Epidemiology and outcomes of Carbapenem-resistant Enterobacterales infection in high-risk patients in Saudi Arabia

Basem M Alraddadi¹Emily Heaphy^1*Reem Almaghrabi²Sahar Althawadi²Ahmad M Alshahrani³Salma Almosallam¹Abdullah Alraddadi¹Lama Hefni¹Mohammad Bosaeed⁴Mooza S Almannaei⁴Ibrahim Bahabri⁴Rabab Taha⁵Ebtihal Alamoudi⁶

• ¹King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
• ²King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
• ³King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
• ⁴King Abdulaziz Medical City, Riyadh, Saudi Arabia
• ⁵International Medical Center, Jeddah, Saudi Arabia
• ⁶King Abdulaziz University, Jeddah, Saudi Arabia

Introduction: Solid organ transplant (SOT) recipients, bone marrow transplant (BMT) recipients, and patients with hematological malignancies suffer from increased morbidity due to developing infections caused by multi-drug-resistant Carbapenem-resistant Enterobacterales (CRE). The current study aims to further describe the epidemiology and outcomes associated with CRE infection in high-risk SOT patients and BMT recipients and in patients with hematological malignancies in Saudi Arabia. Methods: Patients aged 16 years and older admitted to a participating hospital from October 2018 to August 2024 who received a SOT or a BMT or were diagnosed with a hematological malignancy and had a confirmed CRE infection were included in this retrospective cohort study. A total study population of 155 eligible patients were included. The primary outcome of interest was all-cause mortality within 90 days of the date of first CRE culture. Results: Among the 155 patients, 118 (76.1%) had received a solid organ transplant and 37 (23.9%) had a bone marrow transplant or a hematological malignancy. BMT recipients and patients with hematological malignancies were 2.84 times more likely to die within 90 days of their first positive culture (adjusted odds ratio [AOR] = 2.84, 95% confidence interval [CI] = 1.01-8.01, p = 0.049). Compared to patients having CRE infection carrying with the blaNDM gene isolated, after controlling for other predictors, patients with an infection revealing the blaOXA-48 gene isolate were 3.97 times more likely to die within 90 days of the first culture (AOR = 3.97, 95%CI = 1.04-15.15, p =0.044).BMT recipients in comparison to SOT patients and patients with CRE infections harboring the molecular typing of blaOXA-48 gene in their CRE infections were at greater risk for 90 day all-cause mortality in Saudi Arabia, confirming previous findings of a high mortality rate associated with CRE infection in immunocompromised populations.