Impact of Public Policy and COVID-19 Pandemic on Hepatitis C Testing and Treatment in France, 2014-2021.

Given the World Health Organization's target to eliminate the hepatitis C virus (HCV) by 2030, we assessed the impact of French public policies and the COVID-19 pandemic on HCV testing and initiation of direct-antiviral agents (DAAs). Using the French National Health Data System, we identified individuals living in metropolitan France with at least one reimbursement for an anti-HCV test and those with a first delivery of DAAs between 1 January 2014 and 31 December 2021. During this period, the annual number of people tested increased each year between 3.3 (in 2015) and 9.3% (in 2021), except in 2020, with a drop of 8.3%, particularly marked in April (-55.0% compared to February 2020). A return to pre-pandemic testing levels was observed in 2021. The quarterly number of patients initiating DAAs presented an upward trend from Q1-2014 until mid-2017, with greater increases in Q1-2015, and Q1- and Q2-2017, concomitant with DAA access policies and availability of new therapies. Then, quarterly numbers decreased. A 65.5% drop occurred in April compared to February 2020. The declining DAA initiations since mid-2017, despite new measures improving access and screening efforts, could be due to the shrinking pool of patients requiring treatment and a need to increase awareness among undiagnosed infected people. Further action is needed to eliminate HCV in France.

Prevalence of chronic HCV infection in EU/EEA countries in 2019 using multiparameter evidence synthesis.

Background: Epidemiological data are crucial to monitoring progress towards the 2030 Hepatitis C Virus (HCV) elimination targets. Our aim was to estimate the prevalence of chronic HCV infection (cHCV) in the European Union (EU)/European Economic Area (EEA) countries in 2019. Methods: Multi-parameter evidence synthesis (MPES) was used to produce national estimates of cHCV defined as: π = πrecρrec + πexρex + πnonρnon; πrec, πex, and πnon represent cHCV prevalence among recent people who inject drugs (PWID), ex-PWID, and non-PWID, respectively, while ρrec, ρex, and ρnon represent the proportions of these groups in the population. Information sources included the European Centre for Disease Prevention and Control (ECDC) national operational contact points (NCPs) and prevalence database, the European Monitoring Centre for Drugs and Drug Addiction databases, and the published literature. Findings: The cHCV prevalence in 29 of 30 EU/EEA countries in 2019 was 0.50% [95% Credible Interval (CrI): 0.46%, 0.55%]. The highest cHCV prevalence was observed in the eastern EU/EEA (0.88%; 95% CrI: 0.81%, 0.94%). At least 35.76% (95% CrI: 33.07%, 38.60%) of the overall cHCV prevalence in EU/EEA countries was associated with injecting drugs. Interpretation: Using MPES and collaborating with ECDC NCPs, we estimated the prevalence of cHCV in the EU/EEA to be low. Some areas experience higher cHCV prevalence while a third of prevalent cHCV infections was attributed to PWID. Further efforts are needed to scale up prevention measures and the diagnosis and treatment of infected individuals, especially in the east of the EU/EEA and among PWID. Funding: ECDC.

Clinical and virological features of chronic hepatitis B in the French national surveillance program, 2008-2012: A cross-sectional study.

