5.3 Preventing infections

Question 1

How can you prevent infections with hygiene

Answer 1

• Hand washing, before cooking, contact with animal, someone with infectious illness
• Using disinfectant on kitchen work surfaces, reduce number of pathogens
• Raw meat away from food that is eaten uncooked to reduce number of pathogens
• Coughing or sneezing into handkerchief
• Maintaining hygiene of people and agricultural machinery

Question 2

How can isolating someone prevent infection

Answer 2

• for serious diseases such as Ebola or cholera
• the fewer healthy people come into contact with infected person, the less likely that pathogens will be passed on

Question 3

how can destroying or controlling vectors prevent the spread of infection

Answer 3

• some communicable diseases passed on by vectors
• if vectors destroyed, spread of disease can be prevented

Question 4

how can vaccine prevent infection

Answer 4

• harmless form of a specific pathogen introduced into your body
• if you come in contact with live pathogen, not become ill, immune system is prepared

Question 5

why does disease spread more easily in highly populated areas

Answer 5

more frequent contact with people who can pass on disease

Question 6

why does disease spread more quickly in areas with poor hygiene

Answer 6

less likely to kill germs and microbes that carry disease, increased chance of drinking untreated water, carry pathogens if not boiled

Question 7

What are some examples of vectors?

Answer 7

• mosquitoes (eg malaria, dengue fever)
• houseflies
• rats
• aphids
• beetles (in plants)

Question 8

Who was Ignaz Semmelweis and what did he do?

Answer 8

• he was doctor in mid-1850s
• he noticed that medical students went from dissecting corpses to delivering babies without washing hands
• noticed that doctor died from symptoms identical to baby fever after cutting himself while working on body
• he insisted that medical students should wash their hands before delivering babies
• fewer mothers died from fever
• some people were against his ideas

Question 9

What did Louis Pasteur do

Answer 9

• showed that microorganisms caused disease
• developed vaccines against anthrax and rabies

Question 10

What did Joseph Lister do

Answer 10

used antiseptic chemicals to destroy pathogens before they caused infection in operating theatres

Question 11

What did the development of microscopes do

Answer 11

• became possible to see microorganisms more clearly
• this helped convince people that they really were there

Question 12

Name a piece of equipment that helped scientists to prove that infectious diseases are caused by microorganisms. Explain how it helped.

Answer 12

• microscope
• it helped because scientists could study diseased tissue and see the microorganisms (they are too small to be seen with the naked eye)

Question 13

Suggest why Ignaz’s policy led to a reduced number of deaths

Answer 13

less pathogens would be transferred by their hands to the mother, so less mothers are infected