A queue of international travellers lining up for a plane, silhouetted against a yellow sunset.

International travellers spread dangerous antibiotic-resistant bacteria with ease, study finds

Gemma King Research

New research, published in The Lancet Microbe on 23 February 2021, shows how antibiotic-resistant infections can spread easily when we travel. The study highlights how international travellers/tourists who share facilities can spread resistant infections. In one case, tourists staying separately were found to have the same strain of a bacteria after sharing a shower facility.

Study details

Scientists from the Universities of Basel, Birmingham, Helsinki and Oslo as well as the Wellcome Sanger Institute monitored European travellers to Lao People’s Democratic Republic. They analysed stool samples and recorded other data for three weeks. Previous studies of travellers carried out sampling only at the beginning and end of trips. This study gives a much more comprehensive picture of how bacterial colonisation occurs.

Study findings

The researchers found that strains of bacteria colonised the guts of multiple international travellers that stayed at the same hotel and spent time with each other, with 70% colonised at the end of their stay. Worryingly, every single participant in the study acquired bacterial-produced enzymes called extended-spectrum beta-lactamases (ESBL) at some point during the study. These enzymes are produced by some strains of bacteria and create resistance to most antibiotics.

In total, 83 unique strains of bacteria were found during the course of the study. This includes more than 50 types of Escherichia coli, and more than 20 ESBL-producing strains.

This study offers new insight into the ease with which bacterial infections can be transmitted between those who travel internationally. People who travel internationally are already known to be more likely to acquire and spread antibiotic-resistant bacteria. High-risk regions for such transmission include India, Southeast Asia and South America.

Related research

Earlier this year, samples from septic tanks on airplanes were analysed. Sewage collected from five German airports was found to be loaded with antibiotic-resistant bacteria. Around 90% of the E. coli tested in the study were found to be resistant to at least some antibiotics. These studies show just how easy it is for bacteria to hitch a ride in a variety of ways.

What Antibiotic Research UK is doing about it

We have long been aware of the threat posed by international travel to high-risk areas. Our collaborative clinical trial, DIAMOND, is looking at a promising treatment for Travellers’ Diarrhoea that we hope will provide a suitable alternative to the antibiotics that are usually given for this very common condition. That way, we can preserve precious antibiotics for when we really need them.

Colin Garner, Chief Executive of Antibiotic Research UK, says: “We welcome this research and particularly the new insights in the importance of continuous sampling during future studies. The findings themselves are as grim as we would have expected; although vital, international travel is also a major contributor to the global spread of antibiotic resistance. We hope that further studies like these, and our own contributions via clinical trials like DIAMOND, will allow us to reduce this threat in the near future.”

For more information about travel and resistant bacteria, the study and its findings, read this news item from the University of Birmingham. You can also find out more about bacterial infections and antibiotic-resistant infections.

Antibiotic Research UK is the world’s first charity dedicated to fighting antibiotic resistance. COVID-19 has put a stop to much of our fundraising; please consider making a donation to support our work and help us save modern medicine.

Sign up to our newsletter to stay up to date with the latest news.