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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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D

Glossary

95% immunity – 95% of people that are immunized become immune. For most of the millions of people who get immunized every year, a protective effect occurs; however, in a small percentage of people, this is not the case. Ineffective immunization results when an individual’s immune system does not respond appropriately. While unlikely to occur in the United States, vaccines can also be ineffective if not manufactured properly or not stored and handled properly.

acetaminophen – A crystalline compound used in chemical synthesis and in medicine to relieve pain and reduce fevers.

adherence – The extent to which the patient continues the agreed-upon mode of treatment under limited supervision when faced with conflicting demands, as distinguished from compliance or maintenance.

Affordable Care Act – Legislation passed by Congress and then signed into law by the president on March 23, 2010. On June 28, 2012, the Supreme Court rendered a final decision to uphold the health care law. The Affordable Care Act refers to two separate pieces of legislation—the Patient Protection and Affordable Care Act (P.L. 111-148) and the Health Care and Education Reconciliation Act of 2010 (P.L. 111-152)—that together expanded Medicaid coverage to millions of low-income Americans.

AIDS Drug Assistance Program – The program was authorized under the Ryan White Comprehensive AIDS Resources Emergency (CARE) Act and

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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provides HIV-related prescription drugs to underinsured and uninsured individuals living with HIV/AIDS.

anamnestic response – A rapid increase in production of antibodies in response to an immunogenic substance after serum antibodies from the first response can no longer be detected in the blood.

anti-HBc immunoglobulin M (IgM) – Anti-HBc indicates precious or ongoing infection with hepatitis B virus in an undefined time frame. IgM is an antibody to the HBV core antigen that appears during acute infection, with levels typically decreasing within 6 months despite persistence of infection.

antibody – A protein produced by the body’s immune system when it detects harmful substances, called antigens.

antigen – A harmful substance that is capable of stimulating an immune response, specifically activating lymphocytes. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.

ascites – The accumulation of fluid in the peritoneal cavity, causing abdominal swelling.

B cell non-Hodgkin’s lymphoma – A cancer the presents itself when B cells grow and multiply uncontrollably and then travel to many parts of the body and form tumors. Hodgkin’s lymphoma is marked by the presence of Reed-Sternberg cells, which are mature B cells that have become malignant, are unusually large, and carry more than one nucleus. Non-Hodgkin’s lymphoma, by contrast, can be derived from B cells or T cells and can arise in the lymph nodes as well as other organs.

B cell response – B cells are a type of lymphocyte that differentiates into plasma cells in the presence of a specific antigen. The plasma cells produce antibodies that attack or neutralize the antigen in what is called the humoral immune response.

carcinoma – An invasive malignant tumor derived from epithelial tissue of the skin or the lining of the internal organs that tends to metastasize to other areas of the body.

carotid plaque – Carotid artery disease occurs when fatty deposits (plaques) clog the blood vessels that deliver blood to the brain and head (carotid arteries). The blockage increases the risk of stroke.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

case management – A collaborative process of assessment, planning, facilitation, care coordination, evaluation, and advocacy for options and services to meet an individual’s and family’s comprehensive health needs through communication and available resources to promote quality, cost-effective outcomes.

cell surface – Cell surface receptors (membrane receptors, transmembrane receptors) are receptors at the surface of a cell (built into its cell membrane) that act in cell signaling by binding to extracellular molecules.

cellular response – The immune response produced when sensitized T cells attack foreign antigens and secrete lymphokines that initiate the body’s humoral immune response.

