Brucellosis

Credit: International Livestock Research Institution, ILRI

Many livestock diseases can also affect farmers, Brucellosis is one of them. Diseases that can spread from livestock to humans are called zoonotic diseases

Brucellosis is a contagious disease caused by a bacteria called Brucella. It is also called undulant fever because of its remittent character.

It affects man, livestock and wild animals with a global distribution but eradicated in few countries from the animal reservoir.

Brucellosis mainly causes reproductive problems (abortions, stillbirth, infertility) in animals as well as recurring fevers, arthritis or udder infection

Symptoms in cattle are: Increased incidences of third trimester abortions, placental retention, stillbirths, infertility, arthritis and sterility in males

It is characterized by joint pain in pigs, udder infection and lameness in goats, and skin lesions in horses.

Animal Transmission

Brucellosis mainly affects sheep, goats, cattle, pigs and dogs as well as horses, camels, rodents, and wild animals such as wild pigs and water buffalo.

It is usually spread between animals thru contact with infected birth materials e.g. placenta, aborted fetuses,fetal fluids and vaginal discharges

Brucellosis can also be transmitted through contaminated objects such as, equipment, clothing, shoes, feed (e.g. hay, grass) or water.

Some animals are carriers; they will have the disease but show no signs of illness. These animals can infect other animals and people for a long period.

Some of the germs causing brucellosis are also found in semen and thus natural breeding can be a source of infection for cows for long periods or lifelong

Human symptoms

Brucellosis is usually an occupational disease; most cases occur in livestock producers, veterinarians, abattoir workers, hunters, farmers, and herders

Brucella causes undulant fever in man, which presents as febrile flu-like illness (recurring fever, night sweats, headaches, back pain) and arthritis.

Gastrointestinal signs including anorexia, nausea, vomiting, diarrhea and constipation occur frequently in adults but less often in children.

In many patients, the symptoms typically wax and wane (come and go) at 2 to 14 day intervals followed by spontaneous recovery.

Many human infections are asymptomatic (self-limiting);affecting different body parts with non-specific clinical signs that appear insidiously or abruptly

Human transmission 

Humans get infected by direct or indirect contact with infected animals, their products or by-products and by inhalation of Brucella germs in the air.

People who work with animals (e.g., livestock producers, veterinarians, herders, abattoir workers, hunters) have a higher risk of infection

People are infected by consuming infected raw milk, unpasteurized dairy products (raw cheese) or undercooked meat, bone marrow or other meat products.

People can also be infected through direct contact with infected animal materials e.g abortion products like afterbirth, aborted fetuses and animal discharges

Human to human transmission is rare. 

Prevention

• Do not consume unpasteurized dairy products (milk, cheese, ice cream) and raw/undercooked animal products (including bone marrow and meat
• Thoroughly clean and disinfect areas exposed to infected animals, their urine, blood, milk, or discharges using disinfectants e.g. hypochlorite solutions
• Brucella species are readily killed by heat. Therefore boil milk and liquids for at at least 10 minutes
• Separate sick animals from other animals to avoid spreading the disease
• Take precautions to avoid contamination of the skin, as well as inhalation when assisting at a birth, post mortem, or butchering an animal for consumption
• Good hygiene and protective clothing/equipment should always be used to avoid contamination through the skin or inhalation when handling sick animals
• Particular care should be taken when handling an aborted fetus or its membranes and fluids e.g. wear gloves, wear a face mask
• People who handle animal tissues (such as hunters and animal herdsman) should protect themselves by using: rubber gloves, goggles or gowns or aprons
• Risky practices such as crushing the umbilical cord of newborn livestock with the teeth or skinning aborted fetuses should be avoided.
• Animals from other sources should be isolated and tested before mixing or adding them to the herd.
• Properly identify your animals using ear tags or branding and vaccinate all breeding animals (cattle, goats and sheep) to raise herd immunity
• Vaccinate calves for Brucelosis 3-8 months of age with live vaccine for life long prevention. Vaccinate older animals yearly with dead vaccine. Use vaccine with care.

Action

• There is treatment for humans. Before treatment begins, a diagnosis of brucellosis infection must be made by a doctor.
• If you suspect your animals have brucellosis contact your Vet immediately!!

All zoonotic diseases are NOTIFIABLE, this means that they must be reported to the nearest Director of Veterinary Services or nearest Vet.

Information on Brucellossis can also be accessed on iCow in two parts be sending the Key Words in an SMS to 20285 (Kenya-Safaricom *285#)

Brucellosis content on iCow has been provided by the International Livestock Research Institution (ILRI) and ZED Group (Zoonotic and Emerging Diseases University of Liverpool)