Lecture 1 - Asepsis and Infection Control

‭Lecture 1: Asepsis and Infection Control‬ ‭Terms‬ ‭●‬ ‭Nosocomial infection: All hospital-related infections‬ ‭●‬ ‭Iatrogenic infection: Infection obtained during medical procedure/treatment‬ ‭●‬ ‭Medical asepsis: No pathogenic, disease-causing organisms (may be spores)‬ ‭●‬ ‭Surgical asepsis: No microorganisms whatsoever‬ ‭●‬ ‭Disinfection: Procedure to make medical asepsis‬ ‭●‬ ‭Sterilization: Procedure to make surgical asepsis‬ ‭Components of the Infection Cycle‬ ‭●‬ ‭Infectious agent: Pathogen that causes‬ ‭disease‬ ‭●‬ ‭Reservoir: Where an infectious agent‬ ‭lives; may be a body‬ ‭●‬ ‭Portal of exit: “Door” out of reservoir‬ ‭●‬ ‭Means of transmission:‬ ‭“Transportation” to another‬ ‭reservoir/host‬ ‭●‬ ‭Portal of entry: “Door” to another‬ ‭reservoir‬ ‭●‬ ‭Susceptible host: New place of‬ ‭infectious residence; person, animal,‬ ‭etc. (cycle continues)‬ ‭ uestion:‬‭Which of the following is the most‬ Q ‭significant and commonly found infection-causing agent in healthcare institutions?‬ ‭a.‬ ‭Bacteria‬ ‭i.‬ ‭Most nosocomial infections caused by bacteria‬ ‭b.‬ ‭Fungi‬ ‭c.‬ ‭Viruses‬ ‭d.‬ ‭Mold‬ ‭Infectious Agents‬ ‭●‬ ‭Bacteria: Most prevalent in hospital settings‬ ‭○‬ ‭Spherical (cocci), rod-shaped (bacilli), corkscrew-shaped (spirochetes)‬ ‭○‬ ‭Gram-positive or gram-negative; based on reaction to gram stain‬ ‭○‬ ‭Aerobic or anaerobic; based on need for oxygen‬ ‭●‬ ‭Virus: Smallest of all microorganisms, causes infections including the common cold‬ ‭○‬ ‭Do not respond to antibiotics‬ ‭●‬ ‭Fungi (mold and yeasts): Plant-like organisms; can cause infections and are present in the‬ ‭air, soil, and water‬ ‭○‬ ‭Do not respond to antibiotics‬ ‭Factors Affecting an Organism’s Potential to Produce Disease‬ ‭●‬ ‭Number of microorganisms‬ ‭○‬ ‭Larger number → more potential for infection‬ ‭●‬ ‭Virulence of microorganisms‬ ‭○‬ ‭Strength of microorganism; ability to cause disease‬ ‭●‬ ‭Competence of person’s immune system‬ ‭○‬ ‭Immunity is compromised → more potential for infection‬ ‭●‬ ‭Length and intimacy of contact between person and microorganism‬ ‭○‬ ‭More time spent closely with a reservoir‬ ‭Possible Reservoirs for Microorganisms‬ ‭●‬ ‭Carrier: Humans‬ ‭●‬ ‭Vectors: Animals‬ ‭●‬ ‭Vehicles: Soil, food milk, water, inanimate objects‬ ‭○‬ ‭Ex. influenza‬ ‭●‬ ‭Fomite: Inanimate objects‬ ‭ uestion:‬‭Which one of the following infectious agents‬‭or diseases may be spread by touching a‬ Q ‭contaminated inanimate article?‬ ‭a.‬ ‭Rabies‬ ‭i.‬ ‭By animal bite‬ ‭b.‬ ‭Giardia‬ ‭i.‬ ‭Parasite in GI tract‬ ‭c.‬ ‭E. coli‬ ‭i.‬ ‭Bacteria in GI tract‬ ‭d.‬ ‭Influenza‬ ‭i.