Colonization with multidrug-resistant bacteria among children hospitalized abroad-a study from Finland

International travel contributes to the global spread of antimicrobial resistance: a substantial proportion of travellers visiting low- and middle-income countries (LMICs) are colonized by multidrug-resistant organisms (MDRO), with those hospitalized abroad at a particular risk. In some, colonization leads to symptomatic MDRO infection. Although children are a recognized risk group, research on travel-acquired MDRO among paediatric patients remains limited.

At our hospital, patients hospitalized abroad within the past 12 months are routinely screened for MDROs upon admission. To assess MDRO colonization among children following hospitalization abroad, we analysed MDRO screening data from paediatric patients at HUS Helsinki University Hospital 2010-2024, and explored associated risk factors.

Among the 459 paediatric patients screened after hospitalization abroad, 158 (34.4%) were colonized with MDROs. The most common MDROs were extended-spectrum β-lactamase-producing Enterobacterales (29.0%) and methicillin-resistant Staphylococcus aureus (7.6%). Carbapenemase-producing Enterobacterales were identified in 14 children (3.1%).Multivariable analysis identified antibiotic use (P = 0.002), travel type (P < 0.001) and income level of the hospitalization country (P < 0.001) as independent risk factors for colonization. The income level gradient was substantial: 87.5% (21/24) of children hospitalized in low-income countries, 68.1% (49/72) in lower-middle-income, 46.6% (55/118) in upper-middle-income and 13.5% (33/245) in high-income countries were colonized with MDROs. Clinical MDRO infection was recorded in five of the 158 (3.2%) MDRO carriers.

MDRO colonization is common among children hospitalized abroad, showing a clear gradient increase with decreasing country income level. Screening and infection control measures are warranted after recent care abroad. Particular focus should be placed on those hospitalized in LMICs, and those with additional risk factors such as visiting friends and relatives travel, foreign residence, or recent antibiotic use.