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Recommendations for Prevention of
HIV Transmission in Health-Care Settings
Supplements to the MMWR
are published by the Epidemiology Program Office, Centers for Disease
Control, Public Health Service, U.S. Department of Health and Human Services,
Atlanta, Georgia 30333. SUGGESTED CITATION Centers for Disease
Control. Recommendations for prevention of HIV transmission in health-care
settings. MMWR 1987;36 (suppl no. 2S) :{inclusive page numbers}. Centers for Disease
Control ................. James O. Mason, M.D., Dr,P.H. The material in this
report was developed (in collaboration with the Center for Prevention
Services, the National Institute for Occupational Safety and Health, and the
Training and Laboratory Program Office) by: Center for Infectious
Diseases ....... Frederick A. Murphy, D,V.M., Ph,D. Acting Director Hospital Infections
Program .................... James M. Hughes, M.D. Director AIDS Program
.................................... James W. Curran, M.D. Director Publications and Graphics
.................... Frances
H. Porcher, M,A. Chief Karen L. Foster, M.A. This report was prepared
in: Epidemiology Program
Office .................... Carl W. Tyler, Jr., M.D. Michael B. Gregg, M,D.
Editorial Services
......................... R. Elliott Churchill, M,A. Chief Ruth Greenberg Editorial
Assistant Introduction Human
immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency
syndrome (AIDS), is transmitted through sexual contact and exposure to
infected blood or blood components and perinatally from mother to neonate. HIV
has been isolated from blood, semen, vaginal secretions, saliva, tears,
breast milk, cerebrospinal fluid, amniotic fluid, and urine and is likely to
be isolated from other body fluids, secretions, and excretions. However,
epidemiologic evidence has implicated only blood, semen, vaginal secretions,
and possibly breast milk in transmission. The
increasing prevalence of HIV increases the risk that health-care workers will
be exposed to blood from patients infected with HIV, especially when blood
and body-fluid precautions are not followed for all patients. Thus, this
document emphasizes the need for health-care workers to consider ALL patients
as potentially infected with HIV and/or other blood-borne pathogens and to
adhere rigorously to infection-control precautions for minimizing the risk of
exposure to blood and body fluids of all patients. The
recommendations contained in this document consolidate and update CDC
recommendations published earlier for preventing HIV transmission in
health-care settings: precautions for clinical and laboratory staffs (1) and
precautions for health-care workers and allied professionals (2);
recommendations for preventing HIV transmission in the workplace (3) and
during invasive procedures (4); recommendations for preventing possible
transmission of HIV from tears (5); and recommendations for providing
dialysis treatment for HIV-infected patients (6). These recommendations also
update portions of the "Guideline for Isolation Precautions in
Hospitals" (7) and reemphasize some of the recommendations contained in
"Infection Control Practices for Dentistry" (8). The
recommendations contained in this document have been developed for use in
health-care settings and emphasize the need to treat blood and other body
fluids from ALL patients as potentially infective. These same prudent
precautions also should be taken in other settings in which persons may be
exposed to blood or other body fluids. Definition
of Health-Care Workers Health-care workers are
defined as persons, including students and trainees, whose activities involve
contact with patients or with blood or other body fluids from patients in a
health-care setting. Health-Care
Workers with AIDS As
of July 10, 1987, a total of 1,875 (5.8%) of 32,395 adults with AIDS, who had
been reported to the CDC national surveillance system and for whom
occupational information was available, reported being employed in a
health-care or clinical laboratory setting. In comparison, 6.8 million
persons -- representing 5.6% of the U.S. labor force -- were employed in
health services. Of the health-care workers with AIDS, 95% have been reported
to exhibit high-risk behavior; for the remaining 5%, the means of HIV
acquisition was undetermined. Health-care workers with AIDS were
significantly more likely than other workers to have an undetermined risk (5%
versus 3%, respectively). For both health-care workers and non-health- care
workers with AIDS, the proportion with an undetermined risk has not increased
since 1982. AIDS
patients initially reported as not belonging to recognized risk groups are
investigated by state and local health departments to determine whether
possible risk factors exist. Of all health-care workers with AIDS reported to
CDC who were initially characterized as not having an identified risk and for
whom follow-up information was available, 66% have been reclassified because
risk factors were identified or because the patient was found not to meet the
surveillance case definition for AIDS. Of the 87 health-care workers currently
categorized as having no identifiable risk, information is incomplete on 16
(18%) because of death or refusal to be interviewed; 38 (44%) are still being
investigated. The remaining 33 (38%) health-care workers were interviewed or
had other follow-up information available. The occupations of these 33 were
as follows: five physicians (15%), three of whom were surgeons; one dentist
(3%); three nurses (9%); nine nursing assistants (27%); seven housekeeping or
maintenance workers (21%); three clinical laboratory technicians (9%); one
therapist (3%); and four others who did not have contact with patients (12%).
