Control of complement-induced inflammatory responses to SARS-CoV-2 infection by anti-SARS-CoV-2 antibodies.

Dysregulated immune responses contribute to the excessive and uncontrolled inflammation observed in severe COVID-19. However, how immunity to SARS-CoV-2 is induced and regulated remains unclear. Here, we uncover the role of the complement system in the induction of innate and adaptive immunity to SARS-CoV-2. Complement rapidly opsonizes SARS-CoV-2 particles via the lectin pathway. Complement-opsonized SARS-CoV-2 efficiently induces type-I interferon and pro-inflammatory cytokine responses via activation of dendritic cells, which are inhibited by antibodies against the complement receptors (CR) 3 and 4. Serum from COVID-19 patients, or monoclonal antibodies against SARS-CoV-2, attenuate innate and adaptive immunity induced by complement-opsonized SARS-CoV-2. Blocking of CD32, the FcγRII antibody receptor of dendritic cells, restores complement-induced immunity. These results suggest that opsonization of SARS-CoV-2 by complement is involved in the induction of innate and adaptive immunity to SARS-CoV-2 in the acute phase of infection. Subsequent antibody responses limit inflammation and restore immune homeostasis. These findings suggest that dysregulation of the complement system and FcγRII signaling may contribute to severe COVID-19.

Sexual behaviour and incidence of sexually transmitted infections among men who have sex with men (MSM) using daily and event-driven pre-exposure prophylaxis (PrEP): Four-year follow-up of the Amsterdam PrEP (AMPrEP) demonstration project cohort.

BACKGROUND: An increasing number of countries are currently implementing or scaling-up HIV pre-exposure prophylaxis (PrEP) care. With the introduction of PrEP, there was apprehension that condom use would decline and sexually transmitted infections (STIs) would increase. To inform sexual health counselling and STI screening programmes, we aimed to study sexual behaviour and STI incidence among men who have sex with men (MSM) and transgender women who use long-term daily or event-driven PrEP. METHODS AND FINDINGS: The Amsterdam PrEP demonstration project (AMPrEP) was a prospective, closed cohort study, providing oral daily PrEP and event-driven PrEP to MSM and transgender women from 2015 to 2020. Participants could choose their PrEP regimen and could switch at each three-monthly visit. STI testing occurred at and, upon request, in-between 3-monthly study visits. We assessed changes in numbers of sex partners and condomless anal sex (CAS) acts with casual partners over time using negative binomial regression, adjusted for age. We assessed HIV incidence and changes in incidence rates (IRs) of any STI (i.e., chlamydia, gonorrhoea, or infectious syphilis) and individual STIs over time using Poisson regression, adjusted for age and testing frequency. A total of 367 participants (365 MSM) commenced PrEP and were followed for a median 3.9 years (interquartile range [IQR] = 3.4-4.0). Median age was 40 years (IQR = 32-48), 315 participants (85.8%) self-declared ethnicity as white and 280 (76.3%) had a university or university of applied sciences degree. Overall median number of sex partners (past 3 months) was 13 (IQR = 6-26) and decreased per additional year on PrEP (adjusted rate ratio [aRR] = 0.86/year, 95% confidence interval [CI] = 0.83-0.88). Overall median number of CAS acts with casual partners (past 3 months) was 10 (IQR = 3-20.5) and also decreased (aRR = 0.92/year, 95% CI = 0.88-0.97). We diagnosed any STI in 1,092 consultations during 1,258 person years, resulting in an IR of 87/100 person years (95% CI = 82-92). IRs of any STI did not increase over time for daily PrEP or event-driven PrEP users. Two daily PrEP users, and no event-driven PrEP users, were diagnosed with HIV during their first year on PrEP. Study limitations include censoring follow-up due to COVID-19 measures and an underrepresentation of younger, non-white, practically educated, and transgender individuals. CONCLUSIONS: In this prospective cohort with a comparatively long follow-up period of 4 years, we observed very low HIV incidence and decreases in the numbers of casual sex partners and CAS acts over time. Although the STI incidence was high, it did not increase over time. TRIAL REGISTRATION: The study was registered at the Netherlands Trial Register (NL5413) https://www.onderzoekmetmensen.nl/en/trial/22706.

