Spatial analysis of methicillin-resistant Staphylococcus aureus carriage (MRSA) at hospital admission in a livestock dense region

Title Spatial analysis of methicillin-resistant Staphylococcus aureus carriage (MRSA) screening yield at hospital admission in a livestock-dense region Purpose In the Netherlands, patients with a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) carriage, such as foreign hospital stay and contact with livestock (pigs, veal calves and/or broilers) are actively screened upon hospital admission. This study aimed to give insight in the geographical clustering patterns of MRSA carriage among these patients in a livestock-dense region. Methods A retrospective study was performed using medical records and laboratory results of MRSA screened patients admitted to seven hospitals in the provinces of Gelderland and Noord-Brabant, covering the period from 01/2011 to 02/2017. SaTScan spatial scanning identified cluster areas with an increased MRSA carriage risk in postal codes compared to the surrounding areas. Results 15 546 patients were included, among which 10.0% (n=1499) were MRSA carriers. Four significant, typically highly pig-dense MRSA carriage hotspots were identified, where the relative risk of carriage ranged from 2.1 to 3.4 compared to the surrounding area. Conclusion MRSA carriage risk clustered in certain areas, suggesting an association between livestock density (mainly pigs) and the MRSA carriage risk for the screened population at hospital admission. It needs to be explored when proximity (not contact) to livestock should be considered a risk factor. Considering analytical difficulties we encountered it is recommended to harmonize culture methods and data acquisition across hospitals to facilitate analysis for improving MRSA screening policy. Impacts ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by Radboudumc Nijmegen, and in kind by all the participating hospitals. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Radboudumc medical ethical committee approved the study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The datasets generated and/or analyzed during the current study are not publicly available due to privacy protection of patients. * MRSA : Methicillin resistant Staphylococcus aureus