Seroprevalence and SARS-CoV-2 invasion in general populations: A scoping review over the first year of the pandemic.

Since the beginning of the COVID-19 pandemic, counting infected people has underestimated asymptomatic cases. This literature scoping review assessed the seroprevalence progression in general populations worldwide over the first year of the pandemic. Seroprevalence studies were searched in PubMed, Web of Science and medRxiv databases up to early April 2021. Inclusion criteria were a general population of all ages or blood donors as a proxy. All articles were screened for the title and abstract by two readers, and data were extracted from selected articles. Discrepancies were resolved with a third reader. From 139 articles (including 6 reviews), the seroprevalence estimated in 41 countries ranged from 0 to 69%, with a heterogenous increase over time and continents, unevenly distributed among countries (differences up to 69%) and sometimes among regions within a country (up to 10%). The seroprevalence of asymptomatic cases ranged from 0% to 31.5%. Seropositivity risk factors included low income, low education, low smoking frequency, deprived area residency, high number of children, densely populated centres, and presence of a case in a household. This review of seroprevalence studies over the first year of the pandemic documented the progression of this virus across the world in time and space and the risk factors that influenced its spread.

SARS-CoV-2 Variability in Patients and Wastewaters-Potential Immuno-Modulation during the Shift from Delta to Omicron.

The continuous emergence of SARS-CoV-2 variants favors potential co-infections and/or viral mutation events, leading to possible new biological properties. The aim of this work was to characterize SARS-CoV-2 genetic variability during the Delta-Omicron shift in patients and in a neighboring wastewater treatment plant (WWTP) in the same urban area. The surveillance of SARS-CoV-2 was performed by routine screening of positive samples by single nucleotide polymorphism analysis within the S gene. Moreover, additionally to national systematic whole genome sequencing (WGS) once a week in SARS-CoV-2-positive patients, WGS was also applied when mutational profiles were difficult to interpret by routine screening. Thus, WGS was performed on 414 respiratory samples and on four wastewater samples, northeastern France. This allowed us to report (i) the temporally concordant Delta to Omicron viral shift in patients and wastewaters; (ii) the characterization of 21J (Delta) and 21K (Omicron)/BA.1-21L (Omicron)/BA.2-BA.4 mixtures from humans or environmental samples; (iii) the mapping of composite mutations and the predicted impact on immune properties in the viral Spike protein.

SARS-CoV-2 seroprevalence in healthcare workers and risk factors.

BACKGROUND: Exposure of healthcare workers (HCW) to SARS-CoV-2 is a public health concern. Not only are HCWs particularly exposed to SARS-CoV-2, but their contamination can also weaken the healthcare system. METHODS: We analyzed exposure of French University Hospital HCWs to SARS-CoV-2 through history of positive RT-PCR test and SARS-CoV-2 seroprevalence. Potential risk factors, such as age, BMI, having children or not, working in a COVID-19 unit, or smoking were explored. RESULTS: From May to June 2020, among the 8960 employees of the University Hospital of Nancy, a serological test was performed in 4696 HCWs. The average (SD) age was 40.4 (11.4) years, and the sample included 3926 women (83.6%). Of the 4696 HCWs, 1050 were smokers (22.4%). Among them, 2231 HCWs had a history of COVID-19 symptoms and/or flu-like syndrome (47.5%) and 238 were seropositive (5.1%). Neither gender, sex, BMI, nor having children were associated with a history of positive RT-PCR test or seropositive status. Previous work in a COVID-19 unit was associated with a history of positive RT-PCR test (p = 0.045), but not with seroprevalence (p = 0.215). As expected, history of COVID-19 clinical manifestations was more frequent in HCWs with positive serology than in HCWs with negative serology (adjusted OR = 1.9, 95%CI [1.4-2.5], p < 0.001). Less expected, smoking was associated with a reduced risk of seropositivity among HCWs (adjusted OR = 0.6, 95%CI [0.4-0.9], p = 0.019). CONCLUSION: HCW are patently exposed to SARS-CoV-2. Care to COVID-19 patients was not associated with a higher SARS-CoV-2 seroprevalence. Smoking appears here associated to a lower seroprevalence.