Background & Aims: Among people living with HBV, only a subset of individuals with chronic hepatitis is in need of treatment, and this proportion varies according to the population, region, and setting. No estimates of the proportion of people who are infected with HBV and meet the treatment eligibility criteria in France are available. Methods: 552 treatment-naïve individuals with chronic HBV infection referred for the first time to a hepatology reference centre between 2008 and 2012 were prospectively included. Demographic, clinical, and laboratory data were analysed. Results: In total, 61.1% of patients were males, with a median age of 37.5 years. Moreover, 64% were born in an intermediate- or high-HBV endemicity country, and 90% were HBeAg-negative. At referral, median HBV DNA and HBsAg levels were 3.3 and 3.6 log IU/ml, respectively; 37.8% of patients had alanine aminotransferase >40 U/L, and 29.0% had moderate or severe fibrosis (≥F2), including 9.4% with cirrhosis. The most prevalent genotypes were D (34.7%), E (27.4%), and A (25.7%). Coinfections were rare: 2.4% were HIV-positive, 4.0% were HCV-positive, and 6.0% were HDV-positive. According to the 2017 EASL Clinical Practice Guidelines, using a single time point analysis, 2.7% of patients were classified as HBeAg-positive chronic infection, 6.1% as HBeAg-positive chronic hepatitis B, 26.5% as HBeAg-negative chronic hepatitis B, and 61.1% as HBeAg-negative chronic infection, whereas 3.6% patients could not be classified. The performance of HBsAg level quantification to identify individuals with HBeAg-negative chronic hepatitis B was poor. A total of 29.1% met the criteria for initiation of antiviral treatment, whereas 66.5% remained under routine clinical surveillance. Most eligible patients initiated recommended first-line therapies, including tenofovir (45.3%), entecavir (36.8%), or pegylated interferon alpha (11.6%). Conclusions: Of all cases, 9.4% had cirrhosis at presentation and 29.1% met the 2017 EASL Clinical Practice Guidelines treatment criteria. HBsAg levels failed to accurately identify individuals with HBeAg-negative chronic infection. Lay summary: Among French adults chronically infected with HBV referred for the first time to hepatology reference centres, about one-third had a significant liver disease. Approximately one-third of individuals met criteria for initiation of antiviral treatment based on entecavir or tenofovir or, occasionally, pegylated interferon alpha.

Hepatitis B, C, and delta in the general population in Mayotte: hepatitis B as a major public health concern.

BACKGROUND: Located in southwestern Indian Ocean, Mayotte is a French territory, with a very specific demographic, social and health context. To date, epidemiological data on infections by hepatitis B (HBV), C (HCV), and delta (HDV) viruses in Mayotte have been sparse. We aimed to estimate, in the 15-69-year-old general population living in Mayotte, the prevalence of infections by hepatitis B (HBV), C (HCV), and delta (HDV) viruses and the distribution of HBV status: current infection with positive HBs antigen (Ag); resolved infection with positive HBc antibodies and negative HBsAg; immunisation by vaccination with only positive HBs antibodies; and no infection/no immunisation with negative markers. We also described the characteristics of infected people and assessed the determinants of lifetime HBV infection. METHODS: The Unono Wa Maore survey, implemented in a random sample of the general population in 2018-2019, consisted of an at-home collection of epidemiological data and venous blood samples. Detection of hepatitis B, C, and delta serological and molecular markers was performed. RESULTS: Among 5207 eligible people, 4643 responded to the questionnaire (89.2%), with 2917 being tested for HBV and HCV (62.8%). Estimated HBV status was as follows: current infection 3.0% (95% confidence interval [CI]: 2.3-3.9%) (n = 76); resolved infection 27.8% (95% CI: 25.8-29.9); immunisation by vaccination 27.7% (95% CI: 25.9-29.7); and no infection/no immunisation 41.5% (95% CI: 39.3-43.7). One participant was positive for HDV antibodies (Ab) (0.65%) with a negative HDV-RNA viral load. The risk of lifetime HBV infection was higher in men (adjusted prevalence ratio (aPR): 1.55, 95% CI: 1.29-1.89); in people aged 30-49 years (aPR: 3.83, 95% CI: 1.49-9.81) or 50-69 years (aPR: 4.52, 95% CI: 1.77-11.53) compared to those under 20; in individuals who reported no condom use during their first sexual intercourse (aPR: 1.46, 95% CI: 1.01-2.14); and in those living in Dembeni-Mamoudzou (aPR: 1.40, 95% CI: 1.09-1.80) compared to the West-Centre of Mayotte. Finally, six individuals were positive for HCV antibodies (0.21%), including three positive for HCV RNA. CONCLUSIONS: Mayotte is an area of intermediate endemicity for HBV and low endemicity for HCV and HDV. With a prevalence of HBsAg 10 times higher than in mainland France, a high proportion of people susceptible to HBV infection, and a demographic, health, and social context that may favour its transmission, hepatitis B is a major public health concern in Mayotte.

Hepatitis of unknown aetiology in children - epidemiological overview of cases reported in Europe, 1 January to 16 June 2022.

