SOURCES OF INFECTION AND DISINFECTION AND STERILIZATION IN HOME CARE AND

HOSPICE SETTINGS

Module E

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

DiseaseAgent

Host

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

Contact (MRSA)

Direct

Indirect

Droplet (Flu)

Airborne (TB)

Combination (shingles, SARS)

Modes of Transmission

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%

• Micrococcus 100%

• Bacillus subtilis 56.5%

• Enterobacter cloacae 52.2%

• Bacillus sp. 39.1%

• Enterobacter sp. 26.1%

• Klebsiella pneumoniae 23.9%

• E. coli 19.6%

• Bacillus lichenformis 17.4%

• Klebsiella sp. 15.2%

• Pseudomonas aeruginosa 15.2%

Spiers JP, et al. Intern J Environmen Health Research 1995;5:109-122

RISK OF INFECTION

SURFACES RISK OF INFECTIONHigh Food, toilets, pets,

infected people Neonates, elderly, immunocompromised

Moderate Sinks, drains, baths, cleaning utensils

Mild host defense abnormalities (diabetes), ill persons

Low Floors, walls, furniture, linens, clothing

Healthy subjects

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: Noncritical objects will not come in contact with mucous membranes or skin that is not intact.

Object: Can be expected to be contaminated with some microorganisms.

Level germicidal action: Kill vegetative bacteria, fungi and

lipid viruses.Examples: Floors, walls, bedside tables, and

furniture, curtainsMethod: 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

Exposure time > 1 minGermicide Use Concentration

Ethyl or isopropyl alcohol 70-90%Chlorine 100ppm (1:500 dilution)Phenolic UDIodophor UDQuaternary ammonium UDImproved hydrogen peroxide 0.5%, 1.4%____________________________________________________UD=Manufacturer’s recommended use dilution; if prepared on-

site, document correct concentration at some frequency

SEMI-CRITICAL OBJECTS

Classification: Semicritical objects come in contact with mucous membranes or skin that is not intact.

Object: Free of all microorganisms except high numbers of bacterial spores.

Level germicidal action: Kills all microorganisms except high

numbers of bacterial spores.Examples: Respiratory therapy, thermometer,

etc.Method: 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), 20oCGermicide 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 ppmAccelerated 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 low-temperature 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.