Tuberculosis (TB) is a global public health emergency and the leading cause of infectious disease-related mortality, after COVID-19 (1). It predominantly affects marginalized populations and is associated with poverty (2). Although the number of TB deaths declined from 2005 to 2019, the COVID-19 pandemic has reversed this trend due to impeded access to TB services (1). In 2021, an estimated 10.6 million people were infected with TB, resulting in 1.6 million deaths (1). In line with the United Nations Sustainable Development Goal of ending the TB epidemic, the WHO developed The End TB strategy to reduce incidence by 80% and deaths due to TB by 90% compared to 2015 levels and eliminate associated socio-economic impacts by 2030 (3). The strategy has been prioritized in WHO’s Southeast Asia and Western Pacific regions (SEAR and WPR), the two most populous WHO regions accounting for more than half of the world’s population, with the development of region-specific strategies (4–7). The global targets are currently off-track as the target to reduce TB incidence by 80% and deaths by 90% compared to 2015 levels by 2030 seems unachievable.

Human TB is primarily caused by Mycobacterium tuberculosis, but zoonotic TB caused by M. bovis also contributes to the disease burden. Approximately 140,000 people globally (including 43,400 from SEAR and 18,000 from WPR) contracted zoonotic TB in 2019, resulting in about 11,400 (including 2,020 from SEAR and 270 from WPR) deaths (8). Zoonotic TB in people predominantly arises from the transmission of M. bovis from cattle, referred to as bovine TB. M. bovis not only impacts human health but also causes economic losses and trade barriers, affecting the livelihoods of marginalized communities. Diagnosing and treating zoonotic TB presents challenges because M. bovis is naturally resistant to pyrazinamide, a standard first-line TB treatment drug, and routine surveillance systems do not identify zoonotic TB cases. Investigating and acting on zoonotic TB is significant for protecting public health, safeguarding economic stability and ensuring global health security. Zoonotic TB poses a direct threat to public health. Humans can contract the disease through direct contact with infected animals or consumption of contaminated animal products, leading to severe health complications. Secondly, zoonotic TB has substantial economic implications. The disease affects livestock, reducing productivity and causing economic losses for farmers and communities dependent on animal husbandry. Additionally, M. bovis is often associated with extra-pulmonary TB. The Survival and ongoing transmission of M. bovis in its animal reservoirs is a serious deterrent for The End TB strategy in human populations, in particular when human–livestock interactions are not uncommon in TB-endemic areas.

In 2017, WHO, the World Organization for Animal Health (WOAH), the Food and Agriculture Organization of the United Nations (FAO), and the International Union Against Tuberculosis and Lung Disease (The Union) launched the ‘Roadmap for Zoonotic TB’. This roadmap recommends using the One Health approach to tackle zoonotic TB in animals and humans and identifies ten priorities to reduce disease transmission at the human-animal interface. The reduction of transmission at this interface is one of the three recommended axes for investment outlined by the roadmap. More recently, WHO, FAO, and WOAH published the Tripartite Zoonoses Guide, promoting operational multisectoral tools and one health approach to address zoonotic diseases (9). Additionally, FAO, United Nations Environment Programme (UNEP), WOAH, and WHO (collectively known as the Quadripartite) have developed the One Health Joint Plan of Action (2022–2026) to address challenges at the human-animal–plant-environment interface on regional, national, and global scales (10).

We conducted this systematic review of scientific literature and official databases of WHO and WOAH to understand the current status of bovine and zoonotic TB in WHO’s SEAR and WPR to provide an updated consolidated evidence base on the burden of zoonotic and bovine TB. This information will be used to assess the level of implementation of the Roadmap.

We used a two-pronged strategy by evaluating the peer-review literature and data from official reports.

The Asia-Pacific region, comprising the WHO’s SEAR and WPR, is a major hotspot for TB, with a high burden of cases and deaths. These regions accounted for approximately 63% of the estimated 10.6 million global TB cases in 2021 (1). Four countries in WPR, namely Viet Nam, Lao People’s Democratic Republic (PDR), China, and the Philippines, accounted for 90% of new incident cases and 82% of TB-related deaths in 2019 (16). The COVID-19 pandemic has jeopardized the ongoing TB control efforts. To reinvigorate these efforts, the WHO’s SEAR office has developed a new strategic plan for the 2021–2025 (6).

