Evaluating methods to explore antibiotic use on smallholding pig farms in peri-urban Kenya

Claire Dorothy-Anne Scott^1*Nicholas Bor²Kristen Reyher^1*Alex J Tasker¹Henry Buller³Max Korir²Dishon Muloi²IRENE BUENO¹Lian Francesca Thomas^2,4,5

• ¹Bristol Veterinary School, Faculty of Health Sciences, University of Bristol, Bristol, United Kingdom
• ²Animal and Human Health Department, International Livestock Research Institute, Nairobi, Kenya
• ³Department of Geography, University of Exeter, Exeter, United Kingdom
• ⁴Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Leahurst Campus,, Liverpool, United Kingdom
• ⁵Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, United Kingdom

Understanding patterns and practices of antibiotic use in livestock is crucial to make informed recommendations for improved antibiotic stewardship and to measure the impact of interventions aimed at reducing inappropriate antibiotic use. In the absence of a unified tool to determine antibiotic use at the farm level, we aimed to advance the understanding of methodological approaches used to explore antibiotic use by evaluating the strengths and limitations of four different methods on smallholding pig farms in a peri-urban area of Nairobi, Kenya.Antibiotic use collection methods were trialled in parallel over one month on 13 farms. We evaluated four methods for their success in collecting instances of antibiotic use and facilitating further exploration of antibiotic use practices using qualitative discussion. Methods were: waste bucket analysis; medicine-recording sheets; weekly semi-structured interviews; and the 'Drug Bag' medicine sorting technique.We found no single method captured all likely or reported instances of antibiotic use. Waste bucket analysis collected the lowest number of instances of reported antibiotic use. The 'Drug Bag' collected the highest number of instances but risked over-reporting due to misrecognition, duplication and recall errors. We found that contextual factors, such as antibiotic use practices specific to the study context, affected methodological success. An example of this was individual animal treatments being the mainstay of antibiotic use, meaning that empty packaging was not available for the waste bucket. The use of multiple methods in parallel and qualitative data collection was helpful to ascertain the likelihood of over-or under-reporting of antibiotic use and allowed us to gather a more detailed understanding of antibiotic use practices.Our results highlight the challenges of gathering accurate farm-level antibiotic use data. Future studies must consider methodological suitability when planning data collection; we recommend that methodological suitability statements should be included in future publications. Triangulation of methods and qualitative data collection should be used where possible. Comparative analyses between antibiotic use studies should be carefully structured to account for methodological but also contextual variation.