Hepatitis C virus infection is uncommon at baseline and during follow-up among individuals using PrEP in the Dutch national PrEP programme between 2019 and 2022.

OBJECTIVES: Studies showed that men who have sex with men (MSM), including those using pre-exposure prophylaxis (PrEP), are at increased risk of hepatitis C virus (HCV) infection. We evaluated HCV prevalence and incidence, along with their associated determinants, in a cohort of PrEP-using individuals in the Netherlands. METHODS: In 2019, the Netherlands launched a 5-year national programme that offers subsidised PrEP to eligible individuals. We used prospectively collected data from individuals registered in this programme between 2019 and 2022. Individuals underwent annual testing for HCV antibodies and additional HCV-RNA testing when antibodies were present. We calculated the prevalence of past/current HCV infection at first visit and overall incidence rate (IR) during follow-up. Univariable logistic and Poisson regression models were used to identify determinants associated with past/current prevalent or incident HCV infection, respectively. Behavioural factors referred to those occurring in the previous 6 months. RESULTS: A total of 10 563 (n=10 319, 97.7% MSM) were included. At first visit, 66 of 10 563 (0.6%) had a past/current HCV infection, which was associated with older age [odds ratio (OR) per 10 years=1.57, 95% confidence interval (CI)=1.31 to 1.88], the use of PrEP before first visit (OR=3.03, 95% CI=1.79 to 5.13), receptive condomless anal sex (CAS) (OR=2.73, 95% CI=1.25 to 5.98), chemsex (OR=2.44, 95% CI=1.49 to 3.99) and injecting drug use (IDU) (OR=6.61, 95% CI=2.35 to 18.61). Among 9851 individuals contributing to 17 150 person-years (PYs) of follow-up, 64 incident HCV infections (IR=0.37 per 100 PYs, 95% CI=0.29 to 0.48) were identified. Factors associated with incident HCV infection were receptive CAS [incidence rate ratio (IRR)=2.59, 95% CI=1.12 to 6.02], chemsex (IRR=1.78, 95% CI=1.06 to 2.98), sexually transmitted infection diagnosis (IRR=2.30, 95% CI=1.23 to 4.31) and IDU (IRR=6.15, 95% CI=2.20 to 17.18). CONCLUSIONS: Past/current prevalence and incidence of HCV were low among individuals in the Dutch PrEP programme. Infections were associated with behaviour known to be associated with HCV. Instead of annual HCV testing, as stated in most PrEP care guidelines, testing frequency for HCV could be based on behaviours associated with HCV acquisition.

SARS-CoV-2 vaccination uptake in six ethnic groups living in Amsterdam, the Netherlands: A registry-based study within the HELIUS cohort.

OBJECTIVE: Ethnic minority groups have experienced a disproportionate burden of COVID-19, and should therefore be especially encouraged to receive SARS-CoV-2 vaccination. This study compared first-dose uptake of the primary SARS-CoV-2 vaccination series across six ethnic groups in Amsterdam, the Netherlands in 2021. METHODS: We analyzed data from participants of the population-based HELIUS cohort. We linked their data to the SARS-CoV-2 vaccination registry data of the Public Health Service of Amsterdam. We included registry data from January 6, 2021 (the start of the Dutch vaccination campaign) until September 6, 2021 (a date by which all adults in the Netherlands could have received one or two vaccine doses). SARS-CoV-2 vaccination uptake was defined as having received at least one vaccine dose of the primary vaccination series. We examined the association between ethnicity and vaccination uptake using multivariable logistic regression, while accounting for the age and sex distribution of ethnic groups in Amsterdam. RESULTS: We included 19,006 participants (median age 53 years [interquartile range 41-62], 57% female). SARS-CoV-2 vaccination uptake was highest in the South-Asian Surinamese group (60.3%, 95%CI = 58.2-62.3%), followed by the Dutch (59.6%, 95%CI = 58.0-61.1%), Ghanaian (54.1%, 95%CI = 51.7-56.5%), Turkish (47.7%, 95%CI = 45.9-49.6%), African Surinamese (43.0%, 95%CI = 41.2-44.7%), and Moroccan (35.8%, 95%CI = 34.1-37.5%) groups. After adjusting for age, sex, perceived social support, and presence of relevant comorbidities, participants of African Surinamese, Ghanaian, Turkish and Moroccan origin were significantly less likely to be vaccinated than those of Dutch origin. CONCLUSIONS: Prevention strategies should continue tailoring to specific ethnic groups to encourage vaccination uptake and reduce barriers to vaccination.

