1377 - Perinatal Transmission Dynamics of Antimicrobial Resistance

Background: Antimicrobial resistance (AMR) is a global health threat that disproportionately affects low- and middle-income countries. An ongoing study of childhood mortality in Bangladesh revealed a common cause of death among neonates is sepsis from Gram-negative multi-drug-resistant organisms.

Methods: To ascertain factors leading to neonatal exposure, we enrolled 100 women presenting for delivery to Faridpur Hospital during February-March 2020. We collected vaginal and rectal swabs from mothers on presentation and at least 24 hours after delivery as well as rectal swabs from newborns. Swabs were plated on chromogenic agars selective for extended-spectrum-beta-lactamase-(ESBL) producing organisms and carbapenem-resistant Enterobacteriaceae (CRE).

Results: Eight-five percent of women underwent C-section. Prior to delivery, ESBL organisms were isolated from 15% of vaginal and 63% of rectal swabs. CRE was detected in 2% of vaginal and 8% of rectal swabs. Following delivery, colonization exceeded 90% (ESBL) and 70% (CRE) in both swab sets. Similarly, among newborns, 85% were colonized with ESBL and 67% with CRE. Maternal AMR colonization on admission did not correlate with income, education, parity, prenatal care, or prior antibiotic use, but was associated with hospitalization during pregnancy (rectal CRE OR 11.9, p< 0.01). Maternal colonization at discharge was positively associated with membrane stripping (vaginal ESBL OR 9.0, p< 0.01; rectal CRE OR 5.0, p=0.03), C-section (OR 4.0-15.4, p< 0.05), and administration of third-generation cephalosporins (OR 5.0-10.1, p< 0.05). Newborn colonization correlated with maternal colonization on discharge (p< 0.005) but not on admission. Among newborns delivered by C-section, there was an 8-9-fold increased risk of ESBL and CRE colonization (p< 0.01).

Conclusion: These results demonstrate that AMR is driven by nosocomial factors in the perinatal setting, and invasive procedures and perinatal antibiotic use increase risk of AMR colonization. These findings emphasize the urgent need for enhanced antibiotic stewardship and infection prevention and control practices to preserve the benefits of hospital-based deliveries.