Introduction to the disease

Mammalian tuberculosis, caused by members of the Mycobacterium tuberculosis complex (MTBC), primarily by M. bovis, is a chronic bacterial disease affecting livestock, wildlife, and occasionally humans. It can have a considerable impact on the welfare of livestock, as well as farmers, vets and butchers, and disrupt the balance of ecosystems. Despite its impact, vaccination is limited due to its interference with TB surveillance and diagnostics. Consequently, control relies heavily on testing, culling, and biosecurity measures.

Ingestion of Raw Animal ProductsHumans can contract zoonotic TB by consuming raw milk and dairy products from infected cows, as well as by eating contaminated meat that is raw or undercooked. This poses a public health risk, particularly in rural communities with limited access to pasteurisation and thorough meat cooking practices. Ensuring all milk undergoes heat treatment to kill TB bacteria and that meat is thoroughly cooked is essential to prevent disease transmission. Prevention involves educating farmers and the public about the risks of consuming raw animal products, promoting pasteurisation, and implementing rigorous testing of dairy products and meat. Regulatory measures to enforce pasteurisation standards and safe cooking practices are crucial to safeguarding human health.

Introductionto the disease Mammalian tuberculosis, caused by members of the Mycobacterium tuberculosis complex (MTBC), primarily by M. bovis, is a chronic bacterial disease affecting livestock, wildlife, and occasionally humans. It can have a considerable impact on the welfare of livestock, as well as farmers, vets and butchers, and disrupt the balance of ecosystems. Despite its impact, vaccination is limited due to its interference with TB surveillance and diagnostics. Consequently, control relies heavilyon testing, culling, and biosecurity measures.

Inhalation of Contaminated AerosolsMammalian TB is most commonly spread through inhalation of aerosols and infected respiratory droplets from infected animals, such as sneezes or coughs. The disease can spread rapidly within herds, leading to economic losses from reduced productivity. Control measures include regular testing and culling of infected animals, separating infected animals from the uninfected herd, maintaining proper ventilation in animal housing, and minimising overcrowding to reduce aerosol spread. Implementing strict biosecurity protocols can help prevent the introduction and dissemination of TB within and between herds.

Inhalation of Contaminated Aerosols Mammalian TB is most commonly spread through inhalation of aerosols and infected respiratory droplets from infected animals, such as sneezes or coughs. The disease can spread rapidly within herds, leading to economic losses from reduced productivity. Control measures include regular testing and culling of infected animals, separating infected animals from the uninfected herd, maintaining proper ventilation in animal housing, and minimising overcrowding to reduce aerosol spread. Implementing strict biosecurity protocols can help prevent the introduction and dissemination of TB within and between herds.

Direct Contact with Infected AnimalsDirect human contact with infected animals or contaminated materials through mucous membranes or broken skin is a potential route for zoonotic tuberculosis transmission (tuberculosis in humans can be caused by any members of the Mycobacterium tuberculosis complex from animal sources). This risk is particularly present during activities like milking, slaughtering, and handling animals. Such transmission threatens both animal and public health and can result in considerable economic losses.Preventive strategies include identifying and segregating infected animals, enforcing quarantine measures, and restricting animal movement between farms. Strengthening biosecurity practices—such as disinfecting equipment and maintaining proper hygiene during animal handling—helps reduce the risk of direct contact transmission. Educating farmers on early detection and management remains vital for effective control of zoonotic tuberculosis.

Ingestion of Contaminated Feed and WaterTB transmission via contaminated feed and water is also a major concern, especially in shared grazing areas. This route affects both livestock and wildlife, complicating control efforts. To prevent spread, it is crucial to manage feeding practices by providing clean water and ensuring feed is stored and handled properly to avoid contamination. Regular testing of water sources and feed, combined with effective management of grazing areas, can mitigate the risk. Additionally, preventing wildlife access to livestock feed and water can help reduce transmission.