Following the report of an excess in paediatric cases of severe acute hepatitis of unknown aetiology by the United Kingdom (UK) on 5 April 2022, 427 cases were reported from 20 countries in the World Health Organization European Region to the European Surveillance System TESSy from 1 January 2022 to 16 June 2022. Here, we analysed demographic, epidemiological, clinical and microbiological data available in TESSy. Of the reported cases, 77.3% were 5 years or younger and 53.5% had a positive test for adenovirus, 10.4% had a positive RT-PCR for SARS-CoV-2 and 10.3% were coinfected with both pathogens. Cases with adenovirus infections were significantly more likely to be admitted to intensive care or high-dependency units (OR = 2.11; 95% CI: 1.18-3.74) and transplanted (OR = 3.36; 95% CI: 1.19-9.55) than cases with a negative test result for adenovirus, but this was no longer observed when looking at this association separately between the UK and other countries. Aetiological studies are needed to ascertain if adenovirus plays a role in this possible emergence of hepatitis cases in children and, if confirmed, the mechanisms that could be involved.

French hepatitis C care cascade: substantial impact of direct-acting antivirals, but the road to elimination is still long.

BACKGROUND: Hepatitis C virus (HCV) elimination by 2030, as targeted by the World Health Organization (WHO), requires that 90% of people with chronic infection be diagnosed and 80% treated. We estimated the cascade of care (CoC) for chronic HCV infection in mainland France in 2011 and 2016, before and after the introduction of direct-acting antivirals (DAAs). METHODS: The numbers of people (1) with chronic HCV infection, (2) aware of their infection, (3) receiving care for HCV and (4) on antiviral treatment, were estimated for 2011 and 2016. Estimates for 1) and 2) were based on modelling studies for 2011 and on a virological sub-study nested in a national cross-sectional survey among the general population for 2016. Estimates for 3) and 4) were made using the National Health Data System. RESULTS: Between 2011 and 2016, the number of people with chronic HCV infection decreased by 31%, from 192,700 (95% Credibility interval: 150,900-246,100) to 133,500 (95% Confidence interval: 56,900-312,600). The proportion of people aware of their infection rose from 57.7 to 80.6%. The number of people receiving care for HCV increased by 22.5% (representing 25.7% of those infected in 2016), while the number of people on treatment increased by 24.6% (representing 12.1% of those infected in 2016). CONCLUSIONS: This study suggests that DAAs substantially impact CoC. However, access to care and treatment for infected people remained insufficient in 2016. Updating CoC estimates will help to assess the impact of new measures implemented since 2016 as part of the goal to eliminate HCV.

HCV and HBV prevalence based on home blood self-sampling and screening history in the general population in 2016: contribution to the new French screening strategy.

BACKGROUND: The advent of effective direct-acting antivirals (DAAs), has prompted an assessment of the French Hepatitis C virus (HCV) screening strategy, which historically targeted high-risk groups. One of the options put forward is the implementation of combined (i.e., simultaneous) HCV, Hepatitis B virus (HBV) and HIV screening for all adults at least once during their lifetime ("universal combined screening"). However, recent national survey-based data are lacking to guide decision-making regarding which new strategy to implement. Accordingly, we aimed to provide updated data for both chronic hepatitis C (CHC) and B (CHB) prevalence and for HCV and HBV screening history, using data from the BaroTest and 2016 Health Barometer (2016-HB) studies, respectively. METHODS: 2016-HB was a national cross-sectional phone based health survey conducted in 2016 among 20,032 randomly selected individuals from the general population in mainland France. BaroTest was a virological sub-study nested in 2016-HB. Data collected for BaroTest were based on home blood self-sampling on dried blood spots (DBS). RESULTS: From 6945 analyzed DBS, chronic hepatitis C (CHC) and B (CHB) prevalence was estimated at 0.30% (95% Confidence Interval (CI): 0.13-0.70) and 0.30% (95% CI: 0.13-0.70), respectively. The proportion of individuals aware of their status was estimated at 80.6% (95% CI: 44.2-95.6) for CHC and 17.5% (95% CI: 4.9-46.4) for CHB. Universal combined screening would involve testing between 32.6 and 85.3% of 15-75 year olds according to whether we consider only individuals not previously tested for any of the three viruses, or also those already tested for one or two of the viruses. CONCLUSIONS: Our data are essential to guide decision-making regarding which new HCV screening recommendation to implement in France. They also highlight that efforts are still needed to achieve the WHO's targets for eliminating these diseases. Home blood self-sampling may prove to be a useful tool for screening and epidemiological studies.