Influenza-like illness symptoms due to endemic human coronavirus reinfections are not influenced by the length of the interval separating reinfections.

After 3 years of its introduction to humans, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been declared as endemic. Little is known about the severity of the disease manifestation that future infections may cause, especially when reinfections occur after humoral immunity from a previous infection or vaccination has waned. Such knowledge could inform policymakers regarding the frequency of vaccination. Reinfections by endemic human coronaviruses (HCoVs) can serve as a model system for SARS-CoV-2 endemicity. We monitored 44 immunocompetent male adults with blood sampling every 6 months (for 17 years), for the frequency of HCoV (re-)infections, using rises in N-antibodies of HCoV-NL63, HCoV-29E, HCoV-OC43, and HCoV-HKU1 as markers of infection. Disease associations during (re-)infections were examined by comparison of self-reporting records of influenza-like illness (ILI) symptoms, every 6 months, by all participants. During 8,549 follow-up months, we found 364 infections by any HCoV with a median of eight infections per person. Symptoms more frequently reported during HCoV infection were cough, sore throat, and myalgia. Two hundred fifty-one of the 364 infections were species-specific HCoV-reinfections, with a median interval of 3.58 (interquartile range 1.92-5.67) years. The length of the interval between reinfections-being either short or long-had no influence on the frequency of reporting ILI symptoms. All HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1 (re-)infections are associated with the reporting of ILIs. Importantly, in immunocompetent males, these symptoms are not influenced by the length of the interval between reinfections. IMPORTANCE: Little is known about the disease following human coronavirus (HCoV) reinfection occurring years after the previous infection, once humoral immunity has waned. We monitored endemic HCoV reinfection in immunocompetent male adults for up to 17 years. We found no influence of reinfection interval length in the disease manifestation, suggesting that immunocompetent male adults are adequately protected against future HCoV infections.

Gender Affirming Hormones Do Not Affect the Exposure and Efficacy of F/TDF or F/TAF for HIV Preexposure Prophylaxis: A Subgroup Analysis from the DISCOVER Trial.

Purpose: Transgender women are disproportionately affected by HIV and are underutilizing preexposure prophylaxis (PrEP). The lower uptake of PrEP by transgender women may be, in part, owing to the perception that taking PrEP may lower the efficacy of gender-affirming hormone therapy (GAHT) or to provider concerns that GAHT may lower the efficacy of PrEP. Methods: DISCOVER was a randomized, double-blind, noninferiority trial comparing emtricitabine (FTC, F) and tenofovir alafenamide (F/TAF) versus emtricitabine and tenofovir disoproxil fumarate (F/TDF) as PrEP among transgender women and cisgender men who have sex with men (MSM). This nested substudy of the DISCOVER trial compared the exposure of the active intracellular metabolites of FTC and tenofovir (TFV), FTC triphosphate (FTC-TP) and TFV diphosphate (TFV-DP), in peripheral blood mononuclear cells (PBMC) among transgender women receiving GAHT versus MSM within the F/TAF and F/TDF groups. Results: Our results demonstrate that TFV-DP and FTC-TP levels in PBMC were comparable between transgender women on GAHT and MSM receiving F/TAF, and between transgender women on GAHT and MSM receiving F/TDF. TFV-DP concentrations remained above the EC90 of 40 fmol/106 cells across all groups. No clinically significant drug-drug interactions of GAHT were observed with either F/TAF or F/TDF in this subanalysis. Conclusions: These findings are consistent with the clinical pharmacology of GAHT, FTC, TDF, and TAF reported in previous studies, and support the continued use of F/TAF and F/TDF for PrEP in transgender women.Clinicaltrials.gov registration number: NCT02842086.

