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Safety
and Health Hazards of Personnel Using Laboratory Animals at Washington
University
I.
INTRODUCTION
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A. Safety is an important objective of
the University. Safety is promoted and achieved through good
facilities and equipment, the establishment and enforcement of
safety rules, informed and trained personnel, and the use of
appropriate protective equipment. |
B. General Safety Principles:
· Each individual is responsible
for safety
· Don't take unnecessary chances
· Read posted signs and information manuals
· Obey safety precautions
· Ask questions, if you are not sure
· Don't hurry
· Use common sense at all times |
C. Health Hazards of Personnel Working with Laboratory
Animals
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1. As a rule, the incidence of human zoonoses
(i.e. diseases of animals transmissible to man) is very low among
personnel handling laboratory animals, and a complete listing
of these diseases is apt to produce a distorted impression of
the actual danger. Some of the more common and serious diseases
will be highlighted later in this document (Section VIII). In general, health and safety matters
relate to the species with which you work and the frequency and
type of contact. |
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2. Some animals in research facilities may be inoculated
with biohazardous agents such as infectious agents and toxic
or radioactive chemicals. When such agents are used, the room
and cages are clearly marked and employees are given instruction
on the appropriate and safe methods of handling animals, bedding,
and cages. Use of biohazards in animals is reviewed and approved
by University committees to minimize risk to personnel. |
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3. Visits to animal facilities by outside
personnel, guests and relatives of University staff pose a special
problem, due to their unknown health status. Of special concern
are zoonoses involved with children and certain species of nonhuman
primates. Authorized visitors shall be accompanied by a facility
staff or faculty member and wear appropriate protective garments
to minimize health hazards while in the facility. |
 
II.
HAZARDS ASSOCIATED WITH ANIMALS
A. Rodents and Rabbits
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Practically all of the smaller laboratory
animals (e.g. mice, rats, rabbits, hamsters, guinea pigs, etc.)
are procured from vendors having animal colonies free of human
and most animal pathogens (disease causing organisms). Thus the
chance of contracting an infectious disease from a laboratory
bred rodent or rabbit is small. The most significant hazard associated
with these animals is the possibility of developing or exacerbating
an allergy or being bitten (see discussion of laboratory animal
allergies, bites and scratches, section VIII.A). |
B. Dogs and Cats
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These animals are generally obtained
from colonies bred for research purposes. Their health status
and history are known and exposure to serious zoonotic diseases,
including rabies, is minimized. However, care and discretion
must be exercised around these animals. Cats can transmit toxoplasmosis
which can cause birth defects if a pregnant woman is infected
early in gestation. The most frequent injuries associated with
dogs and cats are bites, scratches and allergies. |
C. Farm Animals
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Animals such as swine, goats, sheep,
and poultry, are purchased from varied sources, usually without
complete information on their health and immunization history.
This dictates the need for care in handling these animals and
taking appropriate measures such as quarantine and isolation
to control and identify diseases, especially those transmissible
to man. The most common laboratory-acquired infection associated
with these species is Q-fever. Q-fever is most commonly associated
with sheep and is a particular problem when working with pregnant
sheep and newborn lambs. This disease will be discussed in more
detail later. Care must be exercised when working with farm animals
to avoid bites, scratches, kicks and strains. |
D. Nonhuman Primates
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Nonhuman primates can harbor and
transmit a number of serious human diseases. The most important
of these will be discussed later. In addition, monkeys are wild,
strong, unpredictable, and all are considered dangerous. Rooms
housing monkeys should always be locked and access restricted
to trained personnel. |
E. Feral Animals and Unusual Species
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Nontraditional laboratory animals
are frequently used in biomedical research. It is not unusual
to have ferrets, bats, pigeons, amphibians and reptiles in our
facilities. Most of these species will be maintained in an isolated,
restricted setting with specific safety instructions, as indicated. |
F. Summary
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Though laboratory animals are capable
of carrying zoonotic diseases, all can be used safely if there
is awareness of the potential risks and hazards and adherence
to certain procedures. The purpose of this document is to describe
appropriate procedures for working with animals in a safe manner.
