Multidrug-resistant organism carriage in Vietnamese district hospitals before and after an antimicrobial stewardship intervention

Antimicrobial resistance is a critical global health challenge, with Southeast Asia identified as a hotspot of multidrug-resistant organism (MRO) carriage in hospitalised patients and the general population. This study aimed to estimate the prevalence of gastrointestinal and nasal MRO carriage among district hospital inpatients in Vietnam and assess changes following an antimicrobial stewardship (AMS) intervention.

Two repeated cross-sectional prevalence surveys were conducted among inpatients at four district hospitals in Vietnam (two urban hospitals in Hanoi and two rural hospitals in Ca Mau). The baseline survey was undertaken immediately prior to implementation of a 6-month AMS intervention (March 2022), and the post-intervention survey was conducted during the final 2 weeks of the intervention (August 2022). The intervention bundle comprised establishing hospital AMS committees and teams, implementing antimicrobial prescribing guidelines, healthcare worker education, and regular antimicrobial prescribing audits with feedback to clinicians. Carriage of extended spectrum β-lactamase (ESBL)-producing Enterobacterales and carbapenemase-producing Enterobacterales (CPE) was determined from stool or rectal swabs, and methicillin-resistant Staphylococcus aureus (MRSA) carriage using nasal swabs. MROs were characterised using phenotypic antimicrobial susceptibility testing and molecular analyses. A participant questionnaire assessed demographic, behavioural and healthcare-related risk factors. Pre- and post-intervention prevalence estimates were compared using two-proportion tests. Mixed-effects binary regression models were used to identify risk factors for ESBL-producing Enterobacterales carriage.

A total of 402 participants (ages 18–99 years, M:F 176:226) provided nasal swabs and rectal or stool samples across both surveys. Participant demographics differed modestly between surveys. Overall, 76.1% of participants carried Enterobacterales isolates harbouring bla_CTX-M (ESBL) genes, while carriage of representative CPE (2.7%) and MRSA (3.0%) were low. Risk factors for ESBL-producing Enterobacterales carriage included female sex, older age, recent antibiotic use, smoking and admission to an urban hospital. The prevalence of ESBL-producing Enterobacterales and CPE were unchanged following the AMS intervention. MRSA carriage decreased from 5 to 1% following the intervention [− 4.0%, 95% CI − 7.2%, − 0.7%).

ESBL-producing Enterobacterales carriage was highly prevalent among inpatients in four Vietnamese district hospitals, while CPE and MRSA carriage remained low. A 6-month AMS intervention was associated with a modest reduction in MRSA carriage but no change in ESBL-producing Enterobacterales or CPE carriage.