Transcript Brucellosis
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 1-6 discharge 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 Brucella suis Swine 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 – • Can be transmitted by ingestion of feedstuffs that are contaminated by birth and/or abortion products and uterine discharges – • Suckling pigs may become infected by means of mother, but most reach weanling age without becoming infected 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 Brucella abortus Bovine 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 Can by ingestion of organisms 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. Brucella abortus Equine 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, 256258). 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/brucellosi s.pdf