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.