Discussion on a Selection of Key Scientific Articles


Zoonoses of poverty: Measuring and managing the multiple burdens of zoonoses and poverty.

Zoonoses - Infections Affecting Humans And Animals: Focus On Public Health Aspects, pp. 1127 – 1137, Grace, D., 2015.

Key Thoughts: Zoonoses and poverty are closely linked. Poor people in developing countries are most at risk of zoonotic diseases, while the presence of zoonoses keeps people locked in poverty.  The cycle can only be interrupted by active intervention, and both investment and innovation are required to tackle long-standing problems.  History shows that the burden can be reduced.  Endemic and common diseases are often overlooked by donors and research, due to greater focus on emerging zoonoses, although these typically have a lower impact on the population. The lifestyle of poor people puts them at higher risk from zoonoses. Conversely, the livestock can also be a route out of poverty. The top five diseases have been identified as gastrointestinal, leptospirosis, cysticercosis, tuberculosis, and rabies.

Article Review:  It has been estimated that approximately 60% of all human diseases and 75% of emerging diseases are zoonotic.  Many diseases that are transmittable between people have originated in animals (referred to as “old zoonoses”).  Zoonoses can be considered as endemic, epidemic, or emerging.  The impact of these diseases is greatest in poor populations, where poverty is defined as existing on less than $1.25 USD a day.

Endemic diseases such as cysticercosis and tuberculosis are common in poor populations.  However, they do not receive high levels of investment from donors or research bodies as these diseases are considered “low profile”.

Epidemic diseases are often triggered by external events such as flooding or concomitant hunger.  Diseases such as Rift Valley Fever can cause sudden outbreaks and as such, lead to a “shock” to the local ecosystems.

Emerging zoonoses are either new in a population or of increasing incidence.  In general, the impact is lower than the endemic diseases because they hold the potential for a disaster. HI-AIDS is an example where typically more focus and funding is placed.

While the general poverty level globally appears to be falling, this is actually a result of development in specific countries, such as China.  In fact, the level of poverty in Africa and South Asia may be increasing.  Eighty percent of the people living in poverty worldwide live in just 12 countries.  Although zoonoses are often under-reported, it is clear that the poor countries bear the greatest burden of zoonotic disease.

Zoonotic disease is both a cause and a consequence of poverty.
The following poverty-related factors lead to increased risk:

  • Increased close contact with animals
  • Increased consumption of bushmeat
  • Poor sanitation and waste disposal leads to increased contact with peridomestic animals
  • Increased exposure to vectors such as prevention methods are less common
  • Increased levels of pathogens in food
  • Increased vulnerability due to reduction of the immune  system (because of malnutrition)
  • Less access to healthcare for prevention or treatment

However, animals can also bring benefits and can reduce poverty.  Firstly, they are an asset and provide stability to the household.  Secondly, by allowing specialization and intensification, they also increase income.  Thirdly, they increase market opportunities and profitability.

In order to reduce the risks and maximize the benefits of livestock, there is a need for improved understanding on the prevalence, impact and dynamics of disease, as well as the changing land-uses, such as irrigation and urbanification.  Not all countries are alike and the differences must be examined to generate a strong evidence base for decision making.


Farmers' beliefs and voluntary vaccination schemes: Bluetongue in Dutch dairy cattle.

Food Policy, 57, pp. 40 – 49, Sok, J., Hogeveen, H., Elbers, A.R.W., Oude Lansink, A.G.J.M., 2015.

Key Thoughts:  Disease control as a sustainable program is complex and there are a number of factors that need to be considered. While it seems obvious that compulsory vaccination programmes will have the greatest impact, in fact well managed voluntary schemes can be more sustainable because they achieve greater “buy in” from the farmer and they can be more economically viable. For voluntary campaigns to work, it is important to target the farmers’ beliefs by understanding the motivators. Then the correct communication mechanisms can be established. Although the most influential belief was to avoid economic damage from the disease, there was also a significant indication that a key reason for vaccination was that the farmer did not want to be emotionally confronted by cows suffering. The paper establishes that there are already intrinsic motivators for farmers to vaccinate, and communication can reinforce beliefs, thus influencing the success of a voluntary campaign. However, this communication must be from a trusted source with a high level of “similarity” to the audience, as local and personal contacts have greater impact.

Article Review:  The World Organisation of Animal Health (OIE) has listed a number of transboundary and emerging diseases which governments have agreed to control. In the face of disease some countries have shifted from mandatory vaccination to voluntary schemes. This is based on the economic theory that such interventions will result in lower public cost, with a greater shift of responsibility to the agricultural sector. During the 2006 Bluetongue outbreak, the Netherlands, among others, elected for such a voluntary scheme. This was considered to have been epidemiologically successful with eradication of the disease. Previous studies have shown that the motivation for farmers to participate was driven by both economic and social-psychological objectives. However, the farmers’ beliefs were not well understood, and this paper seeks to explore them further by using a Reasoned Action Approach (RAA).

RAA predicts that an individual behavior (B) is driven by the intention (I) to perform the behavior. The intention is influenced by four main beliefs: an evaluation of performing the behavior, or attitude (A); perceptions of what others think you should do, or injunctive norms (NI); the behavior of others, or descriptive norms (ND); and the social pressure to perform, or perceived behavioural control (PBC).

In order to collect the necessary information, semi-qualitative interviews were conducted with 7 dairy farmers and 1 veterinarian in order to first establish the beliefs. The questions asked the respondents to list the positive and negative aspects around each of the beliefs. For instance, injunctive norms were established by asking the respondents to list the individuals or groups that would either approve or disapprove of their performing an action. Based on the responses, a questionnaire was created and sent to a random sample of dairy farms with at least 40 dairy cows. 415 responses were returned. From these responses the main influences behind each of the beliefs were determined.

The analysis indicates that farmers already have intrinsic motivators to vaccinate, both from economic and social beliefs. The use of subsidies can complement the communication, as it indicates the seriousness of the situation taken by the government. Peer group pressure can be used to act as a catalyst to drive the required behavior.


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