Supporting the National Action Plan on AMR in Tanzania (SNAP-AMR) Antimicrobial resistance (AMR) is recognised as a global threat to human and animal health, productivity and prosperity. AMR is widespread in both resource-rich nations such as the UK and in low and middle income countries (LMICs). The United Republic of Tanzania is one such LMIC, and in response to a call to action from the World Health Organisation, it has created a National Action Plan (NAP) to combat AMR.   The NAP is an ambitious plan outlining five strategic routes for tackling AMR: i) improved awareness and understanding; ii) enhanced surveillance and research; iii) better sanitation, hygiene and infection prevention; iv) optimized use of antibiotics; and v) sustainable investment in alternatives. In common with many LMICs, the challenge posed by AMR is exacerbated by widespread or unregulated use in both humans and livestock, whilst successful implementation of the NAP is threatened by lack of human and financial resources. Prioritisation of activities and targeting of interventions is therefore an essential component of an effective and efficient campaign to control AMR.  Our research will provide new evidence to support this prioritisation and targeting, taking an approach that recognises that behavioural change is a complex phenomenon depending not just on policy, regulation or knowledge provision but also on cultural background and social norms. Our team of UK and Tanzania-based researchers and policy experts will take an interdisciplinary approach to provide novel insights into the biological, social and cultural drivers influencing antibiotic use in the community and health care system; the spread of AMR between the humans and animals in the community and health care settings; knowledge about AMR; and how to change behaviours to reduce antibiotic use and the spread AMR.  We will contrast doctor prescribing practices in different health care settings (referral hospitals, district hospitals, health centres, dispensaries), as well as investigating community access and attitudes to antibiotics among householders, community 'drug' shops and unregulated sources such as roadside traders. We will use focus groups to examine factors that influence prescribing and usage, e.g. availability of antibiotic drugs, diagnostic facilities, patient demands, medical training and knowledge, coupled with choice-based experiments to establish how best to create change in prescribing behaviour or use. We will also use choice-based experiments to examine use in livestock by individuals with different levels of knowledge about AMR, e.g. district vets, community livestock officers and livestock holders. In parallel, bacterial isolates from people or livestock in hospital and community settings will be DNA-sequenced and examined used genomic tools to establish whether resistant commensal bacteria found in faecal samples in the community are those responsible for illness (respiratory infections, diarrhoea, sepsis and urinary tract infections) in hospitalised children.  The final component will be to assess the knowledge and sources of knowledge held by the public, health care and veterinary workers, policy makers and educators; to design interlinked targeted media campaigns that reflect educational, professional and cultural differences; and to assess the uptake of these materials and their impact on attitudes and approaches to antibiotic drugs and resistance.  The outcomes of our research will help priority setting and targeting in the NAP by identifying the settings (health care system or community) where most effective change can be achieved; showing how to create change in antibiotic usage (e.g. via improved training or education, diagnostic facilities or a social-norm based 'nudge') and identifying the individuals to target to create the most effective change; and by designing and delivering a mass media campaign to create awareness and behavioural change that will help Tanzania to combat the threat posed to its future by AMR. 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.