Anti-spike IgG antibody kinetics following the second and third doses of BNT162b2 vaccine in nursing home residents.

BACKGROUND: Duration of post-vaccination protection against COVID-19 in nursing home (NH) residents is a critical issue. The objective of this study was to estimate the duration of the IgG(S) response to the mRNA BNT162b2 vaccine in NH residents with (COV-Yes) or without (COV-No) history of SARS-CoV-2 infection. METHODS: A 574 COV-Yes and COV-No NH residents were included in 2 cohorts: Main (n = 115, median age 87 years) or Confirmatory (n = 459, median age 89 years). IgG(S) quantification was carried out at three different time points following the BNT162b2 vaccine: three (1st) and seven (2nd) months after the 2nd dose, and 1 month after the 3rd dose (3rd quantification) in the Main cohort, and twice (2nd and 3rd) in the Confirmatory cohort. The seroneutralization capacity according to COVID-19 history was also measured in a subgroup of patients. RESULTS: Neutralization capacity was strongly correlated with IgG(S) levels (R2 :76%) without any difference between COV-Yes and COV-No groups for the same levels of IgG(S). After the 2nd dose, duration of the assumed robust protection (IgG(S) >264 BAU/ml) was two-fold higher in the COV-Yes vs. COV-No group: 12.60 (10.69-14.44) versus 5.76 (3.91-8.64) months, with this advantage mainly due to the higher IgG(S) titers after the 2nd dose and secondary to a slower decay over time. After the 3rd dose, duration of robust protection was estimated at 11.87 (9.88-14.87) (COV-Yes) and 8.95 (6.85-11.04) (COV-No) months. These results were similar in both cohorts. CONCLUSIONS AND RELEVANCE: In old subjects living in NH, history of SARS-CoV-2 infection provides a clear advantage in the magnitude and duration of high IgG(S) titers following the 2nd dose. Importantly, the 3rd dose induces a much more pronounced IgG(S) response than the 2nd dose in COV-No subjects, the effect of which should be able to ensure a prolonged protection against severe forms of COVID-19 in these subjects.

Evaluation of a Lateral Flow Immunoassay COVIDTECH® SARS-CoV-2 IgM/IgG Antibody Rapid Test.

The new coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for severe respiratory illness (i.e., COVID-19). RT-PCR of respiratory samples is the gold standard for COVID-19 diagnosis, and serological tests may contribute to the detection of post-infection and post-vaccination immunity and enable seroprevalence studies. The lateral flow immunoassay (LFIA) COVIDTECH® SARS-CoV-2 IgM/IgG antibody rapid test that detects anti-SARS-CoV-2 IgM and IgG using an S protein recombinant antigen has been independently evaluated in two laboratories. The specificity evaluated for 65 pre-pandemic samples was 100% for IgM/IgG. An analysis of samples from patients with RT-PCR-confirmed infection revealed that IgM/IgG antibodies were detected in 18/26 (69%) samples before day 13 and in 58/58 (100%) samples from day 14 post-symptom onset. Before day 14 post-symptom onset, the COVIDTECH Test was less sensitive than other LFIA method (BIOSYNEX COVID-19 BSS IgM/IgG) and a chemiluminescent immunoassay (LIAISON® SARS-CoV-2 TrimericS IgG assay). Overall, this LFIA method is suitable for SARS-CoV-2 serological diagnosis for patients after > 14 days since the onset of symptoms.

[How genetic variability of hepatitis E virus (VHE) may impact its clinical relevance and transmission]. / Comment la variabilité génétique du virus de l'hépatite E (VHE) peut influencer ses manifestations cliniques et sa circulation dans l'environnement.