It describes procedures for human and animal health maintenance
and some of the common zoonotic diseases of animals used in research
at Washington University. |
III.
PERSONAL HYGIENE
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A. Personnel are advised and encouraged to wear a
uniform, scrubs or a full length laboratory coat in animal holding
rooms or when working with animals. These should not be worn
in public areas and should never be taken home. |
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B. Wear disposable gloves when handling animals or
related equipment. Sinks, soap, and hand towels should be available
in all animal rooms. Wash your hands before leaving the room. |
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C. When hands, arms, neck, face, or head become accidentally
or unavoidably contaminated with animal blood, urine, feces,
or hair, remove contamination as quickly as possible by washing
thoroughly with water and soap. When such contamination enters
the mouth or eyes, remove quickly by washing and rinsing with
generous amounts of water. Note locations of eye wash stations
for use in such an emergency. |
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D. Any person entering a monkey room for any reason
must wear a gown or coveralls, disposable nose-mouth mask, and
disposable plastic gloves. |
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E. Many animal rooms at the University are dedicated
to a special purpose or project such as pathogen-free rabbits
or biohazardous material use. Special instructions for entering
rooms are posted on room doors. For your health, the health of
the animals, and the success of the project, follow all instructions
exactly. |
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F. Do not smoke, eat, drink, or apply cosmetics in
rooms or areas where laboratory animals are housed and/or used. |
IV.
SAFETY RELATED TO SANITATION
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A. Floors, walls, sinks, and all fixed equipment
should be kept uncluttered and clean. Countertops should be disinfected
after each use involving animals. |
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B. Movable equipment should be properly stabilized
when in use or stored. |
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C. Animal carcasses, soiled bedding and other biological
wastes are best disposed by incineration. Carcasses and other
wastes should be carefully sealed in plastic bags and placed
in the assigned refrigerated storage area. |
V.
GENERAL SAFETY RULES
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A. WEAR protective clothing and use proper animal
restraint techniques and equipment as instructed by a supervisor. |
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B. REPORT immediately all bites, scratches, and other
injuries inflicted on you by any animal. Your supervisor or the
divisional or departmental office should have information on
reporting animal-related injuries. |
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C. KEEP your work area uncluttered and allow sufficient
aisle space between cage racks and work tables to provide comfortable
work space. |
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D. DO NOT smoke, eat, drink, or apply cosmetics in
animal use or housing areas. |
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E. SET damaged or defective cages and racks aside
and notify a supervisor so the equipment can be repaired. |
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F. DO NOT overload carts, obscure vision, or exceed
weight capacity of transport carriers. This often requires the
use of good judgment and common sense. |
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G. DO NOT recap or otherwise manipulate by hand any
used needle, scalpel or disposable instrument. Dispose of all
sharps (scalpels or blades), needles and syringes; glassware
(pipettes, microscope slides and broken glass); and disposable
instruments in a puncture resistant container. Broken glassware
should be swept up with a brush and dust pan, being careful not
to cut yourself on shards of glass. DO NOT put any of these items
in the trash. |
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H. DO NOT handle animal species that you have not
been taught to handle. This is for your safety as well as that
of the animal. |
VI.
BIOHAZARDOUS PROJECTS
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A. Special containment rooms, designed for projects
involving known hazardous agents, are available. Check with the
Division of Comparative Medicine (DCM) office (362-3700) for
locations. |
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B. Projects involving hazardous agents or materials
will have very strict requirements for clothing and procedures.
Containment procedures are for the protection of personnel and
other animals. Specific standard operating procedures will be
posted. Check with DCM office for more information. |
VII.
