A condition in which the host interacts physiologically and immunologically with a microorganism
Infection
Occurs when another organism enters your body and causes disease
Infection
The organisms that cause infections are very diverse and can include
things like: (4)
viruses, bacteria, fungi, and parasites
Chain of Infection
Infectious agent
Reservoir
Portal of exit
Means of transmission
Portal of entry
Susceptible host
Infectious Agents (5)
- bacteria
- fungi
- viruses
- rickettsiae
- protozoa
Reservoirs (3)
- people
- equipment
- water
Portal of exit (4)
- excretions
- secretions
- skin
- droplets
Means of transmission (4)
- direct contact
- ingestion
- fomites
- airborne
Portal of entry (5)
- mucuous membrane
- gi tract
- gu tract
- respiratory tract
- broken skin
Susceptible host (5)
- immunosuppression
- diabetes
- surgery
- burns
- elderly
Break the chain: Infectious Agent
rapid accurate identification of organisms
Break the chain: Reservoirs
- employee health
- environmental sanitation
- disinfection/sterilization
Break the chain: Portal of Exit
- hand hygiene
- control of excretions and secretions
- trash and waste disposal
Break the chain: Means of transmission
- isolation
- food handling
- airflow control
- standard precautions
- sterilization
- hand hygiene
Break the chain: Portal of entry
- wound care
- catheter care
- aseptic technique
Break the chain: Susceptible host
- recognition of high-risk patients
- treatment of underlying diseases
____ occurs only when infectious particles of <5 μm, known as ___, are propelled into the air. The prevention of such transmission is expensive, requiring N95 respirators and negative pressure isolation rooms.
Airborne transmission, aerosols
__________ occurs when bacteria or viruses travel on relatively large respiratory droplets that people sneeze, cough, drip, or exhale. They travel only short distances before settling, usually less than 3 feet.
Droplet transmission,
The ____ is the chain that is easiest to break.
mode of transmission
True or False:
All infectious agents are alive.
False. Viruses are not alive! However, they need a host to replicate. At a basic level, viruses are proteins and genetic material that survive and replicate within their environment, inside another life form. In the absence of their host, viruses are unable to replicate and many are unable to survive for long in the extracellular environment.
True or False:
In the absence of their host, viruses are unable to replicate and many are unable to survive for long in the extracellular environment.
True
The microorganisms that live on another living organism (human or animal) or inanimate object without causing disease.
Normal flora
Stages of Infection (6)
1. Exposure
2. Incubation or Latent
3. Prodromal
4. Acute Disease
5. Convalescence
6. Relapse
Stage of contact with the infectious agent
Exposure
Entry and multiplication of the organism in the body so as to manifest an actual illness
Incubation or Latent
Manifestation of vague signs and symptoms (e.g. Fever, cough, Pain)
Prodromal
Illness stage/appearance of pathognomonic signs
Acute Disease
Stage of resolution; homeostasis is maintained, and infectious organism is under control
Convalescence
Reactivation of previous infection due to reexposure
Relapse
How to determine the pathogen?
Laboratory (e.g. culture and sensitivity)
Infectious diseases are caused by ___. They can be spread, directly or indirectly, from one person to another.
✓ Use of PPE (gloves, gown, mask, googles). Hand hygiene, needle stick injury prevention,
etc.
✓ Applied to all patients regardless of clinical diagnosis
First tier: STANDARD PRECAUTION
Second tier: TRANSMISSION BASED PRECAUTION (3)
- Contact
- Airborne
- Droplet
Protection against direct and indirect transmission. Mask and gown are
added
Contact
Use of airfilters (N95, AIIR)
Airborne
Maintaining a distance of 3 ft from the source of infection to avoid droplet nuclei; room windows are open & use of mask.
Droplet
Levels of Prevention (3)
- Primary
- Secondary
- Tertiary
Focuses on health promotion and disease prevention
Primary Prevention
Focuses on the curative aspect of care -> Effort is directed for early treatment. Move is also undertaken to avoid possible complications
Secondary Prevention
Focuses on the rehabilitative aspect -> Effort of helping the patient adjust with the limitations and disability brought about by the previous disease
Tertiary Prevention
Specific Organisms with Health Care–Associated Infection Potential
1. Clostridium Difficile
2. Methicillin-Resistant Staphylococcus Aureus
spore-forming bacterium
Clostridium Difficile
refers to S. aureus that is resistant to methicillin or its comparable pharmaceutic agents
Methicillin-Resistant Staphylococcus Aureus
Clostridium difficile management (3)
- Use contact precaution
- Use bleached-based solution
- Clean touched equipment frequently
Preventing Health Care-Associated Bloodstream Infections (Bacteremia and Fungemia)
• Any vascular access device (VAD) can serve as the source for a
bloodstream infection
• Change infusion set – every 3 days
• Change IV line – every 3 days
• Blood line- within 24 hours from start of infusion
• Clean injection ports with 70% alcohol
General management (5)
• Infection control measures:
• Hand hygiene
• Use of PPE
• Wound care
• Medications (e.g. antibiotic, antiviral,
antiprotozoal)
Generation of Cephalosporins:
Very effective against Grampositive bacteria. But they’re only somewhat effective against Gram-negative bacteria
1st generation
Generation of Cephalosporins:
Target some types of Gram-positive and Gram-negative bacteria. But they’re less effective against certain Gram-positive bacteria than first generation cephalosporins are
2nd generation
Generation of Cephalosporins:
More effective against Gram negative bacteria compared to both the first and second generations. They’re also more active against bacteria that may be resistant to previous generations of cephalosporins.
3rd generation
Generation of Cephalosporins:
While effective against a variety of Gram-positive and Gram-negative bacteria, it’s usually reserved for more severe infections.
4th generation
Generation of Cephalosporins:
This cephalosporin can be used to treat bacteria, including resistant Staphylococcus aureus (MRSA) and Streptococcus species, that are resistant to penicillin antibiotics.
