Acute hep C
The initial six-month phase of infection following contracting hep C virus. Although visible symptoms are uncommon, it can be observed via markers in the blood, e.g. PCR viral load, liver function testing.

ALT
Alanine aminotransferase - a protein or enzyme which, when found in the blood in elevated quantities, generally indicates liver damage.

Antibody
A protein secreted by cells of our immune system in response to infection. The antibody binds to an enemy molecule, in this case, a specific part of the hep C virus. This is meant to destroy the virus or prevent it from infecting other cells. As with other viral infections, the presence of antibodies does not necessarily mean a virus will be eliminated from the body.

Antigen
Anything introduced into the body which is seen as foreign. An antigen stimulates the immune system into producing cells that attack it.

AST
Aspartate aminotransferase - a protein which, when found in the blood in elevated quantities, generally indicates liver damage (although less specific for liver damage than ALT).

Asymptomatic
Having no symptoms or signs of illness.

Autoantibodies
These antibodies are aimed at specific body tissues rather than external agents such as viral infections. They are implicated in the cause of some autoimmune diseases such as rheumatoid arthritis and lupus. Research suggests that autoantibodies might be more common among people with hep C.

Blood & blood products
These are components of blood (including red cells, platelets and plasma) which are separated out by blood banks and used to treat medical conditions. Plasma is processed and purified to produce products for treating haemophilia, e.g. Factor VIII.

Blood awareness
The practice of being alert to the potential or actual presence of blood in any situation or environment.

Carrier
Although all people with chronic hep C are technically ‘carriers’ of the virus, the term ‘carrier’ usually refers to someone who has hep C yet is in good health. It is not a useful term and better definitions of hep C status are antibody-positive or antibody-negative, and symptomatic or asymptomatic.

Chronic hep C
A hep C infection that lasts six months or longer. Unless successfully treated, people with chronic hep C are likely to have an ongoing lifelong infection.

Cirrhosis
Scar tissue which develops in the liver - to the extent where such scarring becomes extensive and permanent. Cirrhosis interferes with the normal functioning of the liver.

Coinfection
Generally refers to hep C infection and another virus (e.g. HIV or hep B). In contrast, ‘mixed infection’ generally refers to infection involving different hep C genotypes.

Decompensated cirrhosis
The liver can often endure a certain amount of cirrhosis before its ability to carry out normal functions is affected. The term decompensated cirrhosis refers to when the level of damage has started to interfere with the liver’s ability to function properly (as shown by blood tests measuring albumin, prothombin and bilirubin), resulting in serious illness (weight loss, fluid retention, stomach swelling, bleeding problems).

DNA
The genetic material which determines a cell’s activities. It carries the cell’s genetic code.

Epidemiology
The study of patterns of disease in a population.

Exposure prone procedure
These are medical and surgical procedures where there is potential for contact between the skin (usually finger or thumb) of a healthcare worker and sharp surgical instruments, needles or sharp tissues (splinters/ pieces of bone/tooth) in confined body sites or where visibility is poor, including the mouth. Other medical procedures in normal circumstances are unlikely to pose a risk of transmission of blood borne viruses from infected healthcare workers to patient, or vice versa.

FibroScan
When liver tissue is damaged the liver tissue becomes stiffer. FibroScan is a new way of measuring liver condition measures liver tissue stiffness using advanced technology similar to ultrasound. It is most effective at measuring low level or high level damage (cirrhosis). It takes only 15 minutes and does not involve needles or other invasive instruments.

Fibrosis
Scar formation resulting from the repair of tissue damage. If it occurs extensively in the liver, it is called cirrhosis.

Gastroenterology
A branch of medicine specialising in diseases of the stomach, intestines, oesophagus and related organs.

Genotype
Different genotypes of the one virus are similar enough to be regarded as the same type of virus but have some minor differences in their genetic code. These differences may mean the virus reacts differently to our immune response or to drug treatments and natural therapies.

Haemophilia
A hereditary blood disease where the blood fails to clot and abnormal bleeding occurs. It is found only in males and is treated by injections of Factor VIII.

HCV
Hepatitis C virus

HCV antibody tests (1st generation)
These were the initial tests, developed in 1990, to detect hep C antibodies (our body’s response to the virus). The test searches for a certain number of signs of the antibody, such as substances that help make up its outer envelope. These tests have been superseded by newer generation tests with improved sensitivity and specificity.

HCV antibody tests (2nd generation)
These were developed after 1992 and search for more specific signs of hep C antibodies. Because they identify more parts of the antibody, they are more sensitive and specific than the first generation tests. Subsequent improved antibody tests are referred to as 3rd, 4th generation, etc.