RESPONSE TO INJURIES
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A. When an employee is injured while at work, he/she
should always report the injury to a supervisor or the division
or departmental office. |
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1. WUMS
Employees: On the job injuries that occur during the day and
are directly animal-related (bites, scratches, cuts, needle sticks)
should be treated at Washington University Medical School Employee
Health Service, (4525 Scott Ave., 362-3528) if they
take place on the Medical Center campus. |
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2. Hilltop personnel: The two principal
facilities authorized to provide initial treatment are the Barnes-Jewish
Hospital South Emergency Room for acute or traumatic injuries
requiring immediate emergency medical treatment, and for other
injuries, BarnesCare Corporate Health Services. Injuries will be
handled by the Barnes-Jewish Emergency Room (362-9123). |
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3. On-the-job
injuries that are not animal-related are to be referred to the
Barnes Emergency Room, for immediate emergency medical treatment,
and for other injuries to BarnesCare Corporate Health Services,
5000 Manchester, which is located one-quarter mile west of the
Manchester/South Kingshighway intersection. |
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B. The employee should thoroughly and immediately
wash the affected site with a disinfectant soap and water before
seeking treatment. |
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C. A "Washington University Report of Animal Exposure"
should then be filled out, keeping a copy for the department file, and
sending a copy to the Insurance/Safety Office, campus box 1069. The
original should be taken to the Employee Health Service. |
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D. Any bites or scratches from bats, dogs, cats,
feral or nontraditional species, or nonhuman primates MUST be
examined by the EHS. In addition, these incidents should
be reported to a veterinarian so that a decision can be made
regarding euthanasia or quarantine of the animal for rabies diagnosis. |
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E. Bites or scratches from nonhuman primates of the
genus Macaca (rhesus, pigtail, cynomolgus monkeys) or from anything
that may be contaminated by their secretions require special
attention and adherence to strict protocol because of the risk
of herpes B virus infection. A Washington University School of
Medicine protocol for dealing with these injuries should be posted
in all facilities where contact with nonhuman primates occurs.
For specific instructions, refer to the Standard Operating Procedures
for Case Management of Employees Potentially Exposed to HERPES
VIRUS SIMIAE (B VIRUS), located in Tab 2. THIS PROTOCOL MUST
BE FOLLOWED. |
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F. Personnel health monitoring procedures for animal-related
injuries will be initiated and managed by Employee Health Services,
as appropriate for the exposure to specific infectious disease
agents. For more information, refer to the document in Tab 1,
Occupational Health and Safety Program for Personnel with Animal
Contact. |
VIII.
ZOONOSES ASSOCIATED WITH
LABORATORY
ANIMALS
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A. General Considerations for Exposure to All Species |
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1. Laboratory
Animal Allergies: A common health hazard associated with rodents
and rabbits, but which can occur with any animal, is the development
of allergies. The symptoms of allergic reactions can be mild
(runny nose, watery eyes, sneezing), especially during the first
few exposures. With repetitive exposures, however, the allergy
can progress to asthma that may require hospitalization. Direct
contact with animal hair or skin may result in hives, wheals,
or more serious skin rashes. Symptoms may be delayed for hours
after the exposure. A history of allergies to animals increases
the chances that a severe reaction will develop. Diagnosis of
lab animal allergy is based on patient history, physical examination,
and skin testing. The use of masks, gloves, and protective clothing,
working in well-ventilated areas, and housing animals in filter-top
cages will help minimize exposure to animal allergens. Antihistamines
taken prior to animal contact may prevent symptoms from developing.
In some cases allergy shots may be necessary to desensitize an
individual. Symptoms of allergic reaction should be treated by
a physician.
2. Bites and Scratches: Bites and scratches
pose a significant hazard to personnel working with laboratory
animals. Effects of bites and scratches can include pain, anxiety,
wound disfigurement, wound infection, and disease transmission.
Wound infections can be caused by a number of pathogenic bacteria
which are indigenous in animals. These include Pasteurella multocida,
Clostridium tetani, Staphylococcus aureus, and Streptococcus
spp. Infection is common following animal bites especially from
rats, cats, dogs, and monkeys. Most zoonotic diseases of importance
in laboratory animal science are transmitted via animal bites
or scratches. These are discussed below. All animal bites and
scratches should be reported to the supervisor, or the department/division
office, and an incident report completed. All wounds require
meticulous cleansing with soap and water or a povidone-iodine
solution. In addition, bites or scratches from cats, dogs, bats,
feral or nontraditional species and nonhuman primates require
special attention and MUST be seen by the EHS physician or nurse
or the ER when the incident occurs after hours.
