Controlling and monitoring emerging zoonoses in the poultry farming and trading system in Bangladesh: an interplay between pathogens, people, policy

Early in the 20th century, about 20 million people died from a great influenza epidemic which swept across the whole world. Since then, there have been other, smaller but still significant global influenza epidemics. Influenza is a zoonotic disease. It is caused by a family of viruses which live in pigs, poultry, humans and some other animals and birds, both domestic and wild. It is able to shift genetic material around between different versions of the virus found in these diverse species. This ability to for influenza viruses to combine and change makes it hard to develop generally effective vaccines for different strains. Global and national health authorities are constantly on the lookout for signs that a new global pandemic of this potentially fatal disease is about to move from a localised outbreak to a global pandemic. Increases in living standards and in global trade mean that there is a rapidly rising demand for and supply of animal protein. Poultry and specifically chickens are the major source of all protein consumed in the world. Bangladesh is undergoing large changes in economic and social development. Poverty alleviation through livestock production plays an increasing part in these developments. Due to their high reproduction and growth rates as well as the ease of scaling up production from backyard to large industrial farms, poultry production adapts better than any other livestock sector to increased demand, and will further expand in the near future. But with these advantages comes increased risk of outbreaks of novel influenza strains, some of them highly pathogenic, as in the case of the recent H5N1. Such outbreaks can have up to 100% mortality in chickens and other domestic poultry and very high mortality rates in human beings when the influenza "jumps" species from the animal/bird reservoir to humans - a process called zoonosis. In the face of disease outbreaks in poultry, farmers and traders worry about economic loss. They may change their behaviour to avoid such loss and in the process may facilitate the spread of infection. Such behavioural changes can modify the way disease spreads, and even prolong and strengthen the epidemic so that it becomes a widespread "pandemic" moving beyond a local area to the whole world. This research will study the behaviour of people working in the Bangladeshi poultry farming and trading system so as to understand how to develop effective policies which will (a) reduce the risk that people's behaviour will spread the disease (b) develop practical and effective interventions which will control widespread disease dissemination. The team will do this by combining two areas of work: (a) sophisticated mathematical modelling of how poultry production and marketing works; (b) detailed qualitative and quantitative study of the social, cultural and economic factors which may promote disease maintenance and dissemination in Bangladesh. An innovation in this study will be the inclusion of an experimental component whereby farmers and traders will be asked to play a number of epidemiological "games". This approach will mean that the insights from the qualitative study of cultural socio-economics will feed into a more sophisticated understanding of people's behaviour in the face of disease outbreaks. This in turn will enable refinement of the systems modelling component of the project. The approaches we will adopt in this research will produce both specific local knowledge and more general knowledge which will be useful for understanding influenza outbreaks and even some aspects of other animal and human infectious disease outbreaks and pandemics in other parts of the world.