International travellers are at risk of picking up a number of drug-resistant pathogens, according to a new European study.
In the COVID pandemic, international travel has become a distant memory for most of those used to it. As restrictions are lifted and international travel resumes, travellers are still at risk from other dangerous pathogens. In recent years, the rise of intestinal multidrug resistant gram-negative (MDR-GN) bacteria around the world poses a serious health threat, with MDR clones of E.coli and Klebsiella pneumoniae threatening more antibiotic resistant infections around the world. The spread of MDR-GN is a known threat in long-term care facilities, with residents forming a reservoir for the microbes but is also common in international travel as well. It is well documented that international travel results in the spread of multidrug-resistant E. coli, with up to 80% of travellers returning from high-risk regions being colonised by MDR-GN bacteria for up to a year. However, the existing research only compared participants before and after travel. A group of researchers from Universities of Basel, Birmingham, Helsinki and Oslo, and the Wellcome Sanger Institute set out to investigate the spread of such bacteria on a day by day basis.
Over a period of three weeks, the researchers monitored the health of a group of European travellers in the Lao People’s Democratic Republic by analysing daily information returns and stool samples. They found that by the end of the study period, 70% of the travellers had been colonised. The bacterial strains colonised travellers staying at the same hotel and spending time in one another’s company. In one case, a participant was colonised by taking a shower in another’s bathroom.
“International travel is strongly linked to the spread of MDR-GN bacteria, with transmission highest in India and Southeast Asia, Africa and South America,” said senior study author Professor Alan McNally, University of Birmingham. “Travellers visiting these high-risk regions are at substantial risk of acquiring the bacteria. Colonisation by MDR-GN bacteria is a highly dynamic process. We found constant ‘competition’ between circulating strains acquired by individual hosts and the travelers’ ‘native’ bacteria. Travellers can pick up the bacteria even during short visits and further spread the strains after returning home.”
All of the participants had acquired extended-spectrum beta-lactamases (ESBL) during their stay in Laos. ESBL enzymes create resistance within the body to most beta-lactam antibiotics, including penicillins, cephalosporins, and aztreonam. Infections with ESBL-producing organisms have proved difficult to treat. Also, all but one participant acquired multiple strains of bacteria with 83 unique strains identified (53 E. coli, 10 Klebsiella, 20 other ESBL-GN species), with up to four other participants sharing strains.
Study co-senior author, Professor Jukka Corander, at the University of Oslo and the Wellcome Sanger Institute, commented: “Our study reveals the true scale and complexity at which drug-resistant bacteria colonise the intestinal tract during travel, demonstrating that it has been seriously underestimated previously.
“In addition, several of our participants lost some of their travel-acquired ESBL-GN strains while still abroad – indicating that previous studies solely employing pre- and post-travel sampling have under-reported the extent to which travellers are colonised by ESBL-GN.”
Source: News-Medical.Net
Journal information: Kantele, A., et al. (2021) Dynamics of intestinal multidrug-resistant bacteria colonisation contracted by visitors to a high-endemic setting: a prospective, daily, real-time sampling study. The Lancet Microbe. doi.org/10.1016/S2666-5247(20)30224-X.