Primary resistance of hepatitis B virus to nucleoside and nucleotide analogues.

Nucleoside and nucleotide analogues (NUCs) targeting hepatitis B virus are capable of selecting resistant viruses upon long-term administration as monotherapies. The prevalence of resistance-associated substitutions (RASs) and fitness-associated substitutions at baseline of NUC therapy and their impact on treatment responses remain unknown. A total of 232 treatment-naïve patients chronically infected with hepatitis B virus (HBV) consecutively referred for the first time to one of French reference centres were included. The nearly full-length HBV reverse transcriptase was sequenced by means of deep sequencing, and the sequences were analysed. RASs were detected in 25% of treatment-naïve patients, generally representing low proportions of the viral quasispecies. All amino acid positions known to be associated with HBV resistance to currently approved NUCs or with increased fitness of resistant variants were affected, except position 80. RASs at positions involved in lamivudine, telbivudine and adefovir resistance were the most frequently detected. All patients with RASs detectable by next-generation sequencing at baseline who were treatment-eligible and treated with currently recommended drugs achieved a virological response. The presence of pre-existing HBV RASs has no impact on the outcome of therapy if potent drugs with a high barrier to resistance are used.

Innovative Approach for Enhancing Testing of HIV, Hepatitis B, and Hepatitis C in the General Population: Protocol for an Acceptability and Feasibility Study (BaroTest 2016).

BACKGROUND: Despite substantial screening for HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in France, a great number of infected persons remain undiagnosed. In this context, Santé publique France experimented with a new screening approach for HBV, HCV, and HIV infection, based on home self-sampling using dried blood spot (DBS) for blood collection. OBJECTIVE: The objectives of the BaroTest study were to assess the acceptability and feasibility of this approach and to update the prevalence estimates of HBV, HCV, and HIV infections in the general population. METHODS: Participants were enrolled using the 2016 Health Barometer, a national cross-sectional telephone survey based on a large representative sample of the general population aged 15 to 75 years (N=15,000). Upon completion of the questionnaire, any participant in the Health Barometer aged 18 to 75 years, having medical health insurance, and not under guardianship was invited to receive a self-sampling kit delivered by standard postal mail and to return the DBS card to the laboratory. The laboratory was then responsible for reporting the results to the participants. Acceptability of the protocol was based on the percentage of eligible individuals agreeing to receive the self-sampling kit, on the proportion of people returning the DBS card, and on the proportion of participants out of the total eligible population. The feasibility of the approach was based on the number of participants with adequately filled blood spots and the number of participants with blood spots for which at least one virological analysis could be performed. A complex system of reminders was implemented to increase the participation rate. Accordingly, we assumed that 35.00% (4900/14,000) of eligible persons would accept and return their DBS card. As the highest expected prevalence was for HBV infection, estimated at 0.65% in 2004, 5000 persons would make it possible to estimate this prevalence with an accuracy of approximately 0.22%. All indicators can be analyzed according to the characteristics of the participants collected in the Health Barometer questionnaire. BaroTest was approved by the French Ethics Committee (November 11, 2015) and the Commission on Information Technology and Liberties (December 24, 2015). The study has been registered by the French medical authority under number 2015-A01252-47 on November 10, 2015. RESULTS: The results on acceptability and feasibility are expected in the last quarter of 2018 and those on the prevalence estimates in the first semester of 2019. CONCLUSIONS: The BaroTest results will help to inform new strategies for HIV, HBV, and HCV screening, and the Health Barometer provides a reliable updated assessment of the burden of HBV, HCV, and HIV infections in the general population in France while reducing the costs typically associated with this type of research. REGISTERED REPORT IDENTIFIER: RR1-10.2196/9797.

