Gastrointestinal Colonization of Carbapenem-Resistant Acinetobacter baumannii: What Is the Implication for Infection Control?

Abstract

The epidemiology of patients with gastrointestinal colonization of carbapenem-resistant Acinetobacter baumannii (CRAB) has not been systematically analyzed. We aimed to analyze the incidence, risk factors, and clinical outcomes of patients with newly identified gastrointestinal colonization of CRAB in a healthcare region in Hong Kong, where a multi-pronged screening strategy for gastrointestinal colonization of CRAB, together with other multidrug-resistant organisms (MDROs), was conducted by collecting fecal specimens (rectal swab or stool) upon admission and during hospitalization. From 1 October 2015 to 31 December 2019, a total of 161,339 fecal specimens from 63,588 patients, 61,856 (97.3%) of whom were hospitalized patients, and 54,525 (88.1%) were screened upon admission, with 1309 positive for CRAB (2.4% prevalence). Among patients positive for CRAB in fecal specimens, 698 (53.3%) had newly detected gastrointestinal colonization of CRAB, giving an incidence of 10.03 per 10,000 patient admissions and constituting 2646 CRAB colonization days in the general wards. Excluding the 164 patients with co-colonization of other MDROs, 534 patients had gastrointestinal colonization with only CRAB, and 12.5% (67/534) developed symptomatic CRAB infections at a median of 61 days (range: 2 to 671 days), during prospective follow-up for 2 years. Compared with age- and sex-matched controls, patients being referred from residential care homes for the elderly, the presence of indwelling devices, use of beta-lactam/beta-lactamase inhibitors, carbapenems, and proton pump inhibitors in the preceding 6 months, and history of hospitalization in the past 6 months were significantly associated with gastrointestinal colonization with CRAB, as shown by multivariable analysis. Log-rank test showed that cases had significantly shorter survival duration than controls (p < 0.001). The adjusted hazard ratio of gastrointestinal colonization of CRAB was 1.8 (95% CI: 1.5–2.2; p < 0.001), as shown by Cox regression analysis. Whole-genome sequencing of eight patients with CRAB isolates in their blood cultures and rectal swabs during the same episode of hospitalization revealed ST-195 as the predominant type, as shown by multilocus sequencing type. Gastrointestinal colonization of CRAB poses a considerable challenge for infection prevention and control.

Epidemiology of multidrug-resistant organisms before and during COVID-19 in Hong Kong

“…The incidence of MDRO infection among our COVID-19 patients was 6%, which was lower than that reported previously in the United States (52%) and in the Republic of Korea (28%) [ 49 , 50 ]. The risk factors for MDRO infection among COVID-19 patients, as shown in the multivariable analysis, were similar to our local population with MDRO colonization, including the prior use of antimicrobial agents and proton pump inhibitors, and recent history of hospitalization [ 22 , 51 , 52 ]. In addition, patients referred from RCHE were particularly associated with MDRO infection in this study, given that the prevalence of MDROs among our elderly, especially MRSA and CRA, were on a rising trend during our active surveillance studies conducted in the RCHE in the past decade [ [53] , [54] , [55] ].…”

“…The appropriate use of broad-spectrum antimicrobial agents by the frontline clinicians is determined by clinical microbiologists based on a locally prepared IMPACT (Interhospital Multi-disciplinary Programme on Antimicrobial ChemoTherapy) guideline [ 21 ]. The data on patients infected with MDROs, COVID-19, and antimicrobial consumption were retrieved from the Clinical Data Analysis and Reporting System, which is an electronic database of health records under the governance of the Hospital Authority, as previously described [ 22 ].…”

The Emergence of Candida auris is Not Associated with Changes in Antifungal Prescription at Hospitals

“…This platform allows access to the records for the purpose of service planning and medical research, as previously described. [18][19][20][21][22] A specific hospital number is assigned to each episode of hospitalization per patient. During data retrieval, a reference number is generated to replace the patient's personal identity number in order to protect patient confidentiality.…”