3. Gastrointestinal Tract Disease: Animals
are capable of asymptomatically carrying a number of agents which
can cause gastrointestinal disease in man. These include: the
bacterial pathogens, Salmonella, Shigella, Yersinia, Campylobacter,
and E. histolytica, the protozoal pathogen which causes amebiasis.
Symptoms of gastrointestinal disease usually include diarrhea
with or without vomiting, abdominal cramps, and general malaise.
Preventive measures include protective clothing and proper personal
hygiene.
4. Dermatomycoses (Ringworm): Infection
of laboratory animals with numerous species of dermatophytic
fungi is common. These infections are often asymptomatic and
can go unrecognized until personnel become infected. Transmission
occurs via direct or indirect contact with infected carrier animals
or spore-contaminated animal bedding, equipment, etc. Ringworm
in humans is often unnoticed but is generally characterized by
one or more circular red scaled lesions. Occasionally pruritic
vesicles may be present. Personnel can prevent ringworm infections
with protective clothing and proper personal hygiene.
5. Leptospirosis: This is a spirochete
that infects a number of different animal species. In the U.S.
the most common sources of infection are dogs, livestock, rodents,
wild mammals, and cats. Infection usually occurs after contact
with the urine of infected animals or from aerosol exposure during
cage cleaning. The organisms may penetrate skin abrasions or
mucous membranes. Infection may be asymptomatic, but most patients
will develop an illness characterized by flu-like symptoms which
may resolve. This may be followed by a more severe illness with
kidney, liver, and central nervous system involvement.
6. Preventive measures:
· Use high quality animals
from reputable vendors
· Vaccinate random-source animals when indicated
· Strict attention to personal hygiene
· Avoid urine and potentially contaminated water
· Monitor animals for infection
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B. Rodents, Rabbits and Farm Animals (Category 1
or 2 Exposure) |
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Category 1 includes mice, rats,
guinea pigs, hamsters, gerbils, and rabbits. In general these
animals are obtained from vendors who maintain animal colonies
free of animal and human pathogens. Therefore the risk of contracting
a disease from these animals is small. Category 2 includes farm
animals which are capable of carrying Q-fever. The specific diseases
to consider are: |
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1. LCM or lymphocytic choriomeningitis:
This is a latent viral disease of mice and, to a lesser extent,
hamsters, which can infect man. This disease can also be seen
in guinea pigs, chinchillas, rats, dogs, and monkeys. The infection
has been eliminated from most reputable domestic colonies and
vendors. However, it is endemic in the wild mouse population
in this country and in many laboratory mice obtained from foreign
sources. The virus may also be present in experimental mouse
tumors which can serve as a source of infection for humans and
animals alike. LCM infections in man range from a flu-like syndrome
in most patients (fever, headache, muscle aches, fatigue), to
signs and symptoms of meningitis (severe headache, fever) and
encephalitis (headache, psychosis, coma). Preventionis based
on obtaining high quality, virus-free mice and hamsters from
reliable vendors, and the use of disposable gloves, and careful
hand washing.
2. Q-Fever: This is a disease caused by
the rickettsial organism Coxiella burnetti. Q-fever is found
around the world, and can naturally infect a variety of animals.
Livestock, especially sheep, are the most common source of infection
to man. These animals generally do not have clinical disease.
The organism is shed in the urine, feces, and milk. In addition,
large numbers of infective organisms are shed in the placental
membranes and amniotic fluid of infected animals. (Personnel
involved in protocols utilizing parturient sheep, or the products
of parturition, are at high risk to develop this disease). The
principal mode of transmission to man is by inhalation of infective
aerosols. The symptoms of Q-fever develop after a 14 to 28 day
incubation period, and consist of fever, headache, and chills.
