Microbiology transmission of infection

Question 1

What is the chain of infection?

Answer 1

1. Reservoir
2. Infectious agent
3. Portal of exit
4. Portal of entry
5. Mode of transmission

Question 2

What is ‘reservoir’ in the chain of infection?

Answer 2

Reservoir is the source.

It is the habitat where the microorganisms normally live for long periods and multiply.

Question 3

What is ‘infectious agent’ in the chain of infection?

Answer 3

Infectious agent is the pathogen..

It is disease causing microorganisms. Microorganisms spread through either direct or indirect contact.

Question 4

What is ‘portal of exit’ in the chain of infection?

Answer 4

The way that the microorganisms are shed from the human body during normal activities such as coughing, sneezing, defecating and changing clothes.
It is how microorganisms leave the body.

Question 5

What is ‘portal of entry’ in the chain of infection?

Answer 5

The way in which microorganisms gain entry to the human body.
It is how microorganisms enter a new host.

Question 6

What is ‘mode of transmission’ in the chain of infection?

Answer 6

The spread of an organism from a reservoir (source) to a susceptible host.
The method of transfer - moving from an old host to a new host.

Question 7

What is ‘susceptible host’ in chain of infection?

Answer 7

The ability of the person to resist invasion by the pathogen.
This is the potential target for an infection.

Question 8

How can viral and bacterial microorganisms be transmitted?

Answer 8

• Contact - direct and indirect
• Vehicles
• Airborne
• Droplet
• Vectors
• Autogenous

Question 9

What is the difference between direct and indirect contact?

Answer 9

Direct - close proximity (direct touch, by clothing through droplets from the mouth or nose).

Indirect - contact with the personal article of an infected individual (tissues, dentures, chairs).

Question 10

What are vehicles?

Answer 10

Transmission that has gotten into the food, water, medications or blood.

Question 11

What is airborne?

Answer 11

Droplets from the respiratory tracts of an infected persons, contaminated dust and microorganisms shed into the air from hair, skin.
Smaller particles than droplets carried on air currents (sweeping, dusting, shaking out linen).

Question 12

What is droplet?

Answer 12

Contact with infectious upper respiratory secretions (sneezing, coughing, talking, spitting)

Question 13

What is vectors?

Answer 13

Contaminated animals / insects. An animal or insect as a host between two people. (cats, dogs, birds, ticks, fleas, mosquitoes).

Question 14

What is autogenous?

Answer 14

Infection from the clients usual microbial flora.

Question 15

Name factors that are considered to be a potential target for infection:

Answer 15

• Age
• Comorbidities (pre existing conditions: Immune disease)
• Those having invasive procedures
• Wounds
• Reduced immunity
• Medications
• Poor nutrition / smokers / stress

Question 16

Name ways you can control routes of transmission:

Answer 16

• Hand hygiene
• Use of appropriate barriers
• Sterilisation of disinfection of patient care equipment
• Isolating or cohorting individuals with communicable diseases and conditions
• Environmental and engineering control measures
• Work practice controls

Question 17

What is cross infection?

Answer 17

The transmission of infection from one person to another. Eg / from a patient or staff member to others.

Question 18

How can cross infection occur?

Answer 18

• Poor compliance with hand hygiene
• Contaminated clothing
• Sharing personal items
• Poor cleaning of equipment
• Wearing jewellery while working
• Shaking bed linen
• Face and body piercings
• False fingernails

Question 19

What are the 5 phases of illness?

Answer 19

1. Incubation
2. Prodromal
3. Illness
4. Decline
5. Convalescence period

Question 20

Explain the incubation period of the phases of illness:

Answer 20

The host is getting sick - the pathogen has entered the body and the host is beginning to multiply. The host is unaware that a disease is beginning in their body. Insufficient numbers of pathogens present to cause signs and symptoms.

Question 21

Explain the prodromal period of the phases of illness:

Answer 21

The host is beginning to feel experience general signs and symptoms (fever, pain, soreness, swelling or inflammation).

Question 22

Explain the illness period of the phases of illness:

Answer 22

Signs and symptoms are most obvious and severe.

Question 23

Explain the decline period of the phases of illness:

Answer 23

Pathogens are beginning to decrease, signs and symptoms are declining, host is susceptible to developing secondary infections.

Question 24

Explain the convalescence period of the phases of illness:

Answer 24

Final period, host is feeling better, no longer experiencing symptoms, still carrying infectious microorganisms and can pass onto others.

Question 25

What is a nosocomial infection?

Answer 25

A disease or infection that originates or occurs in a hospital.

Question 26

How can nurses minimise the incidence of nosocomial infection?

Answer 26

• Frequent hand washing
• Correct antiseptic technique
• Critical thinking in planning nursing care
• Reduce the number of healthcare workers assessing the client.