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UPDATE: EBOLA-RELATED FILOVIRUS INFECTION IN NONHUMAN PRIMATES AND INTERIM GUIDELINES FOR HANDLING NONHUMAN PRIMATES DURING TRANSIT AND QUARANTINE

In November 1989, infections caused by a filovirus closely related to
Ebola virus were detected in cynomolgus (Macaca fascicularis ) monkeys
imported from the Philippines and held in a primate quarantine facility
in Virginia (1). One hundred forty-nine persons who came in contact
with infected animals or the blood or tissues of these animals were
placed under surveillance for 21 days after their last known exposure,
and all were tested for Ebola virus antibody. Active surveillance was
discontinued December 25. No illness compatible with that known to be
caused by Ebola virus has occurred among these persons, and none had
antibodyto Ebola virus. Twelve nonhuman primates in two of 12 holding
rooms in the Virginia facility were infected; these and all remaining
animals in the facility were euthanized, and the building was
decontaminated. Extensive investigation at transit points in Amsterdam
and New York did not implicate cross-infection of the monkeys by
African primates. 

In December, a telephone survey of 40 other U.S. primate importers
identified another shipment of cynomolgus monkeys that had arrived in
Pennsylvania from the Philippines on November 28 and in which a number
of unexplained deaths had occurred shortly after arrival. An
Ebola-related filovirus was isolated from liver tissue of one of these
animals. The specific geographic origin within the Philippines of these
animals is being identified, and active surveillance has been initiated
at the facility in Pennsylvania to establish whether the virus has
spread to other groups of monkeys or to human contacts. No unusual
illnesses in staff of the facility have been reported. Animals
currently quarantined are being tested for serologic evidence of Ebola
virus infection. 

Inspection of the four major holding facilities in the Philippines,
including the facility that had supplied the monkeys in Virginia, did
not identify unusual illness compatible with Ebola virus disease in
either workers or nonhuman primates. The infected animals had been
captured from widely separated remote areas. Serologic and virologic
studies of animals and workers are under way in these and other
facilities in the Philippines.  

Reported by: RK Miller, MD, Faiffax Health District: JY Baumgardner,
MAS, CW Armstrong, MD, SR Jenkins, VMD, CD Woolard, MPH, GB Miller,
Jr, MD, State Epidemiologist, Virginia State Dept of Health. GG
Wrigley, Buckshire Corporation, Perkasie; LD Polk, MD, Bucks County
Health Dept; DR Tavris, MD, State Epidemiologist Pennsylvania State
Dept of Health. MEG Miranda, DVM, MM Dayrit, MD, field Epidemiology
Training Program, MC Saniel, MD, Research Institute for Tropical
Medicine, Philippine Dept of Health. Div of Quarantine, Center for
Prevention Svcs; Div of Global EIS, International Health Program
Office; Scientific Resources Program, Div of Viral ond Rickettsial
Diseases, Center for Infectious Diseases, CDC  

Editorial Note: The episodes documented in Virginia and Pennsylvania
are the first known instances of Ebola-related filovirus infection in
imported primates in the United States. Numerous infectious agents,
including other filoviruses, with a range of pathogenic potential may
be circulating in Africa, Asia, and other parts of the world. 

The ecology, natural history, and mode of transmission in nature of
Ebola virus end the related Marburg virus are unknown. Humans have
acquired the disease from nosocomial transmission (often by
contaminated needles) and from person-to-person transmission to those
in close contact with blood or secretions from seriously ill patients.
The only known episode of the transmission of a filovirus from monkeys
to humans resulted from direct handling, without protective measures,
of blood and tissues from monkeys infected in the wild by Marburg
virus. Animal caretakers did not become infected (2 ). 

The lack of human infection in these incidents suggests the
effectiveness of the quarantine measures instituted in 1975.
Nonetheless, CDC has developed the following interim guidelines that
update and modify the procedures used in the transportation and
quarantine of nonhuman primates. These guidelines are intended for
interim use. A comprehensive set of guidelines will be developed by
CDC, with input from organizations and institutions involved in the
transport, quarantine, care, and regulation of nonhuman primates. 

