Spread of Cholera

• https://www.youtube.com/watch?v=jG1VNSCsP5Q

Chain of Infection

• Infectious agent• Reservoir host• Portal of exit• Route of transmission• Portal of entry• Susceptible host

Chain of Infection

The Chain of Infection

Reservoir Host

Portal of Exit

Mode of TransmissionPortal of Entry

Susceptible Host

Infectious Agent

Infection Control

• Defense mechanisms• Scope of problem– Nosocomial infection– Handwashing– Industrial illness– Needlestick injuries

Infection Control

• Regulatory agencies – CDC – OSHA

Asepsis

• The state of being free from disease-causing contaminants

• Medical asepsis or clean technique– Free of living pathogenic microorganisms

• Surgical asepsis or sterile technique– Absence of viable pathogenic organisms

Breaking the Chain

• Breaking just one link, stops the infection

Break the Chain

– ID source of infecting microorganism– Stop means of transmission– Protect susceptible host– Hand washing– Decontaminate surfaces and equipment– Avoid contact when contagion – Wear Personal Protective Equipment

(PPE)– Follow isolation precautions

Maximize Resistance

• Provide good hygiene• Ensure proper nutrition and fluid

intake• Decrease stressors that weaken the

immune response

Normal Flora

• Resident flora: microorganisms that normally inhabit specific sites of the human body– No problem in one area, infection in

another• Transient flora: microorganisms that

are not normally present– Can cause infection

Normal Flora

• Use standard precautions• Hand washing – Removes transient flora– Diminishes resident flora

Standard Precautions

• Follow at ALL times– Prevents contact with microbes– Blood– Body fluids, secretions, and excretions

except sweat– Nonintact skin– Mucous membranes

Standard Precautions are

• Hand washing• PPE• Patient-care equipment• Environmental control• Linen• Needle disposal

Isolation

• Consequences to patient• Transmission-based precautions– Airborne precautions– Droplet precautions– Contact precautions

• Neutropenic precautions

Methods toInhibit or Destroy Microbes

• Bacteriostatic• Bacteriocidal or germicidal• Antiseptics- kill microorganisms• Disinfectants- kill microorganisms on

non-living objects• Sterilization- kills all forms of microbial

life

The Risks

• Blood-borne pathogens– Hepatitis B– Hepatitis C– Hepatitis D– HIV

Tuberculosis (TB)

• Airborne pathogen• Caused by Mycobacterium

tuberculosis• No prevention• Skin test give for detection• Still a problem in the United States• Drug-resistant strains developing

Drug Resistant Organisms

• Developed from overuse of antibiotics• Developed from patients who do not

complete antibiotic treatment• Methicillin-resistant Staphylococcus

(MRSA)• Vancomycin-resistant Enterococcus

(VRE)

Reporting exposure

• Any exposure to blood or body fluids must be reported immediately

• Written incident or injury report• Exposure Control Plan

• Scrubbing: https://www.youtube.com/watch?v=L8OLnyJ3mAc