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Published on: March 3, 2023
Antimicrobial resistance acquisition after international travel in U.S. travelers
Dana M Blyth1, Katrin Mende1,2,3, Ashley M Maranich4
1Infectious Disease Service, San Antonio Military Medical Center, JBSA Fort Sam Houston, 3551 Roger Brooke Drive, Houston, Texas 78234-4505 USA.
Background:
Prior studies have shown an increase in multidrug-resistant (MDR) E. coli colonization from two percent in U.S.-based to 11 % in deployed, healthy military personnel. It is unclear if colonization with MDR organisms occurs through deployment exposures or risks related to routine overseas travel. This study prospectively evaluates rates and risk factors associated with MDR gram-negative bacterial and methicillin-resistant S. aureus (MRSA) colonization after international travel.
Methods:
Participants traveled internationally for five or more days. Pre- and post-travel, colonizing bacteria from oropharyngeal, nares, groin, and peri-rectal (PR) areas were collected using BD CultureSwab™ MaxV(+). Identification and susceptibilities were done utilizing the BD Phoenix™ Automated Microbiology System. Non-MDR pre- and post-travel MDR bacteria within a subject were compared by pulsed-field gel electrophoresis (PFGE). A questionnaire solicited demographics and potential risk factors for MDR acquisition.
Results:
Of 58 participants, 41 % were male and median age was 64 years. Pre- and post-travel swabs were obtained a median of ten and seven days before and after travel, respectively. Itineraries included 18 participants traveling to the Caribbean and Central America, 17 to Asia, 16 to Africa, 5 to Europe, 4 to South and North America. Seventeen of 22 travelers used atovaquone/proguanil for malaria prophylaxis. The only MDR organism isolated was extended-spectrum β-lactamase (ESBL)-producing E. coli in five (9 %) participants post-travel (all PR and unrelated by PFGE). There were no statistically significant associations between exposure risks and new ESBL-producing E.coli colonization. Of 36 participants colonized with E. coli pre- and post-travel, new resistance was detected: TMP/SMX in 42 % of isolates (p < 0.01), tetracycline in 44 % (p < 0.01), and ampicillin-sulbactam in 33 % (p = 0.09). No participants were colonized with MRSA pre- or post-travel.
Conclusion:
Consistent with prior studies, new antimicrobial resistance was noted in colonizing E. coli after international travel. Nine percent of participants acquired new strains of ESBL-producing E.coli without identified risks.
Insights
International travel increases multidrug-resistant (MDR) E. coli colonization, with 9% acquiring new strains of extended-spectrum beta-lactamase (ESBL)-producing E. coli. New antimicrobial resistance was observed in E. coli after travel, highlighting potential global health risks.
Area of Science:
- Microbiology
- Infectious Diseases
- Public Health
Background:
- Multidrug-resistant (MDR) E. coli colonization increased from 2% in U.S. to 11% in deployed military personnel.
- It remains unclear if MDR organism colonization stems from deployment or routine international travel exposures.
- This study investigates MDR gram-negative bacteria and MRSA colonization rates and risk factors post-international travel.
Purpose of the Study:
- To prospectively evaluate the rates of MDR gram-negative bacterial and MRSA colonization after international travel.
- To identify potential risk factors associated with acquiring MDR organisms during international travel.
Main Methods:
- Prospective study involving participants traveling internationally for five or more days.
- Collection of oropharyngeal, nares, groin, and peri-rectal (PR) bacterial swabs pre- and post-travel.
- Identification and susceptibility testing using BD Phoenix™ Automated Microbiology System; PFGE for strain comparison; questionnaire for risk factors.
Main Results:
- Five percent (9%) of participants acquired new strains of extended-spectrum β-lactamase (ESBL)-producing E. coli post-travel, primarily in the PR area.
- No statistically significant associations were found between reported exposure risks and new ESBL-producing E. coli colonization.
- New antimicrobial resistance (TMP/SMX, tetracycline) was detected in existing E. coli colonizations; no MRSA colonization was observed.
Conclusions:
- International travel is associated with an increased risk of acquiring MDR E. coli, including ESBL-producing strains.
- New antimicrobial resistance in colonizing E. coli was observed post-travel, even without identified specific risk factors.
- Findings underscore the importance of monitoring antimicrobial resistance patterns in travelers.
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