero-molecular data on HBV infection gathered over the past two decades by the French haemovigilance surveillance network, blood screening laboratories, and the national reference center for transfusion infectious risks (NRC). Between 2000 and 2020, 6149 of the 58,160,984 donations (1.06/10,000) tested HBV positive, 98% of them from first-time blood donors (FTBDs). In addition, 2212 (0.0071%) of the 30,977,753 donations screened for HBV DNA tested DNA positive, of which 25 (1.1%) were positive only for this marker. HBV prevalence decreased by 2.8-fold and the residual risk for transfusion-transmitted HBV infection decreased 13-fold and was divided by 13. The major risk factor for HBV infection was the origin of donors (endemic country, 66.5%), followed by parenteral exposure (10.7%). In the whole HBV-positive BD population, genotype D was predominant (41.8%), followed by genotypes A (26.2%) and E (20.4%), reflecting the geographical origin of donors. The low and decreasing prevalence and incidence of HBV infection in French BDs, coupled with a screening strategy using three HBV markers (HBsAg, anti-HBc and DNA), ensures a high level of blood safety, further reinforced by the implementation of pathogen-reduction measures.
Project description:A point prevalence study of hepatitis E virus (HEV) in Chinese blood donors was conducted, and the prevalences of antibodies against HEV immunoglobulin G (IgG) and IgM among Chinese blood donors were 32.60% and 0.94%, respectively. HEV viremia was 0.07%.