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MMWR,
August 21, 1987 |
Supersedes Guideline for Hospital Environmental
Control
Published in 1981
Revised by Julia S. Garner, R.N, M.N.
and
Martin S. Favero, Ph.D.
Hospital Infections Program
Center for Infectious Diseases
Centers for Disease Control
Public Health Service
U.S. Department of Health
and Human Services
Atlanta, Georgia
Contributions from the Hospital
Infections Program,
Center for Infectious Diseases, Centers for Disease Control
James M. Hughes, M.D., Director
Roger L. Anderson, Ph.D.
Lee A. Bland, M.A., M.P.H.
Walter W. Bond, M.S.
Barry J. Davis, M.S.
T. Grace Emori, R.N., M.S.
Teresa C. Horan, M.P.H.
William J. Martone, M.D.
Donald C. Mackel, M.S., M.P.H.
U.S. DEPARTMENT OF HEALTH &
HUMAN SERVICES
Public Health Service
Measures in Category I are strongly supported
by well-designed and controlled clinical studies that show their
effectiveness in reducing the risk of nosocomial infections, or are viewed as
effective by a majority of expert reviewers. Measures in this category are
viewed as applicable for most hospitals--regardless of size, patient
population, or endemic nosocomial infection rates.
Measures in Category II are supported by
highly suggestive clinical studies in general hospitals or by definitive
studies in specialty hospitals that might not be representative of general
hospitals. Measures that have not been adequately studied but have a logical
or strong theoretical rationale indicating probable effectiveness are
included in this category. Category II recommendations are viewed as
practical to implement in most hospitals.
Measures in Category III have been proposed
by some investigators, authorities, or organizations, but, to date, lack
supporting data, a strong theoretical rationale, or an indication that the
benefits expected from them are cost effective. Thus, they are considered
important issues to be studied. They might be considered by some hospitals
for implementation, especially if the hospitals have specific nosocomial
infection problems, but they are not generally recommended for widespread
adoption. |
Preface
Major Changes in the Guideline
Section 1: Handwashing
Section 2: Cleaning, Disinfecting, and Sterilizing Patient-care Equipment
Section 3: Microbiologic Sampling
Section 4: Infective waste
Section 5: Housekeeping
Section 6: Laundry
In 1980, the Centers for Disease
Control (CDC) began developing a series of guidelines entitled Guidelines
for the Prevention and Control of Nosocomial Infections. The purpose of the
Guidelines was twofold: 1) to disseminate advice on how to prevent or
control specific nosocomial infection problems and 2) to cover the questions
most frequently asked of the Hospital Infections Program staff on different
aspects of the hospital's inanimate environment (1). One of the first Guidelines
to be published was the Guideline for Hospital Environmental Control. It
was written by Bryan P. Simmons, M.D. in consultation with Thomas M. Hooton,
M.D., and George F. Mallison, M.P.H., and in collaboration with a working group
consisting of Edward J. Bertz; Mary K. Bruch; Sue Crow, R.N., M.S.N.; William
E. Scheckler, M.D.; Harold Laufman, M.D., Ph.D.; Janet K. Schultz, R.N.,
M.S.N.; Earle H. Spaulding, Ph.D.; and Richard P. Wenzel, M.D.
In February 1981, CDC mailed to each
U. S. acute-care hospital Part I of the Guideline for Hospital Environmental
Control, which contained sections entitled "Antiseptics, Handwashing,
and Handwashing Facilities," "Cleaning, Disinfection, and
Sterilization of Hospital Equipment," and "Microbiologic Surveillance
of the Environment and of Personnel in the Hospital." In October 1981,
Part II of the Guideline for Hospital Environmental Control, which
contained the sections "Housekeeping Services and Waste Disposal,"
"Laundry Services," "Intensive Care Units," and "Pharmacy,"
was published. In July 1982, the section on "Cleaning, Disinfection, and
Sterilization of Hospital Equipment" was revised. In November 1982, the
two parts of the Guideline were combined into a single document entitled
Guideline for Hospital Environmental Control, and copies were mailed to
all U.S. acute-care hospitals.
In October 1983, CDC issued a
statement entitled "Clarification of Guideline Recommendations on Generic
Antiseptic, Disinfectant, and Other Products," which was mailed to all
U.S. acute-care hospitals. The statement emphasized that CDC recommendations
are not intended to endorse any particular commercial product or to exclude the
use of other commercial products containing generic ingredients not mentioned
in the Guideline for Hospital Environmental Control.
In November 1983, a follow-up
statement requested that users delete the portion of the Guideline for
Hospital Environmental Control that recommended specific generic
antimicrobial ingredients for use in health care personnel handwashes and
announced that the entire Guideline would be comprehensively revised. In
June 1984, a draft of the proposed revision was mailed to 150 scientists and
infection control professionals for review and comment. Rather than using an
expert working group to finalize the content of this Guideline, we used
the written comments and suggestions which we received from the reviewers to
determine the final content of the Guideline and the ranking of the
recommendations.
This Guideline incorporates
the above revisions, as well as newly available information; the title has been
changed to Guideline for Handwashing and Hospital Environmental Control. It
replaces all previous handwashing and environmental control statements issued
or published by the Hospital Infections Program, Center for Infectious
Diseases, CDC.
MAJOR CHANGES IN THE GUIDELINE
Since this Guideline contains many important changes from the
original Guideline for Hospital Environmental Control, it is important
that users read the entire Guideline carefully. The major changes in the
titles and content of sections are listed below:
1. The section
"Handwashing," which replaces the old section entitled
"Antiseptics, Handwashing, and Handwashing Facilities," contains
updated recommendations for handwashing with plain soaps or detergents and with
antimicrobial-containing products. Rather than recommending specific generic
ingredients for handwashing with antimicrobial containing products, the Guideline
indicates that hospitals may choose from appropriate products in categories
defined by the U.S. Food and Drug Administration (FDA), since preparations used
to inhibit or kill microorganisms on skin are categorized by an FDA advisory
review panel for nonprescription (over-the-counter [OTC]) antimicrobial drug products
(2). Manufacturers of antimicrobial-containing products voluntarily submit data
to the review panel, which categorizes the products according to their intended
use, i.e., antimicrobial soaps, health-care personnel handwashes, patient
preoperative skin preparations, skin antiseptics, skin wound cleansers, skin
wound protectants, and surgical hand scrubs. Generic antimicrobials for each
use category are further divided: Category I (safe and efficacious); Category
II (not safe and/or efficacious); and Category III (insufficient data to
categorize). Consequently, chemical germicides formulated as antiseptics are
categorized by the FDA into groupings by use and efficacy, but they are not
regulated or registered in the same fashion as chemical germicides are by the
U.S. Environmental Protection Agency (EPA).
Persons responsible for selecting
commercially marketed health-care-personnel handwashes can obtain information
about categorization of products from the Center for Drugs and Biologics,
Division of OTC Drug Evaluation, FDA, 5600 Fishers Lane, Rockville, MD 20857.
In addition, information published in the scientific literature, presented at
scientific meetings, documented by manufacturers, and obtained from other
sources deemed important may be considered.
2. The section "Cleaning,
Disinfecting, and Sterilizing of Patient-Care Equipment" has been
rewritten. Medical devices, equipment, and materials are divided into three
categories (critical, semicritical, and noncritical) based on the risk of infection
involved in their use. Revised recommendations for sterilizing and disinfecting
items in these categories are included in this section. Rather than listing
specific chemical germicides, the Guideline indicates that hospitals may
choose from sterilant and disinfectant formulations registered with the EPA,
since chemical germicides are regulated and registered by the EPA (3).