‬ ‭Common to use antiviral cleaning products‬ ‭Common Portals of Exit‬ ‭●‬ ‭Respiratory‬ ‭○‬ ‭Ex. nose‬ ‭●‬ ‭Gastrointestinal tract‬ ‭○‬ ‭Ex. mouth, anus‬ ‭●‬ ‭Genitourinary tract‬ ‭○‬ ‭Ex. urethra‬ ‭●‬ ‭Breaks in skin‬ ‭○‬ ‭Any open wound‬ ‭●‬ ‭Blood and tissue (can carry respiratory secretions)‬ ‭Means of Transmission‬ ‭●‬ ‭Contact‬ ‭○‬ ‭Direct contact‬ ‭■‬ ‭Carrier: Close proximity with susceptible host‬ ‭■‬ ‭ex. touching, kissing, and sexual intercourse‬ ‭○‬ ‭Indirect contact‬ ‭■‬ ‭Vectors: Nonhuman organisms‬ ‭■‬ ‭Fomites: Inanimate objects‬ ‭●‬ ‭Airborne: Less than 5‬µ‭m‬ ‭○‬ ‭Transmitted by air; ability to travel longer distances‬ ‭●‬ ‭Droplet: Greater than 5‬µ‭m‬ ‭○‬ ‭Secretions, cannot travel long distances‬ ‭○‬ ‭Ex. COVID (6 ft)‬ ‭Body’s Defense Against Infection‬ ‭●‬ ‭Normal flora‬ ‭○‬ ‭Colonization resistance: Capacity for some microbes to prevent others from‬ ‭colonizing; occupied space‬ ‭●‬ ‭Inflammatory response‬ ‭●‬ ‭Immune response‬ ‭Factors Affecting Host Susceptibility‬ ‭●‬ ‭Intact skin and mucous membranes‬ ‭●‬ ‭Normal pH levels‬ ‭○‬ ‭pH of blood: 7.4‬ ‭○‬ ‭pH of saliva: 6.5 - 6.7‬ ‭●‬ ‭White blood cells‬ ‭○‬ ‭Elevated WBC count: 4,500 - 10,000 per mcL‬ ‭●‬ ‭Age, sex, race, hereditary factors‬ ‭●‬ ‭Immunization; natural or acquired‬ ‭●‬ ‭Fatigue, climate, nutritional, and general health status‬ ‭●‬ ‭Stress‬ ‭●‬ ‭Use of invasive or indwelling medical devices‬ ‭Question:‬‭In which of the following stages of infection‬‭is the patient most contagious?‬ ‭a.‬ ‭Incubation period‬ ‭b.‬ ‭Prodromal stage‬ ‭c.‬ ‭Full stage of illness‬ ‭d.‬ ‭Convalescent period‬ ‭Stages of Infection‬ ‭●‬ ‭Incubation period: Organisms growing and multiplying‬ ‭●‬ ‭Prodromal stage: Person is most infectious; vague and nonspecific signs of disease‬ ‭○‬ ‭Malaise: General feeling of discomfort, illness, or uneasiness whose exact cause‬ ‭is difficult to identify‬ ‭●‬ ‭Full stage of illness: Presence of specific signs and symptoms of disease‬ ‭○‬ ‭Still contagious‬ ‭●‬ ‭Convalescent period: Recovery from the infection‬ ‭Laboratory Data Indicating Infection‬ ‭●‬ ‭Elevated WBC count: 4,500 to 10,000/mcL‬ ‭●‬ ‭Increase in specific types of WBCs‬ ‭○‬ ‭Neutrophil, eosinophil, monocyte, lymphocyte‬ ‭●‬ ‭Elevated erythrocyte sedimentation rate (ESR)‬ ‭○‬ ‭0 to 15 mm/hr for males‬ ‭○‬ ‭0 to 22 mm/hr for females‬ ‭●‬ ‭Presence of pathogen in urine, blood, sputum, or draining cultures‬ ‭Healthcare-Associated Infections‬ ‭●‬ ‭Nosocomial infection: Originating in a hospital‬ ‭●‬ ‭Iatrogenic infection: From a treatment or diagnostic procedure‬ ‭●‬ ‭Not all nosocomial infections are iatrogenic‬ ‭Factors Predisposing Patients to Nosocomial Infections‬ ‭●‬ ‭Use of invasive medical devices‬ ‭●‬ ‭Urinary catheter or venous access catheter‬ ‭Antibiotic-Resistant Organisms Developed in Hospitals‬ ‭●‬ ‭Clostridium difficile (C. diff) - Colitis‬ ‭●‬ ‭Methicillin-resistant staphylococcus aureus (MRSA)‬ ‭●‬ ‭Vancomycin-intermediate staphylococcus aureus (VISA)‬ ‭●‬ ‭Vancomycin-resistant staphylococcus aureus (VRSA)‬ ‭●‬ ‭Vancomycin-resistant enterococci (VRE)‬ ‭ uestion:‬‭Soaps and detergents (non-antimicrobial‬‭agents) are considered adequate for routine‬ Q ‭mechanical cleansing of the hands and removal of most transient microorganisms.‬ ‭a.‬ ‭True‬ ‭b.