Linkage-to-Care Following Community-Based HBV and HCV Screening Among Immigrants from the Washington–Baltimore Metropolitan Area, 2016–2019

Understanding characteristics that impact linkage-to-care (LTC) among individuals living with HBV and/or HCV can enhance public health efforts to provide tailored care services to prevent and treat viral hepatitis among immigrants. Using HBV/HCV screening and LTC data from immigrants (2016–2019), descriptive and logistic regression analyses were conducted to assess (1) the relationship between LTC and sociodemographic factors and (2) factors associated with HBV/HCV LTC. About 87% of those positive HBsAg had LTC and 52% had LTC among those with HCVAB and confirmed PCR. Access to care was an important LTC predictor for HBV–LTC: those who had neither health insurance nor primary care provider (PCP) were more likely to have HBV–LTC than those who had either health insurance or PCP (aOR = 2.95, 95% CI = 1.32–6.59). It is essential to equally provide HBV/HCV LTC support to all immigrants from countries with high prevalence regardless of access to care.

Abstract PO-242: Viral hepatitis among foreign-born communities in the Washington- Baltimore metropolitan area: 5-year prevalence data and implications for linkage to care follow-up

Background: Viral hepatitis is a major public health problem around the world and in the United States, with significant morbidity and mortality. This research aimed to provide updated prevalence estimates and linkage-to-care rates for hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among foreign-born immigrants in the Washington-Baltimore metropolitan area. Methods: This retrospective cohort study analyzed screening data obtained from over 275 community-based outreach events held from 2015 to 2019. Through strategic collaborations and culturally-appropriate programs, the Hepatitis B Initiative of Washington DC was able to provide no-cost HBV and HCV testing, vaccination, and treatment linkage-to-care services to 9,489 and 9,427 individuals, respectively. We examined the prevalence of positive HBV (HBsAg+) and HCV (HCVAb+) infections and linkage-to-care with associated sociodemographic characteristics. Results: Overall, prevalence amongst foreign-born clients screened over the 5-year period was 4.3% for HBV and 1.1% for HCV. The highest HBV prevalence was among participants born in Malaysia (8.5%), Cambodia (7.7%), and Vietnam (6.9%), whereas HCV prevalence was highest among participants born in Mongolia (5.0%), Cameroon (3.2%), and Burma (1.5%). Among the 378 HBV- and 102 HCV-infected individuals who were referred to care, linkage- to-care rates were 87.0% (2016-2019) and 47.1% (2017-2019) respectively. Among those linked to care, an overwhelming proportion reported not having health insurance (74.8%) and/or a usual source of care (75.3%); the majority were also female (52.8%), over 30 years of age (96.6%), and born in Asia (78.0%). Conclusions: Foreign-born individuals from Asia and Africa had the highest prevalence of viral hepatitis. These results underscore the need to disaggregate screening data by country of birth to inform prevention and linkage-to-care programs and their impact. Additionally, optimal HBV and HCV screening and linkage-to-care can be achieved among harder-to-reach at-risk populations through partnerships with community organizations, health centers, and public health departments.

Citation Format: Daisy Le, Annie Coriolan, Jane Pan, Carla Jean Berg, Y. Alicia Hong, Angeline Nguyen, Hai Chi Le, Lorien Cindy Abroms, Hee-Soon Juon, Y. Tony Yang. Viral hepatitis among foreign-born communities in the Washington- Baltimore metropolitan area: 5-year prevalence data and implications for linkage to care follow-up [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-242.

Expression of doubly labeled Saccharomyces cerevisiae iso-1 ferricytochrome c and (1)H, (13)C and (15)N chemical shift assignments by multidimensional NMR

We have expressed [U-(13)C,(15)N]-labeled Saccharomyces cerevisiae iso-1 cytochrome c C102T;K72A in Escherichia coli with a yield of 11 mg/l of growth medium. Nuclear magnetic resonance (NMR) studies were conducted on the Fe(3+) form of the protein. We report herein chemical shift assignments for amide (1)H and (15)N, (13)C(omicron), (13)C(alpha), (13)C(beta), (1)H(alpha) and (1)H(beta) resonances based upon a series of three-dimensional NMR experiments: HNCA, HN(CO)CA, HNCO, HN(CA)CO, HNCACB, HCA(CO)N, HCCH-TOCSY and HBHA(CBCA)NH. An investigation of the chemical shifts of the threonine residues was also made by using density functional theory in order to help solve discrepancies between (15)N chemical shift assignments reported in this study and those reported previously.

Modeling of gas dynamics for a laser-generated plasma: propagation into low-pressure gases

The physical phenomena involved during three-dimensional axisymmetric laser-induced plasma expansion into background gas are numerically studied. For this purpose, a multispecies hydrodynamic model is developed which considers the effects of mass and ambipolar diffusions, thermal conduction, viscosity, and nonequilibrium conditions for ionization. This model is applied to describe quantitatively the Si plasma plume expansion into Ar or He gases. It is shown that the mechanism of plasma expansion depends critically on both the pressure and mass of the background gas. The shock front expansion is found to be strongly correlated with ion dynamics. A pronounced difference between heavy-particle and electron temperatures indicates a persistent lack of equilibrium between the heavy particle and the electron in the plasma plume expansion. The Si atoms of the rarefied plume are essentially driven by the backward-moving background gas as a result of a mass diffusion process. It is also noted that the diffusion processes are only important in the last expansion stage, and are less significant in the first stage. Therefore, it is shown that a computation which does not include diffusion effects (Euler equations) can adequately describe only the earliest stage of plasma expansion into background gas. The ability of the Navier-Stokes hydrodynamic multispecies model to predict the key role of the background gas type (Ar, He) and pressure is demonstrated.