Geography: Infectious Disease and Example House fly Essay

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Infectious disease

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.

Epidemiology:

• The area of medical studies that examines the frequency, possible sources and prevalence of infectious diseases in communities of people.

Disease:

• 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.

Pathogens:

• 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).

Epidemic:

• 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.

Pandemic:

• the term describing a disease common across a wide geographic area such as a whole country, region or the world.

Endemic:

• 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.

STD’s:

• 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.

Deficiency Disease:

• 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.

Zoonotic Disease:

• 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…