Global prevalence of hepatitis C virus in women of childbearing age in 2019: a modelling study

BACKGROUND

Treatment for infection with hepatitis C virus (HCV) during pregnancy has not yet been approved; however, interventions specifically targeting women, especially those of childbearing age (15-49 years), could prevent vertical transmission and community spread. To assess the impact of such interventions, improved prevalence estimates in this group are needed. We aimed to estimate the global prevalence of viraemic HCV in 2019 among women of childbearing age.

METHODS

In this modelling study, we used previously developed models for 110 countries inputted with country-specific demographic and HCV epidemiology data. We did a literature review, searching PubMed, Embase, and grey literature for studies published between Jan 1, 2000, and June 30, 2018, reporting HCV antibody or viraemic prevalence in women of childbearing age. Studies from the literature review and studies in models were compared by use of a data quality scoring system and models were updated, as appropriate, when a better study was identified. We used these HCV disease burden models to calculate the 2019 prevalence of viraemic HCV in women of childbearing age. In countries without a model, prevalence was extrapolated by Global Burden of Disease (GBD) region.

FINDINGS

An estimated 14 860 000 (95% uncertainty interval [UI] 9 667 000-18 282 000) women aged 15-49 years had HCV infection worldwide in 2019, corresponding to a viraemic prevalence of 0·78% (95% UI 0·62-0·86). Globally, HCV prevalence increased with age, rising from 0·25% (95% UI 0·20-0·27) in women aged 15-19 years to 1·21% (0·97-1·34) in women aged 45-49 years. China (16% of total infections) and Pakistan (15%) had the greatest numbers of viraemic infections, but viraemic prevalence was highest in Mongolia (5·14%, 95% CI 3·46-6·28) and Burundi (4·91%, 3·80-18·75). Of the countries with 500 cases or more, viraemic prevalence was lowest in Chile (0·07%, 95% UI 0·04-0·12). Among the GBD regions, eastern Europe had the highest viraemic prevalence (3·39%, 95% UI 1·88-3·54). By WHO region, the Eastern Mediterranean region had the highest viraemic prevalence (1·75%, 95% UI 1·26- 1·90).

INTERPRETATION

Most research on HCV disease burden among women aged 15-49 years focuses on pregnant women. Using modelling, this analysis provides global and national estimates of HCV prevalence in all women of childbearing age. These data can inform preconception test-and-treat strategies to reduce vertical transmission and total disease burden.

FUNDING

Gilead Sciences, John C Martin Foundation, private donors.

A tool to measure the economic impact of Hepatitis B elimination: A case study in Saudi Arabia

BACKGROUND

No virologic cure exists for hepatitis B virus (HBV) infection, and existing therapies are designed to control viral replication. We aimed to estimate the national prevalence of HBsAg in 2017 and study the impact of an enhanced diagnosis rate and universal treatment administration on HBV-related outcomes in Saudi Arabia.

MATERIALS AND METHODS

A dynamic transmission and disease burden model was developed to estimate the future economic burden of HBV infection. The infected population was tracked by age and gender-defined cohorts; direct costs (healthcare, screening, diagnostics and treatment) and indirect costs (disability-adjusted life years and the value of a statistical life year) were calculated. The impact of two intervention scenarios (Achieve WHO Targets: diagnose 90% of infections and treat 80% of high viral load patients by 2030; and Diagnose and Treat All: diagnose and treat all infected patients by 2022) were compared against the Base Case scenario (no policy action), with near-universal vaccination coverage rates held constant. A sensitivity analysis of future treatment cost was also conducted.

RESULTS

In 2017, HBsAg prevalence was estimated at 1.7%, corresponding to 574,000 infections. The same year, there was an estimated incidence of 490 cases of decompensated cirrhosis, 1500 cases of hepatocellular carcinoma (HCC) and 1740 liver-related deaths (LRD). HBsAg prevalence was 0.1% among 5-year-olds and <0.1% among infants. Disease burden outcomes by 2030, as compared with 2015, were as follows - Base Case: LRDs and HCC incidence were projected to increase by 70%. WHO Targets: A 30-35% decline in both HCC incidence and LRDs. Diagnose and Treat All: A 50-55% decline in HCC incidence and LRDs. In all scenarios, HBsAg prevalence among infants and 5-year-olds declined to <0.1% with the Diagnose and Treat all scenario resulting in a prevalence approaching zero in this age group. Annual direct costs are projected to increase and peak by 2022 in both intervention scenarios due to expansion of treatment and diagnostics. However, these are offset by the reduction of indirect economic costs, starting immediately in the WHO Targets scenario and by 2023 in the strategy to diagnose and treat all. Achieving WHO Targets is estimated to achieve a positive return on investment (ROI) by 2021 when examining direct costs and indirect economic losses at a treatment price of $2700 USD per patient yearly. Diagnosing and treating all patients, however, would require at least a 50% reduction in the unit cost of treatment to achieve a positive ROI by 2029.

