Planet Earth and Its Environment A 5000-million year Journey

Biology in Focus, HSC Course

A Search For Better HealthTopic 2: Hygiene1DOT Point(s) distinguish between infectious and non-infectious diseaseidentify the conditions under which an organism is described as a pathogen

world.eduIntroductionThroughout history, humans have been investigating ways in which the spread of disease can be prevented. Over 3000 years ago the Chinese and Hebrews, along with some other cultures, were advocating cleanliness in food, water and personal hygiene. The Hebrews had rules to be followed to ensure that the health of their population was maintained.history.cultural-china.com

IntroductionSome of these rules included the washing of people and objects, the proper disposal of refuse and excreta, the protection of the water and food supply, and the isolation of diseased individuals.www.routeyou.com

IntroductionFor example, victims of leprosy were forced to live outside the walls of the city. Principles of good health were also developed by certain groups of the Chinese population and included hygiene rules and exercises. Similarly, the people of Mesopotamia preached cleanliness, used toilets and constructed primitive sewerage systems.www.ajtmh.org

IntroductionWhile many cultures have practised the principles of good health, infectious diseases such as bubonic plague and cholera have caused widespread death over many years because of lack of knowledge about the causes of disease and ignorance of the importance of cleanliness in food, water and hygiene.thewellsa.org

Infectious and Non-infectious DiseaseAn infectious disease is a disease that is caused by an organism or infective agent. These causative agents are known as pathogens.fortressaustralia.blogspot.com

Infectious and Non-infectious diseaseSome examples of infectious diseases are measles, chickenpox, AIDS, hepatitis, typhoid, dysentery, conjunctivitis, cholera, chlamydia, thrush and influenza.mikadokids.com

Infectious and Non-infectious diseaseA non-infectious disease is a disease that is not caused by a pathogen and, with the exception of inherited diseases, cannot be passed from one person to another. Non-infectious diseases can have a number of causes including inherited, nutritional or environmental. www.ppsurgery.com.au

Infectious and Non-infectious diseaseSome examples of non-infectious diseases are Down syndrome, cystic fibrosis, haemophilia, scurvy, anaemia, skin cancer and cardiovascular disease.compose21.com

PathogensA pathogen can be defined as any organism or infective agent that lives in or on another living organism, and causes a disease. To cause disease the pathogen needs the right conditions to multiply and be transmitted. There are different types of pathogens such as prions, viruses, bacteria, protozoans, fungi and macro-parasites. englishdictionaryfree.com

PathogensThere are a number of ways in which the pathogens that cause infectious disease can be transmitted:the transmission can be direct, where the pathogens pass directly from person to person the transmission can be indirect, where the pathogen is transferred from the environment (e.g. air, food and water) to the personthe pathogen could also be transmitted from person to person by being carried by another organism (a vector). For example, the mosquito is a vector that can transmit the malaria parasite or the Ross River fever virus from person to person.fortressaustralia.blogspot.comActivity/HomeworkStudents to design PRAC for next lesson.Handout Identifying microbes in food or water Activity (Bio in Focus Text pg 246-248.

Students to read through (hint, this is where you will get your procedure from!!)Watch Videos:http://youtu.be/1VkB8NzrEBshttp://youtu.be/6-chXVgu8Z0

Handout DOT Point 2.4 Microbes in food or in water Students to write up their PRAC using this scaffold.