Brucellosis Overview and Impact

Contagious abortion and Bang's disease are synonyms for brucellosis in animals.

Mediterranean fever, undulant fever, and Malta fever are synonyms for brucellosis in humans.

A contagious bacterial disease affecting all warm-blooded animals characterized by inflammation of the genital organ and fetal membranes, abortion in late gestation, and retained placenta, causing infertility.

Rarely symptomatic in young animals, the disease usually resolves without issues.

Animals can become carriers due to intracellular multiplication, shedding the bacteria in reproductive fluids like milk, potentially infecting others.

Small, Gram-negative, cocco-bacillus, and non-motile bacteria; difficult to diagnose, control, and treat due to being facultative intracellular organisms.

Brucella multiplies in the uterus during animal pregnancy, waiting for the pregnancy. The fetus and its membranes' production of erythritol stimulates multiplication, leading to late-stage abortion.

Differences in the ratio of protein A and protein M antigens between Brucella abortus and Brucella melitensis influence their infectiousness.

Brucella bacteria are found in genital secretions (including semen), milk, and colostrum.

Brucella can survive for extended periods in various environments, depending on the specific conditions, like cheese or manure.

Cattle, and sometimes horse/camel/human (not common).

Sheep and goats, mainly.

Brucella transmission occurs via ingestion (often from raw milk or contaminated products), direct contact with infected tissues, or less commonly, inhalation or inoculation with animal vaccines.

In male animals, Brucella infection typically causes orchitis and epididymitis (inflammation of testes/epididymis) and less commonly, joint involvement .

Non-pregnant females may show inflammation, becoming a carrier, in the udder and supramammary lymph nodes.

Sources of animal infection include aborted fetuses, placenta, vaginal discharges, milk, colostrum, contaminated feed and water, and semen.

Humans can become infected with Brucella species like B. melitensis, B. abortus, B. suis, and B. canis.

B. abortus and B. melitensis are commonly found in Egypt, with B. melitensis subtype 3 being more prevalent.

A disease affecting sheep and goats, causing abortions, birth of weak/dead lambs or kids, skeletal lesions in goats, and fertility problems in males. Generally involves some fever.

A zoonotic disease, characterized by 'undulant fever' (intermittent fever), profuse sweating, headache, weakness, joint pain, depression, weight loss, and fatigue. Potential severe complications like liver dysfunction, or heart issues if untreated

Identifying the cause of the abortion, differentiating between bacterial (e.g., Leptospirosis,listeriosis), viral (e.g., RVF), parasitic (e.g., Toxoplasmosis) or fungal causes among others, to find the correct treatment for the infected animals.

A lack of specific treatment for animals infected from a zoonotic case, which needs controlling in order to prevent spread to humans.

Treatment typically involves a combination of antibiotics including Doxycycline & Rifampin, Tetracycline & Rifampin, Co-trimoxazole & Rifampin, or Cephalosporines & Rifampin, depending on the specific situation.

The difficulty of controlling Brucellosis due to latent or carrier infections in animals, difficulties with accurate diagnosis (false negative / false positive results), wide host range including wild animals, & the viability of the bacteria in the environment, relying on quarantine and testing.

Strategies involving testing and slaughter for positive animals, preventing spread via quarantine and proper hygienic practices (e.g. fetal membrane disposal), controlling the potential vectors such as rodents and dogs, and introducing brucellosis free animals.

Vaccination is an important control measure to increase immunity against brucellosis within the populations. Live vaccine strain 19 is used, with an administration schedule and appropriate doses (S/C - Subcutaneous injection) to be considered.

Erythritol sugar is secreted by the pregnant female after the 5th month of pregnancy.

Shedding of Brucella is intermittent, not continuous.

Diagnosis in the early stage of brucellosis involves serology (blood tests), detecting bacteremia (bacteria in the blood).

Late-stage diagnosis uses cell-mediated immunity tests like the Brucellin test to identify facultative intracellular bacteria.

A sudden and severe abortion, often associated with an acute stage of brucellosis.

Third-trimester abortions are common in cattle with brucellosis, often accompanied by retained placenta. Subsequent pregnancies are usually normal.

Cattle with brucellosis may give birth to dead or weak calves.

A small percentage (5%) of cattle with brucellosis may experience residual sterility.

Brucella bacteria shed in large quantities in the milk and reproductive tissues of infected cattle throughout their lives.

Aborted fetuses in brucellosis may have swollen abdomens due to excessive fluid, thickened umbilical cords, and necrotic liver spots.

The placenta of a brucellosis-infected animal often shows swelling, necrosis, and a leathery appearance.

Brucellosis in bulls can cause orchitis, epididymitis, and seminal vesiculitis.

Brucellosis in bulls can cause arthritis and bursitis, leading to lameness (problems with walking).

Clinical signs of chronic Brucellosis may include localization to reproductive organs but characteristically lacks fever despite bacteremia.

Fistulous Withers/Poll Evil in horses are characterized by inflammation of the supraspinous bursa, which forms fluid pockets.

Brucella Melitensis is prevalent particularly in Latin America, Middle East, Mediterranean, Eastern Europe, Asia & parts of Africa where goats and camels are common reservoirs.

Insidious infection with brucella has no visible clinical symptoms but can cause severe complications later on.

Storm of abortion occurs due to infections by a particular Brucella type, in a non-immune herd, and affected animals are generally at similar stages of pregnancy.

Infection by specific etiology (B. Abortus), first-time infection, and pregnant animals at the same stage of gestation.