CONCLUSIONS

Increased diagnosis and treatment rates of HBV would lead to substantial declines in HCC and LRD. This effect would be dramatically enhanced by administering treatment to all HBV cases regardless of viral load and estimated to be highly cost-effective if treatment prices can be substantially reduced.

Hepatitis C disease burden and strategies for elimination by 2030 in Brazil. A mathematical modeling approach

Introduction and aim

Hepatitis C is a key challenge to public health in Brazil. The objective of this paper was to describe the Brazilian strategy for hepatitis C to meet the 2030 elimination goal proposed by World Health Organization (WHO).

Methods

A mathematical modeling approach was used to estimate the current HCV-infected Brazilian population, and to evaluate the relative costs of two different scenarios to address HCV disease burden in Brazil: (1) if no further changes are made to the HCV treatment program in Brazil; (2) where the WHO targets for 2030 elimination are met through diagnosis and treatment efforts peaking before 2024.

Results

An anti-HCV prevalence of 0.53% was calculated for the total population. It was estimated that the number of HCV-RNA+ individuals in Brazil in 2017 was 632,000 (0.31% of the population). Scale-up of treatment and diagnosis over time will be necessary in order to achieve WHO targets beginning in 2018. Direct costs (diagnostic, treatment and healthcare costs) are projected to increase significantly during the scale-up of treatment and diagnosis in the initial years of the intervention scenario, but then fall below the base case on an annual basis by 2025–2036, once HCV is eliminated, due to health sectors savings from the prevention of HCV liver-related morbidity and mortality.

Conclusion

Achieving the WHO targets is technically feasible in Brazil with a scale-up of treatment and diagnosis over time, beginning in 2018. However, elimination of hepatitis C requires policy changes to substantially scale-up prevention, screening and treatment of HCV, together with public health advocacy to raise awareness among affected populations and healthcare providers.

Serum Antioxidants Are Associated with Serum Reproductive Hormones and Ovulation among Healthy Women

BACKGROUND

Evidence is growing that the equilibrium between reactive oxygen species and antioxidants plays a vital role in women's reproductive health.

OBJECTIVE

The objective of this study was to evaluate variations in serum antioxidant concentrations across the menstrual cycle and associations between antioxidants and reproductive hormones and anovulation among healthy women.

METHODS

The BioCycle Study, a prospective cohort, followed 259 women aged 18-44 y for up to 2 menstrual cycles. Serum fat-soluble vitamin and micronutrient (α-tocopherol, γ-tocopherol, retinol, lutein, lycopene, and β-carotene), ascorbic acid, and reproductive hormone concentrations were measured 5-8 times/cycle. We used weighted linear mixed models to assess associations between antioxidants and hormone concentrations, after adjustment for age, race, body mass index, parity, sleep, pain medication use, total energy intake, concurrent hormones, serum cholesterol, F2-isoprostanes, and other antioxidants. Generalized linear models were used to identify associations with anovulation.

RESULTS

Serum antioxidant concentrations varied across the menstrual cycle. Retinol and α-tocopherol were associated with higher estradiol [RR: 1.00 pg/mL (95% CI: 0.67, 1.34 pg/mL); RR: 0.02 pg/mL (95% CI: 0.003, 0.03 pg/mL), respectively] and testosterone [RR: 0.61 ng/dL (95% CI: 0.44, 0.78 ng/dL); RR: 0.01 ng/dL (95% CI: 0.001, 0.01 ng/dL), respectively]. Ascorbic acid was associated with higher progesterone (RR: 0.15 ng/mL; 95% CI: 0.05, 0.25 ng/mL) and with lower follicle-stimulating hormone (RR: -0.06 mIU/mL; 95% CI: -0.09, -0.03 mIU/mL). The ratio of α- to γ-tocopherol was associated with an increased risk of anovulation (RR: 1.03; 95% CI: 1.01, 1.06).