Assessing the cost-effectiveness of hepatitis C screening strategies in France.

BACKGROUND & AIMS: In Europe, hepatitis C virus (HCV) screening still targets people at high risk of infection. We aim to determine the cost-effectiveness of expanded HCV screening in France. METHODS: A Markov model simulated chronic hepatitis C (CHC) prevalence, incidence of events, quality-adjusted life years (QALYs), costs and incremental cost-effectiveness ratio (ICER) in the French general population, aged 18 to 80 years, undiagnosed for CHC for different strategies: S1 = current strategy targeting the at risk population; S2 = S1 and all men between 18 and 59 years; S3 = S1 and all individuals between 40 and 59 years; S4 = S1 and all individuals between 40 and 80 years; S5 = all individuals between 18 and 80 years (universal screening). Once CHC was diagnosed, treatment was initiated either to patients with fibrosis stage ≥F2 or regardless of fibrosis. Data were extracted from published literature, a national prevalence survey, and a previously published mathematical model. ICER were interpreted based on one or three times French GDP per capita (€32,800). RESULTS: Universal screening led to the lowest prevalence of CHC and incidence of events, regardless of treatment initiation. When considering treatment initiation to patients with fibrosis ≥F2, targeting all people aged 40-80 was the only cost-effective strategy at both thresholds (€26,100/QALY). When we considered treatment for all, although universal screening of all individuals aged 18-80 is associated with the highest costs, it is more effective than targeting all people aged 40-80, and cost-effective at both thresholds (€31,100/QALY). CONCLUSIONS: In France, universal screening is the most effective screening strategy for HCV. Universal screening is cost-effective when treatment is initiated regardless of fibrosis stage. From an individual and especially from a societal perspective of HCV eradication, this strategy should be implemented. LAY SUMMARY: In the context of highly effective and well tolerated therapies for hepatitis C virus that are now recommended for all patients, a reassessment of hepatitis C screening strategies is needed. An effectiveness and cost-effectiveness study of different strategies targeting either the at-risk population, specific ages or all individuals was performed. In France, universal screening is the most effective strategy and is cost-effective when treatment is initiated regardless of fibrosis stage. From an individual and especially from a societal perspective of hepatitis C virus eradication, this strategy should be implemented.

Rapid and large-scale implementation of HCV treatment advances in France, 2007-2015.

BACKGROUND: The last decade was marked by major advances in HCV treatment with the introduction of first wave protease inhibitors (1st-wave PIs, telaprevir or boceprevir) in 2011 and second direct-acting antivirals (2nd-wave DAAs) in 2014, that followed low effective pegylated interferon α / ribavirin bitherapy. We estimated the number of patients initiating HCV treatment in France between 2007 and 2015 according to the type of therapy, described their demographical characteristics, and estimated how many were cured with 2nd-wave DAAs in 2014-2015. METHODS: Individual data from the national health insurance information system were analysed. HCV treatment initiation was defined as a drug reimbursement in the absence of any reimbursement for the same drug in the previous six weeks. RESULTS: Between 2007 and 2015, 72,277 patients initiated at least one HCV treatment. The annual number of patients initiating treatment decreased from 2007 (~13,300) to 2010 (~10,000). It then increased with the introduction of 1st-wave PIs (~12,500 in 2012), before decreasing again in 2013 (~8400). A marked increase followed upon the approval of 2nd-wave DAAs in 2014 (~11,600). Approximately, 8700 and 14,700 patients initiated 2nd-wave DAAs in 2014 and 2015, respectively, corresponding to an estimated 20,300 cured patients in 2014-2015. Patients initiating HCV treatment were mostly male (~65% throughout the 9-year period). Women were older than men (mean age: 55.0 vs. 48.9). Increasing age was associated with more advanced treatment. Among patients initiating 2nd-wave DAAs, the proportions of those under 40 and over 79 years old increased between 2014 and 2015, whereas the proportion of those previously treated for HCV 2007 onwards declined. CONCLUSIONS: Successive advances in HCV treatment have been rapidly and widely implemented in France. With the announcement of universal access to DAAs in mid-2016 and price reductions, access to 2nd-wave DAAs is expected to expand even more.

