The Waning of BNT162b2 Vaccine Effectiveness for SARS-CoV-2 Infection Prevention over Time: A Test-Negative Study in Health Care Professionals of a Health Department from January 2021 to December 2021

The duration of protection of vaccines against SARS-CoV-2 infection has been evaluated in previous studies, but uncertainty remains about the persistence of effectiveness over time and the ideal timing for booster doses. Therefore, the aim of this study was to evaluate BNT162b2 vaccine effectiveness against SARS-CoV-2 infection in health care workers (HCWs) at a tertiary hospital depending on time elapsed since the completion of a two-dose vaccination regimen. We conducted a case–control with negative test study between 25 January and 12 December 2021 that included 1,404 HCWs who underwent an active infection diagnostic test (AIDT) to rule out SARS-CoV-2 infection due to COVID-19 suspicion or prior close contact with patients diagnosed with COVID-19. The adjusted vaccine effectiveness (aVE) for the prevention of SARS-CoV-2 infection 12 to 120 days after completing the full two-dose vaccination regimen was 91.9%. Then, aVE decreased to 63.7% between 121 to 240 days after completing the full two-dose regimen and to 37.2% after 241 days since the second dose. Vaccination against SARS-CoV-2 infection in HCWs remains highly effective after 12 to 120 days have elapsed since the administration of two doses of the BNT162b2 vaccine; however, effectiveness decreases as time elapses since its administration

Estimated Costs Associated with Surgical Site Infections in Patients Undergoing Cholecystectomy

Among healthcare-associated infections, surgical site infections (SSIs) are the most frequent in Spain. The aim of this work was to estimate the costs of SSIs in patients who underwent a cholecystectomy at the Hospital General Universitario de Alicante (Spain) between 2012–2017. This was a prospective observational cohort study. The Active Epidemiological Surveillance Program at our hospital recorded all the cholecystectomies performed. Risk factors associated with the development of SSIs were determined by multivariate analysis and two homogeneous comparison groups were obtained by using the propensity score. The number of extra days of hospital stay were recorded for patients with an SSI and with the cost per hospitalised day data, the additional cost attributed to SSIs was calculated. A total of 2200 cholecystectomies were considered; 110 patients (5.0%) developed an SSI. The average length of hospital stay was 5.6 days longer among patients with an SSI. The cost per SSI was EUR 1890.60 per patient, with the total cost for this period being EUR 207,961.60. SSIs after cholecystectomy lead to a prolongation of hospital stay and an increase in economic costs. It is essential to implement infection surveillance and control programs to reduce SSIs, improve patient safety, and reduce economic burden

Effectiveness of the systematic use of antimicrobial filters in the water taps of critical care units for the prevention of healthcare-associated infections with Pseudomonas aeruginosa

Background: Pseudomonas aeruginosa (PA) is the third leading aetiological agent in healthcare-associated infections (HAIs) and the one most frequently found in patients with pneumonia associated with mechanical ventilation. In intensive care units (ICU), its appearance is associated with higher mortality, an increase in the days spent on ventilation, and hospital stay length and costs. Thus, evaluating strategies for preventing these infections is essential for their control. Therefore, our objective was to evaluate the effectiveness of the systematic use of antimicrobial filters in preventing PA infections in critical care units. Methods: This was an open experimental crossover study. A total of 2,156 patients admitted for more than 24 hours in critical care units were included, 1,129 of them in units with filters, and 1,027 in units without filters. The study groups were followed-up for 24 months and HAIs were checked for the presence of PA. Chi-squared test were used to compare the rate of HAIs between groups and we calculated 95% confidence intervals adjusted by Poisson regression for the rate ratio (RR) of the association magnitude. Results: Both groups were homogeneous in terms of intrinsic and extrinsic patient factors. The incidence of PA infections in the units with filters was 5.5 cases/1,000 hospitalized days and 5.4/1,000 hospitalized days for the units without water filters (RR = 1.09 [0.67-1.79]). Conclusions: Routine placing antimicrobial filters in the water taps in critical care units was not an effective means of preventing the emergence of HAIs caused by PA.This study has been funded by: Instituto de Salud Carlos III (Carlos III Health Institute) through Fund for Health Research (FIS), Ministry of Health, Spanish Government. Project # PI15/01344; Generalitat Valenciana (Valencian Regional Government) Grants for Support to a Research or Technology Transfer Project. Project # APOTIP/2016/A/011; Alicante Institute for Health and Biomedical Research through Grants to supplement the development of active research projects under the State Plan for Scientific and Technical Research and Innovation. Project # 180192 and Project # 190181