Infection-avoidance behaviour in humans and other animals.

Compared with living free, the parasitic way of life has many attractions. Parasites create problems for all animals. Potential hosts can respond by learning to live with parasites (tolerance), actively fighting them (resistance), or they can avoid becoming infected in the first place (avoidance). I propose here a new classification of avoidance behaviour according to the epidemiology of infection risk, where animals must avoid (i) conspecifics, (ii) parasites and their vectors, (iii) parasite-rich environments, and (iv) niche infestation. I further explore how the disgust adaptive system, which coordinates avoidance behaviour, may form a continuum with the immune system through the sharing of signalling pathways, sites of action, and evolutionary history.

Sensor recorded changes in rates of hand washing with soap in response to the media reports of the H1N1 pandemic in Britain.

Objectives To examine how the frequency of information regarding a real disease threat influences hand washing with soap. Design and setting The authors installed wireless devices in highway service station lavatories in England to record the proportion of individuals washing hands with soap from May 2009 to January 2010. Participants Participants were users of men's and women's toilets. Combined there was an average of 6800 participant entrances into the lavatories daily. Primary outcome measure The primary outcome measure is the proportion of soap usage to the number of entries into the lavatories. Results Hand-washing rates were positively related to both H1NI coverage in blogs and the news; however, these relationships were stronger for men than for women. Conclusions Hand washing with soap increases proportionally to the frequency of media key words related to H1N1. Women's hand washing was more strongly associated with incidence of media keywords than men's.

Planned, motivated and habitual hygiene behaviour: an eleven country review.

Handwashing with soap (HWWS) may be one of the most cost-effective means of preventing infection in developing countries. However, HWWS is rare in these settings. We reviewed the results of formative research studies from 11 countries so as to understand the planned, motivated and habitual factors involved in HWWS. On average, only 17% of child caretakers HWWS after the toilet. Handwash 'habits' were generally not inculcated at an early age. Key 'motivations' for handwashing were disgust, nurture, comfort and affiliation. Fear of disease generally did not motivate handwashing, except transiently in the case of epidemics such as cholera. 'Plans' involving handwashing included to improve family health and to teach children good manners. Environmental barriers were few as soap was available in almost every household, as was water. Because much handwashing is habitual, self-report of the factors determining it is unreliable. Candidate strategies for promoting HWWS include creating social norms, highlighting disgust of dirty hands and teaching children HWWS as good manners. Dividing the factors that determine health-related behaviour into planned, motivated and habitual categories provides a simple, but comprehensive conceptual model. The habitual aspects of many health-relevant behaviours require further study.

Dirt, disgust and disease: a natural history of hygiene.

Hygiene has been studied from multiple perspectives, including that of history. I define hygiene as the set of behaviours that animals, including humans, use to avoid infection. I argue that it has an ancient evolutionary history, and that most animals exhibit such behaviours because they were adaptive. In humans, the avoidance of infectious threats is motivated by the emotion of disgust. Intuition about hygiene, dirt and disease can be found underlying belief about health and disease throughout history. Purification ritual, miasma, contagion, zymotic and germ theories of disease are ideas that spread through society because they are intuitively attractive, because they are supported by evidence either from direct experience or from authoritative report and because they are consistent with existing beliefs. In contrast to much historical and anthropological assertion, I argue that hygiene behaviour and disgust predate culture and so cannot fully be explained as its product. The history of ideas about disease thus is neither entirely socially constructed nor an "heroic progress" of scientists leading the ignorant into the light. As an animal behaviour the proper domain of hygiene is biology, and without this perspective attempts at explanation are incomplete. The approaches of biological anthropology have much to offer the practice of cultural history.

Ethics in public health research: masters of marketing: bringing private sector skills to public health partnerships.

Skill in marketing is a scarce resource in public health, especially in developing countries. The Global Public-Private Partnership for Handwashing with Soap set out to tap the consumer marketing skills of industry for national handwashing programs. Lessons learned from commercial marketers included how to (1) understand consumer motivation, (2) employ 1 single unifying idea, (3) plan for effective reach, and (4) ensure effectiveness before national launch. After the first marketing program, 71% of Ghanaian mothers knew the television ad and the reported rates of handwashing with soap increased. Conditions for the expansion of such partnerships include a wider appreciation of what consumer marketing is, what it can do for public health, and the potential benefits to industry. Although there are practical and philosophical difficulties, there are many opportunities for such partnerships.

A natural history of hygiene.

In unpacking the Pandora's box of hygiene, the author looks into its ancient evolutionary history and its more recent human history. Within the box, she finds animal behaviour, dirt, disgust and many diseases, as well as illumination concerning how hygiene can be improved. It is suggested that hygiene is the set of behaviours that animals, including humans, use to avoid harmful agents. The author argues that hygiene has an ancient evolutionary history, and that most animals exhibit such behaviours because they are adaptive. In humans, responses to most infectious threats are accompanied by sensations of disgust. In historical times, religions, social codes and the sciences have all provided rationales for hygiene behaviour. However, the author argues that disgust and hygiene behaviour came first, and that the rationales came later. The implications for the modern-day practice of hygiene are profound. The natural history of hygiene needs to be better understood if we are to promote safe hygiene and, hence, win our evolutionary war against the agents of infectious disease.