brucellosis navies 2011. brucella the causative agent of brucellosis zoonotic disease in food...
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BRUCELLOSIS
Navies 2011
Brucella
The causative agent of Brucellosis Zoonotic disease in food animals
More prevalent in developing countries A genus of Gram-negative rods -
coccobacillus Found in 7 different species
B. canis (canine) B. abortus (equine & bovine) B. melitensis B. neotomae B. ovis B. suis
Etiology
• Caused by Brucella canis– Gram negative bacteria– Causes abortions,
usually in third trimester of pregnancy
– Dogs are the definitive host
• Considered a zoonotic bacteria– Human infections are
rare– Caution when handling
aborted animals
Brucella canis rods
History of disease
Thought to exist since Roman times
In 1887 Dr. Bruce isolated the organism (hence Brucellosis)
In 1966 Brucella Canis was identified as the causative agent of canine brucellosis
B. canis
Transmitted through ingestion/ inhalation Bacterium can be found in:
lymphatic system genital tract eye kidney intervertebral disks spleen
Small red coccobacillus in clumps Associated conditions:
Infertility Abortions Diskospondylitis
B. canis
Signalment Non breed specific Affects males/ females
Sexually mature 5-12mos. Of age
B. canis
Clinical Signs: Scrotal swelling/dermatitis Enlarged epididymis Testicular atrophy
Abortion Infertility Vaginal discharge
1-6 wks postabortion
B. canis
Clinical Signs:• Primary sign is abortion
in last trimester of pregnancy, followed by prolonged vaginal discharge
• Infected dogs may develop generalized lymphadenitis
• Epididymitis• Periorchitis• Prostatisis• Spondylitis and uveitis
are occassional complications
Enlarged Epididymis
B. canis
Transmission:• Can easily penetrate any mucous membrane
– Oral, conjunctival or venereal• Infection though oral route is the most common
though ingestion of infected material• In a pregnant female the organism goes
though the uterus and causes a late abortion– After the abortion, vaginal discharge and the
aborted material contain a large number of the bacteria
– In males, the urine and semen is where large numbers of bacteria are found
Diagnostic tests and expected results Isolated from vaginal exudate, aborted
puppies, blood, milk, semen Simplest test is Rapid Slide
Agglutination Test to look for antibodies against disease
B. canis
Diagnosis:• Isolation and identification of the bacteria is the
only way to diagnose the disease– Organism can be isolated from:
• Vaginal exudate• Aborted puppies• Blood (it takes up to 3 weeks to be detected in blood
stream)• Milk• Semen
• Widely used tests are agglutination test by tube or slide method
• Agar gel immunodiffusion tests used in some laboratories
B. canis
Recommended Treatment:• Usually unsuccessful and not recommended
to eliminate the organism• Long term antibiotics used and show some
promise• Animals treated may remain infected after
treatment• Doxycycline and an aminoglycoside• Tertacycline and streptomycin• Minocycline and streptomycin
B. canis
Prognosis: Animals can naturally heal but may take
up to five years Relapses can occur and symptoms may
occur for several years
B. canis
Prevention: Animals with brucellosis should be
neutered/spayed In large kennels/ shelters daily use of
Roccal will kill the bacteria Keep new animals quarantined before
introducing them to other canines.
Facts
Not common in US; about 100-200 cases each year
More common in countries with no good standardized and effective public health and domestic animal programs, like South and Central America, E. Europe, Asia, Africa
No vaccine in humans Also known as Canine STD
Swine
Brucella suis
B. suis
• Etiology:• Caused by Brucella suis
– Spread by ingesting infected tissues or fluids
– Highest prevalence among feral pigs
– Can remain in some herds for years
• Considered zoonotic– Humans come in contact with
bacteria through:• Laboratory work• Farming• Herding• Veterinary work• Though contact with infected
animals or tissues
Brucella suis
B. suis
Signalment: B. suis has no specific signalment Pigs that are used for breeding do have
a high risk of contracting the bacteria
B. suis
Transmission:• Pigs that are raised for breeding are a source
of infection– Suckling pigs may become infected by means of
mother, but most reach weanling age without becoming infected
• Can be transmitted by ingestion of feedstuffs that are contaminated by birth and/or abortion products and uterine discharges– Pigs will eat aborted fetuses and membranes
• Transmission can occur during copulation or artificial insemination
B. suis
Clinical signs:• After exposure to bacteria, pigs develop a bacteremia
that may persist for up to 90 days– Localization to various tissues may occur during or after
bacteremia• Abortion• Temporary or permanent sterility• Orchitis• Lameness• Posterior paralysis• Spondylitis• Metritis• Abscess formation
B. suis
Diagnosis: Card test (most accurate) Serum agglutination tests Complement fixation tests
Entire herds of pigs must be tested rather than individual pigs
B. suis
Recommended Treatment: No vaccine for Brucella suis No recommended treatment Control of transmission is based on test,
cull(segregation), and slaughter of infected pigs
B. suis
Prognosis: Can be eradicated from infected herds
by means of: Depopulation Tests and removal methods Quarantine of infected herds
B. suis
Prevention: Keeping domesticated swine herds from
coming in contact with wild and feral swine
Test herds and not breeding swine that are infected
Quarantine swine purchased in fairs or other sources until testing can be done
B. suis
Client Education: Perform regular testing of herds Purchase swine from reputable sellers Keep those that are infected in isolation
and do not use for breeding Test semen that will be used for
insemination prior to insemination
Bovine
Brucella abortus
B. abortus- Bovines
History: 1895- Bang in Copenhagen isolated the organism
Brucella abortus and proved that it caused abortions in cattle "Bang's abortion” 1917- Yellowstone Nat’l Park documented brucellosis
among the bison herd. 1956- Due to a $1 billion eradication program, only
the ‘Triple U’ buffalo herd and five infected private cattle herds in Texas and Missouri still harbor brucellosis.