Although 15 of these 33 health-care workers reported parenteral and/or other
non-needlestick exposure to blood or body fluids from patients in the 10 years
preceding their diagnosis of AIDS, none of these exposures involved a patient
with AIDS or known HIV infection. Risk
to Health-Care Workers of Acquiring HIV in Health-Care Settings Health-care
workers with documented percutaneous or mucous-membrane exposures to blood or
body fluids of HIV-infected patients have been prospectively evaluated to
determine the risk of infection after such exposures. As of June 30, 1987,
883 health-care workers have been tested for antibody to HIV in an ongoing
surveillance project conducted by CDC (9). Of these, 708 (80%) had
percutaneous exposures to blood, and 175 (20%) had a mucous membrane or an
open wound contaminated by blood or body fluid. Of 396 health-care workers,
each of whom had only a convalescent-phase serum sample obtained and tested
greater than or equal to 90 days post- exposure, one -- for whom heterosexual
transmission could not be ruled out -- was seropositive for HIV antibody. For
425 additional health-care workers, both acute- and convalescent-phase serum
samples were obtained and tested; none of 74 health-care workers with
nonpercutaneous exposures seroconverted, and three (0.9%) of 351 with
percutaneous exposures seroconverted. None of these three health-care workers
had other documented risk factors for infection. Two
other prospective studies to assess the risk of nosocomial acquisition of HIV
infection for health-care workers are ongoing in the United States. As of
April 30, 1987, 332 health-care workers with a total of 453 needlestick or
mucous-membrane exposures to the blood or other body fluids of HIV-infected
patients were tested for HIV antibody at the National Institutes of Health
(10). These exposed workers included 103 with needlestick injuries and 229
with mucous-membrane exposures; none had seroconverted. A similar study at
the University of California of 129 health-care workers with documented
needlestick injuries or mucous-membrane exposures to blood or other body
fluids from patients with HIV infection has not identified any seroconversions
(11). Results of a prospective study in the United Kingdom identified no
evidence of transmission among 150 health-care workers with parenteral or
mucous-membrane exposures to blood or other body fluids, secretions, or
excretions from patients with HIV infection (12). In
addition to health-care workers enrolled in prospective studies, eight
persons who provided care to infected patients and denied other risk factors
have been reported to have acquired HIV infection. Three of these health-care
workers had needlestick exposures to blood from infected patients (13-15). Two
were persons who provided nursing care to infected persons; although neither
sustained a needlestick, both had extensive contact with blood or other body
fluids, and neither observed recommended barrier precautions (16, 17). The
other three were health-care workers with non-needlestick exposures to blood
from infected patients (18). Although the exact route of transmission for
these last three infections is not known, all three persons had direct
contact of their skin with blood from infected patients, all had skin lesions
that may have been contaminated by blood, and one also had a mucous-membrane
exposure. A
total of 1,231 dentist and hygienists, many of whom practiced in areas with
many AIDS cases, participated in a study to determine the prevalence of
antibody to HIV; one dentist (0.1%) had HIV antibody. Although no exposure to
a known HIV-infected person could be documented, epidemiologic investigation
did not identify any other risk factor for infection. The infected dentist,
who also had a history of sustaining needlestick injuries and trauma to his
hands, did not routinely wear gloves when providing dental care (19). Precautions
To Prevent Transmission of HIV Universal
Precautions Since
medical history and examination cannot reliably identify all patients
infected with HIV or other blood-borne pathogens, blood and body- fluid
precautions should be consistently used for ALL patients. This approach,
previously recommended by CDC (3,4), and referred to as "universal blood
and body-fluid precautions" or "universal precautions," should
be used in the care of ALL patients, especially including those in
emergency-care settings in which the risk of blood exposure is increased and
the infection status of the patient is usually unknown (20). 1.
All
health-care workers should routinely use appropriate barrier precautions to
prevent skin and mucous-membrane exposure when contact with blood or other
body fluids of any patient is antici- pated. Gloves should be worn for
touching blood and body fluids, mucous membranes, or non-intact skin of all
patients, for handling items or surfaces soiled with blood or body fluids,
and for performing venipuncture and other vascular access procedures. Gloves
should be changed after contact with each patient. Masks and protective
eyewear or face shields should be worn during procedures that are likely to
generate droplets of blood or other body fluids to prevent exposure of mucous
membranes of the mouth, nose, and eyes. Gowns or aprons should be worn during
procedures that are likely to generate splashes of blood or other body
fluids. 2.
Hands
and other skin surfaces should be washed immediately and thoroughly if
contaminated with blood or other body fluids. Hands should be washed
immediately after gloves are removed. 3.
All
health-care workers should take precautions to prevent injuries caused by
needles, scalpels, and other sharp instruments or devices during procedures;
when cleaning used instruments; during disposal of used needles; and when
handling sharp instruments after procedures. To prevent needlestick injuries,
needles should not be recapped, purposely bent or broken by hand, removed
from disposable syringes, or otherwise manipulated by hand. After they are
used, disposable syringes and needles, scalpel blades, and other sharp items
should be placed in puncture-resistant containers for disposal; the
puncture-resistant containers should be located as close as practical to the
use area. Large-bore reusable needles should be placed in a
puncture-resistant container for transport to the reprocessing area. 4.
Although
saliva has not been implicated in HIV transmission, to minimize the need for
emergency mouth-to-mouth resuscitation, mouth- pieces, resuscitation bags, or
other ventilation devices should be available for use in areas in which the
need for resuscitation is predictable. 5.
Health-care
workers who have exudative lesions or weeping dermatitis should refrain from
all direct patient care and from handling patient-care equipment until the
condition resolves. 6.
