Chain Of Infection

Question 1

Two basic principles of infection prevention and control is hygiene

Answer 1

Hand hygiene and environmental hygiene

Question 2

Prudent antibiotic stewardship

Answer 2

“The right drug,for the right bug”

Question 3

The traditional epidemiological triad models holds that infectious diseases result from the interaction of agent, host, and environment.

Answer 3

Chain of infection

Question 4

3 parts of chain of infection

Answer 4

1. Reservoir
2. Mode of transmission
3. Vector

Question 5

The reservoir of an infectious agent is the habitat in which the agent normally lives, grows and multiples

Answer 5

Reservoir

Question 6

Diseases that are transmitted from person to person without intermediaries

Answer 6

Human reservoir

Question 7

Carriers commonly transmit disease because they do not realize they are infected, and consequently take no special precautious to prevent transmission

Answer 7

Human reservoir

Question 8

Are those carriers who have recovered from their illness but remain capable of transmitting to others

Answer 8

Convalescent carriers (human reservoir)

Question 9

Are those carriers who can transmit the agent during the incubation period before clinical illness begins

Answer 9

Incubatory carriers (human reservoir)

Question 10

Those carriers who never experience symptoms despite being infected

Answer 10

Asymptomatic or passive or health carriers (human reservoir)

Question 11

May or may not show the effects of illness

Answer 11

Human reservoirs

Question 12

Are those carriers who continue to harbor to a pathogen such as hepatitis B virus or salmonella typhi

Answer 12

Chronic carriers (human reservoir)

Question 13

Many of these disease are transmitted from animal to animal, with humans as incidental hosts

Answer 13

Animal reservoirs

Question 14

Refers to an infectious disease that is transmissible under natural conditions from vertebrate animals to humans

Answer 14

Zoonosis

Ex. Of zoonosis
- brucellosis (cows and pigs)
- anthrax (sheep)
- plaque (rodents)
- trichinellosis/trichinosis (swine)
- Tularemia (rabbits)
- rabies (bats, raccoons, dogs, other mammals)

Question 15

Plants, soild and water in the environment are also reservoirs for some infectious agents

Answer 15

Environmental reservoirs (fungal agents)

Question 16

____ is the path by which a pathogen leaves its host

Answer 16

Portal of exit

Question 17

Where does TB exits, schistosomes, cholera vibrios exits

Answer 17

Tb - respiratory tract
Sch - urine
Cholera - feces

Question 18

portal of exit from the human reservoir includes

Answer 18

Blood
Open wound, needle puncture site
Any break in intact skin
RT
Sneezing, coughing, breathing, talking
GIT
mouth
Anus
Urine

Question 19

Infectious agent may be transmitted from its natural reservoir to a susceptible host in different ways

Answer 19

Mode of transmission

Question 20

Types of mode of transmission and its subtypes

Answer 20

Direct
1. Direct contract
2. Droplet spread

Indirect
1. Air borne
2. Vehicle borne
3. Vector borne (mechanical or biological)

Question 21

An infectious agent is transferred from a reservoir to a susceptible hosts by direct contact or droplet spread

Answer 21

Direct transmission

Question 22

A contact that occurs through skin to skin contract, kissing and sexual intercourse

Answer 22

Direct contact

Question 23

Refers to spray with relatively large, short-range aerosols produced by sneezing, coughing or even talking

Answer 23

Droplet spread

Question 24

Refers to the transfer of an infectious agent from a reservoir to a host by suspended air particles, inanimate objects (vehicles) or animate intermediaries (vectors)

Answer 24

Indirect transmission

Question 25

Occurs when an infectious agents are carried by dust or droplet nuclei suspended in air

Answer 25

Airborne transmission

Question 26

includes materials that has settled on surfaces and become re-suspended by air currents as well as infectious particles blown from the soil by the wind

Answer 26

Airborne dust

Question 27

May indirectly transmit an infectious agent include food, water, biologic products, and fomites, objects such as handkerchiefs, bedding and surgical scalpels

Answer 27

Vehicles

Question 28

a ___ may passively carry a pathogen

Answer 28

Vehicle

Question 29

__ such as mosquitoes, fleas, and ticks may carry an infectious agent through purely mechanical means or may support growth changes in the agents

Answer 29

Vectors

Question 30

Refers to the manner in which a pathogen enters a susceptible host

Answer 30

Portal of entry

Question 31

Final link in the chain of infectious is a susceptible host

Answer 31

Host

Question 32

Refers to the protective antibodies that are directed against a specific agent.

Answer 32

Specific immunity

Question 33

Natural barriers to infection

Answer 33

Intact skin Nasal cilia Lung macrophages Acidic environment in the stomach, urine and vaginal secretions Tears that wash away pathogens Saliva

Question 34

Vehicleborne transmission may be interrupted by

Answer 34

Elimination or decontamination of the vehicle

Question 35

How to rprevent airbore disease

Answer 35

Modifying ventilation or air pressure, filtering or treating the air

Question 36

How to prevent oral-route transmission

Answer 36

Promoting hand washing

Question 37

A way to interrupt vectorborne transmission

Answer 37

Controlling vector population. Spraying to reduce the mosquito population

Question 38

Intervention to increase a host defenses

Answer 38

Vaccination

Question 39

This concept suggests that if a high enough proportion of individuals in a population are resistant to an agent, then those few who are susceptible will be protected by the resistant majority since the pathogen will be unlikely to “find” those few susceptible individuals

Answer 39

Herd immunity

Question 40

Susceptible hosts

Answer 40

Young children Old individuals Ppl with inadequate diets Who are chronicaly ill With open wounds