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.

Prospective monitoring of adverse events following vaccination with Modified vaccinia Ankara - Bavarian Nordic (MVA-BN) administered to a Canadian population at risk of Mpox: A Canadian Immunization Research Network study.

MVA-BN is an orthopoxvirus vaccine that provides protection against both smallpox and mpox. In June 2022, Canada launched a publicly-funded vaccination campaign to offer MVA-BN to at-risk populations including men who have sex with men (MSM) and sex workers. The safety of MVA-BN has not been assessed in this context. To address this, the Canadian National Vaccine Safety Network (CANVAS) conducted prospective safety surveillance during public health vaccination campaigns in Toronto, Ontario and in Vancouver, British Columbia. Vaccinated participants received a survey 7 and 30 days after each MVA-BN dose to elicit adverse health events. Unvaccinated individuals from a concurrent vaccine safety project evaluating COVID-19 vaccine safety were used as controls. Vaccinated and unvaccinated participants that reported a medically attended visit on their 7-day survey were interviewed. Vaccinated participants and unvaccinated controls were matched 1:1 based on age group, gender, sex and provincial study site. Overall, 1,173 vaccinated participants completed a 7-day survey, of whom 75 % (n = 878) also completed a 30-day survey. Mild to moderate injection site pain was reported by 60 % of vaccinated participants. Among vaccinated participants 8.4 % were HIV positive and when compared to HIV negative vaccinated individuals, local injection sites were less frequent in those with HIV (48 % vs 61 %, p = 0.021), but health events preventing work/school or requiring medical assessment were more frequent (7.1 % vs 3.1 %, p = 0.040). Health events interfering with work/school, or requiring medical assessment were less common in the vaccinated group than controls (3.3 % vs. 7.1 %, p < 0.010). No participants were hospitalized within 7 or 30 days of vaccination. No cases of severe neurological disease, skin disease, or myocarditis were identified. Our results demonstrate that the MVA-BN vaccine appears safe when used for mpox prevention, with a low frequency of severe adverse events and no hospitalizations observed.