By: Dr. Geoffrey Modest
A recent Finnish study looked at intestinal colonization by resistant bacteria in travelers to regions with suboptimal hygiene, noting that there are more than 300 million such travelers, and finding rather disturbing results (see DOI: 10.1093/cid/ciu957). They looked specifically for colonization by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) and carbapenemase-producing Enterobacteriaceae (CPE).
Details:
–430 Finns were assessed before and after traveling outside Scandinavia, analyzing for the above bacteria. Participants also filled out questionnaires detailing aspects of their travel.
–mean age 40, 61% female, 45% going to Sub-Saharan Africa, 24% Southeast Asia, 14% South Asia, 9% to South/Central America or Caribbean. 15% were there for <8 days, 47% for 8-15 days, 28% for 16-30 days. 15% used antibiotics (12% for travelers diarrhea, or TD). 96% drank bottled water, 53% took probiotics, 13% neglected hand-washing, 78% consumed salads, 55% took antimalarials
Results:
–5/430 pre-travel and 93/430 post-travel stools were positive for ESBL-PE, 7 had acquired 2 different strains of ESBL-PE. None were colonized by CPE.
–by region, the risk of getting ESBL-PE was highest in South Asia (46%); then Southeast Asia, East Asia, North Africa/Middle East (33% each); then Sub-Saharan Africa (12%). No cases were found in those going to Europe, Australia, Americas
–288/430 (67%) developed TD; 75 of these 288 (26%) and 15 of those who did not develop TD (11%) became colonized with ESBL-PE. The AOR (adjusted odds ratio) for colonization with ESBL-PE was 31.0 for those who developed TD vs those who did not
–antimicrobials were taken in 66/430 (15%), in 52/66 (79% of those on antibiotics) it was for TD. Note: they did not include doxycycline taken as an antimalarial. 79% of the antibiotics for TD were fluoroquinolones, 13% macrolides. The AOR was 3.0 in those who took antimicrobials for TD
–although there was an increase in ESBL-PE with age, there was no increase found in travel companions or if taking antimalarials
–overall numbers for ESBL-PE:
–in those going to South Asia, 46%, with breakdown as: 23% if not develop TD or take antibiotic, 47% if developed TD but no antibiotics, 80% if developed TD and took antibiotics.
–in those going to Southeast Asia, 33%, with breakdown as: 14% if not develop TD or take antibiotic, 32% if developed TD but no antibiotics, 69% if developed TD and took antibiotics
–in those going to Sub-Saharan Africa, 33%, with breakdown as: 12% if not develop TD or take antibiotic, 8% if developed TD but no antibiotics, 28% if developed TD and took antibiotics
–1 year followup, none previously with ESBL-PE were still positive
So, a few points.
–antimicrobial resistance is surging in regions where hygiene is poor, in part by the easy access to antibiotics there, and these strains are being globalized through travelers, food and animal trade.
–antibiotic-resistant Enterobacteriaceae is becoming more of a problem in the US, with increasing reports noted by the CDC
–colonization by these resistant organisms can lead to significant infections especially in immunocompromized and hospitalized patients, so the above represents a potentially significant reservoir of resistant and potentially transmissable bad actors
–this study reinforces issues of hygiene as well as avoiding taking antibiotics for TD unless one is seriously affected (as per the guidelines. For example, see blog)
–this study also reinforces the delicate balance in the microbiome and the potentially serious problems with its disruption. I have posted several blogs on the microbiome (go to category: “microbiome” on the website), but for example, here notes the changes in the microbiome associated with non-caloric artificial sweeteners that may lead to glucose intolerance/metabolic syndrome, or the blog here details both that red meat leads to changes in the microbiome which increase the production of TMAO, a significant cardiotoxin, and that part of metformin’s hypoglycemic action at least in mice is mediated through microbiome changes.