Chain of infection

Question 1

Name four types of resivours.

Answer 1

Humans, Animals, Water and Soil

Question 2

Give an example of diseases associated with Human reservoirs

Answer 2

UTI

Question 3

Give an example of diseases associated with Animal reservoirs

Answer 3

Sars, covid 19

Question 4

Give an example of diseases associated with water reservoirs

Answer 4

tetanus

Question 5

Give an example of diseases associated with soil reservoirs

Answer 5

hepatitis A

Question 6

Define portal of exit

Answer 6

the path by which an infectious microorganism leave a reservoir

Question 7

Define portal of entry

Answer 7

Is the path by which an infectious microorganism gains entry to a new host

Question 8

What are the human portals of entry

Answer 8

Endogenous infections – inside of the body

Exogenous infections – outside of the body, inhalation, ingestion etc

Question 9

What are the human portals of exit

Answer 9

• Respiratory system
• Digestive system
• Reproductive systems
• Urinary system
• Skin
• Blood

Question 10

How can pathogens exit the body

Answer 10

excretion (expelling waste) , secretions (discharge of cell, gland or organ), droplets (sneeze, cough)

Question 11

What are the standard precautions to break chain in the portals of entry and exit.

Answer 11

Hand hygiene, PPE, routine environmental cleaning, waste management, sterilisation.

Question 12

State the categories of diseases transmission.

Answer 12

Contact, Common Vehicle, Vector

Question 13

Explain Direct contact in transmission and what category it is in.

Answer 13

close or intimate contact between infected host and susceptible individual e.g. touch, sexual contact. Contact

Question 14

Explain Indirect contact in transmission and what category it is in.

Answer 14

microbes transferred from one host to another via a non-living object (fomite) e.g. door handle. Contact

Question 15

Explain droplet transmission in transmission and what category it is in.

Answer 15

droplets falling less than 1 meter e.g. sneezing, coughing, laughing, speaking. Contact

Question 16

Explain airborne transmission in transmission and what category it is in.

Answer 16

Organisms are carried in air currents for more than 1 metre and in some cases can circulate in the air for hours. Common vehicle

Question 17

Explain water-borne transmission in transmission and what category it is in.

Answer 17

Occurs when there is faecal contamination of water used for drinking and bathing. Common vehicle

Question 18

Explain mechanical transmission in transmission and what category it is in.

Answer 18

Passive transport of microorganisms on the exterior of an insect’s body. Vector

Question 19

Explain Biological transmission in transmission and what category it is in.

Answer 19

An insect vector bites a host, ingests blood containing the microorganisms and transmits them when it bites another host. Vector

Question 20

What are the five strategies to prevent transmission.

Answer 20

Sanitation , Hygiene practises, Isolation, Immunisation, Treatment

Question 21

State different populations that are susceptible hosts.

Answer 21

Young children, the elderly, Chronically ill people, People receiving treatment ,
People with open wounds

Question 22

Outline 2 methods which can help susceptible hosts avoid infection

Answer 22

Ensure effective use of Standard Precautions,
Treat their underlying disease/condition,
Ensure they have appropriate nutrition,
Vaccination

Question 23

What is the major advantage of antibiotics

Answer 23

An advantage of antibiotics over other antimicrobial agents is their selective toxicity

Question 24

What is Antimicrobial agents?

Answer 24

An antimicrobial agent is a substance that kills or inhibits the growth of microorganisms

Question 25

what are the main causes of antibiotic resistance

Answer 25

Bacteria multiply so quickly that they can mutate and become resistant to antibiotics, the more antibiotics are used, the more likely this is to occur, Susceptible bacteria die off, leaving resistant bacteria to multiply