It is a disease that can be passed from one person or animal to another through contact, usually by food, water, air or vector.
Over 90% of all deaths caused by infectious diseases are caused by a small number of them including pneumonia, malaria, HIV/AIDS, diarrhoeal diseases, tuberculosis and measles.
• The area of medical studies that examines the frequency, possible sources and prevalence of infectious diseases in communities of people.
• Any condition that causes harm or interferes with the normal functioning of a living thing
• Generally caused by parasites and pathogenic micro-organisms, or possibly due to environmental, nutritional or genetic factors.
• are agents of infectious diseases.
Vectors of disease:
• an organism capable of carrying and transmitting pathogenic bacterium and virus from one person to another; for example house fly, mosquito, or flea.
• Vectors can either be mechanical (agent is outside the body and passes it on) or biological (harbours pathogens inside its body and passes it on).
• when a disease spreads rapidly and affects many people at much the same time, resulting in widespread infection
• particularly in an area or time when such infection is not common. Eg Australian influenza outbreak 2007.
• the term describing a disease common across a wide geographic area such as a whole country, region or the world.
• when a disease is common or peculiar to a specific locality, region or people.
Water Borne Disease:
• Contracted from drinking contaminated water or eating food contaminated by unclean water.
• In places where sanitation and hygiene is poor, pathogenic micro-organisms from human or animal faeces can find their way into a water supply.
• Examples include cholera, typhiod, botulism, polio, giardia and hep A.
• In developing countries, water borne diseases are the cause of 80% of illnesses with diarrhoea being the major cause of childhood death.
Nutritional Diseases: Four types of nutritional diseases include:
1. under nutrition-people not getting enough food to meet basic energy needs (developing eg areas of India). Diarrhoel diseases are bought on by malnutrition and lack of potable water.
2. deficiency-when the diet lacks one or more essential chemicals such as vitamins/iodine (developing eg sub-saharan Africa)
3. secondary under nutrition-victim is unable to digest food properly or absorb the nutrients from the food even though the diet may be adequate (anywhere)
4. over nutrition-can lead to heart disease and other complications. Basically when people eat too much in general or too much of a food component (developed Western countries eg Australia)
Air Borne Disease:
• occur when people breathe in bacteria or viruses attached to dust particles, smoke or water vapour, causing them to become ill. These diseases include influenza, tuberculosis, smallpox and chickenpox.
• transmitted through sexual contact
• breast feeding or needle sharing between IV drug users.
• The most common types are HIV, syphilis, gonorrhoea, chlamydia and genital herpes.
• A term used to describe a range of conditions that people acquire due to a lack of food or vitamins and minerals in the diet.
• Such diseases include beri-beri (vit B1 deficiency), scurvy (vit C deficiency) and anaemia (lack of iron and folate). Deficiency diseases are common in malnourished communities and refugee camps.
• a pathogen or virus that originates or lives in another animal and transfers to people such as AIDS, anthrax, avian flu, Ebola virus, SARS, and rabies as examples.
• Zoonotic pathogens