A cough may be present. Most patients will have a self-limited
illness of about 2 weeks, but patients can develop liver disease
(hepatitis), or disease of the heart valves (valvular endocarditis).
The latter infection is of special concern to people who have
undergone valvular replacement surgery. Q-fever is diagnosed
by measuring serum antibody levels (serology). Prevention could
be accomplished by utilizing only animals known to be free of
Q-fever infection; unfortunately Q-fever-free flocks of animals,
especially sheep, are rare.
The most practical approach to
avoid Q-fever involves some of the following:
· Use only male animals
(sheep, goats, cattle) when possible.
· Avoid the products of parturition.
· Wear protective clothing, including face masks, shoe
covers, and disposable gloves when working with any potentially
infected animals.
· Isolate any potentially infected animals.
· Transport potentially infected animals in filtered cages.
a. Policy and Procedure for the Use of Pregnant Sheep
1. A completely contained filtered
transport cage must be used to transfer pregnant sheep from the
delivery dock to the designated housing area and/or in any public
area. These animals must never be transported in public access
areas without approval by a DCM veterinarian.
2. Pregnant sheep shall be housed and
used in a Biosafety Level - 2 area with appropriate signage as
follows: a. entrance into this area shall be
restricted to necessary personnel b. Air pressure in
this area shall be negative with respect to the rest of the
facility. c. Air shall be exhausted directly to the outside.
3. Personnel must wear protective
clothing which is not worn outside the biohazard area. This
include disposable gowns or tyvek coveralls, caps, surgical masks,
boots or shoe covers and disposable gloves. Surgical scrubs shall
be worn underneath protective clothing. Street clothes will not be
permitted. 4. All
potentially contaminated material shall be disinfected, sterilized
or placed in biohazard containers and incinerated.
5. Surgical instruments shall
be cleaned using a 1:100 bleach solution, rinsed twice with water
and sterilized. 6.
Carcasses of sheep, placentas and birth products shall be double
bagged, labeled as a biohazard and disposed of by the EHSO.
7. Excrement will be disposed
of through sanitary sewage system. No bedding will be used.
8. Bleach (1:100 final
concentration) will be used to sanitize the room between animal
groups or every 2 weeks, whichever is sooner.
9. The room used for surgery
shall contain the minimal equipment necessary and will be
disinfected with a 1:100 bleach solution at the end of each day it
is used. 10. Air pressure in
the surgery room shall be negative to the surrounding areas.
11. Persons who are
immunocompromised and women of child bearing age will be informed
of the theoretical risk. Persons with valvular heart disease or
prosthetic valves shall be excluded from this project if possible.
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3. Orf: This is a parapoxvirus disease of sheep, goats
an wild ungulates and is characterized by epithelial proliferation and
necrosis in the skin and mucous membranes of the urogenital and
gastrointestinal tracts. The disease affects all age groups although
young animals are most frequently affected. The organism is
transmitted by direct contact with scabs and exudates from viral laden
lesions. Transmission by fomites or other animals contaminated with
the virus is also possible. Orf virus produces proliferative, pustular
encrustations on the lips, nostrils, and mucous membranes of the oral
cavity and urogenital orifices of infected animals. In humans the
disease is characterized by the development of a solitary lesion
located on the hands, arms, or face. The lesion is pustular initially
and progresses to a weeping nodule. Occasionally several nodules are
present and persists for 3-6 weeks. Personnel should wear gloves and
wash hands, as well as launder clothing and disinfect boots after
contact with sheep. Clippers, ear tagging devices, and other similar
equipment should always be cleaned and disinfected after each use. |
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C. Dogs, Cats, Nontraditional and Feral Species (Category
3 Exposure) |
Animals in this group (dogs, cats,
and any animals which are feral or not traditionally considered
to be laboratory animals) are usually not obtained from sources
which can provide full immunization and health records. For this
reason, and because these animals can transmit a number of diseases
to man, extra care must be taken around members of this group.