Hepatitis E virus is the main cause of acute hepatitis worldwide. The dichotomy between waterborne human-restricted genotypes 1 and 2 circulating in developing countries and zoonotic genotypes 3 and 4 infecting human through consumption of contaminated meat in industrialized countries is currently discussed, with the detection of HEV in waters of industrialized nations. Chronic infections are described in immunocomprommised patients, as well as extra hepatic syndromes. In vivo and in vitro data have shown that HEV genetic variability can impact the bioclinical relevance of the infection, by highlighting mutations associated with severity. Genetic variability has also to be considered when exploring transmission ways, with the description of new animal reservoirs and new strains able to infect humans. HEV genetic variability is one of the keys to better control its transmission and to adapt diagnostic tools and strategies, with the aim to protect vulnerable populations.

Seroprevalence of SARS-CoV-2, Symptom Profiles and Sero-Neutralization in a Suburban Area, France.

The World Health Organisation recommends monitoring the circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated anti-SARS-CoV-2 total immunoglobulin (IgT) antibody seroprevalence and in vitro sero-neutralization in Nancy, France, in spring 2020. Individuals were randomly sampled from electoral lists and invited with household members over 5 years old to be tested for anti-SARS-CoV-2 (IgT, i.e., IgA/IgG/IgM) antibodies by ELISA (Bio-rad); the sero-neutralization activity was evaluated on Vero CCL-81 cells. Among 2006 individuals, the raw seroprevalence was 2.1% (95% confidence interval 1.5 to 2.9), was highest for 20- to 34-year-old participants (4.7% (2.3 to 8.4)), within than out of socially deprived area (2.5% vs. 1%, p = 0.02) and with than without intra-family infection (p < 10-6). Moreover, 25% of participants presented at least one COVID-19 symptom associated with SARS-CoV-2 positivity (p < 10-13), with highly discriminant anosmia or ageusia (odds ratio 27.8 [13.9 to 54.5]); 16.3% (6.8 to 30.7) of seropositive individuals were asymptomatic. Positive sero-neutralization was demonstrated in vitro for 31/43 seropositive subjects. Regarding the very low seroprevalence, a preventive effect of the lockdown in March 2020 can be assumed for the summer, but a second COVID-19 wave, as expected, could be subsequently observed in this poorly immunized population.

Full-length genome sequencing of RNA viruses-How the approach can enlighten us on hepatitis C and hepatitis E viruses.

Among the five main viruses responsible for human hepatitis, hepatitis C virus (HCV) and hepatitis E virus (HEV) are different while sharing similarities. Both viruses can be transmitted by blood or derivatives whereas HEV can also follow environmental or zoonotic routes. These highly variable RNA viruses can cause chronic hepatitis potentially leading to hepatocarcinoma. HCV and HEV can develop new structures and functions under selective pressure to adapt to host immunity, human tissues, treatments or even various animal reservoirs. Elsewhere, with directly acting antiviral treatments, HCV can be eradicated whereas HEV is an emerging pathogen against which specific treatments have to be improved. As a unique molecular tool able to explore viral genomic plasticity, full-length genome (FLG) sequencing has become easier, faster and cheaper. The present review will show how FLG sequencing can explore these RNA viruses with the aim to investigate key genomics data to improve basic knowledge, patients' healthcare and preventive tools.

Performance evaluation of an automated SARS-CoV-2 Ag test for the diagnosis of COVID-19 infection on nasopharyngeal swabs.

