Virginia Department of Health
Brucellosis: Overview for Healthcare Providers
Organism
Infective dose
Occurrence
Natural reservoir
Route of infection
Communicability
Risk factors
Case fatality
Incubation period
Symptoms
Sequelae
Laboratory tests/
Sample collection
Radiography
Treatment
(adults)
Infection Control
Vaccine
Public Health
 Zoonotic bacterial disease caused by four Brucella species that infect humans:
abortus, melitensis, suis, and canis
 Non-spore forming
 Tiny, Gram-negative coccobacillus
10 to 100 organisms
Worldwide, especially in Mediterranean countries of Europe and northern and eastern Africa,
Middle Eastern countries, India, central Asia, Mexico, and Central and South America.
Approximately 100 cases are reported annually in the United States. One to two cases are
reported annually in Virginia.
Cattle, swine, goats and sheep. Infection may occur in bison, elk, caribou, coyotes and some
species of deer. B. canis has occasionally infected dogs.
 Contact (through breaks in skin) with tissues, blood, urine, vaginal discharges, aborted fetuses
and especially placentas of infected animals
 Ingestion of unpasteurized dairy products from infected animals
 Inhalation of infective aerosols or inoculation of conjunctivae
 Self-inoculation with animal vaccines (injection or spraying into open wounds or eyes)
Person-to-person transmission is extremely rare, but has occurred through tissue transplantation,
breast-feeding, and sexual contact
Working on a farm or in a slaughterhouse; consuming unpasteurized dairy products, especially if
imported; handling infective laboratory specimens. Rare cases of B. canis have occurred in dog
breeders.
~ 2% without treatment, usually from endocarditis caused by B. melitensis infections
Highly variable, usually 5 to 60 days; can be several months or more
 Fever (constant or intermittent), chills, sweats, malaise, arthralgia, weakness, headache,
myalgia, anorexia, depression
 Illness may last a few weeks to several months or longer
Extremely variable, including: granulomatous hepatitis, peripheral arthritis, spondylitis, anemia,
leukopenia, thrombocytopenia, meningitis, uveitis, optic neuritis, papilledema, and endocarditis
Blood or bone marrow, tissue specimens (spleen, liver or abscess), paired serology (acute-phase
serum collected as soon as possible after onset of disease with convalescent-phase specimen
collected >14 days after the acute specimen). Alert lab of biohazard. For consult, page the state
lab (DCLS), available 24/7, at 804-418-9923. Specimens should be sent to DCLS for
confirmation of agent and other studies.
Chest x-ray is often normal but may show lung abscesses, single or miliary nodules,
bronchopneumonia, enlarged hilar lymph nods, and pleural effusions
 Doxycycline, 100 mg twice daily for 6 weeks plus Rifampin, 600-900 mg daily for 6 weeks, or
 Doxycycline, 100 mg twice daily for 6 weeks plus Streptomycin, 1 g/day IM for 2 to 3 weeks
 5% relapse occurs due to sequestered organisms; treat with original regimen
 For severely ill patients, corticosteroids may be helpful
Use standard precautions. Contact precautions are indicated for patients with draining wounds.
In the United States, a vaccine is licensed only for animals. Accidental self-inoculation with the
live vaccine has occurred in veterinarians. In such cases:
 Obtain baseline blood sample for antibody testing and a follow-up sample after 2-3 weeks
 For B-19 or REV-1 vaccine, treat with Doxycycline, 100 mg twice per day plus Rifampin,
600-900 mg/day for 3 weeks
 For RB-51 vaccine, treat with Doxycycline, 100 mg twice per day for 3 weeks
 If vaccine was sprayed into eyes, follow regimen for 6 weeks
Suspected cases of brucellosis should be reported to the local health department by the most
rapid means available.
For more information, refer to: Brucellosis: Guidance for Healthcare Providers, available at:
http://www.vdh.state.va.us/EPR/Agents_Biological.asp, or Centers for Disease Control and
Prevention, http://www.cdc.gov/ncidod/diseases/submenus/sub_brucellosis.htm
Updated 05/24/2004