Occupational Health and Safety in the Care and Use of Research Animals (1997) / Chapter Skim
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ZOONOSES
ZOONOSES
Pages 65-105
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From page 65... ...
The laboratory-animal industry has had much success in providing high-quality laboratory animals of defined health status for use in research. And research institutions have developed comprehensive and responsive programs of veterinary care that have fostered the investigation of new disease findings and helped to ensure the continuing health of researchanimal populations.
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From page 66... ...
Material relevant to each zoonotic disease is presented under four headings: reservoir and incidence; mode of transmission; clinical signs, susceptibility, and resistance; and diagnosis and prevention. The discussion on reservoir and incidence addresses the natural infection in the animal host species.
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From page 67... ...
The incubation period between initial exposure and onset of clinical signs ranges from 2 d to about 1 mo, but the time at which symptoms arise after exposure can vary widely. After exposure by bite, scratch, other local trauma, or contamination of vulnerable sites, humans might develop a herpetiform vesicle at the site of inoculation.
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From page 68... ...
. Experimental studies with B virus in animals should be conducted at Animal Biosafety Level 3 (CDC-NIH 1993)
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From page 69... ...
Aerosol transmission has not been a feature of the African Ebola-virus outbreaks to date, but it cannot be discounted completely. During the outbreak of Ebola-Reston disease in the nonhuman-primate colonies in the United States, its spread within rooms between animals without direct contact supported the possibility of droplet or aerosol transmission.
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From page 70... ...
The transmission of Marburg virus from animals to humans has involved direct contact with infected tissues. Aerosol transmission has been suggested as a means of transmission among monkeys (Hunt and others 1978)
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From page 71... ...
The transmission of hantavirus infection is through the inhalation of infectious aerosols, and extremely brief exposure times (5 min) have resulted in human infection.
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From page 72... ...
Animal Biosafety Level 2 is recommended for working with experimentally infected rodent species known not to excrete the virus. All work involving inoculation of the virus into P
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From page 73... ...
Bedding material and other fomites contaminated by LCM-infected animals are potential sources of infection, as are infected ectoparasites. In endemically infected mouse and hamster colonies, the virus is transmitted in utero or early in the neonatal period and produces a tolerant infection characterized by chronic viremia and viruria without marked clinical disease; spread of LCM among animals via contaminated tumors and cell lines also should be recognized (Bhatt and others 1986; Nicklas and others 1993)
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From page 74... ...
. Direct contact with infected animals or contaminated fomites is necessary for disease transmission.
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From page 75... ...
Measles, a highly communicable disease, is transmitted via infectious aerosols, contact with nasal or throat secretions, or contact with fomites freshly contaminated with infectious secretions. Clinical Signs, Susceptibility, and Resistance.
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From page 76... ...
Aerosol transmission is the important means of spread, but contaminated food, water, and equipment also transmit infection within bird populations. Clinical Signs, Susceptibility, and Resistance.
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From page 77... ...
Animal Biosafety Level 2 practices, containment equipment, and facilities are recommended for activities using naturally or experimentally infected chim
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From page 78... ...
. Animal Biosafety Level 2 practices, containment equipment, and facilities are recommended for
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From page 79... ...
Personnel who handle tissue specimens or other materials potentially laden with rabies virus during necropsy or other procedures should be regarded as at risk for infection. Clinical Signs, Susceptibility, and Resistance.
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From page 80... ...
Animal Biosafety Level 2 practices, containment equipment, and facilities are recommended for activities using naturally or experimentally infected animals (CDC-NIH 1993)
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From page 81... ...
. Clinical Signs, Susceptibility, and Resistance.
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From page 82... ...
However, many research studies require the use of pregnant sheep. Neither antimicrobial therapy nor serological testing in combination with the culling of infected animals has led to the reliable development of disease-free flocks for use in biomedical-research programs (Fox and Lipman 1991)
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From page 83... ...
The organism has been isolated on fleas that fed on infected cats, and fleas have been shown to be capable of transmitting the organism between cats. This finding suggests that fleas could serve as a vector in zoonotic transmission (Chomel and others 1996)
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From page 84... ...
Zoonotic transmission of these diseases in the laboratory has involved aerosols, accidental parenteral inoculation, and bites by natural ectoparasitic vectors (CDC-NIH 1993)
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From page 85... ...
Laboratory personnel involved in the care, use, or necropsy of infected animals
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From page 86... ...
Experimentally infected guinea pigs and mice pose a lesser risk to personnel because droplet nuclei are not produced by coughing in these species; however it is prudent to use Animal Biosafety Level 3 for these infected
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From page 87... ...