Manufacturers of chemical germicides formulated as general disinfectants,
hospital disinfectants, and disinfectants used in other environments, such as
the food industry, are required by EPA to test their formulations using
specific protocols for microbicidal efficiency, stability, and toxicity to
humans. In past years, the EPA has reserved the right to test and verify
formulations of chemical germicides for their specified efficacy; however, in
practice only those formulations to be registered as sterilants or sporicides
were actually tested. In 1982, the EPA discontinued this testing. Currently,
formulations of chemical germicides are registered by the EPA based on data
obtained from the manufacturer.
Persons responsible for selecting
chemical germicides should keep in mind that the field is highly competitive,
and exaggerated claims are often made about the germicidal efficiency of specific
formulations. When questions regarding specific claims or use arise, the
Disinfectants Branch, Registration Division, Office of Pesticides, EPA, 401 M
Street, S.W., Washington, D.C. 20460, can be consulted. As with handwashing
products, information in the scientific literature, presented at scientific
meetings, documented by manufacturers, and obtained from other sources deemed
important may be considered.
The recommendation against
reprocessing and reusing single-use items has been removed. Since there is lack
of evidence indicating increased risk of nosocomial infections associated with
the reuse of all single-use items, a categorical recommendation against all
types of reuse was not considered justifiable. Rather than recommending for
or against reprocessing and reusing single-use items, the Guideline
indicates that items or devices that cannot be cleaned and sterilized or
disinfected without altering their physical integrity and function should not
be reprocessed. In addition, reprocessing procedures that result in residual
toxicity or compromise the overall safety or effectiveness of the items or
devices should be avoided. Arguments for and against reprocessing and reusing
single-use items have been summarized in a report from the International Conference
on the Reuse of Disposable Medical Devices in the 1980's (4).
3. The section "Microbiologic
Sampling" replaces the old section entitled "Microbiologic
Surveillance of the Environment and of Personnel in the Hospital." The
recommendation for microbiologic sampling of infant formulas prepared in the
hospital has been removed, since there is no epidemiologic evidence to show
that such sampling reduces the infection rate in hospitals. Information and
recommendations for microbiologic surveillance of personnel have been deleted,
since this topic is addressed in the Guideline for Infection Control in
Hospital Personnel (5).
4. A new section, "Infective
Waste," has been added. It contains information about identifying
infective waste and recommendations for its handling and disposal .
5. The section
"Housekeeping" replaces the old section "Housekeeping Services
and Waste Disposal." Recommendations against use of carpets in patient
care areas have been removed, since there is no epidemiologic evidence to show
that carpets influence the nosocomial infection rate in hospitals (6), whether
to use carpets, therefore, is not considered an infection control issue.
6. The section "Laundry"
contains a discussion of and recommendations for both hot-water and reduced
temperature washing.
7. The section "Intensive Care
Units" has been deleted, since it primarily dealt with information and
recommendations that are covered elsewhere in this Guideline and in the
Guideline for Isolation Precautions in Hospitals (7).
8. The section "Pharmacy"
has been deleted from this Guideline, since it primarily dealt with
recommendations for admixture of parenteral fluids that are contained in the Guideline
for Prevention of Intravascular Infections.
The recommendations presented in this
Guideline were chosen primarily for their acknowledged importance to
infection control, but other factors, such as the feasibility of implementing
them and their potential costs to hospitals, were also considered. Many
recommendations are intended to reduce or eliminate expensive practices that
are not likely to prevent infections. Some of the recommendations are based on
well-documented epidemiologic studies; others are based on a reasonable
theoretical rationale, since for many of these practices little or no
scientifically valid evidence is available to permit evaluation of their effect
on the incidence of infection. Because new studies are constantly revealing
pertinent information in this field, users of this Guideline should keep
informed of other sources. The recommendations presented in this Guideline may
be modified as necessary for an individual hospital and are not meant to
restrict a hospital from developing recommendations that may be more
appropriate to its own unique needs. The recommendations have no force of law
or regulation.
REFERENCES
1. Haley RW. CDC guidelines on infection control. Infect Control
1981;2:1-2.
2. Zanowiak P, Jacobs MR. Topical anti-infective products. In: Handbook of
non-prescription drugs, 7th ed. Washington, D.C. American Pharmaceutical
Association, 1982:525-42.
3. Block SS. Federal regulation of disinfectants in the United States. In:
Disinfection, sterilization and preservation, Block SS, (ed), 3rd ed.
Philadelphia: Lea and Febiger, 1983.
4. Proceedings of International Conference on the Reuse of Disposable Medical
Devices in the 1980's. 1984 Mar 29-30,. Washington, D.C: Institute for Health
Policy Analysis, Georgetown University Medical Center.
5. Williams WW. Guideline for infection control in hospital personnel. Infect
Control 1983;4:326-49.
6. Anderson RL, Mackel DC, Stoler BS, Mallison GF. Carpeting in hospitals: An
epidemiological evaluation. J Clin Microbiol 1982;15:408-15.
7. Garner JS, Simmons BP. Guideline for isolation precautions in hospitals. Infect
Control 1983;4:245-325.
Handwashing is the single most
important procedure for preventing nosocomial infections. Handwashing is
defined as a vigorous, brief rubbing together of all surfaces of lathered
hands, followed by rinsing under a stream of water. Although various products
are available, handwashing can be classified simply by whether plain soap or
detergents or antimicrobial-containing products are used (1). Handwashing with
plain soaps or detergents (in bar, granule, leaflet, or liquid form) suspends
microorganisms and allows them to be rinsed off; this process is often referred
to as mechanical removal of microorganisms. In addition, handwashing with
antimicrobial containing products kills or inhibits the growth of
microorganisms; this process is often referred to as chemical removal of
microorganisms. Routine handwashing is discussed in this Guideline; the
surgical hand scrub is discussed in the Guideline for Prevention of Surgical
Wound Infections.
EPIDEMIOLOGY
The microbial flora of the skin
consists of resident and transient microorganisms; the resident microorganisms
survive and multiply on the skin and can be repeatedly cultured, while the
transient microbial flora represent recent contaminants that can survive only a
limited period of time. Most resident microorganisms are found in superficial
skin layers, but about 10%-20% can inhabit deep epidermal layers (2,3).
Handwashing with plain soaps and detergents is effective in removing many
transient microbial flora (4-6). Resident microorganisms in the deep layers may
not be removed by handwashing with plain soaps and detergents, but usually can
be killed or inhibited by handwashing with products that contain antimicrobial
ingredients.
Many resident skin microorganisms
are not highly virulent and are not implicated in infections other than skin
infections. However, some of these microorganisms can cause infections in
patients when surgery or other invasive procedures allow them to enter deep
tissues or when a patient is severely immunocompromised or has an implanted
device, such as a heart valve. In contrast, the transient microorganisms often
found on the hands of hospital personnel can be pathogens acquired from
colonized or infected patients and may cause nosocomial infections. Several
recent studies have shown that transient and resident hand carriage of aerobic
gram-negative microorganisms by hospital personnel may be more frequent than
previously thought (7-10). More study on the bacteriology of hands is needed to
fully understand the factors that contribute to persistent hand carriage of
such microorganisms (11).
CONTROL MEASURES
The absolute indications for and the
ideal frequency of handwashing are generally not known because of the lack of
well-controlled studies. Listing all circumstances that may require handwashing
would be a lengthy and arbitrary task. The indications for handwashing probably
depend on the type, intensity, duration, and sequence of activity. Generally,
superficial contact with a source not suspected of being contaminated, such as
touching an object not visibly soiled or taking a blood pressure, does not
require handwashing. In contrast, prolonged and intense contact with any
patient should probably be followed by handwashing. In addition, handwashing is
indicated before performing invasive procedures, before taking care of
particularly susceptible patients, such as those who are severely
immunocompromised or newborn infants, and before and after touching
wounds. Moreover, handwashing is indicated, even when gloves are used after
situations during which microbial contamination of the hands is likely to
occur, especially those involving contact with mucous membranes, blood and body
fluids, and secretions or excretions, and after touching inanimate
sources that are likely to be contaminated, such as urine-measuring devices. In
addition, handwashing is an important component of the personal hygiene of all
hospital personnel, and handwashing should be encouraged when personnel are
in doubt about the necessity for doing so.
