Program Information
Carbapenem-resistant organisms, or CROs, are a type of multidrug-resistant (MDRO) organism that can cause both infection and colonization in healthcare settings. CROs include carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) both of which have been identified in Alameda County. When Enterobacterales, a group of Gram-negative, non-spore forming bacteria, develop resistance to carbapenems, they are referred to as carbapenem-resistant Enterobacterales (CRE). In 2017 there were an estimated 13,100 hospitalizations and 1,100 deaths due to CREs in the U.S.
The 2019 CDC Antibiotic Resistance Threats Report lists CROs as Urgent Threats, which is the highest level of concern. Since the COVID-19 pandemic, the threat of antimicrobial resistance has only become more dire. There are many reasons for this increase in antibiotic resistance including changed healthcare-seeking behaviors allowing undiagnosed and untreated infections to spread, increasing chances of developing resistance; from March to October of 2020, more than 80% of patients hospitalized with COVID-19 received unnecessary antibiotic therapy due to difficulty of distinguishing COVID-19 pneumonia from community-acquired pneumonia, increasing ability of bacteria to develop resistance.
CROs can be classified by their mechanism of resistance, non-carbapenemase producing organisms (non-CP), and carbapenemase-producing organisms (CPO). Carbapenemases are enzymes that break down antibiotics and render them ineffective. These enzymes are categorized into Class A, B, and D. Some common carbapenemases are Klebsiella pneumoniae carbapenemase (KPC), imipenamase (IMP), Verona integron-encoded metallo-β-lactamase (VIM), New Delhi metallo-β-lactamase (NDM), and oxacillinase (OXA). CPOs are of special public health concern because of their ability to easily spread resistance between many species of bacteria in healthcare settings.
Risk factors for CRO colonization or infection include prolonged inpatient stays, severe illness and/or comorbid conditions, invasive medical devices (such as catheters, endotracheal tubes, and feeding tubes), and treatment with certain antibiotics. Because patient populations in long-term care facilities (LTCF) and skilled nursing facilities (SNF) tend to have many of these risk factors, healthcare teams in these facilities should be especially cognizant of CROs.
The spread of CROs is mediated by patient transfer between facilities and inconsistently applied infection control measures. This highlights the importance of using the Infection Control Transfer Form and ensuring your facility is prepared for a patient with CRO, such as implementing appropriate infection control practices and environmental cleaning. In addition, California Department of Public Health (CDPH) advocates that all residents of SNFs be on Enhanced Barrier Precautions which is a resident-centered activity-based approach to help limit the spread of resistant organisms.
On June 13, 2017, Alameda County Public Health Department (ACPHD) issued a Health Officer Order requiring providers and clinical laboratories to report carbapenem-resistant Enterobacterales (CRE) cases, which are a subset of CROs, and requiring clinical laboratories to submit clinical isolates of CREs. Since then, CRO surveillance needs have evolved due to increases in cases and advances in identification of carbapenemase genes at healthcare facilities. While the California Department of Public Health (CDPH) mandated laboratory reporting of carbapenemase-producing organisms in 2022 (California Code of Regulations, Title 17, Section 2505), there is still a CPO surveillance gap in Alameda County as not all healthcare facilities can test for carbapenemase genes. This updated Health Officer Order goes beyond the CDPH mandate to include reporting of all CROs and requires isolate submission when the carbapenemase-producing status is unknown or only confirmed through phenotypic testing. This Order will allow ACPHD to close this gap in surveillance and help prevent transmission of CROs in our dynamic patient population. Infection control and prevention protects patients in Alameda County healthcare facilities. We have provided links to resources below. Further questions can be directed to acutecd@acgov.org