Antigenic drift
The process by which the cell surface antigens haemagglutinin and/or neuraminidase change slowly so that people are no longer immune to the new influenza virus; responsible for causing epidemics
Antigenic shift
A sudden and large change in the cell surface antigens haemagglutinin and/or neuraminidase which usually results in a new strain that causes a pandemic
Antigens
Proteins that induce an immune response
Antipyretic
Medicine that reduces fever
Asian Flu
The virus that caused the 1957 pandemic
Asplenia
Having no functioning spleen – through surgical removal, disease, or absence at birth
Avian flu
Influenza virus in birds that is threatening to spread to humans where it could cause a pandemic; type H5N1
Bacteraemia
The condition in which bacteria are present in the bloodstream, a usually sterile site.
Bacterium (pl: bacteria)
A single celled micro-organism which is able to multiply by itself, rather than by using the cellular machinery of its host (see virus). Bacteria are normally found all over a healthy body (e.g. skin, mouth, gut) but can cause disease by invading previously sterile sites (e.g. blood or spinal fluid) or by invading locally into the tissues where they enter the body (e.g. nose, throat). Bacteria are classified according to their shape and structure.
Booster
A further immunisation to increase or restore the immunity given by an earlier immunisation
CAP
Community Acquired Pneumonia
Carriage
A state in which the bacteria are living in the back of the nose and throat but not causing disease.
Chronic
A disease or condition that lasts for a long time
CHD
Chronic heart disease
Cochlear implant
A device that helps improve the hearing abilities of many profoundly or totally deaf people by electrically stimulating the nerve which takes hearing messages from the ear to the brain, hence by-passing the damaged parts of the ear.
Cold Chain
Refers to all the people, equipment and procedures, such as storage and transportation, that ensures vaccines are maintained at the safe temperature range of 2ºC to 8ºC at all times
Conjugate Vaccine
A type of vaccine made from the polysaccharide (sugar) of a bacterium joined to a protein carrier. This type of vaccine gives a better immune response in infants and young children.
COPD
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease
Diseases of the lungs and respiratory system e.g. chronic bronchitis and emphysema, bronchiectasis, cystic fibrosis, interstitial lung fibrosis, pneumoconiosis and bronchopulmonary dysplasia (BPD)
DoH or DH
Department of Health
Epidemic
An outbreak of a disease that has a high incidence in a localised area
Flu season
The season when flu infections are at their highest, usually December through to March
Fungus (pl: fungi)
A type of micro-organism which causes infection. It proliferates by feeding on dead matter or by invading healthy cells. Fungi include yeasts, mildews, rusts, mushrooms and moulds.
Glue ear
The commonest inflammatory condition of the middle ear in children and one of the commonest causes of 'conduction' deafness. A persisting sticky secretion prevents sound vibrations moving through the ear thereby impairing hearing.
H5N1
The influenza strain responsible for avian flu
Haemagglutinin (HA)
A virus encoded protein that is embedded in the influenza virus coat which induces immunity (antigen). When these change, viral immunity is lost
Haemophilus influenzae
A bacterium that can cause infections, usually sinusitis, otitis media and meninigitis.
HCA
Health Care Assistant
Hong Kong Flu
The virus that caused the 1968 pandemic; it was descended from the Asian flu virus and only the haemagglutinin antigen had changed so the results were not as disastrous as in the Asian flu epidemic
HPA
Health Protection Agency
HPV
Human papillomavirus
Inactivated vaccine
Can be either suspensions of killed whole organism, or pieces of pathogens (known as sub-units) that induce a state of specific immunity. The influenza vaccine is an example of an inactivated vaccine that cannot cause disease
Influenza A, Influenza B, Influenza C
Subtypes of influenza virus
Invasive pneumococcal disease (IPD)
Serious disease caused by the bacterium Streptococcus pneumoniae invading a usually sterile site, such as the blood (to cause bacteraemia), the membranes of the brain (to cause cerebral meningitis), and/or the spinal cord (spinal meningitis) and the lungs to cause invasive disease.
