Sources, Seasonality, Transmission and Control: Campylobacter and human behaviour in a changing environment

Few of us would expect to die after a bout of diarrhoea. But the fact is that diarrhoeal disease kills. It can also lead to long-term, debilitating illnesses that adversely affect our industrial productivity and drain significant financial resource from our health and social services. Yet, much about what causes these potentially fatal diseases remains a mystery, not least because research to date has focused largely on one corner of the jigsaw. Our research will change this. Many of the organisms that cause diarrhoea occur naturally in animals. Some are easily transmitted to humans and have managed to adapt to - and thrive in - their new habitat. These organisms are abundant in the environment and there are countless ways for them to get into the human body. Until now, research has concentrated on contaminated food or water as the potential source of disease. No-one has yet studied the extent to which humans collude in their own misfortune. Is there something we do or fail to do that makes some of us more susceptible than others to these diseases? Our research unites experts from a wide variety of disciplines to answer these and other questions about what causes and spreads diarrhoeal disease. We will use Campylobacter spp, the most common bacterial cause of diarrhoea in the developed world, as our case study. In 2010, there were an estimated 700,000 cases of Campylobacter spp in the UK. Around 200 people died; others developed irritable bowel syndrome, arthritis and paralysis. The annual UK cost of acute Campylobacter infection alone tops #600 million, more than the cost of Salmonella, Listeria and E. coli O157 combined. Yet we still do not know how half the cases arose. About 40% of cases occur during the spring peak . Yet we know little if anything about what happens in the environment, or to our food supply, or to our own behaviour to cause this. So our research will investigate and capture what does happen - to us, to our environment and to society - at a number of different intervals, in a variety of locations and over a range of different time periods so we can understand how all these factors combine to influence Campylobacter infection. This type of analysis will benefit future research into how social and ecological systems interact with and affect other organisms that cross the species boundary between animals and people.

Diarrhoeal disease is an important global killer that causes major health and economic problems. Many organisms that cause it are zoonotic. They are widely distributed in the environment and there are several pathways to human disease. Research into diarrhoeal disease to date has been largely biomedical and focussed mainly on transmission through contaminated food or water. Fundamental gaps in our knowledge remain, namely the contributions of human behaviour and human-environment interactions influencing exposure to organisms and risk of disease. We propose a ground-breaking programme, bringing together scientists from a wide variety of disciplines in a ?one health? approach to tackle these fundamental knowledge gaps using Campylobacter spp. as an example. Important in its own right, Campylobacter is the most common bacterial cause of diarrhoeal disease in the developed world. It caused an estimated 700,000 cases in the UK in 2010 with ~200 deaths. Extreme outcomes include irritable bowel syndrome, arthritis and paralysis. The current, underestimated, annual UK cost of Campylobacter infection alone is #600m, exceeding that from Salmonella, Listeria and E. coli O157 combined. The transmission pathways for ~50% of human cases are unknown. Seasonal dynamics are central to the disease burden because ~40% of cases occur during the ?spring peak?, yet the relative roles of environmental and food pathways, and their interaction, in this seasonal emergence are poorly understood. To make major progress we face two important challenges. The first is to develop new methods that incorporate environmental and social systems to understand how they interact with Campylobacter. Secondly, since the behaviours of both humans and Campylobacter involve processes that play out over different temporal and spatial scales, the new methods we develop need to capture this. The challenge of analysing systems and data at different scales, whilst minimising loss of information in so doing, will be generally applicable to research on the interaction of social and ecological systems and zoonoses.