is an important infectious disease of mammals including humans. It primarily affects
cattle, pigs, sheep, goats and dogs (B101, B209.22.w22).
In various mammal species
- Usually involves the reproductive tract.
- In females, characteristically causes abortion.
- Abortion usually occurs mid-gestation or later.
- Abortion usually occurs only on initial infection.
- Birth of non-viable offspring may occur; apparently normal neonates
(born infected, but with the infection being of only limited duration) may also be born.
- In males, orchitis, epididymitis and infertility may result.
(B21, B101, B209.22.w22).
Undulant fever: acute illness, prostration, weakness, with fever in the afternoon and evening, chills and night sweats with the fever subsiding until the next day.
After a few days symptoms may disappear, then reappear after a variable interval.
The acute form may reappear several times.
Debility, weakness, low-grade remittent fever, joint pains.
May also be sweating, lassitude and malaise, gastritis, abdominal pain, skin rashes, headache, irritability, depression, insomnia, arthritis, backache.
Seroprevalence for Brucella suis type 4
was studied in free-ranging grizzly bear (Ursus arctos horribilis)
(Ursus arctos - Brown
bear) populations of Alaska that
are associated with the Arctic or Porcupine caribou (Rangifer tarandus
- Reindeer) herds; seroprevalences
for samples taken in 1971 were approximately 90% and 30% respectively
for bears associated with the two herds. (J1.11.w10)
- Antibodies to brucellosis (Brucella abortus) were detected by tube
agglutination test in 18/332 sera (5%) from 265 Ursus americanus - American black bear
from northcentral Idaho, 1971-1975. (J1.16.w12)
- Antibodies to Brucella abortus were detected by rapid slide
agglutination test in 1% of 283 sera from Ursus americanus - American black bear
from Alberta, Canada, 1976. (J1.17.w11)
- Antibodies to Brucella spp. were detected by the standard plate
test and card test in sera from 6/122 (5%) grizzly bears (Ursus arctos - Brown
bear) from southcentral Alaska, 1978-1981 (but from none of 28
Ursus americanus - American black bear)
A retrospective serological study in California
from 1977 to 1989 showed a seroprevalence of 0.6% (one out of 180) for
Brucella sp. in Ursus americanus - American black
A study conducted at Svalbard and the Barents
Sea, late March to mid May, 1990-1999, revealed a seroprevalence of 5.4% for Brucella sp. from 297 Ursus maritimus - Polar
bears sampled. No evidence of clinical disease was
Antibodies to Brucella sp. were detected, using a buffered
acidified card test and rapid automated presumptive test, in 5% of Ursus maritimus - Polar bear
from the Beauford and Chukchi seas, from samples collected 1982-1999. (J3.156.w2)
A yearling Ursus americanus - American black
bear infected intraperitoneally with 108 - 109
forming units) Brucella suis, and two 10-month old grizzly bears (Ursus arctos
horribilis) (Ursus arctos - Brown
bear) which were experimentally infected orally (1.3 x 109
cfu Brucella suis on canned dog food) with Brucella suis type
4, showing very high levels of antibodies titres within the first two
months of infection. The animals were euthanased on day 83. The black
bear, at necropsy, showed enlarged axillary lymph nodes and Brucella
suis organisms were isolated from various lymph nodes as well as
the spleen and urine. The Ursus arctos - Brown
bears were not necropsied. (J1.17.w9)
Ursus americanus - American black
bears have been experimentally infected with Brucella
abortus strain RBN51 in order to asses the safety and efficacy of
the oral vaccine. The vaccination did not appear to cause any clinical
signs or affect the reproductive performance and was found to induce
an ineffective immunologic response. (J1.40.w6)
Antibodies to Brucella spp. were detected
by the buffered acidified card antigen test in 84/568 (15%) Ursus arctos - Brown
bear and 1/76 (1.3%) Ursus americanus - American black bear
in Alaska (samples collected1988-1991); only 1/40 samples from grizzly
bears from inland Alaska (where all the black bears were from) were
In Lepus europaeus - Brown hare:
Liver, spleen and reproductive organs: multifocal chronic
Reproductive tract and associated lymph nodes: multiple
necrotising pyogranulomas. (J514.1.w1)
spp. are isolated regularly from seals and
cetaceans and serum samples from these animals are often Brucella
- Direct or indirect contact with infected animals excreting Brucella sp. organisms
- Ingestion is a common route of infection.
- Venereal transmission also occurs.
- Infection in utero, by inhalation or via the conjunctiva occurs less commonly.
- In wild Lepus europaeus - Brown
hares, mainly venereal but also orally, via the conjunctiva
and percutaneously. (J514.1.w1)
Prevention of disease in humans
- General hygiene; wear protective clothing and gloves when handling marine mammals.
- Avoid contact with aerosols from marine mammals, e.g. respiratory discharges from the
blow-holes of cetaceans.
Vaccination in bears
|Host taxa groups /species
information on Host species has only been incorporated for species groups
for which a full Wildpro "Health and Management" module has been
completed (i.e. for which a comprehensive literature review has been
Bears (Ursidae - Bears (Family))
(List does not contain all other species groups affected by this