Child-Pugh or Child-Turcotte-Pugh score – A classification used to assess the prognosis of chronic liver disease.

chronic hepatitis B – Hepatitis B is a serious liver infection caused by the hepatitis B virus (HBV). HBV is transmitted in infected blood, causing fever, debility, and jaundice. Hepatitis B becomes chronic when it lasts more than 6 months.

chronic hepatitis C – Hepatitis C is a serious liver infection caused by the hepatitis C virus (HCV). HCV is transmitted in infected blood. Most people infected with HCV have no symptoms. Hepatitis C becomes chronic when it lasts more than 6 months.

cirrhosis – A chronic disease of the liver characterized by the replacement of normal tissue with fibrous tissue and the loss of functional liver cells. It can result from alcohol abuse, nutritional deprivation, or infection especially by the hepatitis viruses.

control Reduction of disease incidence, prevalence, morbidity, or mortality to a locally acceptable level as a result of deliberate efforts; continued intervention measures are required to maintain the reduction.

cost-effective – Economical in terms of tangible benefits produced by money spent.

covalently closed circular DNA (cccDNA) – A double-stranded DNA that originates in a linear form that is ligated by means of DNA ligase to a covalently closed ring. In HBV cccDNA persists within the nuclei of infected liver cells, produces viral RNA transcripts, and is difficult to eradicate.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

cccDNA is thought to be the form of the virus responsible for both chronic HBV infection and persistent viral infection after antiviral treatment.

cryoglobulinemia – A medical condition that occurs when cryoglobulin proteins become insoluble at reduced temperatures, causing inflammation and blocking blood vessels throughout the body. This may lead to problems ranging from skin rashes to kidney failure.

cutaneous vasculitis – A group of disorders in which there are inflamed blood vessels in the skin. These may include capillaries, venules, arterioles, and lymphatics.

cytoplasm – The cell substance between the cell membrane and the nucleus, containing the cytosol, organelles, cytoskeleton, and various particles.

decompensated cirrhosis – Development of clinically evident complications of portal hypertension (ascites, variceal hemorrhage, hepatic encephalopathy) or jaundice. Survival is poor in patients with decompensated cirrhosis and they should be considered for liver transplantation.

diabetes – Any of several metabolic diseases in which the body’s inability to produce any or enough insulin causes elevated levels of glucose in the blood. Diabetes is marked by excessive discharge of urine and persistent thirst.

dyslipidemia – Elevated total or low-density lipoprotein cholesterol levels, or low levels of high-density lipoprotein cholesterol. Dyslipidemia is an important risk factor for coronary heart disease and stroke.

effectiveness – The degree to which something is successful in producing a desired result; success.

efficacy – The ability to produce a desired or an intended result.

electronic health record – an electronic version of a patient’s medical history, that is maintained by the provider over time, and may include all of the key administrative clinical data relevant to that person’s care under a particular provider, including demographics, progress notes, problems, medications, vital signs, past medical history, immunizations, laboratory data, and radiology reports.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

electronic medical record – A digital version of the traditional paper-based medical record for an individual. The electronic medical record represents a medical record within a single facility, such as a doctor’s office or a clinic.

elimination of disease – Reduction to zero of the incidence of a specified disease in a defined geographic area as a result of deliberate efforts; continued intervention measures are required to maintain the reduction.

elimination of infection – Reduction to zero of the incidence of infection caused by a specific agent in a defined geographic area as a result of deliberate efforts; continued measures to prevent reestablishment of transmission are required.

endemic – Regularly found among particular people or in a certain area.

eradication – Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed.

esophageal varices – Abnormal, enlarged veins in the lower part of the esophagus—the tube that connects the throat and stomach. Esophageal varices occur most often in people with serious liver diseases when normal blood flow to the liver is obstructed by scar tissue in the liver or a clot. Seeking a way around the blockages, blood flows into smaller blood vessels that are not designed to carry large volumes of blood. The vessels may leak blood or even rupture, causing life-threatening bleeding.

fatty liver disease – A reversible condition wherein large vacuoles of triglyceride fat accumulate in liver cells due to abnormal retention of lipids within the cells. Fatty liver disease occurs when more than 5 to 10 percent of the liver weight is fat. Hepatitis C virus, alcohol, and obesity are common causes of fatty liver disease.