The circumstances that require
handwashing are frequently found in high-risk units, because patients in these
units are often infected or colonized with virulent or multiply-resistant
microorganisms, and are highly susceptible to infection because of wounds,
invasive procedures, or diminished immune function. Handwashing in these units
is indicated between direct contact with different patients and often is
indicated more than once in the care of one patient, for example, after
touching excretions or secretions, before going on to another care activity for
the same patient.
The recommended handwashing
technique depends on the purpose of the handwashing. The ideal duration of
handwashing is not known, but washing times of 15 seconds (6) or less (5) have
been reported as effective in removing most transient contaminants from the
skin. Therefore, for most activities, a vigorous, brief (at least 10 seconds)
rubbing together of all surfaces of lathered hands followed by rinsing under a
stream of water is recommended. If hands are visibly soiled, more time may be
required for handwashing.
The absolute indications for
handwashing with plain soaps and detergents versus handwashing with
antimicrobial-containing products are not known because of the lack of
well-controlled studies comparing infection rates when such products are used.
For most routine activities, handwashing with plain soap appears to be
sufficient, since soap will allow most transient microorganisms to be washed
off (4-6).
Handwashing products for use in
hospitals are available in several forms. It is important, however, that the
product selected for use be acceptable to the personnel who will use it (6).
When plain soap is selected for handwashing, the bar, liquid, granule, or
soap-impregnated tissue form may be used. It is preferable that bar soaps be
placed on racks that allow water to drain. Since liquid-soap containers can
become contaminated and might serve as reservoirs of microorganisms, reusable
liquid containers need to be cleaned when empty and refilled with fresh soap.
Completely disposable containers obviate the need to empty and clean dispensers
but may be more expensive. Most antimicrobial-containing handwashing products
are available as liquids. Antimicrobial-containing foams and rinses are also
available for use in areas without easy access to sinks.
In addition to handwashing,
personnel may often wear gloves as an extra margin of safety. As with
handwashing, the absolute indications for wearing gloves are not known. There
is general agreement that wearing sterile gloves is indicated when certain
invasive procedures are performed or when open wounds are touched. Nonsterile
gloves can be worn when hands are likely to become contaminated with potentially
infective material such as blood, body fluids, or secretions, since it is often
not known which patients' blood, body fluids, or secretions contain hepatitis B
virus or other pathogens. Further, gloves can be worn to prevent gross
microbial contamination of hands, such as when objects soiled with feces are
handled. When gloves are worn, handwashing is also recommended because gloves
may become perforated during use and because bacteria can multiply rapidly on
gloved hands.
The convenient placement of sinks,
handwashing products, and paper towels is often suggested as a means of
encouraging frequent and appropriate handwashing. Sinks with faucets that can
be turned off by means other than the hands (e.g., foot pedals) and sinks that
minimize splash can help personnel avoid immediate recontamination of washed
hands.
Although handwashing is considered
the most important single procedure for preventing nosocomial infections, two
reports showed poor compliance with handwashing protocols by personnel in medical
intensive care units, especially by physicians (12) and personnel taking care
of patients on isolation precautions (13). Failure to wash hands is a complex
problem that may be caused by lack of motivation or lack of knowledge about the
importance of handwashing. It may also be caused by obstacles such as
understaffing, inconveniently located sinks, absence of paper towels, an
unacceptable handwashing product, or the presence of dermatitis caused by
previous handwashing. More study is needed to identify which of these factors,
alone or in combination, contribute significantly to the problem of poor
compliance with handwashing recommendations.
RECOMMENDATIONS
1. Handwashing Indications
a. In the absence of a true emergency,
personnel should always wash their hands.
1) before performing invasive
procedures; Category I
2) before taking care of particularly
susceptible patients, such as those who are severely immunocompromised and
newborns;
Category I
3) before and after touching
wounds, whether surgical, traumatic, or associated with an invasive device;
Category I
4) after situations during which
microbial contamination of hands is likely to occur, especially those involving
contact with mucous membranes, blood or body fluids, secretions, or excretions;
Category I
5) after touching inanimate sources that
are likely to be contaminated with virulent or epidemiologically important
microorganisms; these sources include urine-measuring devices or secretion
collection apparatuses; Category I
6) after taking care of an infected
patient or one who is likely to be colonized with microorganisms of special
clinical or epidemiologic significance, for example, multiply-resistant
bacteria; Category I
7) between contacts with different
patients in high risk units. Category I
b. Most routine, brief patient-care activities
involving direct patient contact other than that discussed in 1.a. above, e.g.,
taking a blood pressure, do not require handwashing. Category II
c. Most routine hospital activities involving
indirect patient contact, e.g., handing a patient medications, food, or other
objects, do not require handwashing. Category I
2. Handwashing Technique
For routine handwashing, a vigorous rubbing
together of all surfaces of lathered hands for at least 10 seconds, followed by
thorough rinsing under a stream of water, is recommended. Category I
3. Handwashing with Plain Soap
a. Plain soap should be used for handwashing
unless otherwise indicated. Category II
b. If bar soap is used, it should be kept on
racks that allow drainage of water. Category II
c. If liquid soap is used, the dispenser should
be replaced or cleaned and filled with fresh product when empty; liquids should
not be added to a partially full dispenser. Category II
4. Handwashing with Antimicrobial-Containing
Products (Health-Care Personnel Handwashes)
a. Antimicrobial handwashing
products should be used for handwashing before personnel care for newborns and
when otherwise indicated during their care, between patients in high-risk
units, and before personnel take care of severely immunocompromised patients.
Category III (Hospitals may choose from products in the product category
defined by the FDA as health-care personnel handwashes. Persons responsible for
selecting commercially marketed antimicrobial health-care personnel handwashes
can obtain information about categorization of products from the Center for
Drugs and Biologics, Division of OTC Drug Evaluation, FDA 5600 Fishers Lane,
Rockville, MD 20857. In addition, information published in the scientific
literature, presented at scientific meetings, documented by manufacturers, and
obtained from other sources deemed important may be considered.)
b. Antimicrobial-containing products
that do not require water for use, such as foams or rinses, can be used in
areas where no sinks are available. Category III
5. Handwashing Facilities
a. Handwashing facilities should be
conveniently located throughout the hospital. Category I
b. A sink should be located in or just outside
every patient room. More than one sink per room may be necessary if a large
room is used for several patients. Category II
c. Handwashing facilities should be located in
or adjacent to rooms where diagnostic or invasive procedures that require
handwashing are performed (e.g., cardiac catheterization, bronchoscopy,
sigmoidoscopy, etc.). Category I
REFERENCES
1. The tentative final monograph for OTC topical antimicrobial products.
Federal Register 1978 Jan 6;43 FR 1210:1211-49 T.
2. Price PB. New studies in surgical bacteriology and surgical technique. JAMA 1938;111:1993-6.
3. Ulrich JA. Techniques
of skin sampling for microbial contaminants. Hosp Topics 1965;43:121-3.
4. Lowbury EJL. Lilly HA, Bull JP. Disinfection of hands removal of transient
organisms. Br Med J 1964;2:230-3.
5. Sprunt K, Redman W, Leidy G. Antibacterial effectiveness of routine
handwashing. Pediatrics 1973;52:264-71.
6. Ojajarvi J. The importance of soap selection for routine hygiene in
hospital. J Hyg (Camb) 1981;86:275-83.
7. Knittle MA, Eitzman DV, Bear H. Role of hand contamination of personnel in
the epidemiology of gram-negative nosocomial infections. J Pediatr
1975;86:433-7.