Pregnant
health-care workers are not known to be at greater risk of contracting HIV
infection than health-care workers who are not pregnant; however, if a
health-care worker develops HIV infection during pregnancy, the infant is at
risk of infection resulting from perinatal transmission. Because of this
risk, pregnant health-care workers should be especially familiar with and
strictly adhere to precautions to minimize the risk of HIV transmission. Implementation
of universal blood and body-fluid precautions for ALL patients
eliminates the need for use of the isolation category of "Blood and Body
Fluid Precautions" previously recommended by CDC (7) for patients known
or suspected to be infected with blood-borne pathogens. Isolation precautions
(e.g., enteric, "AFB" {7}) should be used as necessary if
associated conditions, such as infectious diarrhea or tuberculosis, are
diagnosed or suspected. Precautions
for Invasive Procedures In
this document, an invasive procedure is defined as surgical entry into
tissues, cavities, or organs or repair of major traumatic injuries 1)in an
operating or delivery room, emergency department, or outpatient setting,
including both physicians' and dentists' offices; 2) cardiac catheterization
and angiographic procedures; 3) a vaginal or cesarean delivery or other
invasive obstetric procedure during which bleeding may occur; or 4) the
manipulation, cutting, or removal of any oral or perioral tissues, including
tooth structure, during which bleeding occurs or the potential for bleeding
exists. The universal blood and body-fluid precautions listed above, combined
with the precautions listed below, should be the minimum precautions for ALL
such invasive procedures. 1.
All
health-care workers who participate in invasive procedures must routinely use
appropriate barrier precautions to prevent skin and mucous-membrane contact
with blood and other body fluids of all patients. Gloves and surgical masks
must be worn for all invasive procedures. Protective eyewear or face shields
should be worn for procedures that commonly result in the generation of
droplets, splashing of blood or other body fluids, or the generation of bone
chips. Gowns or aprons made of materials that provide an effective barrier
should be worn during invasive procedures that are likely to result in the
splashing of blood or other body fluids. All health- care workers who perform
or assist in vaginal or cesarean deliveries should wear gloves and gowns when
handling the placenta or the infant until blood and amniotic fluid have been
removed from the infant's skin and should wear gloves during post-delivery
care of the umbilical cord. 2.
If a
glove is torn or a needlestick or other injury occurs, the glove should be
removed and a new glove used as promptly as patient safety permits; the
needle or instrument involved in the incident should also be removed from the
sterile field. Precautions
for Dentistry * Blood,
saliva, and gingival fluid from ALL dental patients should be considered
infective. Special emphasis should be placed on the following precautions for
preventing transmission of blood-borne pathogens in dental practice in both
institutional and non-institutional settings. 1.
In
addition to wearing gloves for contact with oral mucous membranes of all
patients, all dental workers should wear surgical masks and protective
eyewear or chin-length plastic face shields during dental procedures in which
splashing or spattering of blood, saliva, or gingival fluids is likely. Rubber
dams, high-speed evacuation and proper patient positioning, when appropriate,
should be utilized to minimize generation of droplets and spatter. 2.
Handpieces
should be sterilized after use with each patient, since blood, saliva, or
gingival fluid of patients may be aspirated into the handpiece or waterline. Handpieces
that cannot be sterilized should at least be flushed, the outside surface
cleaned and wiped with a suitable chemical germicide, and then rinsed. Handpieces
should be flushed at the beginning of the day and after use with each
patient. Manufacturers' recommendations should be followed for use and
maintenance of waterlines and check valves and for flushing of handpieces. The
same precautions should be used for ultrasonic scalers and air/water syringes.
3.
Blood
and saliva should be thoroughly and carefully cleaned from material that has
been used in the mouth (e.g., impression materials, bite registration),
especially before polishing and grinding intra-oral devices. Contaminated
materials, impressions, and intra-oral devices should also be cleaned and
disinfected before being handled in the dental laboratory and before they are
placed in the patient's mouth. Because of the increasing variety of dental
materials used intra-orally, dental workers should consult with manufacturers
as to the stability of specific materials when using disinfection procedures.
4.
Dental
equipment and surfaces that are difficult to disinfect (e.g., light handles
or X-ray-unit heads) and that may become contaminated should be wrapped with
impervious-backed paper, aluminum foil, or clear plastic wrap. The coverings
should be removed and discarded, and clean coverings should be put in place
after use with each patient. Precautions
for Autopsies or Morticians' Services In
addition to the universal blood and body-fluid precautions listed above, the
following precautions should be used by persons performing postmortem
procedures: 1.
All
persons performing or assisting in postmortem procedures should wear gloves,
masks, protective eyewear, gowns, and waterproof aprons. 2.
Instruments
and surfaces contaminated during postmortem procedures should be
decontaminated with an appropriate chemical germicide. Precautions
for Dialysis Patients
with end-stage renal disease who are undergoing maintenance dialysis and who
have HIV infection can be dialyzed in hospital-based or free-standing
dialysis units using conventional infection-control precautions (21). Universal
blood and body-fluid precautions should be used when dialyzing ALL patients. Strategies
for disinfecting the dialysis fluid pathways of the hemodialysis machine are
targeted to control bacterial contamination and generally consist of using
500-750 parts per million (ppm) of sodium hypochlorite (household bleach) for
30-40 minutes or 1.5%-2.0% formaldehyde overnight. In addition, several
chemical germicides formulated to disinfect dialysis machines are
commercially available. None of these protocols or procedures need to be
changed for dialyzing patients infected with HIV. Patients
infected with HIV can be dialyzed by either hemodialysis or peritoneal
dialysis and do not need to be isolated from other patients. The type of
dialysis treatment (i.e., hemodialysis or peritoneal dialysis) should be
based on the needs of the patient. The dialyzer may be discarded after each
use. Alternatively, centers that reuse dialyzers -- i.e. a specific
single-use dialyzer is issued to a specific patient, removed, cleaned,
disinfected, and reused several times on the same patient only -- may include
HIV-infected patients in the dialyzer-reuse program. An individual dialyzer
must never be used on more than one patient. Precautions
for Laboratories ** Blood
and other body fluids from ALL patients should be considered infective. To
supplement the universal blood and body-fluid precautions listed above, the
following precautions are recommended for health-care workers in clinical
laboratories. 1.