fibrosis – The thickening and scarring of connective tissue as a reparative or reactive process.

fulminant hepatitis – A rare and frequently fatal form of acute hepatitis B in which the patient’s condition rapidly deteriorates, with hepatic encephalopathy, necrosis of the hepatic parenchyma, coagulopathy, renal failure, and coma.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

genotype – The genetic constitution of an organism or a group of organisms.

glomerulonephritis – Renal disease marked by bilateral inflammatory changes in the glomeruli (the filters in the kidneys) that are not the result of kidney infection.

graft survival – The success of an organ transplant.

harm reduction – A set of practical strategies and ideas aimed at reducing negative consequences associated with drug use. Harm reduction is also a movement for social justice built on a belief in, and respect for, the rights of people who use drugs.

harm-reduction services – Strategies aimed at reducing negative consequences associated with drug use such as needle and syringe exchange programs, opioid substitution therapy, training, and education.

Harvoni® – A drug used to treat hepatitis C virus; the US proprietary name of 90 mg of the viral NS5A inhibitor ledipasvir and 400 mg of sofosbuvir, a nucleotide inhibitor of the viral RNA polymerase. Harvoni® provides cure rates of 94 to 99 percent in people infected with genotype 1 but the average cost of treatment in the United States is more than $90,000. The drug became available in October 2014.

HBV core antibody – Anti-HBc appears at the onset of symptoms in acute hepatitis B and persists for life. The presence of hepatitis B virus core antibodies indicates previous or ongoing infection with hepatitis B in an undefined time frame.

HBV e antibody – Anti-HBe is produced by the immune system temporarily during acute hepatitis B infection or consistently during or after a burst in viral replication. Spontaneous conversion from e antigen to e antibody (a change known as seroconversion) is a predictor of long-term clearance of hepatitis B virus (HBV) in patients undergoing antiviral therapy and indicates lower levels of HBV.

HBV e antigen – A secreted product of the nucleocapsid gene of hepatitis B virus (HBV) that is found in serum during acute and chronic hepatitis B. Its presence indicates that the virus is replicating and the infected person has high levels of HBV.

HBV surface antibody – The presence of hepatitis B virus (HBV) surface antibodies is generally interpreted as indicating recovery and immunity

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

from HBV infection. HBV surface antibodies also develop in a person who has been successfully vaccinated.

HBV surface antigen – A protein on the surface of hepatitis B virus (HBV); it can be detected in high levels in serum during acute or chronic HBV infection. The presence of HBV surface antigens indicates that the person is infectious. The body normally produces antibodies to HBV surface antigens as part of the normal immune response to infection. The antigen is also used to make the HBV vaccine.

health disparity – The inequalities that occur in the provision of health care and access to health care across different racial, ethnic, and socioeconomic groups.

hepatic encephalopathy – A decline in brain function that occurs as a result of severe liver disease. In this condition, the liver cannot adequately remove toxins from the blood. This causes a buildup of toxins in the bloodstream, which can lead to brain damage.

hepatitis – An inflammation of the liver. The condition can be self-limiting or can progress to fibrosis (scarring), cirrhosis or liver cancer. Hepatitis viruses are the most common cause of hepatitis in the world but other infections, toxic substances (e.g., alcohol, certain drugs), and autoimmune diseases can also cause hepatitis. There are five main hepatitis viruses, referred to as types A, B, C, D and E. Types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.

hepatitis B immune globulin – A substance that is used as an injection to prevent hepatitis B virus (HBV) from occurring again in HBV surface antigen positive liver transplant patients after surgery. This injection also reduces the chance of the development of HBV after exposure to the virus.

hepatocellular carcinoma – A cancer derived from parenchymal cells of the liver. Hepatocellular carcinoma most commonly occurs in people with liver disease, particularly in people with chronic hepatitis B and hepatitis C. Symptoms often do not appear in the early stages of the cancer. Later, symptoms include weight loss, upper abdominal pain, or jaundice.