8. Larson EL. Persistent
carriage of gram-negative bacteria on hands. Am J Infect Control 1981;9:112-9.
9. Adams BG, Marrie TJ. Hand carriage of aerobic gram-negative rods may not be
transient. J Hyg (Camb) 1982; 89:33-46.
10. Adams BG, Marrie TJ. Hand carriage of aerobic gram-negative rods by health
care personnel. J Hyg (Camb) 1982;89:23-31.
11. Larson E. Current handwashing issues. Infect Control 1984;5:15-7.
12. Albert RK, Condie F. Handwashing patterns in medical intensive-care units.
N Engl J Med 1981;304:1465-6
13. Larson E. Compliance with isolation techniques. Am J Infect Control
1983;11:221-5.
Cleaning, the physical removal of
organic material or soil from objects, is usually done by using water with or
without detergents. Generally, cleaning is designed to remove rather than to
kill microorganisms. Sterilization, on the other hand, is the destruction of
all forms of microbial life; it is carried out in the hospital with steam under
pressure, liquid or gaseous chemicals, or dry heat. Disinfection, defined as
the intermediate measures between physical cleaning and sterilization, is
carried out with pasteurization or chemical germicides.
Chemical germicides can be
classified by several systems. We have used the system originally proposed by
Spaulding (1) in which three levels of disinfection are defined: high,
intermediate, and low (Table 1). In contrast, EPA uses a system that classifies
chemical germicides as sporicides, general disinfectants, hospital
disinfectants, sanitizers, and others. Formulations registered by the EPA as sporicides
are considered sterilants if the contact time is long enough to destroy all
forms of microbial life, or high-level disinfectants if contact times are
shorter. Chemical germicides registered by the EPA as sanitizers probably fall
into the category of low-level disinfectants. Numerous formulations of chemical
germicides can be classified as either low- or intermediate-level
disinfectants, depending on the specific label claims. For example, some
chemical germicide formulations are claimed to be efficacious against Mycobacterium
tuberculosis; by Spaulding's system, these formulations would be
classified at least as intermediate-level disinfectants. However, chemical
germicide formulations with specific label claims for effectiveness against Salmonella
cholereasuis, Staphylococcus aureus, and Pseudomonas aeruginosa
(the challenge microorganisms required for EPA classification as a
"hospital disinfectant") could fall into intermediate- or low-level
disinfectant categories.
The rationale for cleaning, disinfecting,
or sterilizing patient-care equipment can be understood more readily if medical
devices, equipment, and surgical materials are divided into three general
categories (critical items, semicritical items, and noncritical items) based on
the potential risk of infection involved in their use. This categorization of
medical devices also is based on the original suggestions by Spaulding (1).
Critical items are instruments or
objects that are introduced directly into the bloodstream or into other normally
sterile areas of the body. Examples of critical items are surgical instruments,
cardiac catheters, implants, pertinent components of the heart-lung oxygenator,
and the blood compartment of a hemodialyzer. Sterility at the time of use is
required for these items; consequently, one of several accepted sterilization
procedures is generally recommended.
Items in the second category are
classified as semicritical in terms of the degree of risk of infection.
Examples are noninvasive flexible and rigid fiberoptic endoscopes, endotracheal
tubes, anesthesia breathing circuits, and cystoscopes. Although these items
come in contact with intact mucous membranes, they do not ordinarily penetrate
body surfaces. If steam sterilization can be used, it is often cheaper to
sterilize many of these items, but sterilization is not absolutely essential;
at a minimum, a high-level disinfection procedure that can be expected to
destroy vegetative microorganisms, most fungal spores, tubercle bacilli, and
small nonlipid viruses is recommended. In most cases, meticulous physical
cleaning followed by an appropriate high-level disinfection treatment gives the
user a reasonable degree of assurance that the items are free of pathogens.
Noncritical items are those that
either do not ordinarily touch the patient or touch only intact skin. Such
items include crutches, bedboards, blood pressure cuffs, and a variety of other
medical accessories. These items rarely, if ever, transmit disease.
Consequently, depending on the particular piece of equipment or item, washing
with a detergent may be sufficient.
The level of disinfection achieved
depends on several factors, principally contact time, temperature, type and
concentration of the active ingredients of the chemical germicide, and the nature
of the microbial contamination. Some disinfection procedures are capable of
producing sterility if the contact times used are sufficiently long; when these
procedures are continued long enough to kill all but resistant bacterial
spores, the result is high-level disinfection. Other disinfection procedures
that can kill many types of viruses and most vegetative microorganisms (but
cannot be relied upon to kill resistant microorganisms such as tubercle
bacilli, bacterial spores, or certain viruses) are considered to be
intermediate- or low-level disinfection (Table1).
The tubercle bacillus, lipid and
nonlipid viruses, and other groups of microorganisms in Table I are used in the
context of indicator microorganisms that have varying degrees of resistance to
chemical germicides and not necessarily because of their importance in causing
nosocomial infections. For example, cells of M. tuberculosis or M.
bovis, which are used in routine efficacy tests, are among the most
resistant vegetative microorganisms known and, after bacterial endospores,
constitute the most severe challenge to a chemical germicide. Thus, a
tuberculocidal chemical germicide may be used as a high or intermediate-level
disinfectant targeted to many types of nosocomial pathogens but not specifically
to control respiratory tuberculosis.
CONTROL MEASURES
Since it is neither necessary nor
possible to sterilize all patient-care items, hospital policies can identify
whether cleaning, disinfecting, or sterilizing of an item is indicated to
decrease the risk of infection. The process indicated for an item will depend
on its intended use. Any microorganism, including bacterial spores, that come
in contact with normally sterile tissue can cause infection. Thus, it is
important that all items that will touch normally sterile tissues be
sterilized. It is less important that objects touching mucous membranes be
sterile. Intact mucous membranes are generally resistant to infection by common
bacterial spores but are not resistant to many other microorganisms, such as
viruses and tubercle bacilli; therefore, items that touch mucous membranes
require a disinfection process that kills all but resistant bacterial spores.
In general, intact skin acts as an effective barrier to most microorganisms;
thus, items that touch only intact skin need only be clean.
Items must be thoroughly cleaned
before processing, because organic material (e.g., blood and proteins) may
contain high concentrations of microorganisms. Also, such organic material may
inactivate chemical germicides and protect microorganisms from the disinfection
or sterilization process. For many noncritical items, such as blood pressure
cuffs or crutches, cleaning can consist only of 1) washing with a detergent or
a disinfectant-detergent, 2) rinsing, and 3) thorough drying.
Steam sterilization is the most
inexpensive and effective method for sterilization. Steam sterilization is
unsuitable, however, for processing plastics with low melting points, powders,
or anhydrous oils. Items that are to be sterilized but not used immediately
need to be wrapped for storage. Sterility can be maintained in storage for
various lengths of time, depending on the type of wrapping material, the
conditions of storage, and the integrity of the package.
Several methods have been developed
to monitor steam sterilization processes. One method is to check the highest
temperature that is reached during sterilization and the length of time that
this temperature is maintained. In addition, heat- and steam-sensitive chemical
indicators can be used on the outside of each pack. These indicators do not
reliably document sterility, but they do show that an item has not accidentally
bypassed a sterilization process. As an additional precaution, a large pack
might have a chemical indicator both on the outside and the inside to verify
that steam has penetrated the pack.
Microbiological monitoring of steam
sterilizers is recommended at least once a week with commercial preparations of
spores of Bacillus stearothermophilus (a microorganism having spores
that are particularly resistant to moist heat, thus assuring a wide margin of
safety). If a sterilizer is working properly and used appropriately, the spores
are usually killed. One positive spore test (spores not killed) does not
necessarily indicate that items processed in the sterilizer are not sterile,
but it does suggest that the sterilizer should be rechecked for proper
temperature, length of cycle, loading, and use and that the test be repeated.
