BRUCELLOSIS

BRUCELLOSIS


Brucellosis, also known as Bang’s disease in animals and as undulant fever or Malta fever in humans, can cause abortion in both cattle and humans. The disease has been around a long time. Descriptions of what sounds like brucellosis can be found in the Bible, but the Brucella organism was not discovered until 1887, by Sir David Bruce, a Scottish physician. The genus is named after him.



MORBIDITY: +




MORTALITY: + TO +++




ETIOLOGY: BACTERIAL


Brucellosis is caused by bacteria belonging to the genus Brucella. They are small, gram-negative coccobacilli. The five species of Brucella most commonly associated with brucellosis are B. abortus, B. ovis, B. suis, B. melitensis, and B. canis. B. melitensis is not found in the United States.



HOSTS


Brucellosis has been identified in cattle, sheep, goats, pigs, dogs, horses, bison, elk, reindeer, caribou, many species of deer, camels, foxes, hares, mice, rats, ticks, and fleas. Brucellosis has also been found in seals, otters, and dolphins. Humans can be infected by many of the species of Brucella.


B. abortus primarily infects cattle, but is also found in bison, camels, deer, dogs, horses, sheep, and humans.


B. ovis is responsible for testicular inflammation in rams and occasionally for abortion in ewes but does not infect other animals or humans. Goats are susceptible to this species by experimental (deliberate or intentional) infection.


B. suis covers a wider host range than most other Brucella species. Pigs, wild hares, reindeer, wild caribou, and rodents are some of the varied hosts of this species.


B. melitensis causes a highly contagious disease in sheep and goats, although cattle can also be infected. B. melitensis is the most important species in human infection, but is not found in the United States.


B. canis causes testicular inflammation in the male dog and abortion and uterine infection in the female. It has been reported in no other animal species except humans.



TRANSMISSION


In animals, transmission is by direct contact with an infected animal, or by coming in contact with blood, urine, vaginal discharges, placentas, or aborted fetuses from infected animals. During the period of the Brucella life cycle when the bacteria are found in the blood, blood-sucking arthropods may transmit the organism. Domestic and wild canines can spread brucellosis to uninfected herds by dragging dead or aborted fetuses and placentas from the infected herd to the uninfected herd.


Most transmission to humans occurs in one of three ways:


• Drinking unpasteurized milk or eating cheese made from unpasteurized milk, especially soft cheeses. When cattle, sheep, goats, and camels are infected, the Brucella organism is found in their milk. Pasteurizing milk will kill the organisms. This is a problem more often for those traveling in countries where there are not effective public health and animal health programs.

• Coming into direct contact with placental tissues or vaginal secretions from infected animals. The Brucella organism will most often enter the human body through a wound. This is especially a hazard to people working in the veterinary profession, ranchers, hunters, and people working in slaughterhouses.

• Inhaling an aerosol, which occurs primarily in laboratories where Brucella organisms are grown.

Transmission has also been reported through breast milk from an infected mother to her child and through a contaminated tissue transplant. Sexual transmission has also been reported. These cases are extremely rare.



BRUCELLOSIS IN ANIMALS


In animals, brucellosis is usually associated with late-term abortions in females and inflammation in the male reproductive tract.



CATTLE


In cattle, brucellosis is called Bang’s disease, after Bernhard Lauritz Frederik Bang, a Danish veterinarian, who discovered B. abortus as the cause of contagious abortion in cattle in 1887. In cows the organism causes disintegration of the placenta, leading to late-term abortion. In bulls it causes testicular inflammation and sometimes arthritis. Transmission can be through ingestion of the organism or as a sexually transmitted disease (STD). The incubation period can be as short as 2 weeks, or as long as a year or more.

Related posts:

  1. ABOUT THE DISEASES
  2. CAMPYLOBACTERIOSIS (VIBRIOSIS)
  3. EASTERN EQUINE ENCEPHALITIS
  4. LEPTOSPIROSIS

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Oct 1, 2016 | Posted by in EXOTIC, WILD, ZOO | Comments Off on BRUCELLOSIS

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