OBJECTIVES: The detection of SARS-CoV-2 in infected people is a key tool to help in controlling COVID-19 pandemic. Like rapid antigenic tests, automated antigen tests, that present the advantage of a higher throughput flow, may be of interest. The LIAISON® SARS-CoV-2 Ag test was evaluated for the quantification of SARS-CoV-2 nucleocapsid antigen in nasopharyngeal swabs by comparison to RT-PCR. METHODS: The study involved 378 nasopharyngeal samples (UTM® and FLOQSwab™, Copan Diagnostics), including 46 swabs positive for SARS-CoV-2 by RT-PCR. These samples came from asymptomatic (n=99, 26.2%) or symptomatic people (n=279, 73.8%), at different times from symptom onset. The samples were analyzed on LIAISON® XL. RESULTS: The overall specificity was 99.4% (CI95% [98.6-100]). The negative predictive value reached 100% in asymptomatic people. Among the 46 positive samples, the overall sensitivity was 84.8% (CI95% [74.4-95.2]), reached 91.9% (CI95% [83.1-100]) in the first fourth days after symptoms onset and was 100% for Cq values ≤25. Antigen was not detected in samples with Cq values >25. Similar results were observed on nasopharyngeal swabs coming from patients infected with the 20I/501Y.V1 variant or the 20H/501Y.V2 variant. CONCLUSIONS: According to technical performances, the LIAISON® SARS-CoV-2 Ag test may be a useful tool for COVID-19 diagnosis, especially during the first four days of symptoms.

Factors associated with the emergence of integrase resistance mutations in patients failing dual or triple integrase inhibitor-based regimens in a French national survey.

BACKGROUND: Successful 2-drug regimens (2DRs) for HIV were made possible by the availability of drugs combining potency and tolerability with a high genetic barrier to resistance. How these deal with resistance development/re-emergence, compared with 3DRs, is thus of paramount importance. MATERIALS AND METHODS: A national survey including patients who were either naive or experienced with any 2DR or 3DR but failing integrase strand transfer inhibitor (INSTI)-containing regimens [two consecutive plasma viral load (VL) values >50 copies/mL] was conducted between 2014 and 2019. Genotypic resistance tests were interpreted with the v28 ANRS algorithm. RESULTS: Overall, 1104 patients failing any INSTI-containing regimen (2DRs, n = 207; 3DRs, n = 897) were analysed. Five hundred and seventy-seven (52.3%) patients were infected with a B subtype and 527 (47.3%) with non-B subtypes. Overall, 644 (58%) patients showed no known integrase resistance mutations at failure. In multivariate analysis, factors associated with the emergence of at least one integrase mutation were: high VL at failure (OR = 1.24 per 1 log10 copies/mL increase); non-B versus B subtype (OR = 1.75); low genotypic sensitivity score (GSS) (OR = 0.10 for GSS = 2 versus GSS = 0-0.5); and dolutegravir versus raltegravir (OR = 0.46). Although 3DRs versus 2DRs reached statistical significance in univariate analysis (OR = 0.59, P = 0.007), the variable is not retained in the final model. CONCLUSIONS: This study is one of the largest studies characterizing integrase resistance in patients failing any INSTI-containing 2DR or 3DR in routine clinical care and reveals factors associated with emergence of integrase resistance that should be taken into consideration in clinical management. No difference was evidenced between patients receiving a 2DR or a 3DR.

Variability in molecular characteristics of Hepatitis E virus quasispecies could modify viral surface properties and transmission.

Hepatitis E virus (HEV) usually causes self-limited liver diseases but can also result in severe cases. Genotypes 1 (G1) and 2 circulate in developing countries are human-restricted and waterborne, while zoonotic G3 and G4 circulating in industrialized countries preferentially infect human through consumption of contaminated meat. Our aims were to identify amino acid patterns in HEV variants that could be involved in pathogenicity or in transmission modes, related to their impact on antigenicity and viral surface hydrophobicity. HEV sequences from human (n = 37) and environmental origins (wild boar [n = 3], pig slaughterhouse effluent [n = 6] and urban wastewater [n = 2]) were collected for the characterization of quasispecies using ultra-deep sequencing (ORF2/ORF3 overlap). Predictive and functional assays were carried out to investigate viral particle antigenicity and hydrophobicity. Most quasispecies showed a major variant while a mixture was observed in urban wastewater and in one chronically infected patient. Amino acid signatures were identified, as a rabbit-linked HEV pattern in two infected patients, or the S68L (ORF2) / H81C (ORF3) residue mostly identified in wild boars. By comparison with environmental strains, molecular patterns less likely represented in humans were identified. Patterns impacting viral hydrophobicity and/or antigenicity were also observed, and the higher hydrophobicity of HEV naked particles compared with the enveloped forms was demonstrated. HEV variants isolated from human and environment present molecular patterns that could impact their surface properties as well as their transmission. These molecular patterns may concern only one minor variant of a quasispecies and could emerge under selective pressure.