Spore testing of steam sterilization is just one of several methods for
assuring adequate processing of patient-care items (Table 2).
Implantable items, such as
orthopedic devices, require special handling before and during sterilization;
thus, packs containing implantable objects need to be clearly labeled so they
will be appropriately processed. To guarantee a wide margin of safety, it is
recommended that each load of such items be tested with a spore test and that
the sterilized item not be released for use until the spore test is negative at
48 hours. If it is not possible to process an implantable object with a
confirmed 48-hour spore test before use, it is recommended that the unwrapped
object receive the equivalent of full-cycle steam sterilization and not
flash sterilization. Flash sterilization [270°F (132°C) for 3 minutes in a
gravity displacement steam sterilizer] is not recommended for
implantable items because spore tests cannot be used reliably and the margin of
safety is lower.
Because ethylene oxide gas
sterilization is a more complex and expensive process than steam sterilization,
it is usually restricted to objects that might be damaged by heat or excessive
moisture. Before sterilization, objects also need to be cleaned thoroughly and
wrapped in a material that allows the gas to penetrate. Chemical indicators
need to be used with each package to show that it has been exposed to the gas
sterilization process. Moreover, it is recommended that gas sterilizers be
checked at least once a week with commercial preparations of spores, usually Bacillus
subtilis var. niger. Because ethylene oxide gas is toxic,
precautions (e.g., local exhaust ventilation) should be taken to protect
personnel (2). All objects processed by gas sterilization also need special
aeration according to manufacturer's recommendations before use to remove toxic
residues of ethylene oxide.
Powders and anhydrous oils can be
sterilized by dry heat. Microbiological monitoring of dry heat sterilizers and
following manufacturers' recommendations for their use and maintenance usually
provides a wide margin of safety for dry heat sterilization.
Liquid chemicals can be used for
sterilization and disinfection when steam, gas, or dry heat sterilization is
not indicated or available. With some formulations, high-level disinfection can
be accomplished in 10-30 minutes, and sterilization can be achieved if exposure
is for significantly longer times. Nevertheless, not all formulations are
equally applicable to all items that need to be sterilized or disinfected. No
formulation can be considered as an "all purpose" chemical germicide.
In each case, more detailed information can be obtained from the EPA,
descriptive brochures from the manufacturers, peer-review journal articles, and
books. The most appropriate chemical germicide for a particular situation can
be selected by responsible personnel in each hospital based on the object to be
disinfected, the level of disinfection needed, and the scope of services,
physical facilities, and personnel available in the hospital. It is also
important that the manufacturer's instructions for use be consulted.
Gloves may be indicated to prevent
skin reactions when some chemical disinfectants are used. Items subjected to
high-level disinfection with liquid chemicals need to be rinsed in sterile
water to remove toxic or irritating residues and then thoroughly dried.
Subsequently, the objects need to be handled aseptically with sterile gloves
and towels and stored in protective wrappers to prevent recontamination.
Hot-water disinfection
(pasteurization) is a high-level, nontoxic disinfection process that can be
used for certain items, e.g., respiratory therapy breathing circuits.
In recent years, some hospitals have
considered reusing medical devices labeled disposable or single use only. In
general, the primary, if not the sole, motivation for such reuse is to save
money. For example, the disposable hollow-fiber hemodialyzer has been
reprocessed and reused on the same patient in hemodialysis centers since the
early 1970s. By 1984, 51% of the 1,200 U.S. dialysis centers were using
dialyzer reprocessing programs. It has been estimated that this practice saves
more than 100 million dollars per year (3). When standard protocols for
cleaning and disinfecting hemodialyzers are used, there does not appear to be any
significant infection risk to dialysis patients (4). Moreover, the safety and
efficacy of dialyzer reuse programs are supported by several major studies
(5-7). Few, if any, other medical devices that might be considered candidates
for reprocessing have been evaluated in this manner.
Arguments for and against
reprocessing and reusing single-use items in the 1980's have been summarized
(4). Since there is lack of evidence indicating increased risk of nosocomial
infections associated with reusing all single-use items, a categorical
recommendation against all types of reuse is not considered justifiable. Rather
than recommending for or against reprocessing and reuse of all single-use
items, it appears more prudent to recommend that hospitals consider the safety
and efficacy of the reprocessing procedure of each item or device separately
and the likelihood that the device will function as intended after
reprocessing. In many instances it may be difficult if not impossible to
document that the device can be reprocessed without residual toxicity and still
function safely and effectively. Few, if any, manufacturers of disposable or
single-use medical devices provide reprocessing information on the product
label.
Hydrotherapy pools and immersion
tanks present unique disinfection problems in hospitals. It is generally not
economically feasible to drain large hydrotherapy pools that contain thousands
of gallons of water after each patient use. Typically, these pools are used by
a large number of patients and are drained and cleaned every one to two weeks.
The water temperature is typically maintained near 37°C. Between cleanings,
water can be contaminated by organic material from patients, and high levels of
microbial contamination are possible. One method to maintain safe pool water is
to install a water filter of sufficient size to filter all the water at least
three times per day and to chlorinate the water so that a free chlorine
residual of approximately 0.5 mg/l is maintained at a pH of 7.2 to 7.6. Local
public health authorities can provide consultation regarding chlorination,
alternate halogen disinfectants, and hydrotherapy pool sanitation.
Hubbard and immersion tanks present
entirely different problems than large pools, since they are drained after each
patient use. All inside surfaces need to be cleaned with a
disinfectant-detergent, then rinsed with tap water. After the last patient each
day, an additional disinfection step is performed. One general procedure is to
circulate a chlorine solution (200-300 mg/l) through the agitator of the tank
for 15 minutes and then rinse it out. It is also recommended that the tank be
thoroughly cleaned with a disinfectant-detergent, rinsed, wiped dry with clean
cloths, and not filled until ready for use.
An alternative approach to control
of contamination in hydrotherapy tanks is to use plastic liners and create the
"whirlpool effect" without agitators. Such liners make it possible to
minimize contact of contaminated water with the interior surface of the tank
and also obviate the need for agitators that may be very difficult to clean and
decontaminate.