Latency is a common characteristic of the infections and is especially important in the epizootology of the disease in birds; stress can reactivate enteric shedding of the organism and clinical signs. The organism is spread to humans from infectious material in exudates, secretions, or desiccated fecal material via direct contact or the aerosol route.
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From page 88... ...
Animal Biosafety Level 2 practices, containment equipment and facilities, and respiratory protection are recommended for personnel working with naturally or experimentally infected caged birds (CDC-NIH 1993)
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From page 89... ...
Most human cases are the result of bites by infected fleas or contact with infected rodents. In human plague associated with nonrodent species, infection has resulted from bites or scratches, handling of infected animals (especially cats with pneumonic disease)
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From page 90... ...
. Animal Biosafety Level 2 practices, containment equipment and facilities are recommended for personnel working with naturally or experimentally infected animals (CDC-NIH 1993)
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From page 91... ...
. Transmission occurs through skin abrasions and mucous membranes and is often related to direct contact with urine or tissues of infected animals.
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From page 92... ...
Personnel should rely on the use of protective clothing, personal hygiene, and sanitation measures to prevent the transmission of the disease. Animal Biosafety Level 2 is recommended for activities using naturally or experimentally infected animals (CDC-NIH 1993)
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From page 93... ...
Salmonellae are transmitted by the fecal-oral route via food derived from infected animals or contaminated during preparation, contaminated water, or direct contact with infected animals. Clinical Signs, Susceptibility, and Resistance.
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From page 94... ...
Animal Biosafety Level 2 is recommended for activities using naturally or experimentally infected animals (CDC-NIH 1993)
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From page 95... ...
Laboratory animals with yersiniosis should be isolated and treated or culled from the colony. Personnel should rely on the use of protective clothing, personal hygiene, and sanitation measures to prevent the transmission of the disease.
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From page 96... ...
. Although many other laboratory animals could serve as intermediate hosts and harbor T
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From page 97... ...
. Dogs, cats, and nonhuman primates are the laboratory animals most likely to be involved in zoonotic transmission.
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From page 98... ...
Mode of Transmission. The disease is transmitted by ingestion of amebic cysts that are present in the feces of infected animals.
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From page 99... ...
Diagnosis and Prevention. The treatment of clinically apparent infections in a laboratory-animal host should be coupled with good sanitation and personalhygiene practices to eliminate the zoonotic transmission of this organism in an animal facility.
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From page 100... ...
Animal Biosafety Level 2 practices and facilities are recommended for experimental animal activities with dermatophytes (CDC-NIH 1993)
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From page 101... ...
Animal Biosafety Level 2 practices and facilities are recommended for activities using naturally or experimentally infected animals (CDC-NIH 1993)
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From page 102... ...
Every major group of pathogenic organisms -- including bacteria, rickettsiae, chlamydia, viruses, protozoa, spirochetes, and helminths -- is represented among the agents transmitted by arthropod vectors, and personnel who work with research animals that potentially harbor these agents or the ectoparasite vectors should be informed of the hazard. Rigorous ectoparasite-control programs should be instituted as part of the veterinary-care program, especially for wild-caught species that are brought into a laboratory, animals housed previously under field conditions, and animals with inadequate disease profiles from any source.
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From page 103... ...
Strongyloidiasis Strongyloides Old World Oral and transcutaneous stercoralis, primates, infections can occur in animals Strongyloides dog, cat and humans; heavy infections fulleborni can produce dermatitis, verminous pneumonitis, and enteritis; internal autoinfection can occur. Oesophagostomiasis Oesophagostomum Old World Heavy infections result in spp.
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From page 104... ...
nana, H wild rodents diminuta Nasopsyllus fasciatus Dermatitis Mouse, rat, Vector of H
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From page 105... ...
ZOONOSES 105 TABLE 5-2 Continued Disease in Species Humans Host Comments Ticks Rhipicephalus sanguineus Irritation Dog Vector of Rickettsia rickettsia, Francisella tularensis, Ehrlichia canis Dermacentor variabilis Irritation Wild rodents, Vector of Rickettsia cottontail rabbit, rickettsia, Francisella dogs from tularensis, Ehrlichia endemic areas canis Dermacentor andersoni Irritation Small mammals, Vector of Rickettsia uncommon on dog rickettsia, Francisella tularensis, Ehrlichia canis Dermacentor occidentalis Irritation Small mammals, Vector of Rickettsia uncommon on dog rickettsia, Francisella tularensis, Ehrlichia canis Amblyomma americanum Irritation Wild rodents, dog Ixodes scapularis Irritation Ixodes dammini Irritation Dog, wild rodents Vector of Borrelia burgdorferi, Babesia microtis Adapted from: Fox and others 1984.
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