An investigation into antibiotic consumption and use for a better understanding of antibiotic resistance on the island of Mauritius

Antibiotic resistance (ABR) presents a great global threat and Mauritius, an upper middleincome country situated in the Southwest of the Indian Ocean, has not been spared. In order to comprehend the factors contributing to the high rate of resistance in the country, this thesis sheds light on antibiotic consumption, usage, and resistance by determining: 1) the distribution of antibiotic consumption in the different sectors in Mauritius, 2) the pattern of antibiotic consumption and use in public institutions of Mauritius, 3) the prevalence of Multi Drug Resistant (MDR) and Carbapenem resistant bacteria in the public healthcare institutions of Mauritius. The consumption of antibiotics in kilograms, Defined Daily Dose will be explored as well as the AST results of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. A Point Prevalence study on antibiotic use explores the use of antibiotics in hospital settings. It is observed, that in contrast to the global trend, the consumption of antibiotics in the human healthcare institutions of Mauritius (11 500 kg in 2017), plays a more valuable role in the selection pressure, as opposed to the animal sector (700 kg in 2017). Furthermore, the Defined Daily Dose per 1000 inhabitants per day (DID) of antibiotics (21.7 DID in 2017), including carbapenems (0.02 DID in 2017), is not elevated when compared to other African and European countries. Another noteworthy discovery is the substantial consumption of WATCH group of antibiotics in the private human healthcare sector. Regarding the use of antibiotics in hospital settings, it is observed that a proportion (33-48%) of patients were receiving antibiotics for surgical prophylaxis, and more than 60% of them were administered multiple doses of antibiotics over multiple days, contrary to the guidelines recommended by the World Health Organization (WHO). Additionally, around 75% of all antibiotic prescriptions consisted of third generation cephalosporins (ceftriaxone or cefotaxime), amoxicillin, metronidazole, and ciprofloxacin). Another concern is the low percentage (16%) of antimicrobial susceptibility testing (AST) conducted prior to prescribing antibiotics. It is to be noted that data on antibiotic consumption and usage is being presented for the first time in Mauritius. The data on antibiotic resistance shows a decrease susceptibility of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa to the WATCH and RESERVE antibiotics from 2015 to 2023. It is alarming to note that the susceptibility of the above bacteria to meropenem has decreased from 2015 to 2023, from 98% to 94%, 83% to 53%, 45% to 28% and 63% to 47% respectively. Furthermore, the proportion of Multi-Drug Resistant (MDR) pathogens in Mauritius is comparable to that of India and Malawi but high compared to Europe. This thesis highlights important information and identifies gaps that need to be addressed in the country's efforts to combat antibiotic resistance. The findings provide valuable information on misuse of antibiotics and decreasing antibiotic sensitivity, which can eventually help in the formulation of an antibiotic stewardship program. In addition, to tackle the complex issue of bacterial resistance, Mauritius needs to adopt a One Health approach that considers the interplay of humans, animals, and the environment. It offers insights, specific to the local context of Mauritius, which should be incorporated into the National Action Plan on Antimicrobial Resistance 2024-2029.