INTERIM GUIDELINES FOR HANDLING NONHUMAN PRIMATES DURING TRANSIT AND
QUARANTINE 

All imported nonhuman primates are quarantined for the first 31 days
after arrival, including transit time. Nonhuman primates, particularly
those recently captured in the wild, may harbor viruses infectious for
humans. Although such viruses are usually present in the animal's
blood, they may be detected in urine, feces, or saliva. Those at risk
for infection include persons working in temporary or long-term holding
facilities and persons who transport animals to these facilities (e.g.,
cargo handlers and inspectors). Although the risk for human infection
from these activities is low, guidelines are useful to minimize such
risk in persons exposed to nonhuman primates durinq transPOrt and
quarantine.  

General Guidelines for Handling Nonhuman Primates during Transit and
Quarantine 

1. Management of transportation and quarantine facilities should ensure
that personnel are instructed as to the hazards of handling nonhuman
primates, that protective apparel is available, and that the need for
its use is understood. Management should provide periodic retraining
as well as reinforcement of these procedures. 

2. Persons working with nonhuman primates should not drink, eat, or
smoke while handling animals, cages, crates, or materials from such
animals. 

3. Access to animal holding areas should be restricted to essential
personnel. The number of persons involved in the care, transport, and
inspection of nonhuman primates should be the minimum necessary to
expedite efficient and humane handling. 

4. All staff in direct contact with animals should wear protective
clothing (i.e., gloves and surgical masks and gowns) when opening
crates, removing foreign materials from crates, feeding the animals,
removing dead animals, or handling bedding materials. These persons
should remove disposable protective clothing before leaving the animal
holding facilities; this clothing should be autoclaved or incinerated
Nondisposable contaminated clothing should be disinfected on site
before laundering. 

5. Separate nonglass water bottles should be provided for each nonhuman
primate during transit and quarantine. Reusable items should be
adequately decontaminated between uses. 

6. All animal waste, bedding, uneaten food, and other possibly
contaminated items should be treated with appropriate disinfectant
before removal from the animal holding facilities. All cages, feeding
bottles, and other possibly contaminated items should be disinfected
between each use or before disposal. Glass items should not be used.

7. A separate disposable needle and syringe (and, if required, infusion
equipment) should be used for each animal, then autoclaved or
incinerated. A clean needle should be used for any access to multidose
vials (e.g., of ketamine) to avoid contamination. After each use on a
group of quarantined animals, multidose vials must be autoclaved and
discarded. Disposable supplies should be used whenever possible and
must not be reused. Nondisposable equipment should be thoroughly
disinfected. 

8. Caution must be used to prevent infection from potentially
contaminated needles, scalpels, or other sharp instruments,
particularly during disposal of needles. Used needles should not be
recapped by hand; removed from disposable syringes by hand; or bent,
broken, or otherwise manipulated. Only one set of disposable syringes,
needles, and scalpels should be used per animal. Used disposable
syringes and needles, scalpel blades, and other sharp items should be
placed in puncture-resistant containers kept as close to the work site
as practical. 

9. Nonquarantined animals should never be placed in, or permitted
access to, areas with quarantined animals. This includes unrestrained
pets, feral animals, and animals temporarily boarded for overseas
travelers or destined for export. 

10. Management should keep records of all serious febrile illnesses
(fever >101.3 F [>38.5 C] for >2 days) in persons having direct contact
with nonhuman primates in transit or in quarantine and should promptly
notify CDC* if such an illness occurs. Management should ensure that
the physician providing care is informed that the patient works with
and/or has been exposed to nonhuman primates.  