All
specimens of blood and body fluids should be put in a well- constructed
container with a secure lid to prevent leaking during transport. Care should
be taken when collecting each specimen to avoid contaminating the outside of
the container and of the laboratory form accompanying the specimen. 2.
All
persons processing blood and body-fluid specimens (e.g., removing tops from
vacuum tubes) should wear gloves. Masks and protective eyewear should be worn
if mucous-membrane contact with blood or body fluids is anticipated. Gloves
should be changed and hands washed after completion of specimen processing. 3.
For
routine procedures, such as histologic and pathologic studies or
microbiologic culturing, a biological safety cabinet is not necessary. However,
biological safety cabinets (Class I or II) should be used whenever procedures
are conducted that have a high potential for generating droplets. These
include activities such as blending, sonicating, and vigorous mixing. 4.
Mechanical
pipetting devices should be used for manipulating all liquids in the
laboratory. Mouth pipetting must not be done. 5.
Use
of needles and syringes should be limited to situations in which there is no
alternative, and the recommendations for preventing injuries with needles
outlined under universal precautions should be followed. 6.
Laboratory
work surfaces should be decontaminated with an appropriate chemical germicide
after a spill of blood or other body fluids and when work activities are
completed. 7.
Contaminated
materials used in laboratory tests should be decon- taminated before
reprocessing or be placed in bags and disposed of in accordance with
institutional policies for disposal of infective waste (24). 8.
Scientific
equipment that has been contaminated with blood or other body fluids should
be decontaminated and cleaned before being repaired in the laboratory or
transported to the manufacturer. 9.
All
persons should wash their hands after completing laboratory activities and
should remove protective clothing before leaving the laboratory. Implementation
of universal blood and body-fluid precautions for ALL patients
eliminates the need for warning labels on specimens since blood and other
body fluids from all patients should be considered infective. Environmental
Considerations for HIV Transmission No
environmentally mediated mode of HIV transmission has been documented. Nevertheless,
the precautions described below should be taken routinely in the care of ALL
patients. Sterilization
and Disinfection Standard
sterilization and disinfection procedures for patient-care equipment
currently recommended for use (25, 26) in a variety of health- care settings
-- including hospitals, medical and dental clinics and offices, hemodialysis
centers, emergency-care facilities, and long-term nursing-care facilities --
are adequate to sterilize or disinfect instruments, devices, or other items
contaminated with blood or other body fluids from persons infected with
blood-borne pathogens including HIV (21, 23). Instruments
or devices that enter sterile tissue or the vascular system of any patient or
through which blood flows should be sterilized before reuse. Devices or items
that contact intact mucous membranes should be sterilized or receive
high-level disinfection, a procedure that kills vegetative organisms and
viruses but not necessarily large numbers of bacterial spores. Chemical
germicides that are registered with the U.S. Environmental Protection Agency
(EPA) as "sterilants" may be used either for sterilization or for
high-level disinfection depending on contact time. Contact
lenses used in trial fittings should be disinfected after each fitting by
using a hydrogen peroxide contact lens disinfecting system or, if compatible,
with heat (78 C-80 C {172.4 F-176.0 F}) for 10 minutes. Medical
devices or instruments that require sterilization or disinfection should be
thoroughly cleaned before being exposed to the germicide, and the
manufacturer's instructions for the use of the germicide should be followed. Further,
it is important that the manufacturer's specifications for compatibility of
the medical device with chemical germicides be closely followed. Information
on specific label claims of commercial germicides can be obtained by writing
to the Disinfectants Branch, Office of Pesticides, Environmental Protection
Agency, 401 M Street, SW, Washington, D.C. 20460. Studies
have shown that HIV is inactivated rapidly after being exposed to commonly
used chemical germicides at concentrations that are much lower than used in
practice (27-30). Embalming fluids are similar to the types of chemical
germicides that have been tested and found to completely inactivate HIV. In
addition to commercially available chemical germicides, a solution of sodium
hypochlorite (household bleach) prepared daily is an inexpensive and
effective germicide. Concentrations ranging from approximately 500 ppm (1:100
dilution of household bleach) sodium hypochlorite to 5,000 ppm (1:10 dilution
of household bleach) are effective depending on the amount of organic
material (e.g., blood, mucus) present on the surface to be cleaned and
disinfected. Commercially available chemical germicides may be more
compatible with certain medical devices that might be corroded by repeated
exposure to sodium hypochlorite, especially to the 1:10 dilution. Survival
of HIV in the Environment The
most extensive study on the survival of HIV after drying involved greatly
concentrated HIV samples, i.e., 10 million tissue-culture infectious doses
