Ecological problems such as zoonotic diseases, antimicrobial resistance, and environmental issues require a coordinated multidisciplinary approach in order to effectively address them. The growing threats to global health over the past years highlight the significance of the interface between humans, animals, and the ecosystems in the evolution and emergence of existing disease-causing pathogens. Understanding such disease dynamics based on a better grasp of the impacts of certain human activities, lifestyles, and ecosystem behaviors is crucial. Recognizing the interdependence of plant, animal, and human health and how it affects the health of the ecosystems in which they reside is crystallized into the One Health approach. It recognises the interdependency of human, animal and plant health, and that this has consequences on the health of ecosystems in which they coexist. Of these ecological problems, zoonotic diseases are one of the problems that can be best tackled using a One Health approach due to their multi-faceted nature1,2. Of the 175 recently discovered pathogens, 75% are classified as zoonotic. Of the 1415 species known to be harmful to humans, 61% are classified as zoonotic3,4. Numerous studies conducted among Nepal’s ethnic groups have shown that people have close relationships with animals for a variety of reasons, including cultural, religious, and ethnomedical purposes. Furthermore, the majority of domesticated animals may serve as hosts for the spread of zoonoses5.

Nepal is a country with diverse ethnic, linguistic, and socioeconomic characteristics. Among its ethnic, cultural, and traditional practices, fresh yak blood drinking is a common practice among some communities living in the Himalayan region5. Professional bleeders called Aamji collect fresh yak blood by piercing the jugular vein of living yaks (Bos grunniens or Bos mutus) in yak pastures, twice a year, during April/May and July/August6. Some people consume cooked yak blood, not fresh, such as the people from the Tamang community in the Rasuwa district, Nepal7. Community members believe that the yak blood acts as an aphrodisiac8 and provides nutrition and health benefits. However, the people who participate in the practice may be unaware that yak blood could contain zoonotic pathogens, including antimicrobial-resistant bacteria that can be transmitted to humans with negative consequences for health. Here, we discuss how implementing a One Health approach to this specific cultural practice could be beneficial to reduce the risk of spreading infectious disease.

Yak graze on high mountain pastures containing herbs with medicinal properties, such as Yarshagumba (Cordyceps sinensis) and Jatamashi (Nardostachys jatamansi)6. Thus, members of the communities that drink fresh yak blood believe that yak blood contains the medicinal properties of the herbs on which they graze, and that it helps revitalize weak people, cure jaundice, reduce high blood pressure, and improve digestive problems, such as gastritis6,7. Furthermore, they believe that fresh yak blood contains medicinal components, which are less readily available to the human body if blood is processed (First author’s experience while interacting with the local people in Mustang district where raw yak blood drinking is practiced). Generally, blood from a healthy animal is aseptic, so it is usually safe to consume raw. However, yaks brought to these festivals are untested for any diseases as no surveillance system is in place. There is also little research on the knowledge, behaviours, and perceptions of the communities that drink yak blood about zoonosis-related diseases5. Therefore, blood may be collected and drunk from diseased animals carrying zoonotic pathogens, which can be easily transmitted, particularly when the blood is unprocessed.

The fresh yak blood drinking ceremonies result in mass gatherings and overcrowding of people. This, along with poor hygiene practices, can also facilitate the transmission of pathogens. The migration of people from lowland areas to the hillier areas where blood drinking occurs could facilitate further transfer of pathogens, in both animals and humans. Nepalese yak farmers purchase their yak for breeding from the neighbouring Tibetan region of China, and zoonotic pathogens such as Mycobacterium tuberculosis, Brucella spp., Salmonella spp., and Q fever have been reported to be present in yaks from that area9. Evidence of infection with zoonotic pathogens such as Brucella spp10., Mycobacterium tuberculosis, Bacillus anthracis, Staphylococcus aureus, and Streptococcus spp11, have also been reported in yak in Nepal. The prevalence of brucellosis in yak in Upper Dolpa was found to be 0.22%, and this was associated with brucellosis-like symptoms in humans10. In 2022, sudden deaths of yak were reported in the Manang district, which were confirmed to be caused by haemorrhagic septicaemia resulting from infection with Pasturella multocida12, which is also known to cause septicaemia and septic shock in humans13.

Whilst consumption of fresh yak blood may contribute to the transmission of the aforementioned zoonotic diseases, specific studies on the role of yak blood drinking on the spread of zoonotic and human diseases have not been carried out. The lack of clinical and surveillance research poses a substantial knowledge gap. Thus, a reliable evidence base is needed to develop appropriate public health interventions to reduce disease transmission risk. Epidemiological studies should be conducted to identify the link between fresh yak blood drinking practices and possible transmission of zoonotic diseases from such practices. In such a studies, factors associated with consuming fresh yak blood, including the differing cultural practices, should be studied, to enable the most probable risk factors to be delineated. This would enable targeting identified risk factors by control programs.

We encourage the government of Nepal to introduce comprehensive pathogen surveillance and control by isolating and identifying any zoonotic pathogens present in yak blood; analysing the risk posed by the identified pathogens; and introducing strategies to either control zoonotic pathogens at their source, and/or interrupt the transmission of zoonoses to other animals and humans. The quarantine, isolation, vaccination, and treatment of diseased animals, combined with increasing awareness and encouraging improved sanitation and hygiene practices are essential to minimize the risk of zoonotic transmission. Additionally, drinking animal blood, such as yak blood in Nepal, constitutes a cultural occasion associated with ethnic groups and should be put into the context of the “One Health” approach, starting with respecting the social and cultural values associated with fresh blood drinking in communities. Successful implementation of programs must include careful consideration of the communities’ cultural beliefs about the nutritional and health benefits of this practice. Local religious leaders or gurus, community leaders, and social media should be involved, since all can play a role in raising awareness of potential health risks associated with drinking fresh yak blood. We also call on the government of Nepal to commit to researching this issue using an integrated One Health approach with the active participation of local community members. This should allow the development of the best evidence base and adoption of safe practices during the yak blood drinking ceremony to prevent the possible transmission of zoonotic diseases. The One Health-based principles we propose in this article should also be more generally applicable to other communities with similar traditions. Similar examples of this potentially risky behaviour include the Maasai people of southern Kenya and northern Tanzania, who regularly drink cow blood14,15.

Disease control requires a One Health approach that includes expanding veterinarian services and promoting health education. We also encourage sharing of information about the success and failure of different strategies across different communities, to increase knowledge. We hope this will ultimately improve human, animal and plant health in many different communities.