histology – The science concerned with the minute structure of tissues and organs in relation to their function.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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humoral response – The immune response involving the transformation of B cells into plasma cells that produce and secrete antibodies to a specific antigen.

hypertension – Persistent high blood pressure.

immune clearance (or immune active) – The accelerated removal of an antigen from the bloodstream that follows the initiation of an antibody response by the immune system. This leads to the formation of antigen-antibody complexes, which are ingested by macrophages and other phagocytic cells.

immune tolerance – A state of unresponsiveness to a specific antigen or group of antigens to which a person is normally responsive. Immune tolerance is achieved under conditions that suppress the immune reaction and is not just the absence of an immune response.

immunity – Inherited, acquired, or induced resistance to infection by a specific pathogen.

incidence – The extent or rate of occurrence, especially the number of new cases of a disease in a population over a period of time.

insulin resistance – A state of diminished effectiveness of insulin in lowering the levels of blood sugar, usually resulting from insulin binding by antibodies, and associated with such conditions as obesity, ketoacidosis, and infection.

inter-observer variability – The variability between observers of the same phenomenon; the amount observers vary from one another when reporting on the same material.

interoperability – The ability of different information technology systems and software applications to communicate, exchange data, and use the information that has been exchanged.

intra-observer variability – The variability within observers of the same phenomenon; the amount one observer varies between observations when reporting more than once on the same material.

jail – A building designated or regularly used for the confinement of individuals who are sentenced for minor crimes or who are unable to gain release on bail and are in custody awaiting trial.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

latent cellular reservoir – The cells of the body where an infection is able to hide (or “persist”) even in the face of optimal antiviral therapy. These cellular reservoirs are located throughout the body.

LDL receptor – Low-density lipoprotein (LDL) is a complex of lipids and proteins that functions as a transporter of cholesterol in the blood, and which, in high concentrations is associated with an increased risk of atherosclerosis and coronary heart disease. The LDL receptors are on the outer surface of many types of cells, where they bind to LDLs circulating in the bloodstream and transport them into the cell.

lipo-viro-particle – Triglyceride-rich lipoprotein-like particle containing viral RNA and proteins. Lipo-viro-particles are a constant feature of chronic hepatitis C.

lipoprotein – Any of a group of conjugated proteins having at least one lipid component; they are the principal means by which lipids are transported in the blood.

liver aminotransferase level – Liver enzymes include aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT). These enzymes are normally predominantly contained within liver cells and to a lesser degree in muscle cells. If the liver is injured or damaged, the liver cells spill these enzymes into the blood, raising the AST and ALT enzyme blood levels and signaling liver disease.

longitudinal study – An observational research method in which data is gathered for the same subjects repeatedly over a period of time. Longitudinal research projects can extend over years or even decades.

low replicative (or inactive) HBV carrier – A phase of chronic hepatitis B distinguished by loss of hepatitis B virus (HBV) e antigen (if present) and development of HBV e-antibody with suppression of HBV DNA and normalization of liver aminotransferase levels.

magnetic resonance elastography – A noninvasive magnetic resonance imaging–based technique for quantitatively assessing the mechanical properties of tissues in vivo. Magnetic resonance elastography is performed by using a vibration source to generate low frequency mechanical waves in tissue. Specially developed mathematical algorithms are used to analyze the wave images and to generate quantitative images depicting the stiffness and other mechanical properties of tissue. Magnetic resonance elastography is a useful imaging tool with the capability to (1) noninvasively “palpate by

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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imaging” regions of the body that are beyond the reach of the physician’s hand, (2) delineate tumors and other abnormalities before they are severe enough to detect by touch, (3) provide greater sensitivity for assessing changes in tissue mechanical properties, and (4) provide useful new quantitative imaging biomarkers for characterizing tissue properties.

marginalization – Comprises those processes by which individuals and groups are ignored or relegated to the sideline of political debate, social negotiation, and economic bargaining—and kept there. Homelessness, age, language, employment status, skill, race, and religion are some criteria historically used to marginalize. Marginalized groups tend to overlap and groups marginalized in the past have the greatest chance of being marginalized in the future.