‬ ‭False‬ ‭Bacterial Flora‬ ‭●‬ ‭Transient: Attached loosely on skin; removed with relative ease‬ ‭○‬ ‭Medical asepsis requires removal of transient bacteria‬ ‭●‬ ‭Resident: Found in skin creases; requires friction with brush to remove‬ ‭○‬ ‭Surgical asepsis requires removal of transient bacteria‬ ‭Performing Hand Hygiene‬ ‭●‬ ‭Most effective way to help prevent the spread of infectious agents‬ ‭●‬ ‭Hand hygiene according to the CDC (2002):‬ ‭○‬ ‭Handwashing with plain soap and water‬ ‭○‬ ‭Use of antiseptic handrubs, including waterless alcohol-based products‬ ‭○‬ ‭Surgical hand antisepsis‬ ‭ uestion:‬‭After inserting nasogastric tubes, a nurse‬‭found that the gloves remained clean.‬ Q ‭Because her hands were clean when she put her gloves on, and the gloves were not dirty, it is not‬ ‭necessary to perform hand hygiene on nonsoiled hands after gloves are removed.‬ ‭a.‬ ‭True‬ ‭b.‬ ‭False‬ ‭Infection Control Technique‬ ‭●‬ ‭Includes all activities to prevent or break the chain of infection‬ ‭●‬ ‭Two categories:‬ ‭○‬ ‭Medical asepsis‬ ‭■‬ ‭Clean technique‬ ‭■‬ ‭Disinfection‬ ‭○‬ ‭Surgical asepsis‬ ‭■‬ ‭Sterile/aseptic technique‬ ‭■‬ ‭Sterilization‬ ‭Clean Technique‬ ‭●‬ ‭Routine handwashing‬ ‭●‬ ‭Using non-sterile gloves when touching intact skin, intact mucous membranes, or‬ ‭dirty/contaminated items‬ ‭●‬ ‭Appropriate for:‬ ‭○‬ ‭Taking blood pressures‬ ‭○‬ ‭Examining patients‬ ‭○‬ ‭Feeding patients‬ ‭Aseptic Technique‬ ‭●‬ ‭Sterile gloves‬ ‭‬ ● ‭●‬ ‭●‬ ‭●‬ ‭ sed for invasive procedures‬ U ‭Antiseptic (e.g. alcohol) on patient’s skin‬ ‭Used in clean and dedicated area‬ ‭Appropriate for:‬ ‭○‬ ‭Placing an IV catheter‬ ‭○‬ ‭Placing a urinary catheter‬ ‭Isolation Precautions‬ ‭●‬ ‭Current CDC guidelines in healthcare settings (2007):‬ ‭○‬ ‭Standard precautions (tier 1)‬ ‭○‬ ‭Transmission-based precautions (tier 2)‬ ‭Standard Precautions (Tier 1)‬ ‭●‬ ‭Used in care of all hospitalized patients‬ ‭●‬ ‭Hand hygiene‬ ‭●‬ ‭Wearing clean, nonsterile gloves when touching blood, body fluids, secretions, and‬ ‭non-intact skin‬ ‭●‬ ‭Wearing personal protective equipment (PPE)‬ ‭●‬ ‭Respiratory hygiene/cough etiquette‬ ‭●‬ ‭Use safe injection practices‬ ‭○‬ ‭Ex. single dose vials‬ ‭●‬ ‭Avoiding recapping used needles‬ ‭Personal Protective Equipment‬ ‭●‬ ‭Gloves‬ ‭●‬ ‭Gowns‬ ‭●‬ ‭Masks (regular and N95) respiratory‬ ‭○‬ ‭N95 respiratory filters 95% of air‬ ‭●‬ ‭Protective eye gear‬ ‭●‬ ‭Remove gloves first; perform hand hygiene after removing PPE‬ ‭Transmission-Based Precautions (Tier 2)‬ ‭●‬ ‭Used in addition to standard precautions for patients with suspected infection‬ ‭●‬ ‭Contact:‬ ‭○‬ ‭Private room, PPE‬ ‭○‬ ‭Infections by multidrug-resistant organism‬ ‭●‬ ‭Droplet:‬ ‭○‬ ‭Private room, PPE‬ ‭○‬ ‭Ex. Mumps, rubella, diphtheria, adenovirus infection‬ ‭●‬ ‭Airborne:‬ ‭○‬ ‭Private room, PPE, negative air pressure, N95‬ ‭■‬ ‭Negative air pressure prevents infectious agents from exiting private room‬ ‭○‬ ‭Ex. Tuberculosis, measles, varicella (chickenpox)‬ ‭ uestion:‬‭Standard precautions should be used when‬‭caring for a noninfectious, postoperative‬ Q ‭patient who is vomiting blood.‬ ‭a.‬ ‭True‬ ‭b.‬ ‭False‬