Successful methodology for large-scale surveillance of severe events following influenza vaccination in Canada, 2011 and 2012.

In 2011 and 2012, a nationwide Canadian vaccine safety surveillance network rapidly collected safety data from healthcare workers (HCW) during the first weeks of the annual influenza vaccination campaign. This network provided the first available post-marketing safety data on seasonal influenza vaccines with information on background rates as a comparator. In 2012, these data were used to investigate a possible safety concern regarding a particular vaccine. An online questionnaire was provided to participating HCW two weeks before the annual influenza vaccination campaign for controls, and eight days after influenza vaccination for vaccinees. Control and vaccinees were requested to report health events occurring in the seven days prior to receiving the questionnaire. Control data were used to calculate background rates. HCW reporting a severe event were followed-up by telephone within 48 hours of the online report to validate the report and check on their health status. More than 22,000 vaccinated HCW were enrolled and surveyed over two seasons and > 90% reported no severe event following vaccination. Validated severe event rates were similar in vaccinated HCW and unvaccinated HCW (2.2% vs 2.3%; p < 0.70). The questionnaire was accurately completed for most reported symptoms, matched the validated report and was able to detect events of interest. Prior to the safety concern, the implicated vaccine was in use at one centre. Reassuring safety data were provided to public health authorities 48 hours after the vaccine was temporarily suspended. Data from this and similar networks can be used for rapid evaluation of vaccine safety and for safety assessment as required by the European Medicines Agency in 2015.

Epidemiology of healthcare-associated Pseudomonas aeruginosa in intensive care units: are sink drains to blame?

BACKGROUND: Pseudomonas aeruginosa (PA) is a common cause of healthcare-associated infection (PA-HAI) in the intensive care unit (ICU). AIM: To describe the epidemiology of PA-HAI in ICUs in Ontario, Canada, and to identify episodes of sink-to-patient PA transmission. METHODS: This was a prospective cohort study of patients in six ICUs from 2018 to 2019, with retrieval of PA clinical isolates, and PA-screening of antimicrobial-resistant organism surveillance rectal swabs, and of sink drain, air, and faucet samples. All PA isolates underwent whole-genome sequencing. PA-HAI was defined using US National Healthcare Safety Network criteria. ICU-acquired PA was defined as PA isolated from specimens obtained ≥48 h after ICU admission in those with prior negative rectal swabs. Sink-to-patient PA transmission was defined as ICU-acquired PA with close genomic relationship to isolate(s) previously recovered from sinks in a room/bedspace occupied 3-14 days prior to collection date of the relevant patient specimen. FINDINGS: Over ten months, 72 PA-HAIs occurred among 60/4263 admissions. The rate of PA-HAI was 2.40 per 1000 patient-ICU-days; higher in patients who were PA-colonized on admission. PA-HAI was associated with longer stay (median: 26 vs 3 days uninfected; P < 0.001) and contributed to death in 22/60 cases (36.7%). Fifty-eight admissions with ICU-acquired PA were identified, contributing 35/72 (48.6%) PA-HAIs. Four patients with five PA-HAIs (6.9%) had closely related isolates previously recovered from their room/bedspace sinks. CONCLUSION: Nearly half of PA causing HAI appeared to be acquired in ICUs, and 7% of PA-HAIs were associated with sink-to-patient transmission. Sinks may be an under-recognized reservoir for HAIs.

Immunogenicity of a half-dose of adjuvanted 2009 pandemic H1N1 influenza vaccine in adults: a prospective cohort study.

We aimed to assess the immunogenicity of a single half-dose of AS03-adjuvanted monovalent 2009 pandemic H1N1 vaccine in healthy adults. Healthy subjects age 20-60 years were prospectively enrolled in a cohort receiving intramuscular administration of a single half-dose (1.875 µg of hemagglutinin [HA]) of adjuvanted 2009 pandemic H1N1 influenza vaccine. Data from participants enrolled in a concomitant study of immunogenicity following a full-dose (3.75 µg of HA) are presented concurrently. Sera for assessment of hemagglutination-inhibiting (HAI) antibody to the vaccine strain were obtained before and 14 or 21 days after vaccination. Ninety-seven participants received a half-dose and 50 received a full-dose of vaccine. In the half-dose cohort, Food and Drug Administration criteria for immunogenicity regarding seroprotection and seroconversion rates were met for subjects aged 20-45 years, but not for those aged 46-60 years. There was no statistically significant difference in the proportion of individuals achieving a post-vaccination HAI titre of ≥1:40, the geometric mean titres of post-vaccination antibody, or the proportion of individuals with a four-fold or greater increase in antibody levels between the two cohorts. Participants 46-60 years of age were significantly less likely to be seroprotected at day 21 than those 20-45 years old in both cohorts. Immunogenicity of a half dose of adjuvanted pH1N1 influenza vaccine was adequate in subjects aged 20-45 years. Dose reduction is a possible strategy for expanding the availability in the event of vaccine shortage in this age group.

The role of drinking water in the transmission of antimicrobial-resistant E. coli.

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005-2006 were asked to participate in a cross-sectional study. Household members aged ≥12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.

Development of a tool to assess evidence for causality in studies implicating sink drains as a reservoir for hospital-acquired gammaproteobacterial infection.