RECOMMENDATIONS
1. Cleaning
All objects to be disinfected or sterilized
should first be thoroughly cleaned to remove all organic matter (blood and
tissue) and other residue. Category I
2. Indications for Sterilization and High-Level
Disinfection
a. Critical medical devices or patient-care
equipment that enter normally sterile tissue or the vascular system or through
which blood flows should be subjected to a sterilization procedure before each
use. Category I
b. Laparoscopes, arthroscopes, and other scopes
that enter normally sterile tissue should be subjected to a sterilization
procedure before each use; if this is not feasible, they should receive at
least high-level disinfection. Category I
c. Equipment that touches mucous membranes,
e.g., endoscopes, endotracheal tubes, anesthesia breathing circuits, and
respiratory therapy equipment, should receive high-level disinfection. Category
I
3. Methods of Sterilization
a. Whenever sterilization is indicated, a steam
sterilizer should be used unless the object to be sterilized will be damaged by
heat, pressure, or moisture or is otherwise inappropriate for steam
sterilization. In this case, another acceptable method of sterilization should
be used. Category II
b. Flash sterilization [270°F (132°C) for 3
minutes in a gravity displacement steam sterilizer] is not recommended for
implantable items. Category II
4. Biological Monitoring of Sterilizers
a. All sterilizers should be monitored at least
once a week with commercial preparations of spores intended specifically for
that type of sterilizer (i.e., Bacillus stearothermophilus for steam
sterilizers and Bacillus subtilis for ethylene oxide and dry heat
sterilizers). Category II
b. Every load that contains implantable objects
should be monitored. These implantable objects should not be used until the
spore test is found to be negative at 48 hours. Category II
c. If spores are not killed in routine spore
tests, the sterilizer should immediately be checked for proper use and function
and the spore test repeated. Objects, other than implantable objects, do not
need to be recalled because of a single positive spore test unless the
sterilizer or the sterilization procedure is defective. Category II
d. If spore tests remain positive, use of the
sterilizer should be discontinued until it is serviced. Category I
5. Use and Preventive Maintenance
Manufacturers' instructions should be followed
for use and maintenance of sterilizers. Category II
6. Chemical Indicators
Chemical indicators that will show a package
has been through a sterilization cycle should be visible on the outside of each
package sterilized. Category II
7. Use of Sterile Items
An item should not be used if its sterility is
questionable, e.g., its package is punctured, torn, or wet. Category I
8. Reprocessing Single-Use or Disposable Items
a. Items or devices that cannot be cleaned and
sterilized or disinfected without altering their physical integrity and
function should not be reprocessed. Category I
b. Reprocessing procedures that result in
residual toxicity or compromise the overall safety or effectiveness of the
items or devices should be avoided. Category I
REFERENCES
1. Favero MS. Chemical disinfection of medical and surgical materials.
In: Block SS, ed. Disinfection, sterilization and preservation. 3rd ed.
Philadelphia: Lea and Febiger, 1983;469-92.
2. Fed Reg June 22, 1984, 29 CFR 1910, Occupational Exposure to Ethylene Oxide.
3. Romeo AA. The economics of reuse. In: Reuse of disposable medical devices in
the 1980's. Proceedings of International Conference on the Reuse of Disposable
Medical Devices in the 1980's, The Institute for Health Policy Analysis.
Georgetown University Medical Center, 1984 Mar 29-30. Washington, D.C.:
Institute for Health Policy Analysis. 1984:43-9.
4. Institute for Health Policy Analysis, Georgetown University Medical Center.
Proceedings of International Conference on the Reuse of Disposable Medical
Devices in the 1980's. March 29-30, 1984. Washington, D.C.
5. Jacobs C, Brunner FP,
Chantler C, et al. Combined
report on regular dialysis and transplantation in Europe VII. 1976. Proc Eur Dial Transplant Assoc
1977;14:3-69.
6. Levin N. Dialyzer
re-use in a hospital. Dial and Transplant 1980;9(1):40-6.
7. Wing AJ, Brunner FP, Brunner FP, et al. Mortality and morbidity of reusing
dialyzers. Br Med J 1978;2:853-5.
Before 1970, regularly scheduled
culturing of the air and environmental surfaces such as floors, walls, and
table tops was widely practiced in U.S. hospitals. By 1970, CDC and the
American Hospital Association were advocating that hospitals discontinue
routine environmental culturing, since rates of nosocomial infection had not
been related to levels of general microbial contamination of air or
environmental surfaces, and meaningful standards for permissible levels of
microbial contamination of environmental surfaces did not exist (1,2). Between
1970 and 1975, 25% of U.S. hospitals reduced the extent of such routine
environmental culturing (3), and this trend has continued.
In the last several years, there has
also been a trend toward reducing routine microbiologic sampling for quality
control purposes. In 1982, CDC recommended that the disinfection process for
respiratory therapy equipment should not be monitored by routine microbiologic
sampling (4). Moreover, the recommendation for microbiologic sampling of infant
formulas prepared in the hospital has been removed from this Guideline,
since there is no epidemiologic evidence to show that such quality control
testing influences the infection rate in hospitals.
CONTROL MEASURES
The only routine or periodic
microbiologic sampling that is recommended is of the water and dialysis fluids
used with artificial kidney machines in hospital-based or free standing chronic
hemodialysis centers. Microbiologic sampling of dialysis fluids and water used
to prepare dialysis fluids is recommended because gram-negative bacteria are
able to grow rapidly in water and other fluids associated with the hemodialysis
system; high levels of these microorganisms place dialysis patients at risk of
pyrogenic reactions, bacteremia, or both (5). It is suggested that the water
that is used to prepare dialysis fluid also be sampled periodically, because
high levels of bacteria in water often become amplified downstream in a
hemodialysis system and are sometimes predictive of bacterial contamination in
dialysis fluids. Although it is difficult to determine the exact frequency of
such a sampling program in the absence of pyrogenic reactions and bacteremia,
sampling water and dialysis fluid monthly appears to be reasonable.
Routine microbiologic sampling of
patient-care items purchased as sterile is not recommended because of the
difficulty and expense of performing adequate sterility testing with low
frequency contamination.
Microbiologic sampling is indicated
during investigation of infection problems if environmental reservoirs are
implicated epidemiologically in disease transmission. It is important, however,
that such culturing be based on epidemiologic data and follow a written plan
that specifies the objects to be sampled and the actions to be taken based on
culture results.
RECOMMENDATIONS
1. Routine Environmental Culturing of Air and
Environmental Surfaces
Routine microbiologic sampling of the air and
environmental surfaces should not be done. Category I
2. Microbiologic Sampling of Dialysis Fluids
Water used to prepare dialysis fluid should be
sampled once a month; it should not contain a total viable microbial count
greater than 200 colony-forming units (CFU)/ml. The dialysis fluid should be
sampled once a month at the end of a dialysis treatment and should contain less
than 2,000 CFU/ml. Category II
3 Microbiologic Sampling for Specific Problems
Microbiologic sampling, when indicated, should
be an integral part of an epidemiologic investigation. Category I
4. Sampling for Manufacturer-Associated
Contamination
a. Routine microbiologic sampling of
patient-care objects purchased as sterile is not recommended. Category I
b. If contamination of a commercial
product sold as sterile is suspected, infection control personnel should be
notified, suspect lot numbers should be recorded, and items from suspected lots
should be segregated and quarantined. Appropriate microbiologic assays may be
considered; however, the nearest district office of the FDA, local and state
health departments, and CDC should be notified promptly. Category I
REFERENCES
1. Eickhoff TC. Microbiologic sampling. Hospitals 1970;44:86-7.
2. American Hospital Association Committee on Infections Within Hospitals.
Statement on microbiologic sampling in the hospital. Hospitals 1974;48:125-6.
3. Haley RW, Shachtman RS. The emergence of infection surveillance and control
programs in U.S. hospitals: an assessment, 1976. Am J Epidemiol 1980:111;574-91.
4. Simmons BP. Wong ES.
Guideline for prevention of nosocomial pneumonia. Infect Control 1982;3:327-33.
5. Favero MS, Petersen NJ. Microbiologic guidelines for hemodialysis systems. Dialys
Transpl 1977;6:34-6
There is no epidemiologic evidence
to suggest that most hospital waste is any more infective than residential
waste. Moreover, there is no epidemiologic evidence that hospital waste
disposal practices have caused disease in the community. Therefore, identifying
wastes for which special precautions are indicated is largely a matter of
judgment about the relative risk of disease transmission. Aesthetic and
emotional considerations may override the actual risk of disease transmission,
particularly for pathology wastes.
Since a precise definition of
infective waste that is based on the quantity and type of etiologic agents
present is virtually impossible, the most practical approach to infective waste
management is to identify those wastes that represent a sufficient potential
risk of causing infection during handling and disposal and for which some
special precautions appear prudent. Hospital wastes for which special
precautions appear prudent include microbiology laboratory waste, pathology
waste, and blood specimens or blood products. Moreover, the risk of either
injury or infection from certain sharp items (e.g., needles and scalpel blades)
contaminated with blood also needs to be considered when such items are
disposed of. While any item that has had contact with blood, exudates, or
secretions may be potentially infective, it is not normally considered
practical or necessary to treat all such waste as infective. CDC has published
general recommendations for handling infective waste from patients on isolation
precautions (1). Additional special precautions may be necessary for certain
rare diseases or conditions such as Lassa fever (2). The EPA has published a
draft manual (Environmental Protection Agency. Office of Solid Waste and
Emergency Response. Draft Manual for Infectious Waste Management, SW-957, 1982.