Epidemiological surveillance of SARS-CoV-2 by genome quantification in wastewater applied to a city in the northeast of France: Comparison of ultrafiltration- and protein precipitation-based methods.

The aim of the present study was to develop a simple, sensitive, and specific approach to quantifying the SARS-CoV-2 genome in wastewater and to evaluate this approach as a means of epidemiological surveillance. Twelve wastewater samples were collected from a metropolitan area in north-eastern France during April and May 2020. In addition to the quantification of the SARS-CoV-2 genome, F-specific RNA phages of genogroup II (FRNAPH GGII), naturally present in wastewater, were used as an internal process control for the viral concentration and processing of RT-PCR inhibitors. A concentration method was required to allow the quantification of the SARS-CoV-2 genome over the longest possible period. A procedure combining ultrafiltration, phenol-chloroform-isoamyl alcohol purification, and the additional purification of the RNA extracts was chosen for the quantification of the SARS-CoV-2 genome in 100-mL wastewater samples. At the same time, the COVID-19 outbreak was evaluated through patients from the neighbouring University Hospital of Nancy, France. A regular decrease in the concentration of the SARS-CoV-2 genome from ~104 gc/L to ~102 gc/L of wastewater was observed over the eight weeks of the study, during which the population was placed under lockdown. The SARS-CoV-2 genome was even undetectable during one week in the second half of May and present but non-quantifiable in the last sample (28 May). A concordant circulation in the human community was highlighted by virological diagnosis using respiratory samples, which showed a decrease in the number of COVID-19 cases from 677 to 52 per week over the same period. The environmental surveillance of COVID-19 using a reliable viral quantification procedure to test wastewater is a key approach. The real-time detection of viral genomes can allow us to predict and monitor the circulation of SARS-CoV-2 in clinical settings and survey the entire urban human population.

Signs of tracheobronchitis may constitute the principal finding on the lung SPECT/CT images of COVID-19 patients.

BACKGROUND: This study aimed to analyze the rates of tracheobronchitis signs observed on the ventilation scans of COVID-19 patients with shortness of breath, with comparisons to a non-COVID population. METHODS: Lung scintigraphy was collected in 10 such COVID patients, as well as from a non-COVID population investigated outside the epidemic wave period, on a CZT-SPECT/CT system, with ventilation images recorded with 99mTc-labeled Technegas® and perfusion images with 99mTc-labeled albumin macroaggregates. RESULTS: A diffuse tracheobronchial uptake was observed on the ventilation scans from 3 COVID patients (30%), whereas this rate was 3% (3/90) in the non-COVID group (P = 0.013). These 3 patients had no laryngeal extension of Technegas® uptake and limited parenchymal lung abnormalities. Follow-up scintigraphy demonstrated the withdrawal of tracheobronchitis signs in two cases, and the advent of a severe pulmonary embolism in one. CONCLUSION: Signs of tracheobronchitis may constitute the principal finding on lung SPECT/CT images of COVID-19 patients with shortness of breath.

Changes in characteristics and management among patients with ST-elevation myocardial infarction due to COVID-19 infection.

