Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact

INTRODUCTION: The presence of Livestock Associated MRSA (LA-MRSA) in humans is associated with intensity of animal contact. It is unknown whether the presence of LA-MRSA is a result of carriage or retention of MRSA-contaminated dust. We conducted a longitudinal study among 155 veal farmers in which repeated nasal and throat swabs were taken for MRSA detection. Periods with and without animal exposure were covered. METHODS: Randomly, 51 veal calf farms were visited from June-December 2008. Participants were asked to fill in questionnaires (n = 155) to identify potential risk factors for MRSA colonisation. Nasal and throat swabs were repeatedly taken from each participant for approximately 2 months. Swabs were analysed for MRSA and MSSA by selective bacteriological culturing. Spa-types of the isolates were identified and a ST398 specific PCR was performed. Data were analyzed using generalized estimation equations (GEE) to allow for correlated observations within individuals. RESULTS: Mean MRSA prevalence was 38% in farmers and 16% in family members. Presence of MRSA in farmers was strongly related to duration of animal contact and was strongly reduced in periods with absence of animal contact (-58%). Family members, especially children, were more often carriers when the farmer was a carrier (OR = 2,

Associations between MRSA nasal and throat carriage and determinants in a multiple regression analysis.

<p>* p<0.05,</p><p>** Expressed per 10 years,</p><p>*** Refers to duration in days of either empty barn (low exposure) or holiday period (no exposure),</p><p>**** Expressed per 24 hours. Refers to duration of exposure to animals in 3 days before sampling.</p

Mean daily MRSA and MSSA prevalence.

∧<p>CI, confidence interval.</p><p>* mean prevalence over 10 sampling days based on nasal/throat swabs taken in morning.</p><p>** mean prevalence over sampling days in either low (on average 3.4 sampling days) or high exposed period (on average 5.8 sampling days).</p><p>*** mean prevalence over 3 sampling days based on nasal swabs taken in evening.</p

Schematic overview of the study design.

<p>Participants were followed for approximately two months during periods of both high and low/no exposure. The study starts 3 weeks prior to, and ends 3 weeks after, the low/no exposure period. Nasal and throat swabs were taken in the morning and evening once a week in high exposure periods, and twice a week in low exposure period. * Nasal samples taken in the evening of sampling day 2 (high exposed), 5 and 7 (low exposed) were additionally screened for MSSA.</p

Characteristics of study population of 155 participants.

<p>Characteristics of study population of 155 participants.</p

Associations between MRSA carriage and determinants, including MSSA nasal carriage in a multivariate analysis.

<p>Analysis based on samples taken in the evening of sampling day 2, 5 and 7. Associations shown for different dependent variables separately (nasal and/or throat carriage).</p><p>* p<0.05,</p><p>** p<0.10,</p><p>*** Expressed per 10 years,</p><p>**** Refers to duration in days of either empty barn (low exposure) or holiday period (no exposure),</p><p>***** Expressed per 24 hours. Refers to duration of exposure to animals in 3 days before sampling.</p

Characteristics of persistent-, intermittent- and non-carriers of MRSA.

<p>* mean prevalence over 10 sampling days.</p><p>** mean prevalence over 3 sampling days.</p

Persistence of MRSA carriage in farmers, family members and others.

<p>* MRSA positive means MRSA detected in at least one out of 4 samples (nasal and/or throat) taken per sampling day.</p><p>** Persistent carriers in bold (Persistent carrier: MRSA positive results on all sampling days; number of sampling days dependent on duration of low exposed period).</p

Pre-induction checklists and discomfort in patients. An observational study

BACKGROUND Since the WHO release of the Safe Surgery Saves Lives Program in 2008, peri-operative checklists minimise errors and improve patient safety worldwide. Anaesthesia professionals are often reluctant to use these checklists in front of patients because they fear causing patients' discomfort before anaesthesia and surgery. OBJECTIVE To assess and compare the subjective level of patient discomfort caused by the use of pre-operative checklists with the patient discomfort estimated by anaesthesia providers. DESIGN Prospective observational study. SETTING The current single-centre trial included 110 anaesthesia providers and 125 nonpremedicated ear, nose and throat or maxillofacial surgery patients in Switzerland from June to August 2016. Inclusion criterion: signed general research consent. EXCLUSION CRITERIA received premedication, less than 18 years old, day-care patients, dementia or other mental illnesses. INTERVENTIONS Anaesthesia healthcare providers and patients before surgery and on the first postoperative day were asked to rate three statements: MAIN OUTCOME MEASURES: All statements were rated on a 100-mm visual analogue scale, where 0 meant no agreement and 100 meant total agreement. RESULTS Patients overwhelmingly agreed that anaesthesia providers should use checklists in front of them. Anaesthesia providers rated the patient discomfort much higher than actually perceived by patients. Both, patients and anaesthesia providers rated the possibility of reducing the risk of errors high. CONCLUSION Patients experience far less discomfort observing the use of pre-induction checklists than anaesthesia providers expect. Patients value the potential safety benefit significantly higher than anaesthesia providers. These results further support the implementation of peri-operative checklists in the operating room environment. TRIAL REGISTRATION The current observational study had no intervention, therefore, was not registered