per milliliter (31). This concentration is at least 100,000 times greater
than that typically found in the blood or serum of patients with HIV
infection. HIV was detectable by tissue-culture techniques 1-3 days after
drying, but the rate of inactivation was rapid. Studies performed at CDC have
also shown that drying HIV causes a rapid (within several hours) 1-2 log
(90%-99%) reduction in HIV concentration. In tissue-culture fluid, cell-free
HIV could be detected up to 15 days at room temperature, up to 11 days at 37
C (98.6 F), and up to 1 day if the HIV was cell-associated. When
considered in the context of environmental conditions in health- care
facilities, these results do not require any changes in currently recommended
sterilization, disinfection, or housekeeping strategies. When medical devices
are contaminated with blood or other body fluids, existing recommendations
include the cleaning of these instruments, followed by disinfection or
sterilization, depending on the type of medical device. These protocols
assume "worst-case" conditions of extreme virologic and
microbiologic contamination, and whether viruses have been inactivated after
drying plays no role in formulating these strategies. Consequently, no
changes in published procedures for cleaning, disinfecting, or sterilizing
need to be made. Housekeeping Environmental
surfaces such as walls, floors, and other surfaces are not associated with
transmission of infections to patients or health-care workers. Therefore,
extraordinary attempts to disinfect or sterilize these environmental surfaces
are not necessary. However, cleaning and removal of soil should be done
routinely. Cleaning
schedules and methods vary according to the area of the hospital or
institution, type of surface to be cleaned, and the amount and type of soil
present. Horizontal surfaces (e.g., bedside tables and hard- surfaced
flooring) in patient-care areas are usually cleaned on a regular basis, when soiling
or spills occur, and when a patient is discharged. Cleaning of wails, 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. Disinfectant-detergent
formulations registered by EPA can be used for cleaning environmental
surfaces, but the actual physical removal of microorganisms by scrubbing is
probably at least as important as 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. Cleaning
and Decontaminating Spills of Blood or Other Body Fluids Chemical
germicides that are approved for use as "hospital disinfectants"
and are tuberculocidal when used at recommended dilutions can be used to
decontaminate spills of blood and other body fluids. Strategies for
decontaminating spills of blood and other body fluids in a patient-care
setting are different than for spills of cultures or other materials in
clinical, public health, or research laboratories. In patient- care areas,
visible material should first be removed and then the area should be
decontaminated. With large spills of cultured or concentrated infectious
agents in the laboratory, the contaminated area should be flooded with a
liquid germicide before cleaning, then decontaminated with fresh germicidal
chemical. In both settings, gloves should be worn during the cleaning and
decontaminating procedures. Laundry Although
soiled linen has been identified as a source of large numbers of certain
pathogenic microorganisms, the risk of actual disease transmission is
negligible. Rather than rigid procedures and specifi- cations, hygienic and
common-sense storage and processing of clean and soiled linen are recommended
(26). 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. All soiled linen should be bagged at the location where
it was used; it should not be sorted or rinsed in patient-care areas. Linen
soiled with blood or body fluids should be placed and transported in bags
that prevent leakage. If hot water is used, linen should be washed with
detergent in water at least 71 C (160 F) for 25 minutes. If low-temperature
(less than or equal to 70 C {158 F}) laundry cycles are used, chemicals
suitable for low-temperature washing at proper use concentration should be
used. Infective
Waste 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 has caused disease in the community as a result
of improper disposal. Therefore, identifying wastes for which special
precautions are indicated is largely a matter of judgment about the relative
risk of disease transmission. The most practical approach to the management
of infective waste is to identify those wastes with the potential for 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. While any item that has had contact with blood, exudates,
or secretions may be potentially infective, it is not usually considered
practical or necessary to treat all such waste as infective (23, 26). Infective
waste, in general, should either be incinerated or should be autoclaved
before disposal in a sanitary landfill. 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 to dispose of other
infectious wastes capable of being ground and flushed into the sewer. Implementation
of Recommended Precautions Employers
of health-care workers should ensure that policies exist for: 1.
Initial
orientation and continuing education and training of all health-care workers
-- including students and trainees -- on the epidemiology, modes of
transmission, and prevention of HIV and other blood-borne infections and the
need for routine use of universal blood and body-fluid precautions for ALL
patients. 2.
Provision
of equipment and supplies necessary to minimize the risk of infection with
HIV and other blood-borne pathogens. 3.
