Planet Earth and Its Environment A 5000-million year Journey

Biology in Focus, HSC CourseGlenda Childrawi, Margaret Robson and Stephanie Hollis

A Search For Better HealthTopic 15: Other Control Strategies1DOT Point(s) explain how one of the following strategies has controlled and/or prevented disease:public health programspesticidesgenetic engineering to produce disease-resistant plants and animalsIntroduction Other strategies that can be utilised for the control and/or prevention of disease are the implementation of public health programs, the use of pesticides and the use of genetic engineering to produce disease-resistant plants and animals.www.abstinence.net

Public Health ProgramsThere are a number of different types of public health programs in place to help prevent disease. Government regulations ensure that standardised procedures are in place and are to be followed when handling, cooking and storing food. Strict guidelines must also be followed in hospitals, surgeries and clinics when sterilising equipment and when health workers move from patient to patient.www.theage.com.au

Public Health ProgramsGovernment regulations are also in place to ensure that garbage is disposed of correctly, drinking water is treated effectively and sewage is removed and treated. If these sanitation procedures are followed correctly, the spread of pathogens is prevented and hence the occurrence of disease in individuals and communities is prevented.www.123rf.com

Public Health ProgramsLaws require that certain diseases are reported to authorities if they are detected. This allows the early detection of these diseases and allows appropriate strategies to be put in place in order to control the spread of these diseases through the community. Some examples of notifiable diseases are measles, botulism, cholera, meningococcal infection, pertussis (whooping cough) and malaria.everydayfeminism.com

Public Health ProgramsPublic health programs to encourage regular screening for certain diseases are also in place. Women are encouraged to regularly check their breasts for the presence of any unusual lumps and to have regular mammograms between the ages of 50 and 69 years. This will aid in the early detection of breast cancer. www.oncologyupdate.com.au

Public Health ProgramsMen over 50 years are encouraged to have a PSA blood test every 23 years to aid in the early detection of prostate cancer. These screening programs aid in the early detection of these diseases, increase the chances of survival for sufferers and help to control these diseases.www.guardian.co.uk

Public Health ProgramsPublic health programs, such as the childhood immunisation programs that are in place for diphtheria, tetanus, whooping cough, measles, mumps and rubella, help to prevent these diseases occurring. Mass immunisation programs for the human papilloma virus have also been introduced to help prevent the occurrence of cervical cancer.www.dailyexaminer.com.au

Public Health ProgramsPublic education programs are another strategy that aims to help prevent disease. For many years there have been programs aimed at increasing public awareness of lifestyle-related risk factors. These programs aim to change the lifestyle of individuals in order to prevent the occurrence of disease. Quit is an education program that has been in existence for many years.www.watoday.com.auPublic Health ProgramsIts purpose is to raise awareness of the effects of smoking. The latest Quit program shows graphic images of the effects of smoking on different parts of the body. It is designed to reduce the number of people smoking; this would in turn reduce the incidence of diseases that are associated with smoking.www.quitsa.org.au

Public Health ProgramsMany other public education programs are in place to help prevent diseases associated with lifestyle. These include programs to reduce the incidence of skin cancer, cardiovascular disease and sexually transmitted diseases. If lifestyle behaviour is changed due to these programs, many of these diseases could be prevented.www.reuters.com

PesticidesPesticides are chemicals that are used to kill the pests of plants and animals, pathogens, and vectors that transmit pathogens from one organism to another. If these pests and vectors are killed using pesticides, then the occurrence of disease will be prevented and the spread of disease through the population will be controlled.mrforde.blogspot.com

PesticidesPesticides can further be classified into three groups:1. insecticides, which kill insects2. fungicides, which kill fungal pathogens3. herbicides, which kill weeds.growingveggies.com

PesticidesOne of the most well-known insecticides that has been used to kill insects acting as vectors is DDT. It was widely used during World War II to kill lice that transmitted the pathogen that caused the disease typhus. This controlled the spread of the disease by destroying the vector that transmitted the pathogen.www.treehugger.com

PesticidesDDT has also been widely used to kill the Anopheles mosquito, which carries the plasmodium that causes the disease malaria. This controlled the spread of malaria, as transmission of the pathogen was prevented by the death of the vector.www.culturesofresistance.org

PesticidesThe effectiveness of DDT was reduced as mosquitoes built up a resistance to it because of the process of natural selection. Many countries have since banned the use of DDT due to its harmful effects on the environment. Some malaria-infested countries still use DDT to control mosquito numbers even though it is not as effective.www.allposters.co.uk

PesticidesOther insecticides, such as pyrethrum, are now also used. These insecticides are less harmful to the environment and more effective in controlling mosquito numbers. This in turn controls, to some extent, the spread of malaria.www.yates.com.au

PesticidesAnother vector that is controlled by the use of insecticides is the aphid that carries the potato leaf-roll virus, which causes stunted growth and serious loss of yield in potato plants. Pesticides are used to kill the aphids and therefore control the spread of the virus that causes this devastating disease.www.farminguk.com

PesticidesPesticides are also used widely to spray items brought into Australia, to kill any insects or other organisms present. This prevents the spread of any diseases associated with these insects.www.foxnews.com -

PesticidesOne problem associated with the use of pesticides is the ability of insect vectors and disease-causing organisms to build up a resistance to the pesticide through the process of natural selection. This has the effect of decreasing the effectiveness of the pesticide and increasing the necessity for the development and use of different types of pesticides. The use of pesticides is also being discouraged more and more due to their damaging effects on the environment.jacksonville.com

Genetic EngineeringGenetic engineering is a process that involves altering the genetic composition of an organism in some way. By altering the genetic make-up of organisms, it is possible to make them resistant to diseases. This prevents the disease occurring and controls the spread of disease through the population. Organisms with genes from other organisms inserted into their own genetic material are called transgenic specieswww.healthandfitnessemporium.com

Genetic EngineeringA number of agricultural crops have been modified by the insertion of genes from the soil bacterium Bacillus thuringiensis, or Bt. These inserted genes allow the plants to produce a natural insecticide that kills the insect pests that feed on the plant tissue.www.scq.ubc.ca

Genetic EngineeringCotton plants and corn have been genetically modified in this way so that they are able to protect themselves by preventing attack by the insects that feed on them. Potatoes resistant to the Colorado beetle and the potato leaf-roll virus have also been produced.www.abc.net.au

Genetic EngineeringMany disease-resistant transgenic species have been produced or are being developed and trialled. In Canada, genes from a frog have been inserted into potato plants to cause them to produce the same chemicals as the frogs. Scientists claim that this makes them resistant to infection by a broad range of disease-causing fungi and bacteria.www.bbc.co.uk

Genetic EngineeringResearchers are investigating the possibility of producing transgenic animals that are resistant to mastitis or the ticks that infest the cattle in northern Australia. Using genetic engineering to produce disease-resistant plants and animals prevents the occurrence of disease in organisms and controls the spread of disease through the population. The incidence of these diseases and pests has been reduced dramatically.pakagri.blogspot.com

Genetic EngineeringThe use of genetically modified organisms has not received universal acceptance. There are concerns that resistance to the insecticides produced by these organisms will develop and they will no longer be effective. www.flickr.com Genetic EngineeringThere are also concerns about the effect these organisms will have on the environment and biodiversity. As well, there are many ethical issues to be taken into consideration. jimbonham.com

Activity-Students to complete Changing methods of dealing with plant and animal diseases.