as the behaviour change wheel (BCW) (Michie et al., 2011), which is grounded in a synthesis of psychological and sociological theories, have not, to our best knowledge, yet been used in One Health research. Although the BCW approach also takes as self-evident that biomedical knowledge, attitude and practice provide the golden standard for health improvement, it opens a space for studying what study participants do in real life – not just what they should do – and how their thinking and acting is shaped by the particular context in which they live.
Contextual influences are often conceptualized as social determinants of health, i.e. ‘the circumstances in which people are born, grow, work, live, and age’, and the wider set of systems and forces: ‘economics, social policies, and politics’ (CSDH 2008, p. 35). Woldehanna and Zimicki (2015), for example, have proposed an expanded One Health model that highlights the social and cultural determinants of human–animal interaction on the local level, with a focus on emerging viral diseases transmitted from animals to humans by direct or indirect contact. The key determinants they have identified are: (i) biological characteristics of individuals, for example gender; (ii) social characteristics of individuals, households and communities, including norms, livelihood systems and settlement patterns; and (iii) at the public policy level, local and international governance and politics (Fig. 7.1).
Fig. 7.1. Socio-cultural determinants of One Health. Adapted from Dahlgren and Whitehead, 2006; CSDH, 2008; Woldehanna and Zimicki, 2015.
The newly emerging animal and human infectious diseases arise from, and are spread by, a multitude of social determinants and ecological causes interacting at multiple scales, from the local to the regional, national, international to global levels, and across diverse domains. As Weiss and McMichael (2004) have argued these changing contexts are due to increases in population size and density, urbanization and human encroachment on forests and wildlife, poverty, the increased number and movement of people, food and animals around the globe, and conflict and warfare.
Much attention has been focused on identifying the environmental, ecological and social dynamics underlying epidemic outbreaks of emerging zoonotic diseases like Ebola or Nipah. The Nipah virus, for instance, emerged in Malaysia in 1998 when deforestation destroyed the fruit bat habitat. The bats moved to trees near livestock pens where they spread Nipah to pigs, from which humans were subsequently infected. The intensification of pig farming associated with the spillover of the virus from bats to pigs to humans was backed by companies and land deals and by broader economic shifts in regional stockbreeding underpinning local dynamics (Epstein et al., 2006; Otte and Grace, 2012; Pulliam et al., 2012). In later outbreaks of Nipah virus infections in Bangladesh and India, no clear evidence of transmission through pigs has been found. Rather, drinking traditional liquor made from date palm sap contaminated by bat excreta was one of the main sources of infection (Luby et al., 2006).
Other studies have shifted the attention from epidemic outbreaks attracting high media attention to endemic and neglected zoonotic diseases. They have examined the complex interactions of poverty and ecosystems in settings where zoonotic transmission usually occurs. Such transmission is often associated with rapid environmental and land-use change and the close contact between humans and wild and domestic animals (Okello et al., 2014). This analysis of the zoonotic transmission takes diverse and context-specific pathways into account (Cunningham et al., 2017).
Complementary to studies emphasizing a contextual analysis of social determinants, comparative research delving in depth into one determinant, such as gender, across diverse settings also contributes to expanding the social One Health agenda, as illustrated by the following case study of a gender analysis of food safety (Case study 1).
Case study 1. How understanding gender can contribute to understanding and improving food safety. Contributed by Delia Grace, International Livestock Research Institute, Nairobi, Kenya.
Background
Food safety is a One Health issue. Foodborne disease (FBD) has a health burden comparable to malaria, HIV-AIDS or tuberculosis (Havelaar et al., 2015). The majority of the quantified causes of FBD are zoonoses and animal source food is an important source of illness (Grace, 2015). Most FBD burden falls on low- and middle-income countries (LMIC) and is the result of food purchased in wet or informal markets where the poor buy and sell.
Motivation for research
To improve food safety, we first had to understand it, and that meant identifying who was involved in making food risky or safe and their knowledge, practices and motivations. We knew women and men in LMICs have important, but usually different, roles in producing, processing, selling and preparing food. We hypothesized that these roles, as well as biological differences between men and women, may have negative and positive impacts on their health, and also lead to differences in health outcomes. This case study summarizes findings on gender roles, risks and opportunities from studies in 20 informal livestock and fish value chains in Africa and Asia (Grace et al., 2015).
Findings
Men were seen as having greater responsibility for keeping cattle, capturing fish and market-oriented production, giving them opportunity for income generation. Where value chains had an important processing stage, this was usually dominated by women (e.g. smoking or drying fish and producing traditional dairy products in West Africa). In all the value chains studied, the majority of meat and fish was sold in small-scale, traditional markets (which may also be called ‘informal’ or ‘wet’ markets). In such markets, women sell fish and poultry, but meat is typically sold by men (Vietnam was an exception). Overall, this means women were more exposed to occupational hazards such as chemicals and risk of injury. On the other hand, participation also increased their access to food and income. As processing became modernized, the role of women often declined.
In all the case studies, women were responsible for preparing and cooking food for family consumption within the household. Men’s and women’s consumption within the household was generally reported to be similar. There was a tendency for women to consume riskier foods such as offal. However, in many cultures, there were taboos about pregnant women eating risky foods such as tripe and dog meat, which may have reduced risk. Moreover, men tended to consume more meat and fish outside households, often in outlets which also sold alcohol: this exposed them to higher risk of meat-borne disease. In most countries, milk was given preferentially to children.
Gender analysis showed how women and men carried out different activities, which led to different health risks. In around half the value chains, women were more at risk and in half men were more at risk. Understanding this helped develop gender-sensitive interventions that would work for the gender most at risk. Our finding that when value chains become more formal, they tend to exclude women who dominate more traditional value chains, drew attention to a possible unintended consequence of modernizing
