High prevalence of antimicrobial resistant Gram negative colonization in hospitalized Cambodian infants

Background: Antimicrobial-resistant Gram negative infections are a significant cause of mortality in young infants. We aimed to determine characteristics of, and risk factors for, colonization and invasive infection caused by 3rd generation cephalosporin (3GC) or carbapenem-resistant organisms in outborn infants admitted to a neonatal care unit (NU) in Cambodia. Methods: During the first year of operation, patients admitted to the Angkor Hospital for Children NU underwent rectal swabbing on admission and twice weekly until discharge. Swabs were taken also from 7 environmental sites. Swabs were cultured to identify 3GC or carbapenem-resistant Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Results: The study included 333 infants with a median age at NU admission of 10 days (range 0-43). Colonization by >=1 3GC-resistant organism was detected in 85.9% (286/333). Admission swabs were collected in 289 infants: 61.9% were colonized by a 3GC-resistant organism at the time of admission and a further 23.2% were colonized during hospitalization, at a median of 4 days (95% confidence interval (CI) 3-5). Probiotic treatment (hazard ratio 0.58, 95% CI 0.35-0.98) was associated with delayed colonization. Colonization by a carbapenem-resistant organism occurred in 25 (7.5%) infants. Six infants had NU-associated K. pneumoniae bacteremia; phenotypically identical colonizing strains were found in three infants. Environmental colonization occurred early. Conclusions: Colonization by antimicrobial-resistant Gram negative organisms occurred early in hospitalized Cambodian infants and was associated with subsequent invasive infection. Trials of potential interventions such as probiotics are needed