Specific diseases to consider are:
1. Rabies:
This is one of the oldest, and deadliest diseases known to man.
It is caused by the rabies virus, a member of the rhabdovirus
family. Most mammals are susceptible to the virus, and most mammals
can transmit it to man. Animal reservoirs include skunks, raccoons,
foxes, coyotes, and bats. Any wild or random source animal must
be considered a potential source of rabies infection. Rodents
and rabbits are not known to be infected in nature. Rabies is
generally transmitted by the saliva of an infected animal, usually
introduced by a bite, or scratch. Infection has also occurred
by contact with tissue from a rabid animal, and through inhalation
of aerosolized virus. The signs and symptoms of rabies can develop
weeks, months or even years after the initial infection. They
usually begin with vague complaints, such as fatigue, malaise,
and headache, then progress to increasing irritability, nervousness,
and insomnia. In about half the patients numbness or tingling
at the bite or scratch site may be the first sign. Patients then
progress to obvious signs of central nervous system disease,
including paralysis, and coma. Death usually occurs within 7
days in untreated patients, and within months in almost all patients.
Fewer than 10 survivors of rabies have been reported. The only
way to deal with rabies is to prevent it. This is accomplished
by: |
a. Considering any large mammal, especially
wild or random source animals as potentially infected with rabies.
b. Vaccination with the human diploid cell
vaccine (HDCV) for all personnel whose work places them at risk
for rabies infection (all personnel working with category 3 animals).
c. Immediate reporting of any bites or
scratches from potentially rabid animals to a supervisor or PI,
the EHS physician, and the attending veterinarian who should
be notified so that arrangements can be made for diagnostic evaluation
of the suspect animal.
d. Exercising extreme care in the handling
of these animals.
e. Wearing appropriate protective clothing
when working with any of these animals.
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2. Toxoplasmosis:
This disease is caused by the protozoan parasite, Toxoplasma
gondii. The organism infects almost all mammals. Many people
have been infected by ingesting improperly cooked meat (lamb,
pork, or beef) contaminated with Toxoplasma cysts. The disease
can be transmitted to a fetus by an infected mother (if she becomes
infected while pregnant) and result in congenital toxoplasmosis.
In the immunocompetent host toxoplasmosis is most often an asymptomatic
infection; in immunocompromised patients, especially those with
AIDS, it can cause a fatal central nervous system infection.
The definitive host for this organism is the cat, which commonly
sheds Toxoplasma oocysts (eggs) in its feces. These oocysts do
not become infective for 1-5 days. The true occupational risk
is for pregnant women, or personnel who are severely immunosuppressed.
Those who are immunosuppressed should avoid contact with cats,
and especially their feces. Testing for previous infection with
Toxoplasma should be performed on all women of childbearing age
who anticipate contact with cats. If immunity to the disease
is absent or questionable, contact with cats and/or their feces
is contraindicated during pregnancy. In addition, nonimmune pregnant
women should avoid ingestion of raw meat. Prevention of infection
is based on stringent sanitation of cat litter pans (daily changing
prevents eggs from becoming infective), rigorous attention to
personal hygiene, and the wearing of gloves when handling cats.
3. Cat Scratch Disease: As the name suggests
this is a bacterial infection that is almost always associated
with a history of cat contact, bites, or most commonly, scratches.
The disease presents as fever, or malaise, associated with a
swollen lymph node(s), usually proximal to the initial injury.
The disease is generally self-limiting, and complications are
rare. The bacterium is postulated to be part of the normal oral
flora of cats and is transmitted to the claws while grooming.