Contact with Infected Tissues in SlaughterhousesSlaughterhouse workers and butchers face a risk of TB infection through contact with infected animal material. This occupational hazard can impact workers’ health and disrupt meat supply chains. To prevent this, strict hygiene and safety protocols must be followed, including the use of protective gear and proper handling procedures. Regular health checks for workers and routine inspection of carcasses can help identify and manage infections. Educating workers about TB risks and safe practices is vital for controlling transmission in slaughterhouses.

A restaurant serving raw or undercooked animal products

A farm with low biosecurity measures

Wild animals close to human farms and settlements

A grazing herd mixing several species

Feed and water in a grazing area

A slaughterhouse with unsafe practices

Introduction to the disease

Mammalian tuberculosis, caused by members of the Mycobacterium tuberculosis complex (MTBC), primarily by M. bovis, is a chronic bacterial disease affecting livestock, wildlife, and occasionally humans. It can have a considerable impact on the welfare of livestock, as well as farmers, vets and butchers, and disrupt the balance of ecosystems. Despite its impact, vaccination is limited due to its interference with TB surveillance and diagnostics. Consequently, control relies heavily on testing, culling, and biosecurity measures.

Inhalation of Contaminated AerosolsMammalian TB is most commonly spread through inhalation of aerosols and infected respiratory droplets from infected animals, such as sneezes or coughs. The disease can spread rapidly within herds, leading to economic losses from reduced productivity. Control measures include regular testing and culling of infected animals, separating infected animals from the uninfected herd, maintaining proper ventilation in animal housing, and minimising overcrowding to reduce aerosol spread. Implementing strict biosecurity protocols can help prevent the introduction and dissemination of TB within and between herds.

Inhalation of Contaminated Aerosols Mammalian TB is most commonly spread through inhalation of aerosols and infected respiratory droplets from infected animals, such as sneezes or coughs. The disease can spread rapidly within herds, leading to economic losses from reduced productivity. Control measures include regular testing and culling of infected animals, separating infected animals from the uninfected herd, maintaining proper ventilation in animal housing, and minimising overcrowding to reduce aerosol spread. Implementing strict biosecurity protocols can help prevent the introduction and dissemination of TB within and between herds.

Direct Contact with Infected AnimalsDirect human contact with infected animals or contaminated materials through mucous membranes or broken skin is a potential route for zoonotic tuberculosis transmission (tuberculosis in humans can be caused by any members of the Mycobacterium tuberculosis complex from animal sources). This risk is particularly present during activities like milking, slaughtering, and handling animals. Such transmission threatens both animal and public health and can result in considerable economic losses.Preventive strategies include identifying and segregating infected animals, enforcing quarantine measures, and restricting animal movement between farms. Strengthening biosecurity practices—such as disinfecting equipment and maintaining proper hygiene during animal handling—helps reduce the risk of direct contact transmission. Educating farmers on early detection and management remains vital for effective control of zoonotic tuberculosis.

Ingestion of Contaminated Feed and WaterTB transmission via contaminated feed and water is also a major concern, especially in shared grazing areas. This route affects both livestock and wildlife, complicating control efforts. To prevent spread, it is crucial to manage feeding practices by providing clean water and ensuring feed is stored and handled properly to avoid contamination. Regular testing of water sources and feed, combined with effective management of grazing areas, can mitigate the risk. Additionally, preventing wildlife access to livestock feed and water can help reduce transmission.

Contact with Infected Tissues in SlaughterhousesSlaughterhouse workers and butchers face a risk of TB infection through contact with infected animal material. This occupational hazard can impact workers’ health and disrupt meat supply chains. To prevent this, strict hygiene and safety protocols must be followed, including the use of protective gear and proper handling procedures. Regular health checks for workers and routine inspection of carcasses can help identify and manage infections. Educating workers about TB risks and safe practices is vital for controlling transmission in slaughterhouses.