BACKGROUND: Decades of studies document an association between Gammaproteobacteria in sink drains and hospital-acquired infections, but the evidence for causality is unclear. AIM: We aimed to develop a tool to assess the quality of evidence for causality in research studies that implicate sink drains as reservoirs for hospital-acquired Gammaproteobacterial infections. METHODS: We used a modified Delphi process with recruited experts in hospital epidemiology to develop this tool from a pre-existing causal assessment application. FINDINGS: Through four rounds of feedback and revision we developed the 'Modified CADDIS Tool for Causality Assessment of Sink Drains as a Reservoir for Hospital-Acquired Gammaproteobacterial Infection or Colonization'. In tests of tool application to published literature during development, mean percent agreement ranged from 46.7% to 87.5%, and the Gwet's AC1 statistic (adjusting for chance agreement) ranged from 0.13 to 1.0 (median 68.1). Areas of disagreement were felt to result from lack of a priori knowledge of causal pathways from sink drains to patients and uncertain influence of co-interventions to prevent organism acquisition. Modifications were made until consensus was achieved that further iterations would not improve the tool. When the tool was applied to 44 articles by two independent reviewers in an ongoing systematic review, percent agreement ranged from 93% to 98%, and the Gwet's AC1 statistic was 0.91-0.97. CONCLUSION: The modified causality tool was useful for evaluating studies that implicate sink drains as reservoirs for hospital-acquired infections and may help guide the conduct and reporting of future research.

Sources of viral respiratory infections in Canadian acute care hospital healthcare personnel.

BACKGROUND: Viral respiratory illnesses are common causes of outbreaks and can be fatal to some patients. AIM: To investigate the association between laboratory-confirmed viral respiratory infections and potential sources of exposure during the previous 7 days. METHODS: In this nested case-control analysis, healthcare personnel from nine Canadian hospitals who developed acute respiratory illnesses during the winters of 2010/11-2013/14 submitted swabs that were tested for viral pathogens. Associated illness diaries and the weekly diaries of non-ill participants provided information on contact with people displaying symptoms of acute respiratory illness in the previous week. Conditional logistic regression assessed the association between cases, who were matched by study week and site with controls with no respiratory symptoms. FINDINGS: There were 814 laboratory-confirmed viral respiratory illnesses. The adjusted odds ratio (aOR) of a viral illness was higher for healthcare personnel reporting exposures to ill household members [7.0, 95% confidence interval (CI) 5.4-9.1], co-workers (3.4, 95% CI 2.4-4.7) or other social contacts (5.1, 95% CI 3.6-7.1). Exposures to patients with respiratory illness were not associated with infection (aOR 0.9, 95% CI 0.7-1.2); however, healthcare personnel with direct patient contact did have higher odds (aOR 1.3, 95% CI 1.1-1.6). The aORs for exposure and for direct patient contact were similar for illnesses caused by influenza. CONCLUSION: Community and co-worker contacts are important sources of viral respiratory illness in healthcare personnel, while exposure to patients with recognized respiratory infections is not associated. The comparatively low risk associated with direct patient contact may reflect transmission related to asymptomatic patients or unrecognized infections.

Immunogenicity and reactogenicity of high- vs. standard-dose trivalent inactivated influenza vaccine in healthcare workers: a pilot randomized controlled trial.

OBJECTIVES: To compare immunogenicity, reactogenicity and acceptability of high- and standard-dose trivalent inactivated influenza vaccine (HDTIV, SDTIV) in 18- to 64-year-olds. METHODS: We randomized 18- to 64-year-olds to HDTIV or SDTIV in two consecutive years. We collected serum on days 0 and 21, measured haemagglutination inhibition geometric mean titres (GMT) and compared seroconversion, day 21 titres, seroprotection, reactogenicity and acceptability. RESULTS: Immunogenicity was evaluable in 42 of 47 2014 participants, all 33 both-year participants and 87 of 90 2015-only participants. First-dose HDTIV recipients experienced seroconversion more frequently than SDTIV recipients to A(H3N2) in 2014 (13/21, 62% vs. 4/21, 19%, p 0.01) and to all vaccine strains in 2015: (A(H1N1): 24/42, 57% vs. 15/59, 25%; A(H3N2): 42/42, 100% vs. 47/59, 80%; B: 25/42, 60% vs. 13/59, 22%; all p <0.01). Day 21 haemagglutination inhibition GMT were higher in first and two sequential-year HDTIV vs. SDTIV recipients: A(H1N1): GMT 749 and 768 vs. 384 (p <0.0001, p 0.002); A(H3N2): 1238 and 956 vs. 633 (p 0.0003, p 0.1); and B: 1113 and 1086 vs. 556 (p 0.0005, p 0.02). HDTIV was more reactogenic (local pain score 3 vs. 1 of 10 on day 0/1, p 0.0003), but recipients were equally willing to be revaccinated (HDTIV: 76/83 (92%); SDTIV: 76/80 (95%), p 0.54). The ratios of day 21 GMT in SDTIV recipients vaccinated in 0 to 4 prior years to those in SDTIV and HDTIV recipients vaccinated in 15 or more prior years were A(H1N1): 3.73 and 1.38; A(H3N2) 3.07 and 1.16; and B: 2.01 and 1.21. CONCLUSIONS: HDTIV is more immunogenic and reactogenic and as acceptable as SDTIV in 18- to 64-year-olds.

What makes recovered-memory testimony compelling to jurors?

Little is known about how jurors arrive at verdicts in cases involving recovered memories of childhood sexual abuse. Study 1 investigated mock jurors' reactions to the recovered-memory testimony of an alleged victim when a therapist intervened with hypnosis, suggestion, or symptom management. When a therapist used hypnosis, jurors viewed the victim's recovered-memory testimony as particularly accurate and credible, and favored the victim in their verdicts. In Study 2, mock jurors were presented with a therapist who was sued for allegedly influencing a client's recall of false memories of abuse. In this case, however, jurors viewed therapists who used hypnosis or suggestion as more likely to have created false memories, more responsible for having caused harm, and less competent, and tended not to favor these therapists in their verdicts. We discuss these seemingly contradictory findings in terms of how culturally formed expectancies about hypnosis produce different causal explanations depending on the focus of a trial.