Transmission of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in a Malawian neonatal unit: a clinical and genomic analysis of a prospective cohort study.

Summary

In a prospective cohort of 94 mother-neonate pairs, 49% of neonates became colonized with ESBL-producing Klebsiella pneumoniae, with a median time to colonization of 5 days. Whole-genome sequencing and transmission modeling implicated ward surfaces, particularly sinks and oxygen-delivery equipment, as major sources, with additional contributions from cots, maternal hands, and other neonates.

Key Findings

• Among 90 evaluable neonates, 44 (49%) were colonized with ESBL-producing K pneumoniae at least once, with a median time to colonization of 5 days.
• Invasive isolates clustered genetically with stool and environmental isolates; 76% of invasive isolates clustered with these non-invasive sources.
• Transmission analyses attributed approximately 37%-65% of transmission to ward surfaces, 13%-29% to cots, 6%-13% to maternal hands, and 8%-13% to other neonates.

Clinical Implications

Neonatal units should prioritize sink and surface decontamination, containment of neonatal stool, cot cleaning, maternal hand hygiene, and single-use oxygen-delivery equipment. These findings support targeted environmental interventions rather than relying only on patient-focused precautions.

Limitations

• The study was conducted in a single neonatal unit with 94 mother-neonate pairs, which may limit generalizability.
• Transmission estimates are probabilistic and may be affected by incomplete sampling, unobserved contacts, and the short follow-up period.

Future Directions

Multicentre implementation studies should test whether sink redesign, enhanced environmental cleaning, dedicated oxygen equipment, and improved stool containment reduce colonization and invasive infection. Longer-term genomic surveillance is also needed to determine whether targeted interventions alter antimicrobial-resistance transmission.