For this reason the disease is quite difficult to prevent. Declawing
of cats, protective clothing, and care in the proper handling
of cats, are the best preventive measures. Cat scratches should
be reported to a supervisor, and examined by an EHS physician
(see "Bites and Scratches" above). |
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D. Nonhuman Primates (Category 4 Exposure) |
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A number of potentially serious
zoonoses are associated with nonhuman primates. In addition,
these species can contract diseases from man, and, in turn, transmit
them to susceptible personnel. Finally, the strength, and unpredictability
of these animals makes them a constant danger to personnel. Extreme
caution should be exercised at all times, and handling of these
animals should be restricted to well-trained personnel. Some
handling/manipulations of nonhuman primates should be done while
the animal is anesthetized. Small primates such as squirrel monkeys
may be handled by trained personnel using proper protective gloving.
In cases where a conscious primate weighing more than 2 kg must
be manipulated, a pole and collar or other similar approved system
of rigid control should be used. The transportation of nonhuman
primates outside of animal facilities should be done only in
filtered transport caging. Because of the zoonotic risks and
physical dangers it is mandatory that protective measures be
adopted whenever entering an animal room housing nonhuman primates.
This includes the wearing of surgical facemasks; eye protection
when indicated (e.g., changing cages); and protective clothing
(no bare skin exposed). Eye protection is required in all Macaque rooms. |
Specific diseases to consider
are:
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1. Herpesvirus simiae (B virus): This virus
causes a latent infection in all species of the macaque family
of monkeys. The most commonly infected macaque is the rhesus,
but all macaque species (including pigtails, cynomolgus, and
stumptails) should be considered infected. The disease in monkeys
resembles herpes simplex disease in man, with vesicles and ulcers
(fever blisters) appearing on the face, especially on the mouth
and tongue, and on the genitals. Monkeys with such lesions should
be immediately isolated and not handled until the lesions have
healed. The virus can, however, be shed by all macaques WITHOUT
SHOWING ANY SIGNS of disease; hence any macaque should be considered
potentially infectious. The disease is usually transmitted to
man by contact with contaminated saliva, either by the bite or
scratch of an infected monkey. Contaminated caging, infected
tissue and macaque waste have also been implicated in transmission.
The disease in man differs greatly
from the disease in monkeys. The manifestations are those of
a severe central nervous system infection (encephalitis), often
with associated paralysis. Death occurred in 18 of the 27 reported
cases of herpes B virus infection. The early signs of infection
include blister lesions, pain, numbness or itching at the wound
site, headaches lasting more than 24 hours, and fatigue. Symptoms
usually occur within 30 days of the exposure. Because of the
severity of this disease, a special SOP
for dealing with wounds from macaques or contaminated equipment
has been designed by the Employee Health Service and the Division
of Comparative Medicine. It emphasizes the need for immediate
first aid for the wound, culturing the wound for virus, culturing
the monkey for viral shedding, serology on the macaque and the
patient, and the need for meticulous follow up testing, counseling,
and treatment if indicated.
The best preventive measures
are those outlined above. The most important aspect of personnel
protection involves proper training in the handling of these
animals and constant awareness of the potential of these animals.
This minimizes the chance of a bite or scratch occurring.
2. Tuberculosis: This is a bacterial disease
which nonhuman primates may contract from human carriers in this
country or in their country of origin. Spread of the mycobacterial
organisms occurs most commonly via the aerosol route. The disease
in nonhuman primates is generally progressive and fatal and is
characterized by fever, weight loss, cough, and sputum production.
All nonhuman primates are screened via skin testing during quarantine
and biannually. The disease in man is similar to that in monkeys
but generally less severe and very treatable. Surveillance of
all personnel working with nonhuman primates is accomplished
by a preemployment skin test and annual retesting. The wearing
of a face mask greatly reduces the chance of contracting or transmitting
the disease.
3. Ebola-like
Virus: This virus has been found to be carried by imported cynomolgus
macaques (M. fascicularis), African green monkeys (C. aethiops),
and rhesus monkeys (M. mulatta). Thus far no human illnesses
have occurred as a result of this virus although antibodies have
been detected in animal handlers. The virus belongs to a family
of filoviruses, members of which have caused severe hemorrhagic
fevers in man. Symptoms of hemorrhagic fever include headache,
fever, and bleeding tendencies. Prevention of transmission of
this virus is based on previously mentioned protection practices.
