Read condition-specific symptoms and clinical context for Brucella melitensis. A goat-and-sheep bacterium that reaches people through unpasteurised dairy and causes a long, relapsing fever.
PHAC describes Brucella as Gram-negative cocci or small rods, aerobic, non-motile and urease positive, with transmission by ingestion, direct contact via skin abrasions and mucous membranes, and inhalation; the host range covers humans, cattle, swine, goats, sheep, deer, caribou, elk, dogs and coyotes. The LPSN etymology records that the species epithet melitensis refers to the Island of Malta, where the organism was first isolated by Bruce in 1893. PHAC describes a systemic illness with intermittent fever, headache, weakness, profuse sweating, chills and joint pain, a case-fatality rate of less than 2% for untreated cases and a potentially long recovery, and an incubation period that is highly variable at 5 to 60 days and occasionally several months.
PHAC describes a systemic bacterial illness with an incubation period that is highly variable — 5 to 60 days and occasionally several months. CDC lists the initial manifestations.
Possible symptoms: Fever, often intermittent; Headache; Weakness and fatigue; Profuse sweating; Chills; Pain in muscles, joints and back.
PHAC gives a case-fatality rate of less than 2% for untreated cases but notes a potentially long recovery period. Diagnosis and treatment, which typically involve prolonged combination antibiotics, are clinical decisions and are not given here.
CDC describes ongoing effects that can follow the initial illness.
Possible symptoms: Recurring fevers; Arthritis; Swelling of the testicles; Heart infection; Memory loss, confusion and irritability; Depression; Swelling of organs.
These are effects CDC describes as ongoing rather than a separate disease. Their management is clinical and is not given here.
Contact with livestock or unpasteurised dairy does not always cause brucellosis.
The bundled sources give no symptom list for exposure that does not lead to illness, and none is invented here. PHAC lists the infectious dose as unknown and gives an incubation period that is highly variable at 5 to 60 days and occasionally several months, so an exposure and an illness can be hard to connect in time. CDC describes transmission through consuming undercooked meat or unpasteurised dairy, breathing in bacteria, contact with infected animal body fluids, handling animal tissues, and laboratory exposure. This profile assigns no human carriage state.
Laboratory exposure to Brucella is a recognised occupational hazard handled through workplace protocols. Food-safety questions about unpasteurised dairy are separate from clinical assessment.
Source check: 2026-09-20. Educational content; independent scientific review remains pending.