Module E SOURCES OF INFECTION AND DISINFECTION AND STERILIZATION IN HOME CARE AND HOSPICE SETTINGS OBJECTIVES • Disease transmission in the home • Environmental Contamination in the home • Role of the environment in infections • Properties of an ideal disinfectant • Use antimicrobials in the home FACTORS FOR DISEASE TRANSMISSION Host Agent Disease Transmission SOURCES OF INFECTION • Human • Patients • Healthcare Personnel • Visitors/household members • Environmental • Common Vehicles • Vectorborne HOST FACTORS • Age • Mobility • Incontinence • Dysphagia • Chronic diseases • Loss of functional status • Medications • Indwelling devices Modes of Transmission Contact (MRSA) Direct Indirect Droplet (Flu) Airborne (TB) Combination (shingles, SARS) PATHOGENS OF CONCERN IN THE HOME • Bacterial (Streptococcus, Salmonella, Staphylococcus) • Viral (Influenza, Rhinovirus, Herpes, Adenovirus) • Mycobacterial (M. tuberculosis) • Fungal (Trichophyton) • Helminths (Enterobius) • Mycoplasma (M. pneumoniae) VIRUS TRANSMISSION IN THE HOME • Virus discharge (Rhinovirus 103, Norovirus 107) • Virus contamination of surface/objects (hands) • Virus survival on inanimate (Hepatitis B, Adeno-50 d, Rhino-hr) • Virus survival on hands • Virus transfer between vehicles (hands) SOURCES OF MICROBIAL CONTAMINATION IN THE HOME • Contamination of wet/moist areas • Sinks • Drains • Toilets • Food preparation areas • Contamination of dry areas • Floors, carpets • Curtains • Furniture BACTERIAL CONTAMINATION • Staphyloccocus sp. 100% • Klebsiella pneumoniae 23.9% • Micrococcus 100% • E. coli 19.6% • Bacillus subtilis 56.5% • Bacillus lichenformis 17.4% • Enterobacter cloacae • Klebsiella sp. 15.2% 52.2% • Pseudomonas aeruginosa 15.2% • Bacillus sp. 39.1% • Enterobacter sp. 26.1% Spiers JP, et al. Intern J Environmen Health Research 1995;5:109-122 RISK OF INFECTION High Moderate Low SURFACES Food, toilets, pets, infected people Sinks, drains, baths, cleaning utensils RISK OF INFECTION Neonates, elderly, immunocompromised Mild host defense abnormalities (diabetes), ill persons Floors, walls, furniture, Healthy subjects linens, clothing MITIGATING THE RISK FREQUENCY OF DISINFECTION • Surfaces should be disinfected routinely (e.g., daily, weekly, etc.), and when visibly soiled • Frequency of disinfection could be based on frequency of use of the surface and the level of soil present on the surface. • Frequency may need to vary based on host susceptibility and environmental site DISINFECTION OF PATIENT CARE EQUIPMENT AND DEVICES A RATIONAL APPROACH TO DISINFECTION AND STERILIZATION EH Spaulding believed how an object will be disinfected depends on the object’s intended use. CRITICAL - objects which enter normally sterile tissue or the vascular system or through which blood flows should be sterile. SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection) that kills all but high numbers of bacterial spores. NONCRITICAL - objects that touch only intact skin require low-level disinfection. NON-CRITICAL OBJECTS Classification: Object: Level germicidal action: Examples: Method: Noncritical objects will not come in contact with mucous membranes or skin that is not intact. Can be expected to be contaminated with some microorganisms. Kill vegetative bacteria, fungi and lipid viruses. Floors, walls, bedside tables, and furniture, curtains Low level disinfection EXAMPLES OF NON-CRITICAL OBJECTS • Blood Pressure cuffs • Crutches • Stethoscopes • Dopplers • Apnea monitor • Urinal, bed pans • Pulse oximeter LOW-LEVEL DISINFECTION OF NON-CRITICIAL OBJECTS Germicide Exposure time > 1 min Use Concentration Ethyl or isopropyl alcohol 70-90% Chlorine 100ppm (1:500 dilution) Phenolic UD Iodophor UD Quaternary ammonium UD Improved hydrogen peroxide 0.5%, 1.4% ____________________________________________________ UD=Manufacturer’s recommended use dilution; if prepared onsite, document correct concentration at some frequency SEMI-CRITICAL OBJECTS Classification: Object: Level germicidal action: Examples: Method: Semicritical objects come in contact with mucous membranes or skin that is not intact. Free of all microorganisms except high numbers of bacterial spores. Kills all microorganisms except high numbers of bacterial spores. Respiratory therapy, thermometer, etc. High-level disinfection OTHER SEMI-CRITICAL ITEMS • Humidifiers • CPAP • Nebulizers • Laryngeal mirror • Feeding tubes/Syringes • Thermometers • Tracheostomy tubes • Wound care items HIGH-LEVEL DISINFECTION OF SEMI-CRITICAL ITEMS Exposure Time > 8m-45m (US), 20oC Germicide Concentration_____ Glutaraldehyde > 2.0% Ortho-phthalaldehyde 0.55% Hydrogen peroxide* 7.5% Hydrogen peroxide and peracetic acid* 1.0%/0.08% Hydrogen peroxide and peracetic acid* 7.5%/0.23% Hypochlorite (free chlorine)* 650-675 ppm Accelerated hydrogen peroxide 2.0% Glut and isopropanol 3.4%/26% Glut and phenol/phenate** 1.21%/1.93%___ *May cause cosmetic and functional damage; **efficacy not verified HIGH-LEVEL DISINFECTION IN HOME CARE • Items thoroughly cleaned before disinfection and sterilization • Modifications to routine disinfection may be made in the home setting • Semicritical item (i.e., tracheostomy tubes)agents/exposure times • 1:50 dilution (1000 ppm) of 5.25%-6.15% bleach/5 minutes • 70% isopropyl alcohol/5 minutes • 3% hydrogen peroxide/30 minutes CRITICAL ITEMS Classification: Critical objects enter normally sterile tissue or vascular system, or through which blood flows. Object: Sterility. Level germicidal action: Kill all microorganisms, including bacterial spores. Examples: Hypodermic syringes, IV medication and tubing, and hemodialysis tubing and solutions Method: Steam, gas, hydrogen peroxide plasma, ozone, VHP or chemical sterilization. STORAGE OF STERILE/CLEAN ITEMS • Items should be stored in a designated, well ventilated area • Items should be protected from dust, moisture, and temperature and humidity extremes • Packaged items should be stored so packaging is not compromised SUMMARY • Disinfection • Rational approach to disinfection/sterilization • Disinfectants used in home health and hospice • Disinfection practices • Sterilization • Sterilization practices used in home health and hospice REFERENCES • Rutala WA, Weber DJ. CJD: Recommendations for • • • • disinfection and sterilization. Clin Inf Dis 2001;32:1348 Rutala WA, Weber DJ. New disinfection and sterilization methods. Emerg Inf Dis 2001;7:348 Rutala WA, Weber DJ. Clinical effectiveness of lowtemperature sterilization technologies. Infect Control Hosp Epidemiol 1998;19:798-804. Rutala WA. APIC guideline for selection and use of disinfectants. Am J Infect Control 1996;24:313 Rutala WA and DJ Weber. CDC Guideline for disinfection and sterilization in healthcare facilities, 2008.