Reconstruction of transmission chains of SARS-CoV-2 amidst multiple outbreaks in a geriatric acute-care hospital: a combined retrospective epidemiological and genomic study.

Background: There is ongoing uncertainty regarding transmission chains and the respective roles of healthcare workers (HCWs) and elderly patients in nosocomial outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in geriatric settings. Methods: We performed a retrospective cohort study including patients with nosocomial coronavirus disease 2019 (COVID-19) in four outbreak-affected wards, and all SARS-CoV-2 RT-PCR positive HCWs from a Swiss university-affiliated geriatric acute-care hospital that admitted both Covid-19 and non-Covid-19 patients during the first pandemic wave in Spring 2020. We combined epidemiological and genetic sequencing data using a Bayesian modelling framework, and reconstructed transmission dynamics of SARS-CoV-2 involving patients and HCWs, to determine who infected whom. We evaluated general transmission patterns according to case type (HCWs working in dedicated Covid-19 cohorting wards: HCWcovid; HCWs working in non-Covid-19 wards where outbreaks occurred: HCWoutbreak; patients with nosocomial Covid-19: patientnoso) by deriving the proportion of infections attributed to each case type across all posterior trees and comparing them to random expectations. Results: During the study period (1 March to 7 May 2020), we included 180 SARS-CoV-2 positive cases: 127 HCWs (91 HCWcovid, 36 HCWoutbreak) and 53 patients. The attack rates ranged from 10% to 19% for patients, and 21% for HCWs. We estimated that 16 importation events occurred with high confidence (4 patients, 12 HCWs) that jointly led to up to 41 secondary cases; in six additional cases (5 HCWs, 1 patient), importation was possible with a posterior probability between 10% and 50%. Most patient-to-patient transmission events involved patients having shared a ward (95.2%, 95% credible interval [CrI] 84.2%-100%), in contrast to those having shared a room (19.7%, 95% CrI 6.7%-33.3%). Transmission events tended to cluster by case type: patientnoso were almost twice as likely to be infected by other patientnoso than expected (observed:expected ratio 2.16, 95% CrI 1.17-4.20, p=0.006); similarly, HCWoutbreak were more than twice as likely to be infected by other HCWoutbreak than expected (2.72, 95% CrI 0.87-9.00, p=0.06). The proportion of infectors being HCWcovid was as expected as random. We found a trend towards a greater proportion of high transmitters (≥2 secondary cases) among HCWoutbreak than patientnoso in the late phases (28.6% vs. 11.8%) of the outbreak, although this was not statistically significant. Conclusions: Most importation events were linked to HCW. Unexpectedly, transmission between HCWcovid was more limited than transmission between patients and HCWoutbreak. This finding highlights gaps in infection control and suggests the possible areas of improvements to limit the extent of nosocomial transmission. Funding: This study was supported by a grant from the Swiss National Science Foundation under the NRP78 funding scheme (Grant no. 4078P0_198363).

Lower risk of peripheral venous catheter-related bloodstream infection by hand insertion.

INTRODUCTION: Little is known about the bloodstream infection (BSI) risk associated with short-term peripheral venous catheters (PVCs) and no large study investigated the insertion site-related risk for PVC-BSI. METHODS: We performed a cohort study at the University of Geneva Hospitals using the prospective hospital-wide BSI surveillance database. We analyzed the association between insertion site and risk of PVC-BSI on the upper extremity using univariable and multivariable marginal Cox models. RESULTS: Between 2016 and 2020, utilization of 403'206 peripheral venous catheters were prospectively recorded in a 2000-bed hospital consortium with ten sites. Twenty-seven percent of PVC (n = 109'686) were inserted in the hand. After adjustment for confounding factors, hand insertion was associated with a decreased PVC-BSI risk (adjusted hazard ratio [HR] 0.42, 95% CI 0.18-0.98, p = 0.046) compared to more proximal insertion sites. In a sensitivity analysis for PVCs with ≥ 3 days of dwell time, we confirmed a decreased PVC-BSI risk after hand insertion (HR 0.37, 95% CI 0.15-0.93, p = 0.035). CONCLUSION: Hand insertion should be considered for reducing PVC infections, especially for catheters with an expected dwell time of more than 2 days.

Comparison of Routine Replacement With Clinically Indicated Replacement of Peripheral Intravenous Catheters.