Monitoring
adherence to recommended protective measures. When monitoring reveals a
failure to follow recommended precautions, counseling, education, and/or
re-training should be provided, and, if necessary, appropriate disciplinary
action should be considered. Professional associations and labor
organizations, through continuing education
efforts, should emphasize the need for health-care workers to follow
recommended precautions. Serologic
Testing for HIV Infection Background A
person is identified as infected with HIV when a sequence of tests, starting
with repeated enzyme immunoassays (EIA) and including a Western blot or
similar, more specific assay, are repeatedly reactive. Persons infected with
HIV usually develop antibody against the virus within 6-12 weeks after
infection. The
sensitivity of the currently licensed EIA tests is at least 99% when they are
performed under optimal laboratory conditions on serum specimens from persons
infected for greater than or equal to 12 weeks. Optimal laboratory conditions
include the use of reliable reagents, provision of continuing education of
personnel, quality control of proce- dures, and participation in
performance-evaluation programs. Given this performance, the probability of a
false-negative test is remote except during the first several weeks after
infection, before detectable antibody is present. The proportion of infected
persons with a false-negative test attributed to absence of antibody in the
early stages of infection is dependent on both the incidence and prevalence
of HIV infection in a population (Table 1). The
specificity of the currently licensed EIA tests is approximately 99% when
repeatedly reactive tests are considered. Repeat testing of initially
reactive specimens by EIA is required to reduce the likelihood of laboratory
error. To increase further the specificity of serologic tests, laboratories
must use a supplemental test, most often the Western blot, to validate
repeatedly reactive EIA results. Under optimal laboratory conditions, the
sensitivity of the Western blot test is comparable to or greater than that of
a repeatedly reactive EIA, and the Western blot is highly specific when
strict criteria are used to interpret the test results. The testing sequence
of a repeatedly reactive EIA and a positive Western blot test is highly
predictive of HIV infection, even in a population with a low prevalence of
infection (Table 2). If the Western blot test result is indeterminant, the
testing sequence is considered equivocal for HIV infection. When this occurs,
the Western blot test should be repeated on the same serum sample, and, if
still indeterminant, the testing sequence should be repeated on a sample
collected 3-6 months later. Use of other supplemental tests may aid in
interpreting of results on samples that are persistently indeterminant by
Western blot. Testing
of Patients Previous
CDC recommendations have emphasized the value of HIV serologic testing of
patients for: 1 ) management of parenteral or mucous-membrane exposures of
health-care workers, 2) patient diagnosis and management, and 3) counseling
and serologic testing to prevent and control HIV transmission in the
community. In addition, more recent recommendations have stated that
hospitals, in conjunction with state and local health departments, should
periodically determine the prevalence of HIV infection among patients from
age groups at highest risk of infection (32). Adherence
to universal blood and body-fluid precautions recommended for the care of all
patients will minimize the risk of transmission of HIV and other blood-borne
pathogens from patients to health-care workers. The utility of routine HIV
serologic testing of patients as an adjunct to universal precautions is
unknown. Results of such testing may not be available in emergency or
outpatient settings. In addition, some recently infected patients will not
have detectable antibody to HIV (Table 1). Personnel
in some hospitals have advocated serologic testing of patients in settings in
which exposure of health-care workers to large amounts of patients' blood may
be anticipated. Specific patients for whom serologic testing has been
advocated include those undergoing major operative procedures and those
undergoing treatment in critical-care units, especially if they have
conditions involving uncontrolled bleeding. Decisions regarding the need to
establish testing programs for patients should be made by physicians or
individual institutions. In addition, when deemed appropriate, testing of
individual patients may be performed on agreement between the patient and the
physician providing care. In
addition to the universal precautions recommended for all patients, certain
additional precautions for the care of HIV-infected patients undergoing major
surgical operations have been proposed by personnel in some hospitals. For
example, surgical procedures on an HIV-infected patient might be altered so
that hand-to-hand passing of sharp instruments would be eliminated; stapling
instruments rather than hand-suturing equipment might be used to perform
tissue approximation; electrocautery devices rather than scalpels might be
used as cutting instruments; and, even though uncomfortable, gowns that
totally prevent seepage of blood onto the skin of members of the operative
team might be worn. While such modifications might further minimize the risk
of HIV infection for members of the operative team, some of these techniques
could result in prolongation of operative time and could potentially have an
adverse effect on the patient. Testing programs, if
developed, should include the following principles: 1.
Obtaining
consent for testing. 2.
Informing
patients of test results, and providing counseling for seropositive patients
by properly trained persons. 3.
Assuring
that confidentiality safeguards are in place to limit knowledge of test
results to those directly involved in the care of infected patients or as
required by law. 4.
Assuring
that identification of infected patients will not result in denial of needed
care or provision of suboptimal care. 5.
Evaluating
prospectively 1) the efficacy of the program in reducing the incidence of
parenteral, mucous-membrane, or significant cutaneous exposures of
health-care workers to the blood or other body fluids of HIV-infected
patients and 2) the effect of modified procedures on patients. Testing
of Health-Care Workers Although
transmission of HIV from infected health-care workers to patients has not
been reported, transmission during invasive procedures remains a possibility.
