Reviewed by: Leah Mische, M.D., Medical College of Wisconsin
This is a retrospective Israeli cohort study examining the association between carbapenem-resistant Acinetobacter baumanii (CRAB) colonization in patients in post-acute care hospitals (PACHs) and the subsequent development of CRAB in clinical cultures. CRAB carriers were identified through the Israeli National Institute for Antibiotic Resistance and Infection Control. 17 PACHs were included in this study and 523 participants with CRAB colonization were identified. These patients were screened between June of 2021 and December of 2023 at their facilities using skin swabs, rectal samples, and tracheal aspirates in patients with tracheostomies. Positive clinical CRAB cultures were identified through the national CRAB surveillance database. This database only included samples from acute care hospitals. Importantly, this study did not examine specific patient cases, and it is unclear how many of these cases were felt to have a clinical infection at the time of culture acquisition.
Of the 523 patients, 356 were on ventilator wards while 167 were in skilled nursing wards. 103 patients were noted to have a positive CRAB clinical culture prior to the study. In the one year following the first positive screen, there were 47 cases of CRAB isolated in clinical cultures, including 5 from blood cultures. Forty-five percent of the clinical cultures were identified within the first 3 months after the index screen. Seventy-eight percent of positive clinical CRAB isolates were identified in the first three days of admission in the acute care hospitals. Of the non-blood specimens, 62% were respiratory, 21% urine, and 17% wound cultures. Interestingly, older age, oral feeding, and longer time from index culture seemed to be protective from development of a clinical culture growing CRAB. Of note, prior isolation of CRAB from clinical cultures did not seem to be associated with increased risk of developing CRAB in future clinical specimens. There was no difference in the isolation of CRAB from clinical specimens in patients who were in ventilator or skilled nursing wards.
Overall, this study outlined the risk associated with growth of CRAB in clinical cultures from patients in PACHs who were colonized with CRAB. A significant limitation of the study is that the clinical assessment on whether CRAB was determined to be a true pathogen is unknown. Other than the blood cultures (isolated in 1% of participants), all other clinical specimen sites from this study are notorious for relatively frequent colonization with multidrug-resistant pathogens. Future studies examining whether there is an association of colonization with true clinical infections would be helpful in determining patient risk and may, potentially, assist with determining empiric regimens in select patient populations.
Reference:
Schechner V, Cohen A, Atanov R, Temkin E, Masarwa S, Efrati Epchtien R, Keren-Paz A, Carmeli Y; Israel PACH CRAB Working Group. Risk of carbapenem-resistant Acinetobacter baumannii infection in patients with a positive screening test for CRAB in post-acute care hospitals. Infect Control Hosp Epidemiol. 2026 Sep 10:1-3. doi: 10.1017/ice.2026.10535. Epub ahead of print. PMID: 42717504.