
A study conducted at two Rhode Island hospitals found that exposure to opioids was associated with a nearly four-fold risk in vancomycin-resistant Enterococci (VRE) colonization, researchers reported this week in the American Journal of Infection Control.
The matched case-control study, led by researchers at Brown University, aimed to identify specific non-antimicrobial medications associated with VRE rectal colonization. While antimicrobial exposure is one of the main factors contributing to the emergence and spread of VRE and other multidrug-resistant organisms (MDRO), a recent meta-analysis found that more than 16% of patients who acquired an MDRO had no antimicrobial exposure. Cases and controls were defined as patients with and without VRE rectal colonization at hospital admission, respectively, none of whom had received antimicrobials in the prior 12 months.
Opioid exposure only significant risk factor
Among 59,986 admissions to the two hospitals from April 15 to November 12, 2019, 2,919 patients (4.8%) were identified with VRE colonization on admission. Among these patients, 27 were confirmed as having no previous antimicrobial exposure, and they were matched to 63 control patients.
Multivariate analysis found that of the 17 different classes of medications patients had been exposed to, opioids (oxycodone) were the only significant and independent risk factor associated with VRE colonization (adjusted odds ratio, 3.8; 95% confidence interval, 1.4 to 10.8).
"This is a novel finding as previous studies of factors associated with VRE colonization have not focused on non-antimicrobial medications," the study authors wrote.
The authors explain that opioids have been shown to induce gut microbiome dysbiosis, which can reduce microbial diversity and lead to an increased risk of MDRO colonization in the gut. Although more research is needed to elucidate the mechanisms behind the association, they say there may be a need to implement infection prevention strategies aimed at limiting the acquisition and spread of MDROs among opioid users.
This is a novel finding as previous studies of factors associated with VRE colonization have not focused on non-antimicrobial medications.