Growth of transcendental entire solution of some q-difference equation

Technical Reports of Mathematical Sciences, Chiba University, Vol.18(2002

HIV and hepatitis C treatment uptake among people who use drugs participating in the Amsterdam Cohort Studies, 1985-2015

Background: HIV-positive people who use drugs (PWUD) start antiretroviral therapy (ART) later than other risk groups, and among HCV-positive PWUD, HCV treatment uptake is low. Nowadays, HCV direct acting antivirals (DAAs) are available and reimbursed in the Netherlands (since 2014). The Amsterdam Cohort Studies (ACS), initiated in 1985, provides us the opportunity to describe temporal trends in ART and HCV-treatment uptake among PWUD through 2015. Methods: We analyzed data from PWUD participating in the ACS between 1985 and 2015. ART and HCV-treatment data were obtained from ACS questionnaires and medical records. Treatment uptake was defined by: treatment initiation (the proportion initiating any kind of ART/HCV treatment when treatment-naive) and coverage (the proportion ever treated for HIV/HCV) among all HIV-/HCV-RNA-positive PWUD. Each was calculated per calendar year. We estimated the cumulative probability of ART uptake in the pre-cART ( <1996) and cART era (January 1,1996) among HIV seroconverters, with all-cause mortality as a competing risk. Results: Of 1305 PWUD, 263 (20.2%) were HIV-antibody positive and 810 (62.1%) were HCV-antibody positive, at study entry. ART coverage increased over time, from 5.7% in 1990 and 42.2% in 1996 to 91.7% in 2015. The proportion initiating ART ranged from 4.8% in 1990 to 33.3% in 2011. At 8 years after HIV seroconversion, cumulative probability of ART uptake was 42.5% in the pre-cART era and 61.5% in the cART era. HCV treatment initiation peaked in 2006 (9.7%). HCV-treatment coverage was 43.9% in 2015 but lower among HIV-coinfected (23.5%) than HCV-monoinfected PWUD (52.5%). In 2015, 3.0% initiated HCV treatment with DAAs. Conclusion: We observed an increase in ART and HCV-treatment coverage among PWUD over time. As expected, ART uptake was higher in the CART era than the pre-cART era. Although in 2015 HCV treatment coverage was relatively high, DAA uptake was still low. (C) 2017 Elsevier B.V. All rights reserve

High proportions of liver fibrosis and cirrhosis in an ageing population of people who use drugs in Amsterdam, the Netherlands

Background The incidence and prevalence of hepatitis C virus (HCV) infection among people who use drugs (PWUD) peaked in the 1980s in Amsterdam. As liver cirrhosis develops several decades after HCV infection and PWUD have other risk factors for liver fibrosis, we hypothesized that significant liver fibrosis or cirrhosis is now common among PWUD in Amsterdam. Methods PWUD were recruited from the Amsterdam Cohort Studies, methadone programmes and addiction clinics during 2009-2016. Transient elastography was performed to assess liver stiffness. We estimated METAVIR fibrosis levels on the basis of the following liver stiffness measurements (LSMs) cut-offs: F0-F2 (no/mild) less than 7.65 kPa; F2-F3 (moderate/severe) at least 7.65 to less than 13 kPa; and F4 (cirrhosis) at least 13 kPa. Using linear regression models, we assessed the association between LSM and sociodemographic, clinical and behavioural determinants in (a) all PWUD and (b) chronic hepatitis C virus (cHCV)-infected PWUD. Results For 140 PWUD, the median LSM was 7.6 kPa (interquartile range=4.9-12.0); 26.4% had moderate/severe fibrosis and 22.9% had cirrhosis. Of 104 chronically infected PWUD, 57.7% had evidence of significant fibrosis (≥F2). In multivariable analysis including all PWUD, increased LSM was associated significantly with cHCV monoinfection and HIV/HCV coinfection. In cHCV-infected PWUD, older age was associated significantly with increased LSM. In all groups, longer duration of heavy alcohol drinking was associated with increased LSM. Conclusion A high proportion of PWUD had significant fibrosis or cirrhosis that were associated with cHCV infection, HIV/HCV coinfection and duration of heavy alcohol drinking. Increased uptake of HCV treatment and interventions to reduce alcohol use are needed to decrease the liver disease burden in this population

Cost-Effectiveness of Hepatitis C Treatment for People Who Inject Drugs and the Impact of the Type of Epidemic; Extrapolating from Amsterdam, the Netherlands