Concordance between daily diary reported pre-exposure prophylaxis intake and intraerythrocytic tenofovir diphosphate in the Amsterdam Pre-exposure Prophylaxis demonstration project.

OBJECTIVE: We assessed the association and concordance between self-reported oral pre-exposure prophylaxis (PrEP) intake in a diary app and intraerythrocytic drug metabolite concentrations. DESIGN: AMPrEP was a prospective demonstration study providing daily and event-driven PrEP to MSM in Amsterdam, the Netherlands (2015-2020). METHODS: Participants could record their PrEP intake in a diary app. Dried blood spots (DBS) were taken at 6, 12, 24, and 48 months and analysed for tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) concentrations. We included TFV-DP measurements preceded by diary completion on at least 90% of days in the 6 weeks prior. We examined the association between self-reported PrEP intake (i.e. number of pills) and TFV-DP concentrations using tobit regression with a random intercept per participant. We also calculated concordance between categorized PrEP intake (i.e. <2, 2-3, 4-6 or 7 pills per week) and categorized TFV-DP concentrations (i.e. <350, 350-699,700-1249 or ≥1250 fmol/punch) using weighted Cohen's kappa. Last, we calculated concordance between self-reported recent PrEP intake (yes/no, in past 2 days) and quantifiability of FTC-TP (yes/no) using Cohen's kappa. RESULTS: Seven hundred and fifty-nine DBS measurements from 282 MSM were included. Self-reported PrEP intake was strongly and positively associated with TFV-DP concentration ( ß â€Š= 0.77, 95% CI = 0.70-0.84, P  < 0.0001). Concordance between categorized PrEP intake and TFV-DP concentration was moderate ( κ  = 0.44, 95% CI = 0.39-0.50). Concordance between self-reported recent PrEP intake and FTC-TP quantifiability was perfect ( κ  = 0.83, 95% CI 0.76-0.90). CONCLUSION: Self-reported PrEP intake in a diary app is strongly correlated with actual use, and therefore reliable for comparing PrEP adherence between groups. Still, suboptimal criterion validity according to clinically relevant categories warrants caution when assessing 6-week reported adherence for individuals.

Assessing the HIV care continuum among transgender women during 11 years of follow-up: results from the Netherlands' ATHENA observational cohort.

INTRODUCTION: Transgender women are at increased risk of acquiring HIV. Earlier studies reported lower retention in HIV care, antiretroviral therapy uptake, adherence and viral suppression. We assessed the stages of the HIV care continuum of transgender women in the Netherlands over an 11-year period. In addition, we assessed new HIV diagnoses and late presentation, as well as disengagement from care, between 2011 and 2021. METHODS: Using data from the Dutch national ATHENA cohort, we separately assessed viral suppression, as well as time to achieving viral suppression, among transgender women for each year between 2011 and 2021. We also assessed trends in new HIV diagnoses and late presentation (CD4 count of <350 cells/µl and/or AIDS at diagnosis), and disengagement from care. RESULTS: Between 2011 and 2021, a total of 260 transgender women attended at least one HIV clinical visit. Across all years, <90% of transgender women were virally suppressed (207/239 [87%] in 2021). The number of new HIV diagnoses fluctuated for transgender women (ptrend = 0.053) and late presentation was common (ranging between 10% and 67% of new HIV diagnoses). Of the 260 transgender women, 26 (10%) disengaged from care between 2011 and 2021 (incidence rate = 1.10 per 100 person-years, 95% confidence interval = 0.75-1.61). CONCLUSIONS: Between 2011 and 2021, less than 90% of transgender women linked to HIV care were virally suppressed. Late presentation at the time of diagnosis and disengagement from care were common. Efforts are needed to identify barriers to early HIV diagnosis and to optimize the different steps across the care continuum for transgender women.

All-cause mortality before and after DAA availability among people living with HIV and HCV: An international comparison between 2010 and 2019.

