Objective 1 and 2

Question 1

define epidemiology

Answer 1

the study of the factors and mechanisms that influence the frequency and distribution of disease

Question 2

what is the importance of epidemiology? (4)

Answer 2

1. Identify - the cause and risk factors
2. Measure - the impact on the community
3. develop and evaluate - interventions
4. inform - public policy (prevention and health promotion)

Question 3

What are the 4 methods of transmission of pathogenic micro-organisms?

Answer 3

1. Contact infection
2. Air-borne
3. water and food borne
4. trauma mediated

Question 4

what are the 3 types of contact infection (direct person to person)?

Answer 4

1. congenital
2. sexual
3. other

Question 5

what is congenital infection?

Answer 5

being born with the infection

Question 6

what are 3 ways congenital infection can occur?

Answer 6

1. transmitted across the placenta
2. acquired from mother during birth
3. passed from mother to child, directly from one generation to the next

Question 7

what are 3 examples of viral congenital infection?

Answer 7

1. rubella
2. HIV
3. cytomegalovirus

Question 8

what is an example of a bacterial congenital infection>

Answer 8

treponema pallidum - syphilis

neisseria gonorrhoeae - acquired during delivery

Question 9

what is an example of a protozoa congenital infection?

Answer 9

Toxoplasma gondii - toxoplasmosis

Question 10

how does sexual contact infection occur?

Answer 10

organisms are transferred from one person to another bu direct mucous membrane contact or in shared body fluids

Question 11

what are 7 examples of STI’s?

Answer 11

• herpes
• gonorrhoea
• syphilis
• HIV
• hepatitis B
• trichomoniasis
• chlamydia

Question 12

what are the 3 other forms of contact infection?

Answer 12

• non sexual direct contact
• auto-infection
• fomites

Question 13

what are examples of non-sexual direct contact?

Answer 13

handshaking
hugging
important in nursing when carrying organisms from one pt to another

Question 14

what is auto-infection?

Answer 14

infection due to contact with oneself

Question 15

what are 3 examples of auto-infection?

Answer 15

• e.coli from large intestine causing UTI
• inunction where surface organisms are driven deeper into the skin due to pressure or friction
• staphylococcal infections of hair follicles (boils)

Question 16

What are fomites?

Answer 16

infections acquired through contact with inanimate objects contaminated by another person

Question 17

what are 3 examples of fomites?

Answer 17

• athletes foot
• cold sores (contracted from sharing cups etc)
• inadequately cleaned or sterilized instruments or appliances

Question 18

How are airborne infections spread?

Answer 18

transmitted by the deposition of pathogens on the mucous membranes of the nose, pharynx, trachea and bronchial tree during inhalation

Question 19

what are 3 examples of bacterial air borne infections?

Answer 19

• diphtheria (Corynebacterium diphtheriae)
• tuberculosis (Mycobacterium tuberculosis)
• whooping cough (Bordetella pertussis)

Question 20

what are 3 examples of viral airborne infections?

Answer 20

• measles
• influenza
• common cold

Question 21

what are airborne droplets?

Answer 21

• the aerosol from coughing or sneezing
• droplets are mainly saliva from front of mouth
• contain very few pathogens
• not mian vehicle of transmission

Question 22

what are air-borne dried particles?

Answer 22

• derived from nasal mucus or sputum (actual site of infection)
• pathogens are alive in dried deposits and protected by dry mucus
• small size so can remain suspended in air currents for a long times making them more infectious over distance

Question 23

what are 4 examples of water and food borne infections?

Answer 23

• Dysentery (Shigella dysenteriae)
• Cholera (Vibrio cholerae)
• Typhoid (Salmonella typhi)
• Poliomyelitis (virus)

Question 24

what are prevention methods for water and food borne infections?

Answer 24

• Proper water treatment (filtration, chlorination, routine monitoring)
• correct sewage treatment and disposal
• Proper food hygiene in food production processing and preparation

Question 25

what are trauma mediated infections?

Answer 25

• occurs when integrity of body surface (i.e. skiin barrier) is lost
• can occur by implantation or injection

Question 26

what is implantation trauma?

Answer 26

accidental trauma or deliberate surgical procedures that expose underlying tissue to potential pathogens

Question 27

what are examples of infections caused by implantation trauma?

Answer 27

• haemolytic streptococci
• staphylococcus aureus
• pseudomonas aeruginosa
• clostridium perfringes and clostridium teatani (spore forming)

Question 28

what is injection trauma?

Answer 28

penetration of the skin and the introduction fo micro-organisms to tissues wiuthout disruption to outer layers of body

Question 29

what are the 2 categories of injection?

Answer 29

• natural

- artificial

Question 30

what is natural injection?

Answer 30

occurs as part of the normal disease transmission process adopted by micro-organisms that use blood-sucking insects as vectors of the disease

Question 31

what are examples of natural injection infection?

Answer 31

malaria (Plasmodium spp), bubonic plague (Yersinia pestis), Dengue fever, yellow fever
- Animal bites that puncture rather than rip

Question 32

what is artificial injection?

Answer 32

transmission of disease from one perosn to another via needles, syringes, blood or blood clots

Question 33

what are 3 examples of artificial injection infections>

Answer 33

• hep B and C
• HIV
• malaria