The impact of the COVID-19 pandemic on hospital-acquired infections and multi-drug resistant organisms, in comparison to seasonal influenza.

Background: While effective preventive measures reduce hospital-acquired infections (HAIs) and the spread of multi-drug resistant organisms (MDROs), studies on the impact of the COVID-19 pandemic and its associated preventive measures remain inconclusive.

Objective: To assess the impact of COVID-19 on HAIs and MDROs and to compare it with the effect of seasonal influenza.

Methods: A retrospective cohort study analyzed prospectively collected data from a tertiary hospital in Haifa, northern Israel, from 2016 to 2021. It compared pre/during COVID-19 and influenza (Dec-Feb)/non-influenza (Mar-Nov) seasons. Studied parameters: hospital-acquired bloodstream infections (HA-BSI), MDROs, nosocomial Clostridioides difficile infections (CDI) per 10,000 hospital days (HD), central line-associated BSI (CLABSI) per 1000 catheter days (CD) and hand hygiene compliance (HHC).

Results: During the COVID-19 period, rates of HAIs and MDROs decreased compared to the pre-COVID era for methicillin-resistant Staphylococcus aureus (MRSA) (4.2 vs. 6.9/10,000 HD; p < 0.001), carbapenem-resistant Acinetobacter baumani (CRAB) (2.2 vs. 3.1/10,000 HD; p = 0.02), and nosocomial CDI (3 vs. 4.6/10,000 HD; p < 0.001). However, there was a higher rate of carbapenem-resistant Enterobacteriaceae (CRE) (4.6 vs. 2.7/10,000 HD; p < 0.001) and HA-BSI (29.7 vs. 27.3/10,000 HD; p = 0.006) during the COVID-19 era. CLABSI rates showed no significant difference (2.3 vs. 2.7/1000 CD; p = 0.910). HHC rate remained at 70% in both eras (p = 0.151). No significant differences were observed in MDROs, CDI, HA-BSI, or CLABSI rates (p = 0.233, 0.675, 0.267, and 0.563, respectively) between influenza and non-influenza seasons.

Conclusions: In the COVID-19 era, HAIs and MDROs rates significantly declined, while CRE rates increased, possibly due to a national trend in Israel since 2016. Steady HHC rates suggest additional factors like enhanced environmental cleaning, personal protective equipment usage, and increased infection prevention awareness contributed to this decline. Influenza had no noticeable impact, likely due to healthcare workers' varying perceptions and the brevity of the influenza season, making it challenging to assess impact.