BACKGROUND: Among people living with HIV and hepatitis C virus (HCV), people who inject drugs (PWID) have historically experienced higher mortality rates. Direct-acting antivirals (DAA), which have led to a 90 % HCV cure rate independently of HIV co-infection, have improved mortality rates. However, DAA era mortality trends among PWID with HIV/HCV remain unknown. Using data from the International Collaboration on Hepatitis C Elimination in HIV Cohorts (InCHEHC), we compared pre/post-DAA availability mortality changes in three groups: PWID, men who have sex with men (MSM), and all other participants. METHODS: We included InCHEHC participants with HIV/HCV followed between 2010 and 2019 in Canada, France, the Netherlands, Spain, and Switzerland. All-cause mortality hazard was compared in the three groups, using Cox proportional hazards regression models adjusted for sex, age, advanced fibrosis/cirrhosis, and pre/post DAA availability. RESULTS: Of the 11,029 participants, 76 % were men, 46 % were PWID, baseline median age was 46 years (interquartile range [IQR] = 40;51), and median CD4 T-cell count was 490 cells/mm3 (IQR = 327;689). Over the study period (median follow-up = 7.2 years (IQR = 3.7;10.0)), 6143 (56 %) participants received HCV treatment, 4880 (44 %) were cured, and 1322 participants died (mortality rate = 1.81/100 person-years (PY) [95 % confidence interval (CI)=1.72-1.91]). Overall, PWID had higher mortality rates than MSM (2.5/100 PY [95 % CI = 2.3-2.6] vs. 0.8/100 PY [95 % CI = 0.7-0.9], respectively). Unlike women with other transmission modes, those who injected drugs had a higher mortality hazard than men who did not inject drugs and men who were not MSM (adjusted Hazard-Ratio (aHR) [95 % CI] = 1.3[1.0-1.6]). Post-DAA availability, mortality decreased among MSM in the Netherlands, Spain, and Switzerland and increased among PWID in Canada (aHR [95 % CI] = 1.73 [1.15-2.61]). CONCLUSION: Post-DAA availability, all-cause mortality did not decrease in PWID. Determinants of cause-specific deaths (drug-related, HIV-related, or HCV-related) need to be identified to explain persistently high mortality among PWID in the DAA era.

Inflammatory profiles are associated with long COVID up to 6 months after COVID-19 onset: A prospective cohort study of individuals with mild to critical COVID-19.

BACKGROUND: After initial COVID-19, immune dysregulation may persist and drive post-acute sequelae of COVID-19 (PASC). We described longitudinal trajectories of cytokines in adults up to 6 months following SARS-CoV-2 infection and explored early predictors of PASC. METHODS: RECoVERED is a prospective cohort of individuals with laboratory-confirmed SARS-CoV-2 infection between May 2020 and June 2021 in Amsterdam, the Netherlands. Serum was collected at weeks 4, 12 and 24 of follow-up. Monthly symptom questionnaires were completed from month 2 after COVID-19 onset onwards; lung diffusion capacity (DLCO) was tested at 6 months. Cytokine concentrations were analysed by human magnetic Luminex screening assay. We used a linear mixed-effects model to study log-concentrations of cytokines over time, assessing their association with socio-demographic and clinical characteristics that were included in the model as fixed effects. RESULTS: 186/349 (53%) participants had ≥2 serum samples and were included in current analyses. Of these, 101/186 (54%: 45/101[45%] female, median age 55 years [IQR = 45-64]) reported PASC at 12 and 24 weeks after COVID-19 onset. We included 37 reference samples (17/37[46%] female, median age 49 years [IQR = 40-56]). In a multivariate model, PASC was associated with raised CRP and abnormal diffusion capacity with raised IL10, IL17, IL6, IP10 and TNFα at 24 weeks. Early (0-4 week) IL-1ß and BMI at COVID-19 onset were predictive of PASC at 24 weeks. CONCLUSIONS: Our findings indicate that immune dysregulation plays an important role in PASC pathogenesis, especially among individuals with reduced pulmonary function. Early IL-1ß shows promise as a predictor of PASC.

Association between butyrate-producing gut bacteria and the risk of infectious disease hospitalisation: results from two observational, population-based microbiome studies.