This systematic review aimed to assess the burden of bovine and zoonotic TB in the region and inform the ongoing control efforts, particularly the Roadmap for zoonotic TB launched by the WHO in 2017. The review aimed to identify countries where bovine and zoonotic TB have been reported and countries with no available information on these forms of TB. The review findings indicate that zoonotic TB is not limited to infections caused by M. bovis. The role of M. orygis in zoonotic TB epidemiology is gaining importance and requires further investigation. M. orygis has been reported from human patients in India, and the pathogen has been reported from bovines in Bangladesh, India, and Nepal in South East Asia. A bovine case of M. orygis transmitted by an immigrant suffering with M. orygis associated TB has also been reported in New Zealand. Currently, the M. orygis appears to be circulating in India and its neighboring countries, but its global spread in the near future cannot be ruled out. Differentiating pathogen species in zoonotic TB infections is important for informing TB control efforts. Detecting M. tuberculosis infections in cattle and the possibility of human-to-bovine transmission can complicate TB eradication efforts.

The true impact of zoonotic TB in SEAR and WPR remains largely unknown. In 2019, there were an estimated 43,400 zoonotic TB cases and 2020 deaths in Southeast Asia, and 18,000 cases and 270 deaths in Western Pacific (8). Having reliable regional, national, and subnational data is crucial for policy development and determining zoonotic TB control priorities. In countries like Indonesia and Myanmar, among the 30 countries defined by WHO between 2021 and 2025 as high-TB burden (8), there is a lack of data on the presence/absence of bovine TB or on the prevalence of infection in cattle populations despite the fact that there are substantial cattle populations and interactions at the human-bovine interface in these countries. Efforts are needed to estimate the true burden of zoonotic TB in these regions.

The One Health approach, integrating zoonotic TB surveillance and control strategies in humans, bovines, and wildlife, has been advocated to end the zoonotic TB (17). This approach recommends estimating the zoonotic TB burden, using novel diagnostic tools, and implementing One Health interventions to improve zoonotic TB response and prevention (17). The approaches such as the estimation of zDALYs (zoonotic disability adjusted life years), including animal loss equivalents (ALE), have been recommended for zoonotic diseases (18). Developing prompt bovine and zoonotic TB notification capable surveillance systems, roadmaps for enhanced intersectoral coordination, and the use of both WOAH and WHO joint external evaluation tools is recommended. Encouraging milk pasteurization, mandatory meat inspection and condemnation of infected carcasses are important strategies to be adopted in the animal health sector (19). Environment focused strategies such as having dispersed water sources and the use of hedgerows on boundaries could reduce the risk of bTB transmission (19, 20). However, not much progress using such approaches has been achieved in many countries in the Southeast Asia and Western Pacific regions.

The lack of data reported to WHO for 2018 for zoonotic TB in people indicates that these regions need to establish zoonotic TB surveillance systems, strengthen diagnostic laboratory capacity, and incorporate species differentiation into routine TB diagnostic protocols.

The systematic review utilized multiple sources to compile data on bovine and zoonotic TB infections in the Southeast Asia and Western Pacific regions. However, the search strategy focused on country-level keywords, potentially excluding some studies. Additionally, the exclusion of non-English literature may have resulted in missed studies. It is also possible that studies available in national or subnational databases were not included. Nevertheless, the study’s purpose of highlighting the bovine and zoonotic TB situation in the regions was achieved.

In conclusion, zoonotic TB is not much investigated in SEAR and WPR, emphasizing the need to enhance surveillance and strengthen diagnostic laboratory capacity and capability to achieve the goal of human TB eradication.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author.

BS: Formal analysis, Writing – original draft. ND: Formal analysis, Methodology, Writing – review & editing. SC: Methodology, Writing – review & editing. AD: Conceptualization, Funding acquisition, Supervision, Writing – review & editing. CM: Conceptualization, Funding acquisition, Methodology, Supervision, Writing – review & editing.