No nosocomial transmission under standard hygiene precautions in short term contact patients in case of an unexpected ESBL or Q&A E. coli positive patient: a one-year prospective cohort study within three regional hospitals

Abstract

BackgroundMany Highly Resistant Gram Negative Rod (HR-GNR) positive patients are found unexpectedly in clinical cultures, besides patients who are screened and isolated based on risk factors. As unexpected HR-GNR positive patients are isolated after detection, transmission to contact patients possibly occurred. The added value of routine contact tracing in such situations within hospitals with standard hygiene precautions is unknown.MethodsIn 2014, this study was performed as a prospective cohort study. Index patients were defined as those tested unexpectedly HR-GNR positive in clinical cultures to diagnose a possible infection and were nursed under standard hygiene precautions before tested positive. After detection they were nursed in contact isolation. Contact patients were still hospitalized and shared the same room with the index patient for at least 12 h. HR-GNR screening was performed by culturing a rectal and throat swab. Clonal relatedness of HR-GNR isolates was determined using whole genome sequencing (WGS).ResultsOut of 152 unexpected HR-GNR positive patients, 35 patients (23.0%) met our inclusion criteria for index patient. ESBL E. coli was found most frequently (n = 20, 57.1%), followed by Q&A E. coli (n = 10, 28.6%), ESBL K. pneumoniae (n = 3, 8.5%), ESBL R. ornithinolytica (n = 1, 2.9%) and multi resistant P. aeruginosa (n = 1, 2.9%). After contact tracing, 69 patients were identified as contact patient of an index patient, with a median time between start of contact and sampling of 3 days. None were found HR-GNR positive by nosocomial transmission.ConclusionsIn a local setting within hospitals with standard hygiene precautions, routine contact tracing among unexpected HR-GNR positive patients may be replaced by appropriate surveillance as we found no nosocomial transmission in short term contacts.

Contact isolation versus standard precautions to decrease acquisition of extended-spectrum β-lactamase-producing Enterobacterales in non-critical care wards: a cluster-randomised crossover trial

“…32 Published literature indicates that outside of outbreaks, only a fraction of ESBL-E identified on wards is transmitted between patients. 24,28,33 Similar results for prevalence on admission and new acquisitions indicate no systematic differences between the intervention periods. Patients readmitted to the wards might have had complex courses of treatment, and thus selection could have had a large role in this group of patients, but the results of sensitivity analyses of first admissions alone were consistent with the primary analysis.…”

Isolation strategy for controlling the spread of multidrug-resistant organisms: Is this still an essential option in hospitals?

“…In a previous prospective cohort Dutch study, in which surveillance cultures were taken from contact patients when an MDRO was identified in the index patient roommate, no nosocomial transmission was documented using whole genome sequencing (WGS). 12 Finally, Tschudin-Sutter and colleagues found a remarkably low ESBL-E transmission rate (1.5%) from non-isolated index patients to roommates, with a mean contact period of 4.4 days in a large study performed in a Swiss university hospital. They concluded that nosocomial ESBL-E transmission rates were low when a high level of standard hygiene precautions was applied and that the community reservoir may be an important driver of the emergence and spread of ESBL-E, with an emphasis on the food chain.…”

“… 2 In addition to the MDR-GNB-colonized patients found during active surveillance studies, MDR bacteria are also unexpectedly found in clinical cultures. 12 …”

Isolation strategy for controlling the spread of multidrug-resistant organisms: Is this still an essential option in hospitals?

“…2 In addition to the MDR-GNB-colonized patients found during active surveillance studies, MDR bacteria are also unexpectedly found in clinical cultures. 12 The published literature shows a difference in the transmission risk of ESBL-E, suggesting that CPs may not be necessary for all ESBL-positive organisms. Colonization with this kind of organisms usually persists during hospitalization and often for months following discharge.…”