BACKGROUND: Microbiota alterations are common in patients hospitalised for severe infections, and preclinical models have shown that anaerobic butyrate-producing gut bacteria protect against systemic infections. However, the relationship between microbiota disruptions and increased susceptibility to severe infections in humans remains unclear. We investigated the relationship between gut microbiota and the risk of future infection-related hospitalisation in two large population-based cohorts. METHODS: In this observational microbiome study, gut microbiota were characterised using 16S rRNA gene sequencing in independent population-based cohorts from the Netherlands (HELIUS study; derivation cohort) and Finland (FINRISK 2002 study; validation cohort). HELIUS was conducted in Amsterdam, Netherlands, and included adults (aged 18-70 years at inclusion) who were randomly sampled from the municipality register of Amsterdam. FINRISK 2002 was conducted in six regions in Finland and is a population survey that included a random sample of adults (aged 25-74 years). In both cohorts, participants completed questionnaires, underwent a physical examination, and provided a faecal sample at inclusion (Jan 3, 2013, to Nov 27, 2015, for HELIUS participants and Jan 21 to April 19, 2002, for FINRISK participants. For inclusion in our study, a faecal sample needed to be provided and successfully sequenced, and national registry data needed to be available. Primary predictor variables were microbiota composition, diversity, and relative abundance of butyrate-producing bacteria. Our primary outcome was hospitalisation or mortality due to any infectious disease during 5-7-year follow-up after faecal sample collection, based on national registry data. We examined associations between microbiota and infection risk using microbial ecology and Cox proportional hazards. FINDINGS: We profiled gut microbiota from 10 699 participants (4248 [39·7%] from the derivation cohort and 6451 [60·3%] from the validation cohort). 602 (5·6%) participants (152 [3·6%] from the derivation cohort; 450 [7·0%] from the validation cohort) were hospitalised or died due to infections during follow-up. Gut microbiota composition of these participants differed from those without hospitalisation for infections (derivation p=0·041; validation p=0·0002). Specifically, higher relative abundance of butyrate-producing bacteria was associated with a reduced risk of hospitalisation for infections (derivation cohort cause-specific hazard ratio 0·75 [95% CI 0·60-0·94] per 10% increase in butyrate producers, p=0·013; validation cohort 0·86 [0·77-0·96] per 10% increase, p=0·0077). These associations remained unchanged following adjustment for demographics, lifestyle, antibiotic exposure, and comorbidities. INTERPRETATION: Gut microbiota composition, specifically colonisation with butyrate-producing bacteria, was associated with protection against hospitalisation for infectious diseases in the general population across two independent European cohorts. Further studies should investigate whether modulation of the microbiome can reduce the risk of severe infections. FUNDING: Amsterdam UMC, Porticus, National Institutes of Health, Netherlands Organisation for Health Research and Development (ZonMw), and Leducq Foundation.

Changes in incidence of hepatitis C virus reinfection and access to direct-acting antiviral therapies in people with HIV from six countries, 2010-19: an analysis of data from a consortium of prospective cohort studies.

BACKGROUND: Reinfection after successful treatment with direct-acting antivirals is hypothesised to undermine efforts to eliminate hepatitis C virus (HCV) infection among people with HIV. We aimed to assess changes in incidence of HCV reinfection among people with HIV following the introduction of direct-acting antivirals, and the proportion of all incident cases attributable to reinfection. METHODS: We pooled individual-level data on HCV reinfection in people with HIV after spontaneous or treatment-induced clearance of HCV from six cohorts contributing data to the International Collaboration on Hepatitis C Elimination in HIV Cohorts (InCHEHC) in Australia, Canada, France, the Netherlands, Spain, and Switzerland between Jan 1, 2010, and Dec 31, 2019. Participants were eligible if they had evidence of an HCV infection (HCV antibody or RNA positive test) followed by spontaneous clearance or treatment-induced clearance, with at least one HCV RNA test after clearance enabling measurement of reinfection. We assessed differences in first reinfection incidence between direct-acting antiviral access periods (pre-direct-acting antiviral, limited access [access restricted to people with moderate or severe liver disease and other priority groups], and broad access [access for all patients with chronic HCV]) using Poisson regression. We estimated changes in combined HCV incidence (primary and reinfection) and the relative contribution of infection type by calendar year. FINDINGS: Overall, 6144 people with HIV who were at risk of HCV reinfection (median age 49 years [IQR 42-54]; 4989 [81%] male; 2836 [46%] men who have sex with men; 2360 [38%] people who inject drugs) were followed up for 17 303 person-years and were included in this analysis. The incidence of first HCV reinfection was stable during the period before the introduction of direct-acting antivirals (pre-introduction period; 4·1 cases per 100 person-years, 95% CI 2·8-6·0). Compared with the pre-introduction period, the average incidence of reinfection was 4% lower during the period of limited access (incidence rate ratio [IRR] 0·96, 95% CI 0·78-1·19), and 28% lower during the period of broad access (0·72, 0·60-0·86). Between 2015 and 2019, the proportion of incident HCV infections due to reinfection increased, but combined incidence declined by 34%, from 1·02 cases per 100 person-years (95% CI 0·96-1·07) in 2015 to 0·67 cases per 100 person-years (95% CI 0·59-0·75) in 2019. INTERPRETATION: HCV reinfection incidence and combined incidence declined in people with HIV following direct-acting antiviral introduction, suggesting reinfection has not affected elimination efforts among people with HIV in InCHEHC countries. The proportion of incident HCV cases due to reinfection was highest during periods of broad access to direct-acting antivirals, highlighting the importance of reducing ongoing risks and continuing testing in people at risk. FUNDING: Australian National Health and Medical Research Council.

