Who gets what and when? Pathways of antibiotic use among people and animals in Bangladesh Bangladesh is a low-income country with an estimated 40% of the population living in extreme poverty. Against this background of poverty, Bangladesh is internationally recognised for achieving 'good health at low cost' through community-based interventions to improve the health of the most disadvantaged. However, antibiotic resistant bacteria are known to be present in drinking water, wastewater and in patient samples, and the availability of over-the-counter, inexpensive antibiotics means that there is a high risk of a rapid and uncontrolled spread of antibiotic resistance throughout the population. Studies in Bangladesh suggest that 63% of prescriptions for antibiotics are from practitioners with no qualifications, and antibiotics are prescribed in nearly half (44%) of all consultations in primary health care. Tackling antibiotic resistance is essential for the long term economic development and welfare of the country. In order to slow the spread of antibiotic resistance, there are complexities around balancing the need for access to health for the disadvantaged, at the same time as introducing greater regulation around the prescribing and ready availability of antibiotics. Research is required to better understand the needs of households and individuals for antibiotic treatment for their family and livestock, as well as understanding the prescribing behaviours of qualified and unqualified practitioners.  We will study the pathways of antibiotic use 1) from the perspective of lay people who buy or consume antibiotics either for themselves, family members or for livestock and 2) from the perspective of the healthcare practitioners, including qualified and unqualified providers (market sellers, unqualified drug shop owners and untrained 'doctors'). Through in-depth interviews in urban and rural Bangladesh, we will gain a better understanding of behaviours around antibiotic prescribing and consumption as well as establishing whether there is an awareness of antibiotic resistance among healthcare practitioners, or their patients and clients. By interviewing practitioners across the whole range of formal and informal outlets we will assess the potential for practitioners to change prescribing practices or act as agents of change. The third aim of the study is to work with government and non-government agencies to inform the development of interventions to reduce antibiotic use. We will use the formative research from interviews to work with a professional communication team to develop culturally appropriate messages and materials for awareness-raising and communication campaigns on antibiotic resistance. These materials will be pre-tested with lay people, healthcare providers and drug shop owners to establish the acceptability of messages, who should be targeted, and what potential there is for the users and stakeholders in antimicrobial resistance to develop national awareness-raising or behaviour change interventions. The benefits of this research are to shed light on the behaviours around antibiotic treatment seeking behaviour and prescribing, the relationships between lay people and their local healthcare practitioner, motivations for seeking or selling antibiotics for people and animals; who and what the antibiotic treatment is sought for; what happens to antibiotics after prescription or purchase, and on the perceived effects of antibiotics on the resolution of symptoms. The findings will provide formative data on which to identify pathways for behaviour change. Our international partner, the International Centre for Diarrhoeal Disease Research Bangladesh (ICDDR, B), is internationally recognised for the development and delivery of low-cost, scalable solutions to major health problems. Capacity-building in Bangladesh and establishing a leading centre for research on antimicrobial resistance are integral parts of this pump-priming initiative. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.