Immunocompromised
Having an immune system that is not working normally, usually through disease or as an effect of a medical treatment
Live vaccine
A type of vaccine that provides active immunisation by giving the recipient a mild form of the disease
Meningitis
Inflammation affecting the membranes of the brain (cerebral meningitis) or spinal cord (spinal meningitis) or both. It can be the result of a trauma but is more likely to be caused by an infective agent. Viral meningitis is most common, but generally less serious than that caused by bacteria. Fungal infections are the least common causes of meningitis.
MMR
A vaccine to protect against measles, mumps and rubella
Morbidity
State of suffering a disease
Neuraminidase (NA)
A virus encoded protein that is embedded in the influenza virus coat which induces immunity (antigen). When these change, viral immunity is lost
Non-invasive pneumococcal disease
Non-invasive pneumococcal disease is more common than invasive. It is caused by the inflammation of mucosal tissue, such as the upper respiratory tract, middle ear and sinuses. This can lead to pneumonia, otitis media and sinusitis.
Orthomyxovirus
The family of viruses to which influenza belongs
Otitis Media
Inflammation of the middle section of the ear often caused by infection.
Pandemic
A pandemic is a worldwide epidemic of a disease. It does not necessarily mean mass fatalities. A pandemic refers to how far across the globe the disease has spread, rather than its severity, and as such a pandemic can result in a low fatality count. It may start mild and become severe, or vice versa. It may also start mild and stay that way, or start severe and stay severe.
Passive immunity
Provided by antitoxins and immunoglobulins that are directly injected into the patient and which give immediate short-term protection against disease
Pathogenic
Capable of causing disease
Pneumococcal Infection
Infection caused by Streptococcus pneumoniae (pneumococcus)
Pneumococcal meningitis
Meningitis caused by the bacterium Streptococcus pneumoniae.
Pneumococcal pneumonia
Pneumonia caused by the bacterium Streptococcus pneumoniae.
Pneumonia
Pneumonia is an infection that causes the air sacs in the lungs (called the alveoli), and the smaller bronchial tubes to become inflamed and fill with fluid. This makes it hard for the lungs to do their job, which is to get oxygen from the air into the bloodstream and then around the whole body. Pneumonia can be caused by viruses and bacteria but in most cases the precise cause is not discovered.
PCV
Pneumococcal conjugate vaccine
Polysaccharide conjugated vaccine
A type of vaccine in which the polysaccharide coating molecules are joined together with an antigen that the body already recognises, induces an immune response to the polysaccharide component of certain pathogens
Polysaccharide vaccine
A type of vaccine made from the polysaccharide (sugar) coat of a bacterium.
PPV
Abbreviation for "Pneumococcal polysaccharide vaccine". PPV protects against 23 serotypes of the pneumococcal bacterium. It is not recommended for use in infants and children under the age of two because there is no evidence of effectiveness of PPV in this age group.
Renal disease
Disease of the kidney
Septicaemia
A condition in which bacteria enter the blood stream where they release toxins or poisons.
Serotype
A sub type of a class of bacteria.
Sinus
Any bodily cavity or hollow space. In the context of this web site, the term refers to the nasal sinus.
Sinusitis
Inflammation of the membrane lining of a sinus.
Spanish Flu
The virus that caused a pandemic during the First World War (1918), which killed millions including healthy young men
Staphylococcus aureus
A bacterium that is commonly carried by healthy individuals on the skin and the mucous membranes which line the body's cavities, for example in the nose and throat. It can cause disease, particularly if offered the opportunity to enter the body. Illnesses such as skin and wound infections, urinary tract infections, pneumonia and bacteraemia (blood stream infection) may develop.
Streptococcus pneumoniae
A bacterium that is commonly carried by healthy individuals at the back of the nose/throat. It can cause disease, particularly if offered the opportunity to enter the body, more specifically meningitis, septicaemia (blood poinsoning), pneumonia and otitis media (middle ear infection).
Swine flu
An influenza virus first found in pigs, subsequently becoming infectious to humans and is currently causing a pandemic in humans.
Virus
A type of micro-organism which causes infection. A virus consists of genetic material (DNA or RNA) surrounded by a protective coat of protein. It cannot multiply on its own so it invades healthy cells in order to proliferate.
WHO
World Health Organisation