Bovine Tuberculosis (Bovine TB)

Bovine Tuberculosis (TB) is a chronic zoonotic bacterial disease caused by Mycobacterium bovis, which primarily affects cattle but can also infect other animals, including humans. Mycobacterium bovis is a sub-specie of the Mycobacterium tuberculosis complex, the bacterium responsible for human TB, but it is more common in animals. The disease can spread to humans through the consumption of unpasteurized dairy products, direct contact with infected animals, or inhalation of aerosolized bacteria. The disease poses a significant public health concern, especially in regions. Bovine TB in humans causes similar symptoms to TB caused by Mycobacterium tuberculosis, including persistent cough, fever, night sweats, weight loss, and chest pain. However, the disease may also present in non-typical forms which affects areas such as the lymph nodes, gastrointestinal tract, or bones 

The following are standard case definitions to allow national health authorities to interpret data in an international context. However, during an outbreak case definitions may be adapted to the local context and the Red Cross Red Crescent should use those agreed/established by national health authorities. NB: Consider that during community-based surveillance, volunteers should use broad (simplified) case definitions (referred to as community case definitions) to recognize most or all possible cases, provide relevant risk communication and appropriate actions and encourage them to seek care. Other actors such as healthcare workers or investigators studying the cause of a disease, on the other hand, can use more specific case definitions that may require laboratory confirmation. 

Suspected case: Any individual experiencing TB-related symptoms. The most common symptom is a productive cough of more than two weeks, which may be accompanied by other respiratory symptoms (e.g. shortness of breath, chest pains) and/or constitutional symptoms (e.g. weight loss, fever).  

Confirmed case: A patient with Mycobacterium spp identified from a clinical specimen, either by culture or by a more modern method: https://www.hpsc.ie/a-z/vaccinepreventable/tuberculosistb/casedefinition/  

It depends on various factors. Communities with bovine TB endemicity and poor healthcare facilities may have a lower epidemic threshold due to higher case incidences.  

Additionally, socioeconomic conditions, living standards, and the effectiveness of TB control programs can influence the threshold, as improved healthcare infrastructure and robust prevention strategies can help contain and reduce the spread of TB, raising the pidemic threshold. Understanding these variations is crucial for public health experts in designing targeted interventions and implementing effective control measures. 

In any case, it is important to note that TB has been considered a global public health emergency since 1993, when the WHO labelled it as such. Consequently, the global health community must be in constant alert concerning this deadly disease irrespective of regional discrepancies 

• People who work with animals (farmers, veterinarians, livestock breeders) or animal products such as wool, hides or hair (butchers, weavers).
• People who eat raw or undercooked meat from infected animals.
• Close contact with an infectious person with bovine TB disease
• People returning from areas with high rates of bovine TB 

Generally low and depends on the type of exposure. However, attack rates will vary from one outbreak to another. In case of an outbreak, consult the latest information provided by health authorities. 

• People living with HIV
• Babies and young children under the age of 5
• Elderly individuals
• People with chronic conditions such as diabetes or kidney disease
• Cancer patients undergoing chemotherapy
• Organ transplant recipients 

Mycobacterium bovis (bacterium).  

Zoonotic disease: Cattle. Animals typically become infected when they come in contact with respiratory secretions of an infected cattle. Humans can also become infected by eating meat and dairy products from infected cattle.  

People get infected with bovine TB via: 

• Direct Contact with Infected Humans and Animals: The most common route of transmission is through close contact with infected cattle and humans. Mycobacterium bovis is shed in respiratory secretions, saliva, urine, faeces, and milk of infected animals. In close quarters, the infection can spread via aerosol.
• Vehicle-borne transmission: Humans and other animals can also become infected by consuming meat, milk, and water contaminated with the bacteria. The bacteria can survive in the environment, especially in damp, cool conditions. 

A few months to several years 

Humans can spread the disease to one another, especially if the infected person has an active TB 

Symptoms will include: 

• Prolonged cough
• Chest pain
• Coughing up blood or sputum (phlegm) 
• Weakness or fatigue
• Weight loss
• Fever
• Night Sweats
• Loss of appetite
• Chills 

• Isolation of Mycobacterium tuberculosis complex (excluding Mycobacterium bovis-BCG) from a clinical specimen
• Detection of Mycobacterium tuberculosis complex nucleic acid in a clinical specimen AND positive microscopy for acid-fast bacilli or equivalent fluorescent staining bacilli on light microscopy
• Microscopy for acid-fast bacilli or equivalent fluorescent staining bacilli on light microscopy
• Histological appearance of granulomata. 

Please refer to the appropriate local or international guidelines for clinical management. All clinical management including the administration of a treatment or vaccine should be conducted by a health professional.  

• The treatment can take 4, 6, or 9 months depending on the programme. 
• It usually involves a 4-drug regimen, with some of the most common TB drugs being:
  • Isoniazid
  • Rifampin
  • Rifabutin
  • Rifapentine
  • Pyrazinamide
  • Ethambutol 

To confer immunity, the Bacillus Calmette-Guérin (BCG) vaccine (which is attenuated Mycobacterium bovis) has been in use for a long time to prevent severe forms of tuberculosis in children but its effectiveness has not been proven for routine use in cattle.