Transmission of hepatitis B virus (HBV) -- a blood- borne agent with a
considerably greater potential for nosocomial spread -- from health-care
workers to patients has been documented. Such transmission has occurred in
situations (e.g., oral and gynecologic surgery) in which health-care workers
when tested had very high concentrations of HBV in their blood (at least 100
million infectious virus particles per milliliter, a concentration much
higher than occurs with HIV infection), and the health-care workers sustained
a puncture wound while performing invasive procedures or had exudative or
weeping lesions or microlacerations that allowed virus to contaminate
instruments or open wounds of patients (33, 34). The
hepatitis B experience indicates that only those health-care workers who
perform certain types of invasive procedures have transmitted HBV to
patients. Adherence to recommendations in this document will minimize the
risk of transmission of HIV and other blood-borne pathogens from health-care
workers to patients during invasive procedures. Since transmission of HIV
from infected health-care workers performing invasive procedures to their
patients has not been reported and would be expected to occur only very
rarely, if at all, the utility of routine testing of such health-care workers
to prevent transmission of HIV cannot be assessed. If consideration is given
to developing a serologic testing program for health-care workers who perform
invasive procedures, the frequency of testing, as well as the issues of
consent, confidentiality, and consequences of test results -- as previously
outlined for testing programs for patients -- must be addressed. Management
of Infected Health-Care Workers Health-care
workers with impaired immune systems resulting from HIV infection or other
causes are at increased risk of acquiring or experiencing serious
complications of infectious disease. Of particular concern is the risk of
severe infection following exposure to patients with infectious diseases that
are easily transmitted if appropriate precautions are not taken (e.g., measles,
varicella). Any health-care worker with an impaired immune system should be
counseled about the potential risk associated with taking care of patients
with any transmissible infection and should continue to follow existing
recommendations for infection control to minimize risk of exposure to other
infectious agents (7, 35). Recommendations of the Immunization Practices
Advisory Committee (ACIP) and institutional policies concerning requirements
for vaccinating health-care workers with live-virus vaccines (e.g., measles,
rubella) should also be considered. The
question of whether workers infected with HIV -- especially those who perform
invasive procedures -- can adequately and safely be allowed to perform
patient-care duties or whether their work assignments should be changed must
be determined on an individual basis. These decisions should be made by the
health-care worker's personal physician(s) in conjunction with the medical
directors and personnel health service staff of the employing institution or
hospital. Management
of Exposures If
a health-care worker has a parenteral (e.g., needlestick or cut) or
mucous-membrane (e.g., splash to the eye or mouth) exposure to blood or other
body fluids or has a cutaneous exposure involving large amounts of blood or
prolonged contact with blood -- especially when the exposed skin is chapped,
abraded, or afflicted with dermatitis -- the source patient should be
informed of the incident and tested for serologic evidence of HIV infection
after consent is obtained. Policies should be developed for testing source
patients in situations in which consent cannot be obtained (e.g., an
unconscious patient). If
the source patient has AIDS, is positive for HIV antibody, or refuses the
test, the health-care worker should be counseled regarding the risk of
infection and evaluated clinically and serologically for evidence of HIV
infection as soon as possible after the exposure. The health-care worker
should be advised to report and seek medical evaluation for any acute febrile
illness that occurs within 12 weeks after the exposure. Such an illness --
particularly one characterized by fever, rash, or lymphadenopathy -- may be
indicative of recent HIV infection. Seronegative health-care workers should
be retested 6 weeks post-exposure and on a periodic basis thereafter (e.g.,
12 weeks and 6 months after exposure) to determine whether transmission has
occurred. During this follow-up period ·
especially
the first 6-12 weeks after exposure, when most infected persons are expected
to seroconvert -- exposed health-care workers should follow U.S. Public
Health Service (PHS) recommendations for preventing transmission of HIV (36,
37). No
further follow-up of a health-care worker exposed to infection as described
above is necessary if the source patient is seronegative unless the source
patient is at high risk of HIV infection. In the latter case, a subsequent
specimen (e.g., 12 weeks following exposure) may be obtained from the
health-care worker for antibody testing. If the source patient cannot be
identified, decisions regarding appropriate follow-up should be
individualized. Serologic testing should be available to all health-care
workers who are concerned that they may have been infected with HIV. If
a patient has a parenteral or mucous-membrane exposure to blood or other body
fluid of a health-care worker, the patient should be informed of the
incident, and the same procedure outlined above for management of exposures
should be followed for both the source health-care worker and the exposed
patient. ·
General
infection-control precautions are more specifically addressed in previous
recommendations for infection-control practices for dentistry (8). **
Additional precautions for research and industrial laboratories are addressed
elsewhere (22,23). References
1.
CDC.
Acquired immunodeficiency syndrome (AIDS): Precautions for clinical and
laboratory staffs. MMWR 1982;31:577-80. 2.
CDC.
Acquired immunodeficiency syndrome (AIDS): Precautions for health- care
workers and allied professionals. MMWR 1983;32:450-1. 3.
CDC.
Recommendations for preventing transmission of infection with human
T-lymphotropic virus type III/lymphadenopathy-associated virus in the
workplace. MMWR 1985;34:681-6, 691-5. 4.
CDC.
Recommendations for preventing transmission of infection with human
T-lymphotropic virus type III/lymphadenopathy-associated virus during
invasive procedures. MMWR 1986;35:221-3. 5.
CDC.
Recommendations for preventing possible transmission of human T-lymphotropic
virus type III/lymphadenopathy-associated virus from tears. MMWR
1985;34:533-4. 6.
CDC.
Recommendations for providing dialysis treatment to patients infected with
human T-lymphotropic virus type III/lymphadenopathy- associated virus
infection. MMWR 1986;35:376-8, 383. 7.
Garner
JS, Simmons BP. Guideline for isolation precautions in hospitals. Infect
Control 1983;4 (suppl):245-325. 8.
CDC.
Recommended infection control practices for dentistry. MMWR 1986;35:237-42. 9.
McCray
E, The Cooperative Needlestick Surveillance Group. Occupational risk of the
acquired immunodeficiency syndrome among health care workers. N Engl J Med
1986;314:1127-32. 10. Henderson DK, Saah AJ, Zak BJ, et
al. Risk of nosocomial infection with human T-cell lymphotropic virus type
III/lymphadenopathy-associated virus in a large cohort of intensively exposed
health care workers. Ann
Intern Med 1986;104:644-7. 11. Gerberding JL, Bryant-LeBlanc CE, Nelson
K, et al. Risk of
transmitting the human immunodeficiency virus, cytomegalovirus, and hepatitis
B virus to health care workers exposed to patients with AIDS and AIDS-
related conditions. J
Infect Dis 1987;156:1-8. 12.