*Program Operations Branch, Division of Quarantine, Center for
Prevention Services, telephone (404) 639-1437, Special Pathogens
Sranch, Division of Viral and Rickettsial Diseases (DVRD), Center for
Infectious Diseases (CID) telephone (404) 639-1115; Epidemiology
Activity Branch, DVRD, CID, telephone (404) 639-3091; and the Animal
Resources Branch, Scientific Resources Program, CID, telephone (404)
639-1320. 

Additional Guidelines for Handling Nonhuman Primates during Transit 

1. Persons who handle crates or pallets containing nonhuman primates
should be protected with elbow-length reinforced leather gloves,
long-sleeved shirts and trousers of sufficient thickness to resist
minor tears, and sturdy waterproof shoes or boots. The gloves should
be of a thickness that prevents penetration of splinters or other
crating debris. During warm weather, garments may be of lightweight
materials to minimize discomfort. Disposable coverall suits can be used
for added protection. 

2. Crates should be free of sharp projections that can cause scratches
or wounds to workers. Handles should be present on the sides of crates,
and mechanical lifting and transporting devices should be used whenever
possible.  

3. Crates containing nonhuman primates should be separated by a
physical or spatial barrier from all other animals and cargo at all
times. 

4. Wherever possible, nonhuman primates should not be handled directly.
Live animals should be removed from cages only when staff can be
supervised by a qualified veterinarian. Procedures that may result in
bites or scratches should be avoided. 

5. Management of holding facilities should maintain records to document
the removal of dead animals; documentation should include the date,
shipment number, country of origin, species, importer, and disposition
of the removed animal. The carcass must be placed in waterproof double
bags and incinerated. The Division of Quarantine, Center for Prevention
Services (CPS), CDC, should be notified. 

6. Temporary holding facilities should document all injections or
parenteral infusions administered to nonhuman primates. 

7. If animals are removed from a shipment while in transit, facilities
retaining these animals should ensure full compliance with these
guidelines and should maintain records on the care and disposition of
animals. Temporary facilities holding animals in this way must be
registered as importers of nonhuman primates.  

Additional Guidelines for Care of Nonhuman Primates during Quarantine

1. Quarantine facilities should be secure, with access limited to
authorized, trained, and informed personnel. 

2. Quarantine facilities should be designed to be adequately
disinfected. Management and staff should refer to the Guide for the
Care and Use of Laboratory Animals (3 ) and the CDC/National Institutes
of Health Biosafety in Microbiological and Biomedical Laboratories,
second edition (Animal biosafety level 2, p. 52) (4 ), for information
on design and operation of animal holding facilities. 

3. Staff should use protective clothing, gloves, and masks at all times
when in the animal holding facilities; these items should be
disinfected or disposed of properly. Staff should use fresh clothing
when going from room to room. 

4. Adequate equipment and space should be available for discarding and
disinfecting all equipment, clothing, and caging. 

5. Care should be taken to avoid scratches and bites of animals. All
handling of individual animals should be done while the animals are
anesthetized or tranquilized, and animals should be maintained in
squeeze-back cages wherever possible. 

6. Different lots of primates should not be mixed while in quarantine
(minimum 31 days). 

7. Management should notify the Division of Quarantine, CPS, CDC, of
severe illnesses and deaths in recently imported primates. CDC will
advise management on collection of specimens for investigation of cause
of death.  

References 
1. CDC. Ebola virus infection in imported primates--Virginia, 1989.
MMWR 1989;38:831-2, 837-8. 
2. Martini GA, Siegert R, eds. Marburg virus disease. Berlin:
Springer-Verlag, 1971. 
3. National Institutes of Health. Guide for the care and use of
laboratory animals. Bethesda, Maryland: National Institutes of Health,
1985:43-8; document no. 85-23. 
4. CDC/National Institutes of Health. Biosafety in microbiological and
biomedical laboratories. 2nd ed. Bethesda, Maryland: US Department of
Health and Human Services, Public Health Service, 1988; DHHS
publication no. (CDC)88-8395.