HCV genotype
There are six basic variations of the hep C virus. They are similar enough to be all called hep C virus, but differ enough to be called HCV genotypes 1, 2, 3, 4, 5 or 6.

HCV quasispecies
As with other living organisms, it is believed that no two individual hep C viruses are identical. Within HCV subtypes, it is believed there are millions of different, but closely related quasispecies.

HCV subtype
Variation of HCV within the different genotypes can be significant enough to warrant further subclassification, but not to the extent where it would warrant a new genotype. Hence, we have HCV subtypes, 1a, 1b, 1c, 2a, 2b, etc.

Hepatocellular carcinoma (HCC)
Cancer of the liver. It is not common and is usually preceded by cirrhosis of the liver.

Hepatologist
A liver specialist, usually working out of a liver clinic.

Incidence
The number of new infections which occur over a given period of time (usually, a month or year). Sometimes expressed in relation to risk activities: e.g. 1000 person hours of surgical time (could represent the work of 100 surgeons, each working for approximately 10 hours).

Indeterminate
Hep C antibody testing is generally performed using two different types of antibody tests. When one test comes back positive and one negative, the result is called ‘indeterminate’ and further confirmatory testing is done, usually by PCR.

Mutate
When cells divide or viruses multiply, their genetic material must be copied. Sometimes mistakes are made when this happens and the resulting new cell or virus is different in some way. This is important for viruses because mutation can trick the immune system into not recognising them.

Natural history
The natural history of a disease is defined as what happens to people (in the absence of medical treatment or other interventions) over a given period of time.

Needlestick injury
Accidental injury from a needle containing another person’s blood. Usually referred to in context of medical settings and used syringes discarded in public places.

Non-A non-B hepatitis
The old term for hepatitis shown not to be caused by the hep A and B viruses. In 1988, this form of hepatitis was shown to be caused mainly by hep C.

Non-responders
People who, after 12 weeks of interferon-based therapy, fail to normalise their ALT levels.

Nosocomial transmission
Transmission of hep C within a hospital setting (e.g. through blood transfusion or needlestick injury).

Parenteral or percutaneous transmission
Transmission of a disease through injection or a break in the skin – and not through the digestive system (beginning with nose & mouth).

Pathogen
Any organism or substance capable of producing a disease.

PCR (Polymerase chain reaction)
A testing laboratory process used to amplify pieces of the genetic make-up of a cell or virus. The amplified pieces are then detected and the presence of the virus itself can be determined.

Prevalence
In regard to hep C, prevalence relates to the number of people with hep C in the community at any one time. It is usually expressed as a percentage (1% of the population) or ratio (one in 100 people).

Reinfection
Generally describes a second hep C infection, either in a person with chronic hep C already, or in a person who had previously cleared their infection.

Relapsers
People who, after an initial response to interferon-based therapy, subsequently have a recurrence of their illness (typically within six months following end of treatment).

RNA
RNA is a genetic material similar to DNA. It often acts as a message that is delivered to cells, prompting them to change and prepare for reproduction.

S100
Section 100: a Pharmaceutical Benefits Scheme listing of restricted and subsidised medications. The S100 scheme also establishes the criteria under which people qualify for these medications.

Seroconversion
The production of specific antibodies (as part of the body’s immune response) when infected with foreign organisms or following any immunisation.

Serological
Relating to blood and or serum.

Steatosis (fatty liver)
Infiltration of fat within the liver. It appears to increase the risk of cirrhosis and is more common among people with hep C compared to the general population. Severe steatosis is not just related to hep C. It may be associated with obesity, diabetes and chronic alcoholism.

Vertical transmission
Transmission of an infection from mother to baby, during pregnancy or at birth.

Viraemia
The presence of a virus in the blood.

Viral load
The amount of virus present in a person’s blood stream. It is usually measured by the PCR quantitative test and the result is given in number of virus particles per ml of blood.

Virus
A vast group of minute organisms, composed of a sheath of protein encasing a core of nucleic acids which are the building blocks of RNA and DNA. They are capable of infecting almost all members of the animal and plant kingdoms, and are so small they can even infect bacteria. Viruses are characterised by a total dependence on living host cells for reproduction and lack independent metabolism. Most viruses only affect one species. Hep C only affects humans.

Window period
This is the time gap between exposure to a virus, and when a diagnostic test will give an accurate result. With antibody testing for hep C, the window period is 12 weeks. With PCR testing for hep C, the window period is three weeks.

 

 

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Stock photos used. People shown may have no actual connection with hepatitis C.

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This page last updated 12 May 2010

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