Surveillance of Multidrug-Resistant Pathogens in Neonatal Intensive Care Units of Palermo, Italy, during SARS-CoV-2 Pandemic.

Background: Antimicrobial resistance (AMR) is a topic of concern, especially in high-level care departments like neonatal intensive care units (NICUs). The systematic use of an "active" epidemiological surveillance system allows us to observe and analyze any changes in microbial distribution, limiting the risk of healthcare-associated infection (HAI) development.

Methods: We have conducted a longitudinal observational study in the five NICUs of Palermo, comparing the "pre-pandemic period" (March 2014-February 2020) with the "pandemic" one (March 2020-February 2022). The primary aim of the study was to evaluate the cumulative prevalence of carriage from multi-drug resistant (MDR) bacteria in the cumulative NICUs (NICU C).

Results: During the "pre-pandemic period", 9407 swabs were collected (4707 rectal, 4700 nasal); on the contrary, during the "pandemic period", a total of 2687 swabs were collected (1345 rectal, 1342 nasal). A statistically significant decrease in MDR-Gram-negative bacteria (GNB) carriage prevalence was detected during the pandemic. At the same time, there was a general worsening of the carriage of carbapenemase-forming MDR-GNB (CARBA-R+) and methicillin-resistant (MRSA) during the pandemic period. A significant reduction in methicillin-susceptible (MSSA) carriage was detected too.

Conclusions: The surveillance of MDRO carriage in NICUs is fundamental for limiting the social and economic burden of HAIs.