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7.2 Importance of cleanliness – Further questions and answers Q1. Bk Ch7 S7.2 FQ1 Australia has experienced some serious outbreaks of food poisoning related to poor hygiene standards in the handling of foods in recent times. Two notable examples include the contamination of smallgoods (salami) and peanut butter. Choose one of these cases for research. a Name the pathogen responsible for the food poisoning. b Describe the symptoms suffered by the victims. c How many casualties were there? d How did the food products come to be contaminated in the first place? e What regulations need to be in place and enforced to ensure such incidents do not recur? A1. Bk Ch7 S7.2 FA1 Example (1996 Salmonella outbreak): a In 1996 Victoria experienced a food poisoning outbreak in which peanut butter was found to be contaminated with Salmonella bacteria. b Symptoms of Salmonella poisoning include fever, abdominal cramps, nausea and vomiting, and diarrhoea. c During this outbreak there were 51 casualties; one person died. d It is believed that the peanuts used in the manufacture of the peanut butter had been contaminated by the faecal matter of rodents. e Regulations related to the handling, processing, packaging and storage of food items need to be in place to ensure foods are safe for consumption. These include: • storage of foods in a way that excludes entry of animal and other pests • safe food handling practices—this may include using disposable gloves to handle foods during processing as well as other protective clothing, such as head-wear and cover-alls • regular cleaning, between uses, of surfaces and machinery used in the processing of foods • good personal hygiene of workers handling foods or involved in the processing of foods • no cross-contamination of foods; for example, cooked meats should not be stored with uncooked meats or other food items. Q2. Bk Ch7 S7.2 FQ2 a b Do some library or Internet research to find out about ‘Typhoid Mary’. i Who was she? ii When and where did she live? iii What was her occupation? iv Why was she eventually imprisoned? What restrictions are placed on people in Australia today in terms of their occupation, if they have suffered from, or are carriers of, the same disease? A2. Bk Ch7 S7.2 FA2 a b i to iv Typhoid Mary was a woman who lived in New York in the early 20th century. She was a cook who worked in different establishments in New York. Although she showed no symptoms of typhoid fever she was a carrier of the disease — her faeces showed a high level of contamination by the typhoid bacterium. She was imprisoned because she continued to work as a cook, even though courts ordered her not to do so. Between 2% and 5% of people infected with typhoid recover, but they become permanent carriers of the bacterium. Australian health regulations restrict people who have had typhoid from working in occupations involved in the preparation or handling of food for consumption by the public for a period of three months after the infection. They also have to undergo regular blood testing for some time. People working in the food industry are required to wear protective clothing such as disposable gloves to ensure food safety. Q3. 7.2 Importance of cleanliness FQA Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) page 1 of 4 Bk Ch7 S7.2 FQ3 Re-read the information on page 338 about Universal Precautions. a b c Explain the importance of each of the control practices described. What problems could arise if these are not followed? Why is it important to treat every patient as though they were potentially infected with particular blood-borne pathogens? A3. Bk Ch7 S7.2 FA3 a b c Points 1, 2, 3, 7: Reduce to a minimum the risk of contracting dangerous blood-borne diseases such as HIV and hepatitis B. Point 4: Destroys harmful pathogens thereby removing the risk of transmission. Points 5, 6, 10: Infected materials and equipment cannot be used again and are safely disposed of, thereby ensuring the safety of future patients and attending medical staff. Point 8: Protects others from contact with body fluids of patient, thereby reducing the risk of transmission. Point 9: All of the activities listed mean there is a potential for the person concerned to crosscontaminate objects in the workplace with their own body fluids. This point reduces the risk of the person concerned contracting potentially dangerous diseases and passing them on if they are infected. Point 11: Protects medical staff from contracting potentially dangerous diseases. If these Universal Precautions are not followed the risk of contracting or transmitting potentially dangerous blood-borne diseases is increased. It is important to treat every patient as though they were infected with dangerous blood-borne pathogens because only then is the highest standard of hygiene practised, thereby reducing to a minimum the chance of transmission of these diseases. Q4. Bk Ch7 S7.2 FQ4 a b Find out what government regulations are in place concerning: • handling food and money in food outlets • storing foods by food outlets • processing food by food manufacturers. • sewage treatment and disposal • disposing of disposable nappies. Why do such regulations exist? A4. Bk Ch7 S7.2 FA4 a b Australian health regulations have policies in place that demand the following: • Food and money must not be handled