8.1 Review of Infectious Disease Principles and Topics of Concern

Question 1

Carrier vs Host

Answer 1

Host - Person who provides living conditions to support a microorganism

Carrier - Person who carries an organism without apparent signs and symptoms and is able to transmit an infection to others

Question 2

Colonization

Answer 2

• Microorganisms are present without host interference or interaction.
• Infection would include host interactions with the organism
• Disease is a person who has been infected and displays decline in wellness caused by the infection

Question 3

Transient Flora

Answer 3

Recently acquired organisms that are likely to be shed in a relatively short period of time

Question 4

Droplet Precautions

Answer 4

• Face mask is required but door may remain open
• Transmission is limited to close contact

Question 5

How do Infections Occur

Answer 5

Source - Place where infectious agents live

Transmission - A way germs are moved into the susceptible person

Susceptible Person - A person at risk of obtaining the germs into the body

Question 6

Most Common Healthcare Infection

Answer 6

• CDIFF

Question 7

Source of Infection

Answer 7

• Dry surfaces in patient care areas (bed rails, medical equipment, countertops, tables)
• Indwelling medical devices (catheters and IV lines)
• Dust/Decaying Debris (Construction dust, wet materials from water leaks)
• Wet Surfaces or Moist Environments and Biofilms (Cooling towers, faucets, sinks, ventilators)

Question 8

Biofilm

Answer 8

• Assemblage of surface bacteria that are enclosed in extracellular polymeric substance matrix which is irreversible associated (does not remove with gentle rinsing) with a surface.
• The enclosed material is primarily polysaccharide material

Question 9

Healthcare Workers

Answer 9

• We are at risk population for infectious disease

Question 10

Measels

Answer 10

• Highly contagious
• Can lead to pneumonia and encephalitis

Question 11

Herpes Zoster

Answer 11

• Caused by re-activation of varicella-zoster virus (VZV) same virus that causes varicella (chickenpox). Shingles as well.

Vaccines
- Zoster vaccine live
- Recombinant Zoster Vaccine (RZV) - preferred vaccine for shingles

Question 12

Infection

Answer 12

• In order for infection to occur a complete chain is necessary. This chain includes..
• Susceptible host
• Causative organism
• A reservoir of available organisms
• A portal of exit from the reservoir
• A mode of transmission from reservoir to host
• Mode of entry into susceptible host

Question 13

Defintions

Answer 13

Infections agent
- Causative agent

Reservoir
- Place where microorganisms survive, multiply and wait for a host
- These require food, water, oxygen (anaerobic bacteria can live with little oxygen), proper temperature, pH, and light (most like darkness such as under dressings or body cavities)

Portal of Exit
- How they leave their reservoir to a new host (GI, GU, Respiratory, Skin, Mucous Membranes)

Mode of Transmission
- Direct, indirect, droplet, airborne, vehicles, vector

Portal of Entry
- How it enters another host
- GI, GU, Respiratory, Mucous Membranes

Susceptible Host
- Susceptibility to infection depends on the individuals immune system and resistance.

Question 14

First Tier Standard Precautions

Answer 14

• All patients are colonized or infected with microorganisms
• Hand hygiene
• PPE
• Proper equipment handling and linen
• Environmental Control
• Prevention of injury from sharp devices and needles
• Avoidance of splash or spray of bodily fluids
• Patient placed in assigned rooms

Question 15

Second Tier Transmission-Based Precautions

Answer 15

NEXT SLIDES

Question 16

Airborne

Answer 16

• TB, Varicella
• Negative pressure room with doors closed
• N95 masks for hospital workers at all times when in the room

Question 17

Droplet

Answer 17

• Influenza, Meningococcus
• Organisms transmit through close contact through respiratory secretions
• Face masks should be worn but the door may remain open as it only transmits through close contact

Question 18

Herpes Zoster

Answer 18

• If patient is immunocompetent with herpes zoster then the following precautions should be used until the lesions are dry and crusted
• Standard
• Airborne
• Contact
• If the herpes is localized then just standard and contact precautions (lesions should be covered until dry and crusted.

Question 19

Contact

Answer 19

• Organisms that spread skin-to-skin such as ARO (Antibiotic-Resistant Organisms) or C-Diff
• Barriers to prevent transmission
• These are easily transmitted between contact
• Masks are not needed

Question 20

Pharmacoepidemiology

Answer 20

• Study of use and effects of drugs in well-defined populations (including drug use patterns and adverse drug effects)
• It is divided into acute and chronic epidemiology

Question 21

CLABSI Prevention

Answer 21

BUNDLE APPROACH
- Hand hygiene
- Maximal barrier precaution
- Chlorhexidine skin antiseptics
- Optimal catheter site selection
- Daily review of line necessity with prompt removal of unnecessary lines

Question 22

Community Acquired Infections Prevention

Answer 22

• Collaborate with CDC, state, local public health departments

Methods
- Sanitation techniques
- Regulated health practices
- Food preperation
- Immunization program

Question 23

Vaccines

Answer 23

Two vaccines are licensed and recommended to prevent shingles in the US. Zoster vaccine live (ZVL, Zostavax) has been in use since 2006. Recombinant zoster vaccine (RZV, Shingrix), has been in use since 2017 and is recommended as the preferred shingles vaccine.