BACKGROUND: People who inject drugs (PWID) are disproportionally affected by the hepatitis C virus (HCV) infection. The efficacy of HCV treatment has significantly improved in recent years with the introduction of direct-acting antivirals (DAAs). However, DAAs are more costly than pegylated-interferon and ribavirin (PegIFN/RBV). We aimed to assess the cost-effectiveness of four HCV treatment strategies among PWID and treatment scale-up. METHODS: An individual-based model was used describing HIV and HCV transmission and disease progression among PWID. We considered two epidemiological situations. A declining epidemic, based on the situation in Amsterdam, the Netherlands, and a stable HCV epidemic, as observed in other settings. Data on HCV incidence, prevalence, treatment setting and uptake were derived from observed data among PWID in Amsterdam. We assessed the incremental cost-effectiveness ratio (ICER, costs in €/quality-adjusted life year (QALY)) of four treatment strategies: 1) PegIFN/RBV; 2) sofosbuvir/RBV for genotype 2-3 and dual DAA for genotype 1-4; 3) Dual DAA for all genotypes; 4) Dual DAA with 3x treatment uptake. RESULTS: In both types of epidemic, dual DAA therapy was most cost-effective strategy. In the declining epidemic, dual DAA yielded an ICER of 344 €/QALY while in the stable epidemic dual DAA led to cost-savings. Scaling-up treatment was also highly cost-effective. Our results were robust over a range of sensitivity analyses. CONCLUSION: HCV treatment with DAA-containing regimens is a highly cost-effective intervention among PWID. Based on the economic and population benefits of scaling-up treatment, stronger efforts are needed to achieve higher uptake rates among PWID

Cumulative discounted costs, effects, and incremental cost-effectiveness ratios of four Hepatitis C treatment strategies in a declining epidemic and a stable HCV epidemic.

<p>Cumulative discounted costs, effects, and incremental cost-effectiveness ratios of four Hepatitis C treatment strategies in a declining epidemic and a stable HCV epidemic.</p

Cost-effectiveness frontier of DAA-treatment strategies among PWID compared to PegIFN/RBV^a. Strategy 2: DAA/RBV (G2-3) & dual DAA (g1-4); 3: Dual DAA for all genotypes; 4: Dual DAA with a 3x higher treatment uptake.

<p>a The strategies that fall below the dashed blue line are strategies that fall bellow a willingness to pay threshold reflecting 1 GDP per head of the population, i.e., €38,255 for the Netherlands, and are considered highly cost-effective compared to PegIFN/RBV. However, scenarios are compared incrementally to identify the <i>most</i> cost-effective strategy. The most cost-effective strategy is shown on the “cost-effectiveness frontier”, the line that is closest to the X-axis.</p

Base case demographics, annual transition probabilities, and SVR probabilities per treatment scenario.

<p>Base case demographics, annual transition probabilities, and SVR probabilities per treatment scenario.</p

The effect of HIV infection on anal and penile human papillomavirus incidence and clearance : A cohort study among MSM

OBJECTIVES: A large portion of anogenital cancers is caused by high-risk human papillomavirus (hrHPV) infections, which are especially common in MSM HIV-infected men. We aimed to compare the incidence and clearance of anal and penile hrHPV infection between HIV-infected and HIV-negative MSM. DESIGN: Analyses of longitudinal data from a prospective cohort study. METHODS: MSM aged at least 18 years were recruited in Amsterdam, the Netherlands, and followed-up semi-annually for 24 months. At each visit, participants completed risk-factor questionnaires. Anal and penile self-samples were tested for HPV DNA using the SPF10-PCR DEIA/LiPA25 system. Effects on incidence and clearance rates were quantified via Poisson regression, using generalized estimating equations to correct for multiple hrHPV types. RESULTS: Seven hundred and fifty MSM with a median age of 40 years (interquartile 35-48) were included in the analyses, of whom 302 (40%) were HIV-infected. The incidence rates of hrHPV were significantly higher in HIV-infected compared with HIV-negative MSM [adjusted incidence rate ratio (aIRR) 1.6; 95% confidence interval (CI) 1.3-2.1 for anal and aIRR 1.4; 95%CI 1.0-2.1 for penile infection]. The clearance rate of hrHPV was significantly lower for anal [adjusted clearance rate ratio (aCRR) 0.7; 95%CI 0.6-0.9], but not for penile infection (aCRR 1.3; 95%CI 1.0-1.7). HrHPV incidence or clearance did not differ significantly by nadir CD4 cell count. CONCLUSION: Increased anal and penile hrHPV incidence rates and decreased anal hrHPV clearance rates were found in HIV-infected compared with HIV-negative MSM, after adjusting for sexual behavior. Our findings suggest an independent effect of HIV infection on anal hrHPV infections