Neuropsychological functioning after COVID-19: minor differences between individuals with and without persistent complaints after SARS-CoV-2 infection.

Objective: It is unclear how self-reported severe fatigue and difficulty concentrating after SARS-CoV-2 infection relate to objective neuropsychological functioning. The study aimed to compare neuropsychological functioning between individuals with and without these persistent subjective complaints. Method: Individuals with and without persistent severe fatigue (Checklist Individual Strength (CIS) fatigue ≥ 35) and difficulty concentrating (CIS concentration ≥ 18) at least 3 months after SARS-CoV-2 infection were included. Neuropsychological assessment was performed on overall cognitive functioning, attention, processing speed, executive functioning, memory, visuo-construction, and language (18 tests). T-scores -1.5 SD below population normative data (T ≤ 35) were classified as "impaired". Results: 230 participants were included in the study, of whom 22 were excluded from the analysis due to invalid performance. Of the participants included in the analysis, 111 reported persistent complaints of severe fatigue and difficulty concentrating and 97 did not. Median age was 54 years, 59% (n = 126) were female, and participants were assessed a median of 23 months after first infection (IQR: 16-28). With bivariate logistic regression, individuals with persistent complaints had an increased likelihood of slower information processing speed performance on the Stroop word reading (OR = 2.45, 95%CI = 1.02-5.84) compared to those without persistent complaints. Demographic or clinical covariates (e.g. hospitalization) did not influence this association. With linear regression techniques, persistent complaints were associated with lower t-scores on the D2 CP, TMT B, and TMT B|A. There were no differences in performance on the other neuropsychological tests. Conclusions: Individuals with subjective severe fatigue and difficulty concentrating after COVID-19 do not typically demonstrate cognitive impairment on extensive neuropsychological testing.

Determinants of epidemic size and the impacts of lulls in seasonal influenza virus circulation.

During the COVID-19 pandemic, levels of seasonal influenza virus circulation were unprecedentedly low, leading to concerns that a lack of exposure to influenza viruses, combined with waning antibody titres, could result in larger and/or more severe post-pandemic seasonal influenza epidemics. However, in most countries the first post-pandemic influenza season was not unusually large and/or severe. Here, based on an analysis of historical influenza virus epidemic patterns from 2002 to 2019, we show that historic lulls in influenza virus circulation had relatively minor impacts on subsequent epidemic size and that epidemic size was more substantially impacted by season-specific effects unrelated to the magnitude of circulation in prior seasons. From measurements of antibody levels from serum samples collected each year from 2017 to 2021, we show that the rate of waning of antibody titres against influenza virus during the pandemic was smaller than assumed in predictive models. Taken together, these results partially explain why the re-emergence of seasonal influenza virus epidemics was less dramatic than anticipated and suggest that influenza virus epidemic dynamics are not currently amenable to multi-season prediction.