Medicaid – A joint federal and state program that helps low-income individuals or families pay for the costs associated with long-term medical and custodial care. Although largely funded by the federal government, Medicaid is run by states where coverage may vary.

Model for End-Stage Liver Disease – A reliable measure of mortality risk in patients with end-stage liver disease. The model is used as a disease severity index to help prioritize allocation of organs for transplant.

morbidity – How often a disease occurs in a specific area; also used to describe a focus on death.

mortality – The number of deaths in a given time or place; also used to describe the quality or state of being mortal.

nosocomial – Acquired or occurring in a hospital.

NS3/NS4A protease – An enzyme associated with hepatitis C virus (HCV) that mediates four specific cleavages of the viral polyprotein. Its activity is considered essential for the biogenesis of the HCV replication machinery.

NS5A phosphoprotein – A zinc-binding and proline-rich hydrophilic phosphoprotein that plays a key role in hepatitis C virus RNA replication.

NS5B RNA polymerase – NS5B is a protein found in hepatitis C virus. It has the key function of replicating the hepatitis C viral RNA by using the viral positive RNA strand as its template and catalyzes the polymerization of ribonucleoside triphosphates during RNA replication.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

nucleocapsid – The basic structure of a virus, consisting of a core of nucleic acid enclosed in a protein coat.

nucleos(t)ide analogue therapy – Lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxilfumarate are nucleos(t)ide analogues registered for the treatment of chronic hepatitis B. All nucleos(t)ide analogues are given once daily per oral at a fixed dosage and have been shown to dramatically improve the clinical outcome of patients with chronic hepatitis B. The nucleos(t)ide analogues are potent inhibitors of hepatitis B virus (HBV) polymerase/reverse transcriptase activity and are highly effective in the suppression of HBV replication, but rarely eliminate the virus. Long-term therapy is usually required to achieve sustained hepatitis B e antigen seroconversion, HBV DNA suppression, alanine aminotransferase normalization and fibrosis reversal.

obesity-related metabolic conditions – Obesity is excess body weight, defined as a body mass index (BMI) of ≥30 kg/m2. Complications include cardiovascular disorders (particularly in people with excess abdominal fat), diabetes mellitus, certain cancers, cholelithiasis, fatty liver, cirrhosis, osteoarthritis, reproductive disorders in men and women, psychologic disorders, and, for people with BMI ≥35, premature death.

observer bias – A form of reactivity in which a researcher’s cognitive bias causes them to subconsciously influence the participants of an experiment.

occult HBV infection – Defined as hepatitis B virus (HBV) DNA detection in serum or in the liver in HBV surface antigen negative patients with or without serologic markers of previous viral exposure. Occult HBV infection seems to be higher among subjects at high risk for HBV infection and with liver disease.

opportunity cost – The loss of potential gain from other alternatives when one alternative is chosen.

pegylated interferon – Interferons are a group of signaling proteins made and released by host cells in response to the presence of pathogens. Pegylated interferon, usually called peginterferon, is a chemically modified form of the standard interferon. The difference between interferon and peginterferon is a molecule called polyethylene glycol. By attaching to the interferon the polyethylene glycol allows it to stay in the blood much longer. Peginterferon alfa-2a and peginterferon alfa-2b have been approved for the treatment of chronic hepatitis C virus (and sometimes hepatitis B virus) infection in

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

adults who have compensated liver disease and have not been previously treated with interferon alfa.

phylogenetic analysis – Phylogenetics is the study of evolutionary relationships. Phylogenetic analysis is the means of inferring or estimating these relationships. The evolutionary history inferred from phylogenetic analysis is usually depicted as branching, treelike diagrams that represent an estimated pedigree of the inherited relationships among molecules (“gene trees”), organisms, or both.