OBJECTIVES: To assess changes in characteristics and management among ST-elevation myocardial infarction (STEMI) patients with coronavirus disease (COVID-19) who underwent primary percutaneous coronary intervention. METHODS: Our prospective, monocentric study enrolled all STEMI patients who underwent PPCI during the COVID-19 outbreak (n = 83). This cohort was first compared with a previous cohort of STEMI patients (2008-2017, n = 1,552 patients) and was then dichotomized into a non-COVID-19 group (n = 72) and COVID-19 group (n = 11). RESULTS: In comparison with the pre-outbreak period, patients during the outbreak period were older (59.6 ± 12.9 vs. 62.6 ± 12.2, p = .03) with a delayed seek to care (mean delay first symptoms-balloon 3.8 ± 3 vs. .7.4 ± 7.7, p < .001) resulting in a two-fold higher in-hospital mortality (non COVID-19 4.3% vs. COVID-19 8.4%, p = .07). Among the 83 STEMI patients admitted during the outbreak period, 11 patients were infected by COVID-19. Higher biological markers of inflammation (C-reactive protein: 28 ± 39 vs. 98 ± 97 mg/L, p = .04), of fibrinolysis (D-dimer: 804 ± 1,500 vs. 3,128 ± 2,458 µg/L, p = .02), and antiphospholipid antibodies in four cases were observed in the COVID-19 group. In this group, angiographic data also differed: a thrombotic myocardial infarction nonatherosclerotic coronary occlusion (MINOCA) was observed in 11 cases (1.4% vs. 54.5%, p < .001) and associated with higher post-procedure distal embolization (30.6% vs. 72.7%, p = .007). The in hospital mortality was significantly higher in the COVID-19 group (5.6% vs. 27.3%, p = .016). CONCLUSION: The COVID-19 outbreak implies deep changes in the etiopathogenesis and therapeutic management of STEMI patients with COVID-19. The impact on early and long-term outcomes of systemic inflammation and hypercoagulability in this specific population is warranted.

CT abnormalities evocative of lung infection are associated with lower 18F-FDG uptake in confirmed COVID-19 patients.

PURPOSE: CT signs that are evocative of lung COVID-19 infections have been extensively described, whereas 18F-FDG-PET signs have not. Our current study aimed to identify specific COVID-19 18F-FDG-PET signs in patients that were (i) suspected to have a lung infection based on 18F-FDG-PET/CT recorded during the COVID-19 outbreak and (ii) whose COVID-19 diagnosis was definitely established or excluded by appropriate viral testing. METHODS: Twenty-two consecutive patients referred for routine 18F-FDG-PET/CT examinations during the COVID-19 outbreak (March 25th to May 15th 2020) and for whom CT slices were evocative of a lung infection were included in the study. All patients had undergone a SARS-COV-2 diagnostic test to confirm COVID-19 infection (positivity was based on molecular and/or serological tests) or exclude it (negativity of at least the serological test). RESULTS: Eleven patients were confirmed to be affected by COVID-19 (COVID+), whereas the other eleven patients were not (COVID-) and were predominantly suspected of having bacterial pneumonia. CT abnormalities were not significantly different between COVID+ and COVID- groups, although trends toward larger CT abnormalities (p = 0.16) and lower rates of consolidation patterns (0.09) were observed in the COVID+ group. The maximal standardized uptake values (SUVmax) of lung areas with CT abnormalities were however significantly lower in the COVID+ than the COVID- group (3.7 ± 1.9 vs. 6.9 ± 4.1, p = 0.03), with the highest SUVmax consistently not associated with COVID-19. CONCLUSION: Among CT abnormalities evocative of lung infection, those related to COVID-19 are associated with a more limited 18F-FDG uptake. This observation may help improve our ability to detect COVID-19 patients.

Case Series of COVID-19 Asymptomatic Newborns With Possible Intrapartum Transmission of SARS-CoV-2.

Background: Despite the pandemic, data are limited regarding COVID-19 infection in pregnant women and newborns. This report aimed to bring new information about presentation that could modify precautionary measures for infants born of mothers with a remote history of COVID-19. Methods: We report two infants with possible maternofetal transmission, and four mothers without immunologic reactions. Data were collected from the patient files. Results: One mother exhibited infection signs 10 days before uncomplicated delivery, with negative RT-PCR and no antibody detection thereafter. Another mother exhibited infection 6 weeks pre-delivery, confirmed by nasopharyngeal swab testing with positive RT-PCR, and positive antibody detection (IgM and IgG). Both newborns were asymptomatic but tested positive for nasopharyngeal and stool RT-PCR at 1 and 3 days of age for the first one and at 1 day of age for stool analysis for the second one. Two additional mothers exhibited infection confirmed by positive RT-PCR testing at 28- and 31-days pre-delivery but did not present detectable antibody reaction at the time of delivery. Conclusion: These observations raise concerns regarding contamination risk by asymptomatic newborns and the efficacy of immunologic reactions in pregnant mothers, questioning the reliability of antibody testing during pregnancy.

