Pathogen Safety Data Sheet - Brucellosis

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SECTION I: DISEASE / INFECTIOUS AGENT

SYNONYM / CROSS REFERENCE: ⁽¹⁾

• in animals: Bang's disease, enzootic abortion, epizootic abortion, infectious abortion, contagious abortion, or ram epidymitis
• in humans: undulant fever, Malta Fever, Mediterranean Fever, gastric fever, Mediterranean gastric remittent fever, Rock of Gilbralter fever, or intermittent gastric fever

ETIOLOGY / TAXONOMY : ⁽²⁾

Genus: Brucella
Species: traditionally known as melitensis (Bruce 1886), abortus (Bang 1897), suis (Traum 1914), ovis (McFarland 1953), neotomae (Stoenner 1957) and canis (Carmichael 1966); possibly maris (Ewalt 1994)
It is proposed that there be a single species (B. melitensis) and that the classical species should be considered as biovars.

ORGANISM CHARACTERISTICS : ⁽²⁾

• gram negative cocci or short rods (0.5 to 0.7 by 0.6 by 1.5 m) singles, infrequently in pairs, short chains or small groups
• non-motile, acapsular, non-sporulated, aerobic, optimum growth temperature ranges from 20 C to 40 C

SURVEILLANCE :

Brucellosis is a reportable disease in Canada. Animal owners, veterinarians and laboratories are required to immediately report the presence of an animal that is contaminated or suspected of being contaminated to a CFIA district veterinarian. Control or eradication measures will be applied immediately (http://laws.justice.gc.ca/en/H-3.3/fulltoc.html).

DISTRIBUTION :

Brucella abortus and B. suis have been eradicated from Canada except for geographically restricted wildlife reservoirs in northern Canada. Freedom of Canadian livestock from B. abortus and B. suis is confirmed by triennial serological surveys. B. ovis and B. canis are not subject to control or eradication and are considered indigenous and B. melitensis has never been found in Canada.
See OIE list for current status of other countries. http://www.oie.int/eng/info/en_infoan.htm

SECTION II: ANIMAL HEALTH HAZARD AND EPIDEMIOLOGY

CLINICAL DISEASE / PATHOGENESIS : ⁽⁴⁾

In cattle, B. abortus causes abortions, stillbirths and weak calves and bulls may have testicular abscesses or orchitis. Systemic signs are not normally seen. Arthritis can develop after long-term infections.

B. suis in pigs causes abortion, stillbirths and weak piglets. Boars may have temporary or permanent orchitis, may excrete the organism asymptomatically in semen or may exhibit sterility as the only sign of infection.

The infectious dose varies depending on the Brucella and the animal species, and is not known for humans.

The incubation period also varies depending on the Brucella and the animal species. In cattle, abortion and stillbirth usually occurs 2 weeks to 5 months after infection.

SOURCE / MODE OF TRANSMISSION / COMMUNICABILITY : ⁽⁵⁾

Bacteria enter the body through mucous membranes and are spread through the lymphatic system. If the animal is pregnant, the bacteria also invade the uterus and placenta. Sexually mature pregnant animals are more susceptible to infection. The most common modes of transmission for B. abortus and B. suis are ingestion (infected pastures, fetal membranes, contaminated feedstuffs and water), inhalation, direct contact (aborted fetuses, infected newborn), and congenital infection. Fomites, flies, ticks, rats and dogs can also transmit this disease.

VECTORS : ⁽⁵⁾

Blood-sucking parasites may serve as vectors during bacteremic stages of infection but they are not significant vectors.

HOST RANGE : ⁽³⁾

The host range is extensive but there are preferred animal hosts for each Brucella species.
Brucella abortus mainly infects cattle but sheep, goats, dogs, camels, buffalo and feral animals can be infected.
Brucella ovis mainly infects sheep.
Brucella suis mainly infects swine.
Brucella melitensis mainly infects goats.