Importance: Peripheral intravenous catheters (PVCs) are the most frequently used indwelling devices in hospitals worldwide. Peripheral intravenous catheter bloodstream infections (PVC-BSIs) are rare, but severe and preventable, adverse events. Objective: To investigate the incidence of PVC-BSIs after changing the policy of routine PVC replacement every 96 hours to clinically indicated replacement. Design, Setting, and Participants: This institution-wide, observational cohort study evaluated all patients hospitalized at a large university-affiliated hospital with 10 sites in Western Switzerland with a PVC insertion between January 1, 2016, and February 29, 2020. Exposures: Peripheral intravenous catheters were routinely replaced every 96 hours until March 31, 2018 (baseline period). Between April 1, 2018, and October 15, 2019, PVCs were replaced if clinically indicated (intervention period). From October 16, 2019, PVCs were again routinely replaced every 96 hours (reversion period). Main Outcomes and Measures: The PVC-BSI rates and PVC-BSI incidence rate ratios (IRRs) during each period. Results: A total of 412 631 PVCs with documented catheter duration were included (164 331 patients; median [interquartile range] patient age, 51 [33-72] years; 88 928 [54.1%] female): 241 432 PVCs at baseline, 130 779 at intervention, and 40 420 at reversion. Eleven PVC-BSIs were observed during the baseline period, 46 during the intervention, and 4 during the reversion period. Although the monthly number of PVC-days remained stable during all study periods, the number of monthly inserted PVCs decreased during the intervention period. The number of PVCs still in place more than 4 or more than 7 days was higher during the intervention period compared with the baseline and reversion periods. A significantly increased IRR of PVC-BSIs was observed for the intervention period (IRR, 7.20; 95% CI, 3.65-14.22; P < .001) compared with baseline, whereas during the reversion period there was no significant increase (IRR, 1.35; 95% CI, 0.30 6.17; P = .69). Conclusions and Relevance: The results of this cohort study using a large, prospective surveillance database suggest that replacement of PVCs only when clinically indicated may be associated with an increased risk of PVC-BSI compared with routine replacement. Even if PVC-associated BSI is a rare event, the use of PVCs in most patients makes this outcome relevant.

A Serious Game Designed to Promote Safe Behaviors Among Health Care Workers During the COVID-19 Pandemic: Development of "Escape COVID-19".

BACKGROUND: As many countries fear and even experience the emergence of a second wave of COVID-19, reminding health care workers (HCWs) and other hospital employees of the critical role they play in preventing SARS-CoV-2 transmission is more important than ever. Building and strengthening the intrinsic motivation of HCWs to apply infection prevention and control (IPC) guidelines to avoid contaminating their colleagues, patients, friends, and relatives is a goal that must be energetically pursued. A high rate of nosocomial infections during the first COVID-19 wave was detected by IPC specialists and further cemented their belief in the need for an engaging intervention that could improve compliance with COVID-19 safe behaviors. OBJECTIVE: Our aim was to develop a serious game that would promote IPC practices with a specific focus on COVID-19 among HCWs and other hospital employees. METHODS: The first 3 stages of the SERES framework were used to develop this serious game. A brainswarming session between developers and IPC specialists was used to identify the target audience and acquisition objectives. Nicholson's RECIPE mnemonic (reflection, engagement, choice, information, play, exposition) for meaningful gamification was used to guide the general design. A common and simple terminology was used to suit the broad target audience. The game was tested on various platforms (smartphones, tablets, laptops, desktop computers) by different users during each development loop and before its final release. RESULTS: The game was designed to target all hospital staff who could be in direct contact with patients within the Geneva University Hospitals. In total, 10 acquisition objectives were defined by IPC specialists and implemented into the game according to the principles of meaningful gamification. A simple storyboard was first created using Microsoft PowerPoint and was progressively refined through multiple iteration loops. Articulate Storyline was then used to create two successive versions of the actual game. In the final version, a unique graphic atmosphere was created with help from a professional graphic designer. Feedback mechanisms were used extensively throughout the game to strengthen key IPC messages. CONCLUSIONS: The SERES framework was successfully used to create "Escape COVID-19," a serious game designed to promote safe IPC practices among HCWs and other hospital employees during the COVID-19 pandemic. This game can be obtained free of charge for research and educational purposes. A SCORM (shareable content object reference model) package is available to facilitate results and completion tracking on most current learning management systems.

Low frequency of asymptomatic carriage of toxigenic Clostridium difficile in an acute care geriatric hospital: prospective cohort study in Switzerland.