simultaneously. Food outlets meet this regulation in different ways; for example, a cashier handles money while other staff members handle foods. • There are strict regulations regarding the ways in which foods are stored; for example, cooked meats must be stored separately from uncooked meats and other foods. • Separate and strict regulations are in place to ensure the highest level of food safety in food processing plants, for example thorough cleaning of machinery between uses. • Sewage treatment plants apply two stages of treatment to sewage before allowing discharge into waterways. • Disposable nappies contain human waste and so should not be placed in domestic waste bins. Individual councils may have their own regulations about the disposal of disposable nappies. Baby change rooms at community centres such as shopping centres usually have receptacles for collection of disposable nappies. Such regulations exist to ensure the safety of members of the community from exposure to disease-causing pathogens. Q5. 7.2 Importance of cleanliness FQA Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) page 2 of 4 Bk Ch7 S7.2 FQ5 Sydney suffered a water crisis in July 1998 when the disease-causing parasites Giardia and Cryptosporidium were discovered in the water supply. Do some library or Internet research of journal and newspaper articles covering the water crisis. a Describe the symptoms of Giardia and Cryptosporidium infection. b How did the city’s drinking water become infected? c Outline the precautions residents were advised to undertake in order to ensure that the drinking water was safe to consume. d Find out how water for household use is usually treated before it reaches your home. A5. Bk Ch7 S7.2 FA5 a b c d A person infected with Giardia or Cryptosporidium is likely to experience nausea, abdominal cramps, vomiting, fever and diarrhoea. Sydney’s drinking water is believed to have been contaminated by an animal carcass that decomposed in the water catchment, or affected by a fault in the water filtration system. Sydney residents were advised to boil all water used for drinking and food preparation, including water for washing fruits and vegetables as well as water used for personal hygiene such as brushing teeth. Water for domestic use is treated by filtration and disinfection. After water has been subject to ultra-filtration to remove suspended particles it is treated with a disinfecting agent, usually chlorine, to kill micro-organisms including the protozoans that caused Sydney’s water crisis. As well as treating water before it reaches our homes, water treatment plants also monitor the levels of chlorine and micro-organisms in our water supply. Alternative methods of disinfection include chloramination (a combination of chlorine and ammonia is used to kill microbes) and ozone filtration. Q6. Bk Ch7 S7.2 FQ6 Prepare your own set of regulations about hygiene in your kitchen at home. Include statements addressing: the handling of food items the preparation of different food items on particular kitchen surfaces storage of different kinds of foods. A6. Bk Ch7 S7.2 FA6 Regulations to maintain hygiene at home: • Wash hands before handling food. • Wash hands after using the toilet or tissues. • Take care not to cough or sneeze over foods. • Clean kitchen surfaces and utensils before food preparation. • Only use plastic or metal surfaces to prepare meats, not wooden boards. • Do not prepare meats and vegetables on the same surfaces unless thoroughly washed in between uses. • Store perishable foods in the refrigerator. • Do not leave cooked foods containing meats on the bench for protracted periods. • Do not store meats and meat products in the same containers with vegetables. • Thaw frozen meats in the refrigerator. • Do not thaw and then refreeze foods. Q7. Bk Ch7 S7.2 Q7 Explain how the transmission of a disease is affected by features of: a the host organism b the agent of disease c the environment. 7.2 Importance of cleanliness FQA Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) page 3 of 4 A7. Bk Ch7 S7.2 A7 a b c The host organism: The level of resistance that an organism has to a disease affects the likelihood of infection. For example, a young, strong and healthy person will be less likely to contract some diseases, such as influenza, compared with an older, more feeble individual. Other factors also affect a person’s susceptibility to disease; for example, increased stress can leave someone more vulnerable. Adopting certain lifestyles can also put someone at greater risk of certain diseases. The agent of disease: Pathogens are usually specific for a particular species so diseases that affect humans are not generally transmitted to other animals. Sometimes the pathogen does not infect the host with enough vigour to cause the symptoms of disease. When disease symptoms do occur the host usually responds with defensive actions such as increasing the production of white blood cells to fight the infection. The environment: The state of the environment affects the growth of pathogens and the likelihood of the pathogen being passed from host to host. For example, in unhygienic conditions such as those in which there is no running water or proper sewage disposal, the risk of contracting diseases is high. 7.2 Importance of cleanliness FQA Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) page 4 of 4