4. Rubeola (measles): This is most commonly
a disease of man, but nonhuman primates can contract the disease,
and in turn, infect man. Measles can be a fatal disease, and
is highly communicable. For this reason all personnel working
with nonhuman primates should provide evidence of immunity to
measles (evidence of vaccination, serological evidence of prior
infection, or date of birth before 1957). All other personnel
without evidence of prior infection or vaccination should receive
the MMR vaccine, unless a contraindication to receiving a live
virus vaccine exists (see the document in Tab 1, Occupational
Health and Safety Program for Personnel with Animal Contact). |
E. Special Considerations
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1. Immunosuppressed Individuals: These
individuals should be particularly aware of the potential of
animals to transmit diseases to humans. In addition to the aforementioned
zoonotic diseases, animals can be a reservoir of many agents
which can infect immunosuppressed persons. These include Pneumocystis
carinii, the agents causing cryptosporidiosis, giardiasis, balantidiasis
and numerous other bacterial and viral agents.
2. Tick-borne Illnesses: There are a number
of human pathogens which are carried by different members of
the tick family. These include the rickettsial organisms of Rocky
Mountain spotted fever, rickettsialpox, murine typhus, and erlichiosis.
The agent of Lyme disease, Borrelia burgdorferi, is also carried
by these parasites. Symptoms of these diseases include fever,
chills, headache, muscle aches, and possibly a rash. All of these
diseases are very treatable.
Ticks are very common in the
St. Louis area and wild or random-source animals are often laden
with the parasites. All random-source and wild animals to be
used in research protocols at Washington University are treated
for external parasites during the conditioning period and should
be clean when they arrive on campus. |
IX.
CONCLUSIONS
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The safety of the members of the
Washington University community is of critical importance to
us all. Working with laboratory animals poses a number of special
health risks which cannot be ignored or trivialized. The key
to creating a safe environment in which to work, and to minimizing
the individual's risk of contracting a disease or sustaining
an injury, lies in cooperation among all members of the University.
Personnel should be provided with the necessary education and
training to enable them to safely handle the animal species with
which they will work. |
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They should be enrolled in the Washington
University Occupational Health Program to insure they have received
the appropriate vaccinations to prevent disease, and the appropriate
screening procedures to detect any diseases that predate their
contact with animals, or which develop during their contact with
animals. Illnesses and injuries should be dealt with promptly
when they occur. The most important component of the program
lies with the individual. Almost all of the diseases we have
listed can be prevented by adherence to personal hygiene regulations,
the use of protective clothing, and common sense. Strict attention
to each of these preventive measures will help reduce the risks
associated with handling laboratory animals. |
References/Acknowledgments
The guidelines listed are based
in large part on the documents entitled:
1. The Safe Handling of Laboratory
Animals, St. Louis University
2. Animal Exposure Surveillance
Program, National Institutes of Health, October, 1988
3. Occupational Health Program,
The Albany Medical College of Union University.
4. Guide for the Care and Use
of Laboratory Animals, National Research Council, 1996.
5. Biosafety in Microbiological
and Biomedical Laboratories, CDC/NIH Publication 84-8395. 1984
6. Laboratory Animal Medicine;
Fox, Cohen, Loew (eds.), Academic Press,Inc. 1984.
References on specific diseases
include:
1. Mandell, G. et al. 1985 The
Principles and Practice of Infectious Diseases. John Wiley and
Sons, New York.
2. Pike, R.M. Laboratory Associated
Infections: Incidence, Fatalities, Causes, and Prevention. Ann.
Rev. Microb. 33:41, 1979.
3. Zoonotic Diseases in the Veterinary
Clinics of North America, Small Animal Practice, W.B. Saunders
Co., 1987.
4. Guidelines for Prevention
of Herpesvirus simiae (B-Virus) Infection in Monkey Handlers,
Laboratory Animal Science 37:709 1987.
5. Zoonosis Updates; periodically
printed in JAVMA.
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