2014 French guidelines for hepatitis B and C screening: a combined targeted and mass testing strategy of chronic viruses namely HBV, HCV and HIV.

BACKGROUND & AIMS: Worldwide and, to a lesser extent, in France, a minority of individuals infected with hepatitis B (HBV) and C (HCV) is aware of its status. Given the current availability of highly effective anti-HBV and anti-HCV agents, the high rate of undiagnosed people, associated with individual and community prejudices (liver disease worsening, persistence of a hidden transmission reservoir and medicoeconomic burden of delayed care), is unacceptable. METHODS: On the occasion of the first French general report on viral hepatitis, new recommendations for HBV and HCV testing were issued. We aim to introduce the new French strategy for HBV and HCV screening, and to describe the underlying epidemiological data. RESULTS: These recommendations comprise various items. First, the screening of chronic viruses, namely HBV, HCV and HIV, should be quasi-systematically combined. Second, the targeted screening of groups at risk of viral exposure must be strengthened. Third, routine testing for each of these three viruses should be offered at least once to men of 18-60 years old who had never been tested. In parallel, in pregnant women, in addition to HIV-HBV screening, currently recommended HCV testing should be routinely performed during the first trimester of pregnancy. In order to best achieve the target populations, community initiatives that propose testing actions should be encouraged, particularly those including rapid point-of-care tests. CONCLUSIONS: Overall, these recommendations aim to define a comprehensive testing strategy for chronic viral infections, emphasizing both targeted screening and mass screening and considering jointly HBV, HCV and HIV.

The undiagnosed chronically-infected HCV population in France. Implications for expanded testing recommendations in 2014.

BACKGROUND: Recent HCV therapeutic advances make effective screening crucial for potential HCV eradication. To identify the target population for a possible population-based screening strategy to complement current risk-based testing in France, we aimed to estimate the number of adults with undiagnosed chronic HCV infection and age and gender distribution at two time points: 2004 and 2014. METHODS: A model taking into account mortality, HCV incidence and diagnosis rates was applied to the 2004 national seroprevalence survey. RESULTS: In 2014, an estimated 74,102 individuals aged 18 to 80 were undiagnosed for chronic HCV infection (plausible interval: 64,920-83,283) compared with 100,868 [95%CI: 58,534-143,202] in 2004. Men aged 18-59 represented approximately half of the undiagnosed population in 2014. The proportion of undiagnosed individuals in 2004 (43%) varied from 21.9% to 74.1% in the 1945-1965 and 1924-1944 birth cohorts. Consequently, age and gender distributions between the chronically-infected (diagnosed and undiagnosed) and undiagnosed HCV populations were different, the 1945-1965 birth cohort representing 48.9% and 24.7%, respectively. CONCLUSIONS: Many individuals were still undiagnosed in 2014 despite a marked reduction with respect to 2004. The present work contributed to the 2014 recommendation of a new French complementary screening strategy, consisting in one-time simultaneous HCV, HBV and HIV testing in men aged 18-60. Further studies are needed to assess the cost-effectiveness and feasibility of such a strategy. We also demonstrated that data on the undiagnosed HCV population are crucial to help adapt testing strategies, as the features of the chronically-infected HCV population are very distinct.

Hepatitis B knowledge, perceptions and practices in the French general population: the room for improvement.