CONCLUSIONS

These findings shed new light on the intricate associations between serum antioxidants and endogenous hormones in healthy premenopausal women and support the hypothesis that concentrations of serum vitamins affect steroidogenesis even after adjustment for oxidative stress.

Epidemiology, disease burden, and treatment strategies of chronic hepatitis C virus infections in Saudi Arabia in the new treatment paradigm shift

BACKGROUND/AIMS

Around 101,000 individuals are estimated to be viremic for chronic hepatitis C virus (HCV) in the Kingdom of Saudi Arabia (KSA) in 2014; however, only about 20% have been diagnosed. We aim to assess baseline epidemiology, disease burden, and evaluate strategies to eliminate HCV in KSA.

MATERIALS AND METHODS

The infected population and disease progression were modeled using age- and gender-defined cohorts to track HCV incidence, prevalence, hepatic complications, and mortality. Baseline assumptions and transition probabilities were extracted from the literature. The impacts of two scenarios on HCV-related disease burden were considered through increases in treatment efficacy alone or treatment and diagnosis.

RESULTS

In 2030, it is estimated by the base scenario that viremic prevalence will increase to 103,000 cases, hepatocellular carcinoma (HCC) to 470, decompensated and compensated cirrhosis cases to 1,300 and 15,400, respectively, and liver-related mortality to 670 deaths. Using high efficacy treatment alone resulted in 2030 projection of 80,700 viremic cases, 350 HCC cases, 480 liver-related deaths, and 850 and 11,500 decompensated and compensated cirrhosis cases, respectively. With an aggressive treatment strategy, in 2030 there will be about 1,700 viremic cases, 1 HCC case, about 20 liver-related deaths, and 5 and 130 cases of decompensated and compensated cirrhosis, respectively. Delaying this strategy by one year would result in 360 additional deaths by 2030.

CONCLUSIONS

HCV in KSA remains constant, and cases of advanced liver disease and mortality continue to rise. Considered increases in treatment efficacy and number treated would have a significantly greater impact than increased treatment efficacy alone. The projected impact will facilitate disease forecasting, resource planning, and strategies for HCV management. Increased screening and diagnosis would likely be required as part of a national strategy.

Finite-size effects in the conductivity of cluster assembled nanostructures

Atomic clusters have been deposited between lithographically defined contacts with nanometer scale separations. The design of the contacts is based on an appropriate application of percolation theory to conduction in cluster deposited devices and allows finite-size effects to be clearly observed. It is demonstrated, both by experiment and by simulation, that for small contact separations the percolation threshold is shifted to extremely low surface coverages. The selected rectangular contact geometry ensures that wirelike structures are formed close to the percolation threshold.

Kinetics of formation of a phase with an arbitrary stoichiometric composition in a multicomponent solid solution

A kinetic theory of nucleation and growth of a evolving phase with a given stoichiometric composition in a multicomponent solid solution is developed. It is assumed naturally that the phase grows as a result of individual atom incorporation into the phase domain in a stoichiometric ratio. As it is shown, for the case of phase formation in a multicomponent system the basic kinetic equations, describing the nucleation-growth process, can be reduced formally to the respective expression derived for nucleation-growth processes in one-component systems. However, the effective diffusion coefficients and the effective supersaturation are expressed as nontrivial combinations of the thermodynamic and kinetic parameters of the different components involved in the phase formation process. In the determination of these properties, the theory is not restricted in its applicability to perfect solutions but extended to phase formation in real mixtures. Thus, the theory may be applied directly towards the interpretation of experimental data. In the present paper, particular attention is devoted to the analysis of the two stages of the overall transformation process: (1) the stage of quasi-steady-state nucleation and (2) the transient stage of coarsening. As the results of this analysis, the quasi-steady-state nucleation rate, the number of clusters formed via nucleation and growth, and the time evolution of the cluster size distributions are established. Moreover, estimates are given for the duration of the different stages of the transformation process.

