Screening for Human Immunodeficiency Virus Infection by Use of a Fourth-Generation Antigen/Antibody Assay and Dried Blood Spots: In-Depth Analysis of Sensitivity and Performance Assessment in a Cross-Sectional Study.

We evaluated the performance of a fourth-generation antigen/antibody (Ag/Ab) assay for detecting HIV-1 infection on dried blood spots (DBS) both in a conventional laboratory environment and in an epidemiological survey corresponding to a real-life situation. Although a 2-log loss of sensitivity compared to that with plasma was observed when using DBS in an analytical analysis, the median delay of positivity between DBS and crude serum during the early phase postacute infection was 7 days. The performance of the fourth-generation assay on DBS was approximately similar to that of a third-generation (antibody only) assay using crude serum samples. Among 2,646 participants of a cross-sectional study in a population of men having sex with men, 428 DBS were found reactive, but negative results were obtained from 5 DBS collected from individuals who self-reported a positive HIV status, confirmed by detection of antiretroviral (ARV) drugs in their DBS. The data generated allowed us to estimate a sensitivity of 98.8% of the fourth-generation assay/DBS strategy in a high-risk population, even including a broad majority of individuals on ARV treatment among those HIV positive. Our study brings additional proofs that DBS testing using a fourth-generation immunoassay is a reliable strategy able to provide alternative approaches for both individual HIV testing and surveillance of various populations.

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.

Antenatal HIV screening: results from the National Perinatal Survey, France, 2016.

BackgroundUniversal antenatal HIV screening programmes are an effective method of preventing mother-to-child transmission.AimsTo assess the coverage and yield of the French programme on a nationally representative sample of pregnant women, and predictive factors for being unscreened or missing information on the performance/ result of a HIV test.MethodsData came from the medical records of women included in the cross-sectional 2016 French National Perinatal Survey. We calculated odds ratios (OR) to identify factors for being unscreened for HIV and for missing information by multivariable analyses.ResultsOf 13,210 women, 12,782 (96.8%) were screened for HIV and 134 (1.0%) were not; information was missing for 294 (2.2%). HIV infection was newly diagnosed in 19/12,769 (0.15%) women screened. The OR for being unscreened was significantly higher in women in legally registered partnerships (OR: 1.3; 95% CI: 1.1-1.6), with 1-2 years of post-secondary schooling (OR: 1.6; 95% CI: 1.2-2.1), part-time employment (OR: 1.4; 95% CI: 1.1-1.8), inadequate antenatal care (OR: 1.9; 95% CI: 1.5-2.4) and receiving care from > 1 provider (OR: 1.8; 95% CI: 1.1-2.8). The OR of missing information was higher in multiparous women (OR: 1.4; 95% CI: 1.2-1.5) and women cared for by general practitioners (OR: 1.4; 95% CI: 1.1-1.9).ConclusionsThe French antenatal HIV screening programme is effective in detecting HIV among pregnant women. However, a few women are still not screened and awareness of the factors that predict this could contribute to improved screening levels.

Relevance of healthcare reimbursement data to monitor syphilis epidemic: an alternative surveillance through the national health insurance database in France, 2011-2013.

OBJECTIVE: In France, surveillance of early syphilis (primary, secondary and early latent) relies on the clinician-based ResIST sentinel network. Although ResIST enables the monitoring of trends, a complete picture of the syphilis epidemic is not possible. More specifically, cases reported by this network are mostly diagnosed in free sexually transmitted infection clinics and hospitals (75% and 24%, respectively). This study aims to estimate the number and rate of diagnoses made outside these health facilities by exploring health insurance data. METHODS: An algorithm combining healthcare reimbursements for specific diagnostic tests and recommended treatment was fitted to identify syphilis cases. Sensitivity analyses were used to validate the algorithm. Age-standardised and gender-standardised diagnosis rates were estimated using census data. RESULTS: Between 2011 and 2013, 12 644 (7.5 cases per 100 000 inhabitants) reimbursements were made for syphilis-related diagnoses. The annual number of cases increased by 22% from 2011 (n=3771, rate=6.7/100 000) to 2013 (n=4589, rate=8.2/100 000). The rate of syphilis diagnosis increased in men from 12.9/100 000 to 16.0/100 000, while it remained steady in women at approximately 1.8/100 000. The disease burden was greatest in French overseas territories (18.1/100 000) and in the Paris area (11.7 cases/100 000). CONCLUSION: Despite the lack of data on the number of confirmed diagnoses and information on sexual behaviour, these findings demonstrate the relevance of analysing insurance data to help monitor the syphilis epidemic in patients who visit general practitioners and non-hospital-based specialists. Thus, reimbursement database might be a relevant alternative source of continuous information on syphilis in countries with similar insurance-based healthcare systems.

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.

Cost-effectiveness of HIV post-exposure prophylaxis in France.

OBJECTIVE: To assess the cost-effectiveness of HIV post-exposure prophylaxis (PEP) in France. METHODS: We used a decision tree to evaluate, from a society's perspective, the cost of PEP per quality-adjusted life-year (QALY) saved. We used 1999-2003 PEP surveillance data and literature-derived data on per event transmission probabilities, PEP efficacy and quality of life with HIV. HIV prevalence and lifetime cost of HIV/AIDS management in the HAART era were derived from French studies. We assumed that mean life expectancy in full health was 65 years among uninfected individuals and that the mean survival time after HIV infection was 22.5 years. The costs of PEP drugs and follow-up were derived from the French public sector. A 3% annual rate was used to discount future costs and effects. RESULTS: During 1999-2003, PEP was prescribed to 8958 individuals (heterosexual sex: 47.6%; homosexual sex: 28.4%; occupational exposure: 23.4%; drug injection: 0.6%); of those, 2143 were exposed to a known HIV-infected source. PEP was estimated to prevent 7.7 infections and saved 64.5 QALY at a net cost of euro 5.7 million, resulting in an overall cost-effectiveness ratio of euro 88,692 per QALY saved. PEP was cost saving for 4.4% of cases and cost effective (< euro 50,000 per QALY) in a further 11.3% of cases. In contrast, 72 and 52% of prescriptions had a cost-effectiveness ratio exceeding euro 200,000 and euro 2 millions, respectively, per QALY saved. CONCLUSION: Overall, the French PEP programme is only moderately cost effective. PEP guidelines should be revised to target high-risk exposures better.