ZOONOTIC POTENTIAL : ⁽⁴⁾

Brucellosis is zoonotic and the resulting disease is serious. In humans, brucellosis can be caused by B. abortus, B. melitensis, B. suis and, rarely, B. canis. Brucella abortus and B. melitensis livestock vaccines are also pathogenic to humans. People working in occupations requiring frequent contact with animals or meat such as slaughterhouse workers, farmers and veterinarians, or laboratory workers handling large volumes of culture, are at higher risk of acquiring infection. Humans may contract the infection through skin abrasions, mucous membranes or the conjunctiva when they handle infected animals or come in contact with infected tissues or secretions during such activities as butchering, and parturition. Direct person to person spread is rare. The ingestion of unpasteurized dairy products from infected animals may result in infection.

RESERVOIR :

The host carrier animal is the normal reservoir.

Section III: DIAGNOSIS

NECROPSY / HISTOPATHOLOGY FINDINGS : ⁽⁵⁾

Necropsy findings will vary considerably depending on the animal species and the stage of the disease. Necrotizing placentitis and inflammatory changes in the fetus are the most common findings in cattle during the acute clinical phase.

LABORATORY DIAGNOSIS :

Culture of the organism is the definitive diagnosis⁽⁶⁾. The type of serological test used to determine exposure will vary with animal species. Increases in antibody titers may be seen in acute cases, but are not useful for the detection of chronic or recurrent cases. ⁽⁴⁾

DRUG SUSCEPTIBILITY :

Treatment of animals is rarely practical. Humans can be treated with a combination of antimicrobials such as tetracyclines, streptomycin, rifampin, fluoroquinolones, TMP-SMX or doxycycline. Treatment for at least 6 weeks is required to minimize the occurrence of relapses. Long term follow-up care is required since relapses may still occur in 5% of treated cases.

DIFFERENTIAL DIAGNOSIS : ^(4,5)

Other diseases causing abortion in the various species should be considered.

In cattle these may include:

• trichomoniasis
• vibriosis
• leptospirosis
• infectious bovine rhinotracheitis
• various mycosis
• listeriosis
• epizootic viral abortion

SECTION IV: DECONTAMINATION PROCEDURES

Select a registered disinfectant with a drug identification number (DIN). Use according to label directions for concentration and contact time. Consider organic load and temperature. It is recommended that laboratories evaluate the effectiveness of the disinfectant using a validated method (eg. Quantitative Carrier Test). See Table 1 to help select a registered disinfectant for use against Brucella species.

Table 1: Active ingredients considered to be effective against Brucella species.⁽⁷⁾

PHYSICAL INACTIVATION: ⁽⁸⁾

Brucella species are sensitive to temperature, humidity and pH. They are inactivated by ultraviolet irradiation and pasteurization.

SURVIVAL OUTSIDE OF HOST : ⁽⁸⁾

Brucella species have been found to survive under the following conditions:

• 60 days in damp soil and up to 144 days at 20 C and 40 % humidity
• several months in tap water at 4-8 C and 2.5 years at 0 C
• 30 days in urine, 75 days in aborted fetuses and >200 days in uterine exudate
• years in frozen tissues or culture medium

SECTION V: LABORATORY HAZARDS FOR HUMANS

LABORATORY-ACQUIRED INFECTIONS:

Laboratory workers are at the greatest risk through the production of aerosols generated as a result of handling large volumes of culture or from unknowingly processing cultures from brucellosis infected samples. ^(9,10)

BIOSAFETY PRECAUTIONS:

Special precautions must be taken to prevent inhalation of aerosols (eg. handling infected animals especially after abortion, handling of large volumes of cultures), ingestion (contaminated animal products) and accidental injection of vaccine strains.

SECTION VI: PHYSICAL AND OPERATIONAL REQUIREMENTS

CONTAINMENT REQUIREMENTS:

Primary culture and identification of diagnostic specimens is to be performed at Level 2 physical containment provided that Level 3 operational requirements are carried out. All other manipulations, including further identification and sensitivity testing, must be carried out using Level 3 physical and operational requirements as per the Containment Standards for Veterinary Facilities.

