Properties

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment & Prevention

Small gram-negative rods without a capsule.

3 major pathogens & animal reservoirs:

- B.melitensis(goats & sheep)

- B.abortus (cattle)

- B.suis (pig)

Enter the body:

- by ingestion of contaminated milk products.

- through skin by direct contact in an occupational setting such as an abattoir.

Localize in reticuloendothelial system in lymph nodes, liver, spleen & bone marrow.

Host response is granulomatous, with lymphocytes & epitheloid giant cells, which can progress to form focal abscesses & caseation.

Secondary spread from person to person is rare.

Disease: brucellosis (undulant fever)

Incubation period of 1-3 weeks.

Prodromal period: symptoms resembling influenza.

Causes:

- acute febrile illness

- chronic low-grade, undulating fever with malaise.

- bone & joint symptoms.

Signs:

- weakness & marked fatigue.

- enlarged lymph nodes, liver & spleen.

Complication: osteomyelitis.

Slide agglutination test with brucella anti-serum.

Species identified by biochemical tests.

Tetracycline + gentamicin

Doxycycline + streptomycin

Prevention:

- pasteurization of milk.

- immunization of animals.

- slaughtering of infected animals.

No human vaccine.