Washington: 1982) that identifies and categorizes other specific types of waste
that may be generated in some research-oriented hospitals. In addition to the
above guidelines, local and state environmental regulations may also exist.
CONTROL MEASURES
Solid waste from the microbiology
laboratory can be placed in steam-sterilizable bags or pans and steam
sterilized in the laboratory. Alternatively, it can be transported in sealed,
impervious plastic bags to be burned in a hospital incinerator. A single bag is
probably adequate if the bag is sturdy (not easily penetrated) and if the waste
can be put in the bag without contaminating the outside of the bag; otherwise,
double-bagging is indicated. All slides or tubes with small amounts of blood
can be packed in sealed, impervious containers and sent for incineration or
steam sterilization in the hospital. Exposure for up to 90 minutes at 250°F
(121°C) in a steam sterilizer, depending on the size of the load and type
container, may be necessary to assure an adequate sterilization cycle (3,4).
After steam sterilization, the residue can be safely handled and discarded with
all other nonhazardous hospital solid waste. All containers with more than a
few milliliters of blood remaining after laboratory procedures and/or bulk
blood may be steam sterilized, or the contents may be carefully poured down a
utility sink drain or toilet .
Waste from the pathology laboratory
is customarily incinerated at the hospital. Although no national data are
available, in one state 96% of the hospitals surveyed reported that they
incinerate pathology waste (5). Any hospital incinerator should be capable of
burning, within applicable air pollution regulations, the actual waste
materials to be destroyed. Improper incineration of waste with high moisture
and low energy content, such as pathology waste, can lead to emission problems.
Disposables that can cause injury,
such as scalpel blades and syringes with needles, should be placed in
puncture-resistant containers. Ideally, such containers are located where these
items are used. Syringes and needles can be placed intact directly into the
rigid containers for safe storage until terminal treatment. To prevent
needle-stick injuries, needles should not be recapped, purposely bent, or
broken by hand. When some needle-cutting devices are used, blood may be
aerosolized or spattered onto environmental surfaces; however, currently no
data are available from controlled studies examining the effect, if any, of the
use of these devices on the incidence of needle-transmissible infections.
It is often necessary to transport
or store infective waste within the hospital prior to terminal treatment. This
can be done safely if proper and common-sense procedures are used. The EPA
draft manual mentioned above contains guidelines for the storage and transport,
both on-site and off-site, of infective waste. For unique and specialized
problems, this manual can be consulted.
RECOMMENDATIONS
1. Identification of Infective Waste
a. Microbiology laboratory wastes,
blood and blood products, pathology waste, and sharp items (especially needles)
should be considered as potentially infective and handled and disposed of with
special precautions. Category II
b. Infective waste from patients on
isolation precautions should be handled and disposed of according to the
current edition of the Guideline for Isolation Precautions in Hospitals.
(This recommendation is not categorized since the recommendations for isolation
precautions are not categorized.)
2. Handling, Transport, and Storage of
Infective Waste
a. Personnel involved in the
handling and disposal of infective waste should be informed of the potential
health and safety hazards and trained in the appropriate handling and disposal
methods. Category II
b. If processing and/or disposal
facilities are not available at the site of infective waste generation (i.e.,
laboratory, etc.) the waste may be safely transported in sealed impervious
containers to another hospital area for appropriate treatment. Category II
c. To minimize the potential risk
for accidental transmission of disease or injury, infective waste awaiting
terminal processing should be stored in an area accessible only to personnel
involved in the disposal process. Category III
3. Processing and Disposal of Infective Waste
a. Infective waste, in general,
should either be incinerated or should be autoclaved prior to disposal in a
sanitary landfill. Category III
b. Disposable syringes with needles,
scalpel blades, and other sharp items capable of causing injury should be
placed intact into puncture-resistant containers located as close to the area
in which they were used as is practical. To prevent needle-stick injuries,
needles should not be recapped, purposely bent, broken, or otherwise
manipulated by hand. Category I
c. Bulk blood, suctioned fluids,
excretions, and secretions may be carefully poured down a drain connected to a
sanitary sewer. Sanitary sewers may also be used for the disposal of other
infectious wastes capable of being ground and flushed into the sewer. Category
II (Special precautions may be necessary for certain rare diseases or conditions
such as Lassa fever (2).
REFERENCES
1. Garner JS, Simmons BP. Guideline for isolation precautions in
hospitals. Infect Control 1983;4:245-325.
2. Centers for Disease Control. Viral hemorrhagic fever: initial management of
suspected and confirmed cases. MMWR (suppl) 1983;32:275-405.
3. Rutala WA, Stiegel MM, Sarubbi FA. Decontamination of laboratory microbiological waste by steam
sterilization. Appl Environ
Microbiol 1982;43:1311-6.
4. Lauer JL, Battles
DR, Vesley D. Decontaminating infectious laboratory waste by autoclaving. Appl Environ Microbio 1982;44:690-4.
5. Rutala WA, Sarubbi FA. Management of infectious waste from hospitals. Infect Control
1983;4:198-203.
Although microorganisms are a normal
contaminant of walls, floors, and other surfaces, these environmental surfaces
rarely are associated with transmission of infections to patients or personnel.
Therefore, extraordinary attempts to disinfect or sterilize these environmental
surfaces are rarely indicated. However, routine cleaning and removal of soil
are recommended. Recommendations for cleaning in the rooms of patients on
isolation precautions have been published (1).
CONTROL MEASURES
Cleaning schedules and methods vary
according to the area of the hospital, type of surface to be cleaned, and the
amount and type of soil present. Horizontal surfaces (for example, bedside
tables and hard-surfaced flooring) in patient-care areas are usually cleaned on
a regular basis, where soiling or spills occur, and when a patient is
discharged. Cleaning of walls, blinds, and curtains is recommended only if they
are visibly soiled. Disinfectant fogging is an unsatisfactory method of
decontaminating air and surfaces and is not recommended.
Recommendations against use of
carpets in patient care areas have been removed from this Guideline,
since there is no epidemiologic evidence to show that carpets influence the
nosocomial infection rate in hospitals (2). Carpets, however, may contain much
higher levels of microbial contamination than hard-surfaced flooring and can be
difficult to keep clean in areas of heavy soiling or spillage; therefore,
appropriate cleaning and maintenance procedures are indicated.
Disinfectant-detergent formulations
registered by the EPA can be used for environmental surface cleaning, but the
actual physical removal of microorganisms by scrubbing is probably as
important, if not more so, than any antimicrobial effect of the cleaning agent
used. Therefore, cost, safety, and acceptability by housekeepers can be the
main criteria for selecting any such registered agent. The manufacturers'
instructions for appropriate use should be followed.
Special precautions for cleaning
incubators, mattresses, and other nursery surfaces with which neonates have contact
have been recommended (3), since inadequately diluted solutions of phenolics
used for such cleaning and poor ventilation have been associated with
hyperbilirubinemia in newborns (4).
RECOMMENDATIONS
1. Choice of Cleaning Agent for Environmental
Surfaces in Patient-Care Areas
Any hospital-grade disinfectant-detergent
registered by the EPA may be used for cleaning environmental surfaces.
Manufacturers' instructions for use of such products should be followed.
Category II
2. Cleaning of Horizontal Surfaces in
Patient-care Areas
a. Uncarpeted floors and other horizontal
surfaces, e.g., bedside tables, should be cleaned regularly and if spills
occur. Category II
b. Carpeting should be vacuumed regularly with
units designed to efficiently filter discharged air, cleaned if spills occur,
and shampooed whenever a thorough cleaning is indicated. Category II
3. Cleaning Walls, Blinds, and Curtains
Terminal cleaning of walls, blinds, and
curtains is not recommended unless they are visibly soiled. Category II
4. Disinfectant fogging
Disinfectant-fogging should not be done.