Treatment as prevention enrolling at least 75% of individuals on ART will be needed to significantly reduce HIV prevalence in a HIV cohort.

BACKGROUND: "Treatment as Prevention" (TasP) aims to reduce new HIV infections through higher enrolment on suppressive antiretroviral therapy (ART). OBJECTIVES: We studied the current epidemic and possible impact of TasP in a French HIV cohort including MSM and migrant subjects. STUDY DESIGN: Socio-demographic, clinical and laboratory variables were collected during the follow-up of 6995 HIV-infected patients. The numbers of individuals living with HIV in each year were estimated from diagnoses up to that year minus recorded deaths. Patients were classified according to gender, transmission mode, country of birth and treatment status. RESULTS: The cohort includes 6995 individuals diagnosed from 1985 to 2015, of whom 72% were men. Unprotected sexual intercourse was the main mode of transmission. Women were more likely to be migrants (45% versus 13%), whereas men were more likely to have been born in France (52% versus 27%). Diagnoses were more correlated with untreated than treated prevalence in each group. MSM diagnoses was strongly correlated to untreated prevalence whatever the country of birth (p < 0.0001). However, heterosexual diagnoses were better correlated with prevalence within individual country groups (b = 0.29 female diagnoses/year per untreated male born in France, compared to b = 0.73 for foreigners). Using these transmission rates, mathematical modelling estimated that enrolling 75% of untreated individuals per year would decrease diagnoses ten-fold by 2021. CONCLUSIONS: Enrolling at least 75% of individuals on ART is necessary to substantially impact numbers of new HIV infections in this cohort. Treatment as prevention will actually be effective to reduce HIV prevalence.

Resistance to integrase inhibitors: a national study in HIV-1-infected treatment-naive and -experienced patients.

OBJECTIVES: To describe integrase strand transfer inhibitor (INSTI) resistance profiles and factors associated with resistance in antiretroviral-naive and -experienced patients failing an INSTI-based regimen in clinical practice. METHODS: Data were collected from patients failing an INSTI-containing regimen in a multicentre French study between 2014 and 2017. Failure was defined as two consecutive plasma viral loads (VL) >50 copies/mL. Reverse transcriptase, protease and integrase coding regions were sequenced at baseline and failure. INSTI resistance-associated mutations (RAMs) included in the Agence Nationale de Recherches sur le SIDA genotypic algorithm were investigated. RESULTS: Among the 674 patients, 359 were failing on raltegravir, 154 on elvitegravir and 161 on dolutegravir therapy. Overall, 90% were experienced patients and 389 (58%) patients showed no INSTI RAMs at failure. The strongest factors associated with emergence of at least one INSTI mutation were high VL at failure (OR = 1.2 per 1 log10 copies/mL increase) and low genotypic sensitivity score (GSS) (OR = 0.08 for GSS ≥3 versus GSS = 0-0.5). Patients failing dolutegravir also had significantly fewer INSTI RAMs at failure than patients failing raltegravir (OR = 0.57, P = 0.02) or elvitegravir (OR = 0.45, P = 0.005). Among the 68 patients failing a first-line regimen, 11/41 (27%) patients on raltegravir, 7/18 (39%) on elvitegravir and 0/9 on dolutegravir had viruses with emergent INSTI RAMs at failure. CONCLUSIONS: These results confirmed the robustness of dolutegravir regarding resistance selection in integrase in the case of virological failure in routine clinical care.