1. Disease transmission in networks: social and biological Frances Griffiths Warwick Medical School

2. Emergence of ‘health’ of communities/populations Social networks are important where a biological agent of transmission is known - what about social modulation of biological transmission? - what about disease transmission with no known biological mechanism? - what about mimesis?

3. Egocentric social networks and health The number and quality of social relationships impacts on health - susceptibility to infectious disease - contraception usage - depression - premature death Increasing research on sociocentric networks and their impact on health

4. Social modulation of biological transmission Example from rural Ecuador on transmission of diarrhoeal disease (2003-2005): - increased prevalence with increased casual social contact (i.e. crowding) - reduced prevalence with increased ‘food sharing’ contact (quality of social connectedness) Are positive behaviours being mirrored in the food sharing networks?

5. Disease transmission with no known biological mechanism Three longitudinal studies in USA Obesity Social transmission v shared social environment Adolescent smoking Protective: having close circles of friends and social status among peers when one’s friends are smokers Increased risk of smoking: exposure to smokers and opportunity for interacting with them

6. Understanding cause v understanding what makes a successful intervention Friendship networks of obese people - potential for social support as part of intervention Adolescent smoking - increased ‘social competency’ as part of intervention