Methods

From April 1, 2021, to March 31, 2023, we performed a quasi-experimental study with a control group to evaluate the impact of the addition of pulsed xenon UV (PX-UV) terminal disinfection to an ongoing environmental cleaning protocol that included monitoring and feedback of environmental cleaning performance using environmental cultures on the incidence of MDR-GNB in 4 ICUs at Thammasat University Hospital, a 795-bed tertiary-care academic hospital. The study units included 2 medical ICUs (units A and D) and 2 surgical ICUs (units B and C), totaling 38 patient rooms. The intervention included units A and B, and the controls included units C and D. In addition to standard environmental cleaning protocol, pulsed xenon UV (PX-UV) terminal disinfection was implemented in the intervention units. Similar routine daily and terminal cleaning protocols were applied to all 4 study units. ^{Reference Ling, Apisarnthanarak, Thu le, Villanueva, Pandjaitan and Yusof9} Environmental cleaning involved regular cleaning practices that were tailored to the risk level of the patient and were performed in accordance with hospital IP policies. These practices included daily cleaning and terminal manual cleaning, plus chemical disinfection. Cleaning was performed by separate groups of housekeepers. Auditing and feedback mechanisms using postterminal cleaning environmental cultures, without housekeepers’ awareness, were employed every week. ^{Reference Sathitakorn, Jantarathaneewat, Weber, Apisarnthanarak, Rutjanawech and Apisarnthanarak4} The study periods consisted of a 1-year preimplementation period (period 1: April 1, 2021, through March 31, 2022) and a 1-year postimplementation period (period 2: April 1, 2022, through March 31, 2023).

During the entire study, all ICU beds from which a patient had been discharged or transferred after occupying the room for a minimum of 48 hours were cleaned by housekeepers according to the hospital terminal cleaning protocol. Rooms with patients that had MDR-GNB HAI or colonization on admission were excluded. The protocol included using a chlorine disinfectant solution (Aurora Chemical, Thailand) at a concentration of 200 ppm to disinfect the floor with cotton-string mops. High-touch surfaces (eg, infusion pump, medical chart, bedside table) and other room surfaces (eg, chair, light switch, ventilator) were disinfected with quaternary compounds (DUAL QUATS) disinfectant wipes (Pose Health Care, Thailand). We collected one surface sample for each site, including infusion pump, overbed table, bedside table, medication cart, vital signs screen, before and after terminal cleaning in all units and after PX-UV implementation in intervention units using the MacConkey contact plates (Redipor, Cherwell Laboratories, UK) incubated at 36±1°C for 48 hours. ^{Reference Sathitakorn, Jantarathaneewat, Weber, Apisarnthanarak, Rutjanawech and Apisarnthanarak4}

During period 2, PX-UV (Xenex, San Antonio, TX) was implemented in the intervention units in addition to the standard terminal cleaning protocol that utilized a PX-UV device, which emits broad-spectrum irradiation covering the UV-C spectrum of 200–280 nm. The device was positioned within 2 m of high-touch surfaces and was operated for 5–7 minutes at each of 2 distinct locations within the patient’s room (1 cycle per location, n = 2 cycles per room). The disinfection process, including setup, irradiation cycles, and repositioning, took ∼15–20 minutes. Compliance with the protocol was monitored by the PX-UV device.

Data collected included patient characteristics, underlying diseases, length of stay and 30-day all-cause mortality, and the incidence of MDR-GNB in 4 ICUs during period 1 and 2. The targeted MDR-GNB included MDR A. baumannii, extended-spectrum β-lactamase (ESBL)–producing Enterobacterales, carbapenem-resistant Enterobacterales, MDR Pseudomonas aeruginosa. MDR-GNB were defined as resistance to ≥3 antimicrobial classes. ^{Reference Kumar and Khan10} The primary outcome was the incidence of MDR-GNB HAI and colonization in the 4 ICUs. The Centers for Disease Control and Prevention/National Healthcare Safety Network Patient Safety Component Manual 2022 was used to define infection and colonization. ¹¹ Active surveillance for colonization was not performed. Colonization status was defined based on clinical cultures. ¹¹ The secondary outcomes were length of stay and 30-day all-cause mortality.

All analyses were performed using Stata version 16 software (StatCorp, College Station, TX). The primary outcomes were the incidence of MDR-GNB HAIs and colonization. We used χ² tests to compare categorical variables and independent t-tests for continuous data. Trend analyses were performed to evaluate the overall pattern of changes on outcomes of interest over time using segmented regression analysis of interrupted time series. All P values were 2-tailed; P < .05 was considered statistically significant. This study was approved by the Ethics Committee of Thammasat University.