The Standards can be accessed at : http://www.inspection.gc.ca/english/sci/lab/convet/convete.shtml

PERSONAL PROTECTIVE EQUIPMENT :

Laboratory: (Level 3)

• primary layer of dedicated laboratory clothing (e.g. scrubs and head cover) and dedicated laboratory footwear should be worn.
• secondary layer of protective clothing (e.g. solid-front gowns with tight-fitting wrists, 2 pairs of gloves) should be worn over laboratory clothing when directly handling infectious materials.
• adequate respiratory protection should be worn when directly handling infectious material outside BSC.
• when full body protective clothing is not worn a shower is required on exit; where a known or suspected aerosol exposure has occurred a shower is required on exit.

Post Mortem:

• primary layer of dedicated laboratory clothing (e.g. scrubs and head cover) and dedicated laboratory footwear should be worn.
• secondary layer of protective clothing should be worn over laboratory clothing when directly handling infectious materials.
• cut resistant gloves, adequate respiratory protection, steel toed/steel shanked rubber boots.
• a shower is required on exit.

HANDLING INFORMATION:

Spills in laboratory:
Spill protocol must be in place and include the following scenarios:

• spills inside the Biological Safety Cabinet (BSC)
• spills outside the BSC
• spills while performing aerosol generating procedures
• also consider entry and exit procedure modifications if necessary, appropriate PPE, disinfection of spill and surroundings including contact time, flow (pattern) of the clean up and disposal of contaminated materials.

Refer to Table 1 for disinfectant selection.

STORAGE : All cultures and infected material should be stored in leakproof, sealed containers that are accurately labeled and clearly identified as a biohazard risk. The access to infectious material should be controlled at all times. Records must be kept to describe the use, inventory and disposal of infectious material.

DISPOSAL : Decontaminate all infectious material prior to disposal. Use steam sterilization, incineration or chemical disinfection.

REFERENCES:

1. Metcalf HE, Luchsinger DW, Winthrop CR, Brucellosis. In: Beran GW, ed. Handbook of Zoonoses, Second Edition, CRC Press, 1994:9-39
2. Shapiro D, Wong J, Brucella. In: Murray PR, ed. Manual of Clinical Microbiology, 7th Edition, ASM Press, 1999: 625-631
3. Brucella evolution and taxonomy, Moreno E, Cloeckaert A, Moriyon I, Vet Microbiol. 2002 Dec 20:90(1-4):209-27
4. Brucellosis Fact Sheet - PDF (174 kb), OIE Collaborating Center, Iowa State University College of Veterinary Medicine, updated 2003/06/03, http://www.cfsph.iastate.edu/Factsheets/pdfs/brucellosis.pdf
5. Radostits OM, Gay CG, Blood DC, Hinchcliff KW, Veterinary Medicine, Ninth Edition, W.B. Saunders Company Ltd. 2003:867-891
6. Nielsen K, Duncan R, ed. Animal Brucellosis,1990
7. Quinn PJ, Markey BK, Disinfection and Disease Prevention in Veterinary Medicine In: Block SS, ed. Disinfection, Sterilization and Preservation, Fifth Edition, Lippincott Williams and Wilkins, 2001:1076-77
8. Bovine Brucellosis, Animal Health Disease Card, Food Agriculture Organization of the United Nations, 2004/08/17 http://www.fao.org/ag/againfo/subjects/en/health/diseases-cards/brucellosi-bo.html
9. Collins CH, Laboratory- Acquired Infections, Third Edition, Butterworth-Heinemann ed. 1993
10. Noviello S et al, Laboratory-acquired Brucellosis, Emerging Infectious Diseases, Vol 10 No 10, October 2004

LAST UPDATED (DATE): May 8, 2005
PREPARED BY: The Biohazard Containment and Safety Unit, CFIA

Disclaimer: Although the information and recommendations in this Pathogen Safety Data Sheet are compiled from reliable sources, there is no guarantee, warranty or any assurance that the information and recommendations are correct, accurate, sufficient, reliable or current and the Canadian Food Inspection Agency shall not be responsible for any loss or damage resulting from or in connection with the use of or reliance upon the information and recommendations.

The user assumes all risks and responsibility for and shall be liable for the use of and any reliance on the information and recommendations and the results thereof and any loss or damage resulting therefrom.