Category I
REFERENCES
1. Garner JS, Simmons BP. Guideline for isolation precautions in
hospitals. Infect Control 1983;4:245-325.
2. Anderson RL, Mackel DC, Stoler BS, Mallison GF. Carpeting in hospitals: An
epidemiological evaluation. J Clin Microbiol 1982;15:408-15.
3. American Academy of Pediatrics, American College of Obstetricians and
Gynecologists. Guidelines for perinatal care. Evanston, Illinois, Washington,
D.C.: AAP, ACOG, 1983.
4. Wysowski DK, Flym JW, Goldfield M, et al. Epidemic neonatal
hyperbilirubinemia and use of a phenolic disinfectant detergent. Pediatrics
1978;61:165-70.
Although soiled linen has been
identified as a source of large numbers of pathogenic microorganisms, the risk
of actual disease transmission appears negligible. Rather than rigid rules and
regulations, hygienic and common sense storage and processing of clean and
soiled linen are recommended. Guidelines for laundry construction and operation
for health care facilities have been published (1,2).
CONTROL MEASURES
Soiled linen can be transported in
the hospital by cart or chute. Bagging linen is indicated if chutes are used,
since improperly designed chutes can be a means of spreading microorganisms
throughout the hospital (3). Recommendations for handling soiled linen from
patients on isolation precautions have been published (4).
Soiled linen may or may not be
sorted in the laundry before being loaded into washer/extractor units. Sorting
before washing protects both machinery and linen from the effects of objects in
the linen and reduces the potential for recontamination of clean linen that
sorting after washing requires. Sorting after washing minimizes the direct exposure
of laundry personnel to infective material in the soiled linen and reduces
airborne microbial contamination in the laundry (5). Protective apparel and
appropriate ventilation (2) can minimize these exposures.
The microbicidal action of the
normal laundering process is affected by several physical and chemical factors
(5). Although dilution is not a microbicidal mechanism, it is responsible for
the removal of significant quantities of microorganisms. Soaps or detergents
loosen soil and also have some microbicidal properties. Hot water provides an
effective means of destroying microorganisms, and a temperature of at least
71°C (160°F) for a minimum of 25 minutes is commonly recommended for hot-water
washing. Chlorine bleach provides an extra margin of safety. A total available
chlorine residual of 50-150ppm is usually achieved during the bleach cycle. The
last action performed during the washing process is the addition of a mild acid
to neutralize any alkalinity in the water supply, soap, or detergent. The rapid
shift in pH from approximately 12 to 5 also may tend to inactivate some
microorganisms.
Recent studies have shown that a
satisfactory reduction of microbial contamination can be achieved at lower
water temperatures of 22-50°C when the cycling of the washer, the wash formula,
and the amount of chlorine bleach are carefully monitored and controlled (6,
7). Instead of the microbicidal action of hot water, low temperature laundry
cycles rely heavily on the presence of bleach to reduce levels of microbial
contamination. Regardless of whether hot or cold water is used for washing, the
temperatures reached in drying and especially during ironing provide additional
significant microbicidal action.
RECOMMENDATIONS
1. Routine Handling of Soiled Linen
a. Soiled linen should be handled as little as
possible and with minimum agitation to prevent gross microbial contamination of
the air and of persons handling the linen. Category II
b. 1) All soiled linen should be bagged or put
into carts at the location where it was used; it should not be
sorted or prerinsed in patient-care areas. Category II
2) Linen soiled with blood or body
fluids should be deposited and transported in bags that prevent
leakage. Category II
c. If laundry chutes are used, linen should be
bagged, and chutes should be properly designed. Category II
2. Hot-Water Washing
If hot water is used, linen should be washed with a detergent in water
at least 71°C (160°F) for 25 minutes. Category II
3. Low-Temperature Water Washing
If low temperature (<70°C) laundry cycles are used, chemicals
suitable for low-temperature washing at proper use concentration should be
used. Category II.
4. Transportation of Clean Linen
Clean linen should be transported and stored by methods that will ensure
its cleanliness. Category II
REFERENCES
l. U.S. Department of Health and Human Services. Guidelines for
construction and equipment of hospital and medical facilities. Washington:
Government Printing Office, July 1984. DHHS publication No. (HRS-M-HF) 84-l.
2. Joint Committee on Health Care Laundry Guidelines. Guidelines for healthcare
linen service. Mallandale, FL: Textile Rental Services Association of America,
1983, TRSA publication no. 71482.
3. Hughes HG. Chutes in hospitals. J Can Hosp Assn 1964;4l:56-7.
4. Garner JS, Simmons BP. Guideline for isolation precautions in hospitals.
Infect Control 1983;4:245-325.
5. Walter WG, Schillinger JE. Bacterial survival in laundered fabrics. Appl
Microbiol 1975;29:368-73.
6. Christian RR, Manchester JT, Mellor MT. Bacteriological quality of fabrics
washed at lower-than- standard temperatures in a hospital laundry facility. Appl Env Microbiol 1983;45:591-7.
7. Blaser MJ, Smith PF, Cody HJ, Wang WL, LaForce FM. Killing of fabric-associated bacteria in
hospital laundry by low-temperature washing. J Infect Dis 1984; l49:48-57.
Table 1. Levels of Disinfection According to
Type of Microorganism
|
|||||||
Levels |
Vegetative |
Bacteria
|
Spores |
Fungi1 |
Viruses |
||
Lipid
& |
Nonlipid |
||||||
|
|||||||
High |
+2
|
+ |
+3
|
+ |
+ |
+ |
|
Intermediate |
+ |
+ |
±4
|
+ |
+ |
±5
|
|
Low |
+ |
- |
- |
± |
+ |
- |
|
|
|||||||
1Includes asexual spores but not
necessarily chlamydospores or sexual spores. |
|
|
Table 2.
Methods of Assuring Adequate Processing and Safe Use of Medical Devices
|
|||
Object
and |
Example |
Method |
Comment |
|
|||
PATIENT-CARE
OBJECTS |
|
|
|
Critical |
|
|
|
Sterilized in the hospital |
Surgical
instruments and devices; trays and sets |
1.
Thoroughly clean objects and wrap or package for sterilization. |
Sterilization
processes are designed to have a wide margin of safety. If spores are not
killed, the sterilizer should be checked for proper use and function, if
spore tests remain positive, discontinue use of the sterilizer until properly
serviced. Maximum safe storage time of items processed in the hospital varies
according to type of package or wrapping material(s) used; follow
manufacturer's instructions for use and storage times. |
Purchased as |
Intravenous
fluids; |
1. Store
in safe, clean area. |
Notify
the Food and Drug Administration, local and state health departments, and CDC
if intrinsic contamination is suspected. |
Semicritical |
|||
Should be free of vegetative bacteria. May be
subjected to high-level disinfection rather than sterilization process |
Respiratory
therapy |
1.
Sterilize or follow a protocol for high-level disinfection. |
Bacterial
spores may survive after high-level disinfection, but these usually are not
pathogenic. Microbiologic sampling can verify that a high-level disinfection
process has resulted in destruction of vegetative bacteria, however, this
sampling is not routinely recommended. |
Non
critical |
|||
Usually |
Bedpans;
crutches; |
1. Follow
a protocol for cleaning or, if necessary a low-level disinfection process. |
|
Water produced or treated |
Water
used for |
1. Assay
water and dialysis fluids monthly. |
Gram-negative
water bacteria can grow rapidly in water and dialysis fluids and can place
dialysis patients at risk of pyrogenic reactions or septicemia. These water
sources and pathways should be disinfected routinely. |
|