prison – A secure facility that houses people who have been convicted of a felony criminal offense and are serving a sentence of (typically) 1 year or more.

proprietary name – The name of a product or service registered by its owner as a trademark and not usable by others without permission.

public health problem – A disease that by virtue of transmission or morbidity or mortality commands attention as a major threat to the health of the community.

reactivation – To activate again. In hepatitis B virus (HBV) reactivation is an increase in HBV viral replication in patients with chronic or past HBV infection. The chance of HBV reactivation is closely linked to the serological profile of the infected patient.

reservoir of infection – Any person, animal, plant, soil, or substance in which an infectious agent normally lives and multiplies. The reservoir typically harbors the infectious agent without injury to itself and serves as a source from which other individuals can be infected.

resolved HBV infection – Occurs when chronic hepatitis B virus (HBV)infected patients become HBV surface antigen-negative.

reverse transcription – A process in which a sequence of nucleotides is copied from an RNA template during the synthesis of a molecule of DNA.

ribavirin – An antiviral drug that is used orally in combination with interferon for the treatment of chronic hepatitis C. Although the exact mechanism of its action is unknown, ribavirin is thought to interfere with the production and/or action of viral DNA and RNA which are critical to the survival and multiplication of the virus. Ribavirin was approved by the Food and Drug Administration in December 1998.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

ribosome – A minute round cytoplasmic particle composed of RNA and protein that is the site of protein synthesis as directed by mRNA.

Ryan White Program – Named after a teenager who was expelled from his middle school because he had HIV, the Ryan White Program is the largest federal program designed specifically for people with HIV/AIDS in the United States. The program works with cities, states, and local community-based organizations to provide services to an estimated 536,000 people each year who do not have sufficient health care coverage or financial resources to cope with HIV disease.

seroconversion – Development of antibodies in blood serum as a result of infection or immunization.

serum – An amber-colored, protein-rich liquid that separates out when blood coagulates.

Sovaldi® – The US proprietary name of sofosbuvir, a prescription medicine used with other antiviral medicines to treat chronic hepatitis C virus (HCV) infection in adults. Sofosbuvir inhibits the RNA polymerase HCV uses to replicate its RNA. Compared to previous treatments, sofosbuvir-based regimens provide a higher cure rate, fewer side effects, and a two- to four-fold reduced duration of therapy. The drug has been on the market since 2013.

stigma – A mark of disgrace associated with a particular circumstance, quality, or person.

surveillance – The ongoing systematic collection and analysis of data and the provision of information which leads to action being taken to prevent and control a disease, usually one of an infectious nature.

sustained virological response – The most widely used efficacy endpoint of hepatitis C virus (HCV), and represents the eradication of HCV from the body. Sustained virological response is defined as aviremia 24 weeks after completion of antiviral therapy. The incidence of relapse after sustained virological response is less than one percent.

T-cell response – T cells are a type of lymphocyte that play a central role in cell-mediated immunity. T helper cells assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

of antigen-presenting cells. Once activated, they divide rapidly and secrete small proteins called cytokines that regulate or assist in the active immune response. These cells can differentiate into one of several subtypes which secrete different cytokines to facilitate different types of immune responses.

titer – The strength of a solution or the concentration of a substance in solution. Titer is determined by a technique where a solution of known concentration is used to determine the concentration of an unknown solution. Typically, the titrant (the known solution) is added from a buret to a known quantity of the analyte (the unknown solution) until the reaction is complete.