McEvoy
M, Porter K, Mortimer P, Simmons N, Shanson D. Prospective study of clinical,
laboratory, and ancillary staff with accidental exposures to blood or other
body fluids from patients infected with HIV. Br Med J 1987;294:1595-7. 13.
Anonymous.
Needlestick transmission of HTLV-III from a patient infected in Africa. Lancet
1984;2:1376-7. 14.
Oksenhendler
E, Harzic M, Le Roux JM, Rabian C, Clauvel JP. HIV infection with
seroconversion after a superficial needlestick injury to the finger. N Engl J
Med 1986;315:582. 15.
Neisson-Vernant
C, Arfi S, Mathez D, Leibowitch J, Monplaisir N. Needlestick HIV
seroconversion in a nurse. Lancet 1986;2:814. 16.
Grint
P, McEvoy M. Two associated cases of the acquired immune deficiency syndrome
(AIDS). PHLS Commun Dis Rep 1985;42:4. 17.
CDC.
Apparent transmission of human T-lymphotropic virus type III/
lymphadenopathy-associated virus from a child to a mother providing health
care. MMWR 1986;35:76-9. 18. CDC. Update: Human
immunodeficiency virus infections in health-care workers exposed to blood of
infected patients. MMWR
1987;36:285-9. 19. Kline RS, Phelan J, Friedland GH, et al.
Low occupational risk
for HIV infection for dental professionals {Abstract}. In: Abstracts from the
III International Conference on AIDS, 1-5 June 1985. Washington, DC: 155. 20. Baker JL, Kelen GD, Sivertson KT, Quinn TC. Unsuspected human immuno- deficiency virus in critically ill emergency patients. JAMA 1987;257: 2609-11. 21.
Favero MS. Dialysis-associated diseases and their control. In: Bennett JV, Brachman PS, eds. Hospital infections. Boston:
Little, Brown and Company, 1985:267-84. 22.
Richardson
JH, Barkley WE, eds. Biosafety in microbiological and biomedical
laboratories, 1984. Washington, DC: US Department of Health and Human
Services, Public Health Service. HHS publication no. (CDC) 84-8395. 23.
CDC.
Human T-lymphotropic virus type III/lymphadenopathy-associated virus: Agent
summary statement. MMWR 1986;35:540-2, 547-9. 24. Environmental Protection Agency. EPA guide for infectious waste management. Washington, DC:U.S. Environmental Protection Agency, May 1986 (Publication no. EPA/530-SW-86-014). 25.
Favero MS. Sterilization, disinfection, and antisepsis in the hospital. In:
Manual of clinical microbiology. 4th ed, Washington, DC: American Society for
Microbiology, 1985;129-37. 26.
Garner
JS, Favero MS. Guideline for handwashing and hospital environ- mental
control, 1985. Atlanta: Public Health Service, Centers for Disease Control,
1985. HHS publication no. 99-1117. 27. Spire B, Montagnier L,
Barre-Sinoussi F, Chermann JC. Inactivation of lymphadenopathy associated
virus by chemical disinfectants. Lancet 1984;2:899-901. 28. Martin LS, McDougal JS, Loskoski SL. Disinfection and inactivation of
the human T lymphotropic virus type III/lymphadenopathy-associated virus. J Infect Dis 1985;152:400-3. 29. McDougal JS, Martin LS, Cort SP, et al. Thermal inactivation of the
acquired immunodeficiency syndrome virus-III/lymphadenopathy-associated
virus, with special reference to antihemophilic factor. J Clin Invest 1985;76:875-7. 30.
Spire B,
Barre-Sinoussi F, Dormont D, Montagnier L, Chermann JC. Inactivation of
lymphadenopathy-associated virus by heat, gamma rays, and ultraviolet light. Lancet
1985;1:188-9. 31.
Resnik
L, Veren K, Salahuddin SZ, Tondreau S, Markham PD. Stability and inactivation
of HTLV-III/LAV under clinical and laboratory environ- ments. JAMA
1986;255:1887-91. 32. CDC. Public Health Service (PHS) guidelines for counseling and antibody testing to prevent HIV infection and AIDS. MMWR 1987;3:509-15. 33.
Kane MA, Lettau LA. Transmission of HBV from dental personnel to
patients. J Am Dent Assoc 1985;110:634-6. 34.
Lettau
LA, Smith JD, Williams D, et. al. Transmission of hepatitis B with resultant
restriction of surgical practice. JAMA 1986;255:934-7. 35.
Williams
WW. Guideline for infection control in hospital personnel. Infect Control
1983;4 (suppl):326-49. 36.
CDC.
Prevention of acquired immune deficiency syndrome (AIDS): Report of inter-agency
recommendations. MMWR 1983;32:101-3. 37.
CDC.
Provisional Public Health Service inter-agency recommendations for screening
donated blood and plasma for antibody to the virus causing acquired
immunodeficiency syndrome. MMWR 1985;34:1-5. All MMWR HTML
documents published before January 1993 electronic conversions from ASCII
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