Infection Control and Medical Asepsis Chapter 22 Infection Control and Medical Asepsis

Impact of Infectious Diseases Discovery of germ theory: Louis Pasteur and Robert Koch Pharmacologic agents: antibiotics and vaccines Edward Jenner: smallpox vaccine Epidemiology: history, cause, patterns of infectious diseases

Impact of Infectious Diseases Infection control and prevention Resistant microorganisms Bloodborne pathogen transmission Increased immunosuppressed populations Global access Effect infectious diseases have on lifestyles

The Process of Infection Caused by pathogenic microorganisms capable of causing disease Normal flora Similar steps occur in all infectious diseases MAs must apply theory of disease growth and transmission

The Process of Infection Growth requirements for microorganisms Oxygen Lack of or no oxygen Moisture Nutrition Temperature Darkness Time Neutral or slightly alkaline pH

Infection Cycle Infectious agent Reservoir Portal of exit Means of transmission Portal of entry Susceptible host

Infection Cycle Infectious agents Viruses Bacteria Fungi Parasites Rickettsia Prions (See Table 22-1: Common Viral Diseases) (See Table 22-2: Examples of Infectious Bacterial Diseases)

Infection Cycle Reservoir Portal of exit Source of a pathogen Method by which infectious agent leaves reservoir

Infection Cycle Modes of transmission Portal of entry Direct contact Droplet Airborne Vector Portal of entry Enter susceptible host

Infection Cycle Susceptible host Number and specific type of pathogen Duration of exposure to pathogen General physical condition Psychological health status Occupation or lifestyle environment Presence of underlying diseases or conditions Youth or advanced age

Infection Cycle Susceptible host Nosocomial infection or healthcare-associated infections (HAI) Rise of antibiotic resistant bacteria

The Body’s Defense Mechanisms for Fighting Infection and Disease The body’s natural barriers Physical First line of defense Skin and associated accessories Chemical Tears, sweat, mucus, saliva, gastrointestinal secretions, vaginal secretions Cellular White blood cells

The Body’s Defense Mechanisms for Fighting Infection and Disease Inflammatory response Response when body invaded by pathogen or physical trauma Nonspecific response Redness, heat, swelling, pain Antibiotic therapy

The Body’s Defense Mechanisms for Fighting Infection and Disease The immune system and immunity Protect against pathogens and abnormal cell growth Cell-mediated immunity: attacks against viruses, fungi, organ transplants, cancer cells Humoral immunity: antibody mediated system

The Body’s Defense Mechanisms for Fighting Infection and Disease The immune system and immunity Recognition of invader Growth of defenses; multiplication of helper T cells and B cells Attack against infection Slowdown of immune response after death of infectious agent

The Body’s Defense Mechanisms for Fighting Infection and Disease The immune system and immunity Resistance: after exposure to pathogen; antigen–antibody reaction Naturally acquired active immunity Artificially acquired active immunity Congenitally acquired passive immunity Artificially acquired passive immunity

The Body’s Defense Mechanisms for Fighting Infection and Disease The immune system and immunity Specific defenses: things that protect us against specific pathogen Nonspecific defenses: not so particular Immunization: provides immunity with active or passive vaccines Live attenuated (changed) pathogens Pathogenic toxins Killed pathogens

Stages of Infectious Diseases Incubation Prodromal Acute Acme Declining Convalescent Sequelae

Disease Transmission Consider each patient potentially infectious for AIDS, hepatitis B and C, other bloodborne pathogens Apply techniques of Standard Precautions (See Table 22-3: Examples of Infectious Diseases)

HIV and Hepatitis B and C HIV and AIDS AIDS caused by bloodborne virus HIV HIV responsible for T-cell destruction Carried in semen, blood, other body fluids No curative treatment of HIV infections Antiviral drugs used to slow process (See Table 22-4: Facts About HIV and Aids)

HIV and Hepatitis B and C Acute viral hepatitis diseases Liver inflamed; hepatic cells destroyed Several types of viral hepatitis Risk for contracting HBV and HCV greater than for contracting HIV No vaccine to prevent HCV No treatment after exposure to prevent infection Medication: immunomodulators (See Table 22-5: Hepatitis Viruses A to C)

Reporting Infectious Disease Certain infectious diseases must be reported to state and county health departments CDC requires information reported to them Notifiable Disease Surveillance System Helps CDC control spread of infection (See Table 22-6: Partial listing of Diseases that Must Be Reported to the CDC)

Standard Precautions Blood and body fluids Blood, secretions, excretions Personal protective equipment Gloves, mask, gown, goggles/face shield Needlestick Contaminated needles never recapped, broken off, removed from syringes, manipulated Disposed of in approved puncture-proof container designated for sharps

Standard Precautions Blood All body fluids, secretions, excretions regardless of whether they contain visible blood Nonintact skin Mucous membranes Personal protective equipment (PPE) >> [FIGURE 22-12A]

Standard Precautions Transmission-based precautions Airborne, contact, droplet precautions Use of barriers (gown, mask, goggles, gloves, cap) Biohazard puncture-proof sharps container>> [FIGURE 22-13] (See Procedure 22-4: Transmission-Based Precautions: Donning a Gown, Mask, Gloves, and Cap (Isolation Technique))

Standard Precautions Disposal of infectious waste Items in contact with patient blood or body fluids Place in appropriate biohazard containers Incinerated (burned) or sterilization by autoclave

Removing Contaminated Gloves [FIGURE 22-28A, FIGURE 22-28B, FIGURE 22-28G, FIGURE 22-28H] (See Procedure 22-3: Removing Contaminated Gloves)

Standard Precautions Federal organizations and infection control CDC: studies pathogens and diseases Standard Precautions Transmission-Based Precautions Guideline for Isolation Precautions Personal protective equipment (PPE) Respiratory hygiene/cough etiquette

OSHA Regulations The Bloodborne Pathogen Standard Methods of compliance to prevent exposure Universal Precautions Engineering and work practice controls Personal protective equipment (PPE) Cleanliness of work areas Hepatitis B vaccine Follow-up after exposure Medical records

OSHA Regulations and Students Students with potential exposure to chemicals and bloodborne pathogens should follow OSHA safety procedures Students do not fall under OSHA guidelines Potential increases when invasive procedures performed

Medical Asepsis Hand washing Cleaning and disinfecting contaminated surfaces Standard and Transmission-Based Precautions [FIGURE 22-27C and FIGURE 22-27E] (See Table 22-7: Recommendations for Hand Hygiene)

Medical Asepsis Disinfection Sterilization Medical assistant sanitizing instrument>> [FIGURE 22-25] (See Procedure 22-4: Sanitization of Instruments)

Bioterrorism Use of biologic weapons (pathogenic microorganisms) to create fear Agents can spread through air, food, water Can be very difficult to detect and difficult to protect against Most dangerous: anthrax, botulism, pneumonic/bubonic plague, smallpox, tularemia (See Table 22-8: Example of Six Agents that Could Be Used in a Bioterrorism Attack)