BACKGROUND: Little is known about the knowledge, perceptions and prevention practices of the French general population with respect to Hepatitis B virus (HBV) infection. This article describes this population's knowledge of HBV, their perceptions of the disease, and associated screening and vaccination practices. It compares these indicators with those observed in the same population for HIV, an infection with a chronic course and transmission modes resembling those of HBV. METHODS: A module on hepatitis B was added into the HIV KABP (Knowledge, Attitudes, Beliefs and Practices) survey which was carried out telephonically in 2010 among a random sample of 9,014 individuals aged between 18-69 and living in metropolitan France. RESULTS: Compared with HIV, the general population was less aware that needle exchange during intravenous drug use and sexual relationships are HBV transmission modes (HBV: 89.9% and 69.7%; HIV: 99.1% and 99.4%). The fear of both illnesses was similar at 20.3%. The individual perceived risk of infection was higher for HBV than for HIV with, respectively, 60.8% and 40.3% of respondents believing they had an equal or greater risk of being infected than the average person. However, the percentage of those reporting HBV screening during their lifetime (27.4%) was half that for HIV screening (61.4%). In multivariate analysis, HBV screening was reported more often by individuals born in areas with high HBV endemicity (OR = 2.1 [95% CI: 1.5-2.9]) than by those born in low HBV endemicity areas, and more often by those who reported they had taken drugs intravenously during their lifetime (OR = 2.2 [95% CI: 1.2-4.2]) than those who did not report such behavior. Almost one in two respondents (47%) reported HBV vaccination. The intermediate or high endemicity groups did not report vaccination more often than those born in low endemicity areas nor did those reporting intravenously drug use compared with those who did not. CONCLUSIONS: This study highlights very contrasting levels of knowledge, perceptions and practices regarding HBV and HIV in the French general population. Our results demonstrate the need to improve the general and high-risk populations' knowledge of HBV, in particular concerning sexual transmission, in order to improve screening and vaccination practices.

Estimated risk of Chikungunya viremic blood donation during an epidemic on Reunion Island in the Indian Ocean, 2005 to 2007.

BACKGROUND: Between 2005 and 2007, Chikungunya virus (CHIKV) caused a massive epidemic on Reunion Island with a major peak in the number of cases in February 2006. Blood donation was interrupted on the island in January 2006. STUDY DESIGN AND METHODS: Estimates of the mean risk of viremic blood donation on Reunion Island were computed for different phases of the epidemic. Calculations used CHIKV incidence estimates derived from sentinel surveillance, duration of viremia, and frequency of asymptomatic infection. Data on these two last parameters were initially based on hypotheses and subsequently obtained from studies carried out during the outbreak. The estimated risk was compared to the results of CHIKV nucleic acid testing (NAT) implemented for platelet (PLT) donations screening. RESULTS: Over the course of the outbreak, the mean risk was estimated at 132 per 100,000 donations. The risk peaked at 1,500 per 100,000 donations at the height of the outbreak in February 2006. In total, 47 blood donations would have been potentially viremic if blood collection had not been interrupted. During this period, an estimated 312,500 of 757,000 inhabitants had been infected by mosquito-borne transmission. From January to May 2006, the estimated mean risk (0.7%) and observed risk on PLT donations (0.4%) were of the same order of magnitude. CONCLUSION: During this large outbreak, the estimated risk of viremic blood donation was high, but low compared to the risk of mosquito-borne CHIKV transmission. The estimated risk was corroborated by the concordant results with the observed risk.

Two consecutive large outbreaks of Salmonella enterica serotype Agona infections in infants linked to the consumption of powdered infant formula.

BACKGROUND: An increase of isolation of Salmonella Agona was observed in January through February 2005 among infants in France. METHODS: Case-control study, food trace-back and microbiologic investigations were promptly carried out. RESULTS: A total of 141 confirmed cases <12 months of age were identified. Most had diarrhea (99%; bloody 56%) and fever (75%) and 36% were hospitalized for 5 days on average and none died. In the case-control analysis, all 23 cases and none of the 23 controls had consumed powdered formula of brand A (P < 10(-5)). Active follow up of all cases showed that after the withdrawal of formula A, cases that had consumed formula A decreased rapidly, but new cases had consumed another formula (brand B). The trace-back found that 5 batches of formula B had been manufactured on the same production line as formula A. Forty-four cases were linked to formula A and 92 to formula B. All routine controls performed by the producers were negative for Salmonella. However, enhanced microbiologic investigations yielded S. Agona in one of 176 samples of formula A, in 4 of 27 tins of formula B consumed by cases and in 6 of 420 environmental swabs from the production line. All clinical, food and environmental isolates were of the same pulsed-field gel electrophoresis profile. CONCLUSIONS: Powdered infant formulas are not sterile products and may contain low levels of Salmonella. Routine microbiologic controls are insufficient to detect a low-grade contamination, which may cause serious illness and outbreaks among infants.