Kinetics of Nucleation at Increasing Supersaturation

The kinetics of homogeneous nucleation-growth processes under increasing supersaturation is investigated. The increase of the supersaturation is hereby caused by an appropriate variation of external parameters such as pressure and temperature. Analytic expressions are formulated for the dependence of the number of supercritical clusters both on the rate of change of the supersaturation and on time. In generalization of previous studies, both thermal and athermal nucleation are taken into consideration. It turns out that in dependence on the rate of change of the external parameters, either thermal (for moderate rates) or athermal (for higher rates) nucleation, dominates the process. It is shown further that, in the range where thermal nucleation dominates, the onset of nucleation-growth processes, i.e., the minimum value of the supersaturation required for intensive nucleation, depends weakly (logarithmically) on the rate of increase of the supersaturation. Criteria are formulated under which conditions the commonly employed assumption-independence of the nucleation-growth process on the way the initial unstable state is established-is applicable. As shown, quite generally these criteria are not fulfilled. In a further step of the analysis, simultaneously to external variations of the thermodynamic parameters, internally generated changes of the state of the system (depletion effects) are accounted for. For segregation processes in solutions (bubble formation), which are analyzed here as an example, such effects result from a decrease of the supersaturation due to the consumption of solute particles by the clusters of the newly formed phase. Basic characteristics of the nucleation-growth process, such as the maximum number of clusters formed in the system, are determined in dependence on both externally (rate of change of the external parameters) and internally (depletion effects) induced changes of the thermodynamic state of the system. It is shown, in particular, that the interplay of both factors is, in general, of comparable importance for the outcome of the nucleation-growth process. Copyright 1999 Academic Press.

Least restrictive alternatives: do they really work?

Seclusion and restraint continue to spark debate regarding their therapeutic value and ethical, legal, and humanitarian implications, yet they remain frequently used forms of treatment in psychiatric settings. Identifying specific alternatives to seclusion and restraint use, teaching nursing staff how and when to use them, and determining their effect on patient outcome are important quality improvement issues. A quality improvement study conducted at a long-term care psychiatric facility identified alternatives that nursing staff used and their effect on reducing seclusion and restraint rates. A total of 773 incidents of disruptive behavior were managed with least restrictive alternatives and did not require the use of seclusion or restraint. One-to-one verbal intervention followed by medication as needed represented the most frequently used alternative. Total seclusion and restraint hours decreased by 31 percent, and restraint hours decreased by 47 percent.

Small-Angle X-ray Scattering Size Parameters and Higher Moments of the Particle-Size Distribution Function in the Asymptotic Stage of Ostwald Ripening

Small-angle X-ray scattering (SAXS) is a powerful tool to study the kinetics of phase separation in materials. A simple procedure is presented that allows one to prove if the particle-size distribution established in a system in the late stages of phase separation corresponds to the predictions of the classical Lifshitz–Slyozov–Wagner (LSW) theory for the asymptotic stage of Ostwald ripening. The method is based on the correlations between certain SAXS size parameters and the higher moments of the LSW size distribution functions for diffusion-limited or reaction-limited ripening. It is suggested that the use of these size parameters, which can be obtained with high accuracy from the scattering curve, is frequently more advantageous than a direct comparison of the experimentally obtained size distributions with the asymptotic size-distribution functions predicted by the LSW theory. The method is applicable if the suppositions made in the LSW theory that the precipitated particles should be homogeneous spheres with volume fraction tending to zero are fulfilled. The method is applied to a photochromic glass; although the silver-halide precipitates contained in the glass develop according to the power law of diffusion-limited Ostwald ripening, their size distribution is shown not to correspond to the features of the LSW size distribution. Consequently, in this case the LSW theory cannot describe quantitatively the kinetics of ripening.

Endoneurial effects of sera from patients with acute inflammatory polyradiculoneuropathy: electrophysiologic studies on normal and demyelinated rat nerves

Serum from 10 patients with acute inflammatory demyelinative polyradiculoneuropathy (AIDP) and 10 age-matched controls was injected into rat sciatic nerve. No statistically significant changes in any electrophysiologic parameters were found at 1 week. In nerves studied with serial recordings over 60 minutes, a small but significantly greater reduction in compound muscle action potential (CMAP) was observed at 60 minutes with AIDP serum injected into normal or focally demyelinated nerves. The small reduction in CMAP amplitude in the first hour is of uncertain clinical significance.