Reunion, a sentinel island for multidrug-resistant bacteria surveillance in South-western Indian ocean: a retrospective survey using hospitalised patients screening, 2015-2017

Abstract Background Since 2015, antimicrobial resistance was identified as a public health priority for the Southwestern Indian ocean (SWIO) (Comoros, Madagascar, Mauritius, Mayotte (France), Reunion (France), and Seychelles). However, multidrug-resistant Bacteria (MRB) colonization rates in human populations from most islands of SWIO were still unknown in 2020 with neither hospital nor community baseline colonization rates estimated. Methods Based on exhaustive hospital MRB screening laboratory data, we provided the first estimation of MRB colonization rates in hospitalized patients residing in SWIO (2015-2017). Using Reunion (European Union) MRB colonization rate as a baseline we identified at risk patients according to their territory of residence. Results The survey pointed out significantly higher overall MRB colonization rates in patients from Comoros, Madagascar, Mayotte, and Seychelles when compared to Reunion (France) with extended-spectrum betalactamase producing Enterobacteriaceae as a generalized public health issue for these territories. Specific epidemiological dynamics were pointed out in Mayotte and Seychelles patients with significantly higher methicillin-resistant Staphylococcus aureus (MRSA) colonization rates; and in Mauritius patients with higher carbapenemase producing Enterobacteriaceae (CPE) colonization rate. Conclusion These results could be the first step to set up a regional MRB surveillance in SWIO hospitals.