B suis or B melitensis has also rarely been implicated in some cattle herds.
B. abortus- Bovine
Signalment: Males & females Any age or breed
B. abortus- Bovine
Transmission: Occurs by ingestion of organisms
Can be present in: aborted fetuses fetal membranes uterine discharges contaminated feed/water
licking contaminated genitals of other animals artificial insemination when contaminated
semen is deposited in the uterus
B. abortus- Bovine
Clinical Signs: abortion is the most obvious sign!! weak or stillborn calves reduced milk production retained placentas agglutinins in the seminal plasma testicular abscesses in infected bulls arthritis may result from longstanding
infections
B. abortus- Bovine
Diagnostic Tests: Herds: bang test/ Brucellosis ring test:
Herd’s milk and test for agglutination Serum agglutinin tests are the standard
method of diagnosis A complete agglutination at a dilution of 1:100
or more is positive for brucellosis in non vaccinated animals.
1:200 is positive for animals vaccinated between 4 to 12 months of age.
B. abortus- Bovine
Treatment: Treatment for brucellosis of cattle is not
permitted ALL infected cattle and contacts which have
been exposed to infection must be slaughtered.
B. abortus- Bovine
Pathological lesions: granulomatous inflammatory lesions are
present during a necropsy Lesions may be present in:
the reproductive tract udder supramammary lymph nodes joints synovial membranes.
Vaccination
The vaccine is a live product and must be administered only by an accredited veterinarian or State or Federal animal health official.
Brucella vaccine, called Strain RB51, for use in cattle
Female calves should be vaccinated when they are 4 to 6 months old.
At the time of vaccination, a tattoo is applied in the ear; that tattoo identifies the animal as an "official vaccinate." The tattoo identifies the year in which vaccination took place.
Equine
Brucella abortus
B. abortus- Equine
Reported sporactically in the US over the last 70 yrs
Declined in prevalence due to the Brucellosis Cattle Eradication program
Higher infection rates in: Texas Florida Alabama Louisiana
B. abortus- Equine
Signalment: All breeds Males & females No age descrimination
B. abortus- Equine
Clinical Signs: Most commonly manifests as fistulas
located in the withers of the horse A source of exposure to humans
Late term abortions Non-specific lameness due to joint
infections ‘poll evil’
B. abortus- Equine
Prognosis/ Diagnosis Unlike B. abortus in cattle, no specific Equine
Brucellosis eradication program has ever been implemented.
Samples of infection sites are obtained for cultures
B. abortus is difficult to isolate, so horse must also be tested for evidence of anitbodies to B. abortus.
Titers (plate agglutination) greater than or equal to 1:50 is considered + for this bacteria.
B. abortus- Equine
Prevention: Neuter/cull infected animals Quarantine & testing all new animals
especially breeding stock
Brucellois in Humans
Humans can become infected by coming in contact with infected animals or animal products that are contaminated with this bacteria. Eating/drinking the organism Inhalation of the organism (least common) Through open skin wounds
Slaughterhouse & meat packing plant employees, and hunters are at a higher risk
Direct person-to-person spread is rare but can occur through breast milk, and sexual contact
Brucellosis in Humans (Undulant Fever)
Zoonotic cases mostly occur: in countries where animal disease control programs
are in-efficient or non existent Countries that do not have standardized & effectie
public health & domestic animal health programs. DO NOT EAT: un-pasturized dairy
products!!!!!!!! NO vaccine available for humans Mortality is low (less than 2%) & is usually
associated with endocarditis. Wear gloves when handling new animals canines &
food animals) and beware of bodily fluids!
Brucellosis in Humans
Causes a wide range of symptoms: Fever Sweats Headaches Back pains Physical weakness Severe infections of the CNS or lining of the
heart may occur Can also cause long- lasting, chronic
symptoms that include: Recurrent fevers, joint pain & fatigue
References Veterinary Technician’s Daily Reference Guide: Canine and Feline. 2nd Edition (pg.
130, 256-258).
Saunders Comprehensive Veterinary Dictionary 3rd Edition. (pg. 256).
http://www.cfsph.iastate.edu/Factsheets/pdfs/brucellosis_abortus.pdf
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/110502.htm
http://www.merckvetmanual.com/mvm/index.jsp
http://www.greenlewis.com/articles/canine-brucellosis.php
http://www.marvistavet.com/html/brucellosis_in_dogs.html
http://www.infectiousdiseasenews.com/article/40915.aspx
References continued…
• http://www.merckvetmanual.com/mvm/index.jsp• http://www.greenlewis.com/articles/canine-
brucellosis.php• http://www.marvistavet.com/html/
brucellosis_in_dogs.html
• http://www.infectiousdiseasenews.com/article/40915.aspx
www.peteducation.com www.Vetinfo.com www.Medicinenet.com www.cfsph.iastate.edu/Factsheets/
pdfs/brucellosis.pdf
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