Tourists, especially in Asia, Africa and Latin America are more exposed to antibiotic-resistant bacteria which can survive up to a year in the body and therefore be transmitted once returned.
- One in two travelers to the tropics returns with drug-resistant bacteria.
- Up to 80% of travelers returning from high-risk regions are colonized by resistant bacteria that they can keep for a year in their bodies.
Returning from a trip, tourists do not only bring back souvenirs. A recent study, published on August 15, 2015 in the journal Clinical Infectious Diseases, reveals that one in two travelers to the tropics returns with drug-resistant bacteria. In new research, scientists suggest that globetrotters are particularly vulnerable to virulent strains of drug-resistant bacteria they pick up from contact with other tourists. They presented these results on February 23 in the journal The Lancet Microbe.
Short visits are enough
The spread of multi-resistant Gram-negative intestinal bacteria (MDR-GN) poses a serious threat to human health worldwide, such as E. coli and Klebsiella pneumoniae. “International travel is closely linked to the spread of MDR-GN bacteria, with transmission highest in India and Southeast Asia, Africa and Latin Americareveals Alan McNally, professor of microbial evolutionary genomics at the University of Birmingham and co-lead author of the study. Colonization by MDR-GN bacteria is a highly dynamic process. We have seen constant ‘competition’ between circulating strains acquired by individual hosts and ‘native’ bacteria from travellers. Travelers can catch the bacteria even on short visits and spread the strains further after returning home.” Travelers who visit high-risk regions are at significant risk of acquiring the bacteria. Up to 80% of travelers returning from these areas are colonized by MDR-GN bacteria which they can keep for a year in their bodies.
The researchers followed a group of 20 Europeans during a three-week trip to Laos. They obtained daily stool samples in order to obtain maximum information about their intestinal health. During the stay, the bacterial strains colonized several travelers who stayed in the same hotel and spent time together. This study is the first to analyze samples of travelers during a trip and not only before and after. Of the European travelers to Laos followed during the research, 70% were colonized by the end of the study. Daily sampling revealed that all participants acquired extended-spectrum beta-lactamase (ESBL) at some point during their stay abroad. ESBL enzymes create resistance in the body to most beta-lactam antibiotics. Infections with ESBL-producing organisms are difficult to treat.
Hard-to-treat infections
In detail, all but one of the participants acquired several strains of bacteria, some of which were shared by four tourists. “Our study reveals the true scale and complexity to which drug-resistant bacteria colonize the intestinal tract during travel, demonstrating that it has previously been seriously underestimated.says Jukka Corander, co-author of the study. Additionally, several of our participants lost some of their ESBL strains acquired during travel while still abroad – indicating that previous studies using only pre- and post-travel sampling have underestimated estimated the extent to which travelers are colonized with ESBL.”
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