Abstract/Summary

Introduction: Antimicrobial resistance (AMR) is a global threat to humans and livestock. Even though the direct links between the increase in AMR in humans and antimicrobial use (AMU) in livestock is unclear, the reduction and prudent use of veterinary antimicrobials (antibiotics, anthelmintics) in livestock production has been advocated as a mitigation measure. Lack of policies regulating AMU and self-prescribing have been identified as drivers of inappropriate AMU practice, particularly in developing countries. Lack of access to qualified veterinarians and farmers’ lacking knowledge on AMU and AMR have also been identified as drivers of high and inappropriate AMU practices. While the availability of data on AMU patterns is increasing in developed countries, this is currently unknown in Fiji. The drivers of AMU and AMR in livestock production systems including Fiji is also limited in many countries across the globe. Like other developing countries, AMR has been reported in the Fijian human health sector; however, the psychological and contextual drivers of AMU and AMR in Fijian livestock production remains unknown. Aim: This PhD thesis aimed to quantify AMU in Fijian cattle (beef, dairy) and poultry (broiler, layer) enterprises and farming systems (backyard, semi-commercial and commercial), develop a framework for and to evaluate AMU practice, and explore and understand the drivers of AMU and AMR in Fijian livestock production systems located in Central and Western division on Viti Levu, Fiji. Methods: The programme of research in this thesis used a mixed methods approach. The Theory of Planned Behaviour (TPB) was used as a theoretical framework that informed the design of qualitative studies, and a comprehensive literature review informed the development of a conceptual framework, which underpinned the design of the quantitative studies. Livestock farms and managers were recruited in a cross-sectional survey using purposive and snowball sampling methods to collect socio-economic, demographic, livestock production and management, AMU, other medicines use, and feed and feeding systems data. To explore experiences and knowledge on AMU and AMR, livestock farmers and veterinary professionals (veterinarians and para-veterinarians) were recruited to take part in a one-off one to one semi-structured interview using purposive and snowball sampling methods. The survey data were analysed using ANOVA and logistic modelling. Semi-structured interview transcripts were analysed using reflexive thematic analysis and deductively using TPB. Results and Discussion: In the first quantitative study (Chapter 4), a total of 236 farms comprising of 276 enterprises (beef, n = 72, dairy, n = 74, broiler, n = 57, layer, n = 73) were recruited. The survey revealed a little over half (56%) of 276 livestock enterprises used antimicrobials. The quarterly antibiotic use was highest in broiler enterprises (12.4 mg/PCU), and anthelmintic use was highest in dairy enterprises (24,120 mg). The estimated annual antibiotic use in Fijian livestock farms (beef, dairy, broiler, and layer) was 44 mg/PCU (lower than the global average of 118 mg/PCU). The study revealed AMU was higher in the backyard and semi-commercial farming systems. In the second quantitative study (Chapter 5), antimicrobials were used on 309 occasions over 90 days in 276 enterprises. A 7-step framework for categorising AMU practice was developed and used. The decision-making steps revealed that in 298 of 309 (96%) incidents, antimicrobials were used imprudently, comprising antibiotics, 160 of 170 (94%) and anthelmintics, 138 of 139 (99%). The prudent use of antibiotics was associated with commercial farming systems (X2 = 13, p = 0.001); nonetheless, no association was observed with anthelmintic use (p > 0.05). The imprudent antibiotic use was associated with dairy (OR = 7.6, CI = 1.41,41.57, p = 0.018) followed by layer and beef (p > 0.05) compared to broiler enterprises. The study revealed that imprudent AMU was more common in backyard and semi-commercial enterprises compared to commercial broiler enterprises. In the first qualitative study (Chapter 6), 19 livestock farmers and managers took part. The analysis generated four themes: 1) Uninformed use of antimicrobials and lack of awareness of AMR, 2) Safeguarding livestock and generating income source as primary motivators for using antimicrobials 3) Medicine shortage results in hoarding and self-prescribing, and 4) Farm decisions on AMU and livestock management are influenced by foreign farmers and veterinarians. The livestock farmers used antimicrobials to prevent diseases and promote production. However, they lacked knowledge of antimicrobials and were unaware of the risks associated with imprudent AMU. The farmers hoarded and self-prescribed antimicrobials for their animals and rationed antimicrobials by not completing the entire course of antibiotics to save them for future use. The farmers expressed dissatisfaction with their local provision of veterinary services; therefore, they accessed help online and from foreign farmers and veterinarians. In the second qualitative study (Chapter 7), a total of 10 participants (para-veterinarians n = 8, veterinarians n = 2) took part. The analysis generated three key themes: 1) Antimicrobials prescribed and used based on availability and cost rather than clinical need, 2) Para-veterinarians awareness and knowledge of AMR influence treatment decisions , and 3) Limited resources impede effective consultation and veterinary service delivery. The para-veterinarians lacked knowledge and understanding of AMU and AMR. They prescribed and dispensed antimicrobials without knowing the risks associated with inappropriate AMU. The para-veterinarians did not clinically examine sick animals and based their treatment decisions regarding AMU on farmers’ perceived diagnoses. This study demonstrated the lack of knowledge and understanding of para-veterinarians towards AMU and AMR. The final quantitative study (Chapter 8) revealed that farms that raised cattle only for dairy were more likely to use antibiotics and anthelmintics (p = 0.018, OR = 22.97, CI 1.713,308.075). The layer only, broiler only, and layer and broiler mixed farms were most likely to use antibiotics (p > 0.05). Farms that maintained AMU records were more likely to use antibiotics (p = 0.045, OR = 2.65, CI 1.024,6.877) and, similarly, anthelmintics only (p > 0.05). AMU in livestock farms was not influenced by the socio-economic and demographic characteristics of the farmer. Although livestock production and management are different between systems and enterprises, the AMU practice was uncommon. This study demonstrated that the lack of knowledge of AMU may have influenced the AMU practice amongst the livestock farmers. The quantitative studies (Chapter 4 and 5) in this PhD thesis highlighted the need for antimicrobial stewardship (AMS) programmes targeting a reduction in AMU and promoting the prudent use of antimicrobials in smaller livestock production systems and enterprises in Fiji. Additionally, AMS programmes should be tailored to specific enterprises and livestock production systems. The qualitative studies (Chapter 6 and7) highlighted the need for AMS programmes promoting awareness on AMU and AMR amongst Fijian livestock farmers and para-veterinarians. The quantitative study (Chapter 8) highlighted the need for AMS programmes targeting awareness on AMU and livestock management amongst livestock farmers. Additionally, the need to improve the veterinary services infrastructure to allow farmers better access to veterinarians for farm veterinary extension advice on livestock production and management is also recommended. Allocation of physical and human resources to Fijian veterinary services should be considered part of AMS programmes to improve veterinary services to Fijian livestock farmers. This programme of research has generated new knowledge and made an original contribution about AMU and AMR in Fiji. The practice of AMU and the contextual and psychological drivers of AMU and AMR were identified. This contribution has the potential to inform the development of AMS programmes to optimise the use of veterinary antimicrobials in livestock production systems and mitigate AMR risks in the Fijian agri-food value chain at the country level. Future studies exploring the attitude and knowledge on AMU and AMR of other key actors (such as abattoir meat inspectors, farm gate buyers, commercial processors, and consumers) in the agri-food value chain are recommended. Future studies exploring the anthropological, socio-cultural, economic, and environmental factors that may influence AMU behaviour in livestock farmers are required to gain a broader systems knowledge to inform the design of AMS programmes targeting behavioural interventions, improving access to veterinary services and veterinary antimicrobials to promote prudent AMU in livestock production systems nationally.