TORCH titer – A blood test used in infants that measures the presence of antibodies and their level of concentration. The TORCH titer tests for toxoplasmosis and other pathogens including hepatitis B virus.

transient elastography – Known by the brand-name FibroScan, transient elastography is a technique used to assess liver stiffness (measured in kPa correlated to fibrosis) without invasive investigation. The device uses probes to measure wave velocity as they pass through the body. Exam results help to anticipate various complications, as well as to monitor and assess the damage caused by conditions such as cirrhosis.

treatment as prevention – A virus prevention method that use antiviral treatment to decrease the risk of transmission. Antiviral treatment reduces the viral load to very low levels, reducing an individual’s risk of onward transmission. Treatment as preventions has been shown to be a successful tool in preventing the spread of HIV, which has led researchers to consider using it as a tool to decrease the spread of hepatitis C virus.

variceal hemorrhage – Varices are dilated submucosal veins, most commonly detected in the distal esophagus or proximal stomach and are associated with portal hypertension. Varices occur when normal blood flow to the liver is obstructed by scar tissue in the liver or a clot. Seeking a way around the blockages, blood flows into smaller blood vessels that are not designed to carry large volumes of blood. This can sometimes cause hemorrhaging and may be fatal.

vertical transmission – An infection caused by bacteria, viruses, or in rare cases, parasites transmitted directly from the mother to an embryo, fetus, or baby during pregnancy or childbirth. Transmission might occur across the placenta, in the breast milk, or through direct contact during or after birth.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
×

Viekira® – The US proprietary name of ombitasvir, paritaprevir and ritonavir tablets co-packaged with dasabuvir tablets. Viekira® is an oral, interferon-free prescription medicine used with or without ribavirin to treat adults with genotype 1 chronic hepatitis C virus infection. Viekira® provides cure rates of 95 percent in people infected with genotype 1 but the average cost of treatment in the United States is more than $80,000. The drug was approved for public use in December 2014.

viral envelope protein – Virus particles contain their viral genome packaged in a protein coat called the capsid. For some viruses, the capsid is surrounded by a lipid bilayer that contains viral proteins. This lipid and protein structure is called the virus envelope, and is derived from the host cell membranes. The capsid and envelope play many roles in viral infection, including virus attachment to cells, entry into cells, release of the capsid contents into the cells, and packaging of newly formed viral particles.

viral hepatitis – Liver inflammation due to a viral infection. It may present in acute or chronic forms.

viral load – A measurement of the amount of a virus in an organism, typically in the bloodstream, usually stated in virus particles per milliliter.

viral suppression – When antiviral therapy reduces a person’s viral load to an undetectable level. Viral suppression does not mean a person is cured.

viremic – The presence of a virus in the blood.

virion – A complete viral particle, consisting of RNA or DNA surrounded by a protein shell.

virulent – Extremely infectious, malignant, or poisonous. Used of a disease or a toxin.

visceral vasculitis – The visceral arteries supply blood to the intestines, spleen, and liver. Visceral vasculitis occurs when there is inflammation of these blood vessel walls.

Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Suggested Citation:"Appendix D: Glossary." National Academies of Sciences, Engineering, and Medicine. 2016. Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report. Washington, DC: The National Academies Press. doi: 10.17226/23407.
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Eliminating the Public Health Problem of Hepatitis B and C in the United States: Phase One Report Get This Book
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Hepatitis B and C cause most cases of hepatitis in the United States and the world. The two diseases account for about a million deaths a year and 78 percent of world’s hepatocellular carcinoma and more than half of all fatal cirrhosis. In 2013 viral hepatitis, of which hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most common types, surpassed HIV and AIDS to become the seventh leading cause of death worldwide.

The world now has the tools to prevent hepatitis B and cure hepatitis C. Perfect vaccination could eradicate HBV, but it would take two generations at least. In the meantime, there is no cure for the millions of people already infected. Conversely, there is no vaccine for HCV, but new direct-acting antivirals can cure 95 percent of chronic infections, though these drugs are unlikely to reach all chronically-infected people anytime soon. This report, the first of two, examines the feasibility of hepatitis B and C elimination in the United States and identifies critical success factors. The phase two report will outline a strategy for meeting the elimination goals discussed in this report.

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