BACKGROUND: The role of asymptomatic carriers of toxigenic Clostridium difficile (TCD) in nosocomial cross-transmission remains debatable. Moreover, its relevance in the elderly has been sparsely studied. OBJECTIVES: To assess asymptomatic TCD carriage in an acute care geriatric population. METHODS: We performed a prospective cohort study at the 296-bed geriatric hospital of the Geneva University Hospitals. We consecutively recruited all patients admitted to two 15-bed acute-care wards. Patients with C. difficile infection (CDI) or diarrhoea at admission were excluded. First bowel movement after admission and every two weeks thereafter were sampled. C. difficile toxin B gene was identified using real-time polymerase chain-reaction (BD MAX(TM)Cdiff). Asymptomatic TCD carriage was defined by the presence of the C. difficile toxin B gene without diarrhoea. RESULTS: A total of 102 patients were admitted between March and June 2015. Two patients were excluded. Among the 100 patients included in the study, 63 were hospitalized and 1 had CDI in the previous year, and 36 were exposed to systemic antibiotics within 90 days prior to admission. Overall, 199 stool samples were collected (median 2 per patient, IQR 1-3). Asymptomatic TCD carriage was identified in two patients (2 %). CONCLUSIONS: We found a low prevalence of asymptomatic TCD carriage in a geriatric population frequently exposed to antibiotics and healthcare. Our findings suggest that asymptomatic TCD carriage might contribute only marginally to nosocomial TCD cross-transmission in our and similar healthcare settings.

Transmission and effect of multiple clusters of seasonal influenza in a Swiss geriatric hospital.

OBJECTIVES: To investigate a nosocomial outbreak of influenza. DESIGN: Prospective outbreak investigation with active case finding and molecular typing. SETTING: A large academic geriatric hospital in Switzerland. PARTICIPANTS: Elderly hospitalized adults. MEASUREMENTS: Based on syndromic surveillance, a nosocomial influenza outbreak was suspected in February 2012. All suspected cases were screened for respiratory viruses using real-time reverse transcription polymerase chain reaction of nasopharyngeal swabs. Infection control procedures (droplet precautions with single room isolation whenever possible) were implemented for all suspected or confirmed cases. Specimens positive for influenza viruses were processed and sequenced whenever possible to track transmission dynamics. RESULTS: Respiratory samples from 155 suspected cases were analyzed during the outbreak period, of which 69 (44%) were positive for influenza virus, 26 (17%) were positive for other respiratory viruses, and 60 (39%) were negative. Three other cases fulfilled clinical criteria for influenza infection but were not sampled, and one individual was admitted with an already positive test, resulting in a total of 73 influenza cases, of which 62 (85%) were classified as nosocomial. Five distinct clusters of nosocomial transmission were identified using viral sequencing, with epidemiologically unexpected in-hospital transmission dynamics. Seven of 23 patients who experienced influenza complications died. Sixteen healthcare workers experienced an influenza-like illness (overall vaccination rate, 36%). CONCLUSION: Nosocomial influenza transmission caused more secondary cases than repeated community importation during this polyclonal outbreak. Molecular tools revealed complex transmission dynamics. Low healthcare worker vaccination rates and gaps in recommended infection control procedures are likely to have contributed to nosocomial spread of influenza, which remains a potentially life-threatening disease in elderly adults.

Hand hygiene among physicians: performance, beliefs, and perceptions.

BACKGROUND: Physician adherence to hand hygiene remains low in most hospitals. OBJECTIVES: To identify risk factors for nonadherence and assess beliefs and perceptions associated with hand hygiene among physicians. DESIGN: Cross-sectional survey of physician practices, beliefs, and attitudes toward hand hygiene. SETTING: Large university hospital. PARTICIPANTS: 163 physicians. MEASUREMENTS: Individual observation of physician hand hygiene practices during routine patient care with documentation of relevant risk factors; self-report questionnaire to measure beliefs and perceptions. Logistic regression identified variables independently associated with adherence. RESULTS: Adherence averaged 57% and varied markedly across medical specialties. In multivariate analysis, adherence was associated with the awareness of being observed, the belief of being a role model for other colleagues, a positive attitude toward hand hygiene after patient contact, and easy access to hand-rub solution. Conversely, high workload, activities associated with a high risk for cross-transmission, and certain technical medical specialties (surgery, anesthesiology, emergency medicine, and intensive care medicine) were risk factors for nonadherence. LIMITATIONS: Direct observation of physicians may have influenced both adherence to hand hygiene and responses to the self-report questionnaire. Generalizability of study results requires additional testing in other health care settings and physician populations. CONCLUSION: Physician adherence to hand hygiene is associated with work and system constraints, as well as knowledge and cognitive factors. At the individual level, strengthening a positive attitude toward hand hygiene and reinforcing the conviction that each individual can influence the group behavior may improve adherence among physicians. Physicians who work in technical specialties should also be targeted for improvement.