Extensively-drug-resistant bacteria carriers among overseas travellers: one-third had not been hospitalized...

Extensively-drug-resistant bacteria (XDRB) have emerged as a major source of resistance. Hospitalization abroad seems to be the major risk factor associated with carriage, and numerous reports have warned about the risk of in-hospital transmission. However, little is known regarding possible community transmission.

A retrospective matched case-control study was conducted in a Parisian teaching hospital, which included patients admitted to hospital with a history of travel abroad over the preceding 12 months. Each XDRB carrier at admission (case) was matched with two non-carriers (controls) hospitalized in the same ward and admitted during the same month.

To describe and identify risk factors associated with XDRB carriage at admission.

Forty-six cases and 92 controls were enrolled. The results of univariate and multi-variate analyses showed that health repatriation was the only factor associated with a higher risk of carrying XDRB (odds ratio 3.22, 95% confidence interval 1.23-7.84; P=0.01). Surprisingly, one-third of the study population had not been hospitalized abroad within the preceding 12 months. The most frequently identified XDRB species were Escherichia coli (36%), Enterococcus spp. (17%) and Klebsiella pneumoniae (9%), and the most frequently identified enzyme was OXA-48 (36%).

In this retrospective study, health repatriation was the only risk factor for XDRB carriage identified at admission. Furthermore, the data suggest community-onset transmission. Therefore, there is an urgent need to conduct studies in high-risk countries to identify the risk factors associated with community carriage.