Persisting abdominal symptoms after travelers' diarrhea: Is there a genetic predisposition?

Functional gastrointestinal disorders (FGIDs) are defined as ailments of the mid or lower gastrointestinal tract which are not attributable to any discernable anatomic or biochemical defects.1 FGIDs include functional bowel disorders, also known as persisting abdominal symptoms (PAS). Irritable bowel syndrome (IBS) is one of the most common illnesses classified under PAS.2,3 This is the first prospective study that looks at the etiology and pathogenesis of post-infectious PAS in the context of environmental exposure and genetic susceptibility in a cohort of US travelers to Mexico. Our objective was to identify infectious, genetic and environmental factors that predispose to post infectious PAS. ^ Methods. This is a secondary data analysis of a prospective study on a cohort of 704 healthy North American tourists to Cuernavaca, Morelos and Guadalajara, Jalisco in Mexico. The subjects at risk for Travelers' diarrhea were assessed for chronic abdominal symptoms on enrollment and six months after the return to the US. ^ Outcomes. PAS was defined as disturbances of mid and lower gastrointestinal system without any known pathological or radiological abnormalities, or infectious, or metabolic causes. It refers to functional bowel disease, category C of functional gastrointestinal diseases as defined by the Rome II criterion. PAS was sub classified into Irritable bowel syndrome (IBS) and functional abdominal disease (FAD). ^ IBS is defined as recurrent abdominal pain or discomfort present at least 25% and associated with improvement with defecation, change in frequency and form of stool. FAD encompasses other abdominal symptoms of chronic nature that do not meet the criteria for IBS. It includes functional diarrhea, functional constipation, functional bloating: and unspecified bowel symptoms. ^ Results. Among the 704 travelers studied, there were 202 cases of PAS. The PAS cases included 175 cases of FAD and 27 cases of IBS. PAS was more frequent among subjects who developed traveler's diarrhea in Mexico compared to travelers who remained healthy during the short term visit to Mexico (52 vs. 38; OR = 1.8; CI, 1.3–2.5, P < 0.001). A statistically significant difference was noted in the mean age of subjects with PAS compared to healthy controls (28 vs. 34 yrs; OR = 0.97, CI, 0.95–0.98; P < 0.001). Travelers who experienced multiple episodes, a later onset of diarrhea in Mexico and passed greater numbers of unformed stools were more likely to be identified in PAS group at six months. Participants who developed TD caused by enterotoxigenic E.coli in Mexico showed a 2.6 times higher risk of developing FAD (P = 0.003). Infection with Providencia ssp. also demonstrated a greater risk to developing PAS. Subjects who sought treatment for diarrhea while in Mexico also displayed a significantly lower frequency of IBS at six months follow up (OR = 0.30; CI, 0.10–0.80; P = 0.02). ^ Forty six SNPs belonging to 14 genes were studied. Seven SNPs were associated with PAS at 6 months. These included four SNPs from the Caspase Recruitment Domain-Containing Protein 15 gene (CARD15), two SNPs from Surfactant Pulmonary-Associated Protein D gene (SFTPD) and one from Decay-Accelerating Factor For Complement gene (CD55). A genetic risk score (GRS) was composed based on the 7 SNPs that showed significant association with PAS. A 20% greater risk for PAS was noted for every unit increase in GRS. The risk increased by 30% for IBS. The mean GRS was high for IBS (2.2) and PAS (1.1) compared to healthy controls (0.51). These data suggests a role for these genetic polymorphisms in defining the susceptibility to PAS. ^ Conclusions. The study allows us to identify individuals at risk for developing post infectious IBS (PI-IBS) and persisting abdominal symptoms after an episode of TD. The observations in this study will be of use in developing measures to prevent and treat post-infectious irritable bowel syndrome among travelers including pre-travel counseling, the use of vaccines, antibiotic prophylaxis or the initiation of early antimicrobial therapy. This study also provides insights into the pathogenesis of post infectious PAS and IBS. (Abstract shortened by UMI.)^

Susceptibility to travelers' diarrhea and histo-blood group antigens

Histo-blood group antigens (HBGAs) have been associated with susceptibility to enteric pathogens including noroviruses (NoVs), enterotoxigenic Escherichia coli (ETEC), Campylobacter jejuni, and Vibrio cholerae. We performed a retrospective cohort study to evaluate the relationship between traveler HBGA phenotypes and susceptibility to travelers' diarrhea (TD) and post-infectious complications. 364 travelers to Guadalajara, Mexico were followed prospectively from June 1 - September 30, 2007 and from June 7–July 28, 2008 for the development of TD and at 6 months for post-infectious irritable bowel syndrome (PIIBS). Noroviruses were detected from illness stool specimens with RT-PCR. Diarrheal stool samples were also assayed for enterotoxigenic and enteroaggregative E. coli, Salmonella species, Shigella species, Vibrio species, Campylobacter jejuni, Yersinia enterocolitica, Aeromonas species, and Plesiomonas species. Diarrheal stools were evaluated for inflammation with fecal leukocytes, mucus, and occult blood. Phenotyping for ABO and Lewis antigens with an ELISA assay and FUT2 gene PCR genotyping for secretor status were performed with saliva. 171 of 364 (47%) subjects developed TD. HBGA typing for the travelers revealed O (62.9%), A (34.6%), B (1.6%), and AB (0.8%) phenotypes. There were 7% nonsecretors and 93% secretors among the travelers. AB phenotypes were more commonly associated with Cryptosporidium species (P=0.04) and ETEC ( P=0.08) as causes of TD. AB and B phenotype individuals were more likely to experience inflammatory diarrhea, particularly mucoid diarrhea ( P=0.02). However, there were relatively few individuals with AB and B phenotypes. GI and GII NoV and Cryptosporidium species infections and PI-IBS were identified only in secretors, but these differences were not statistically significant, (P=1.00), (P=1.00), and (P=0.60), respectively. Additional studies are needed to evaluate whether AB phenotype individuals may be more susceptible to developing TD associated with Cryptosporidium species or ETEC, and whether AB and B phenotype individuals may be more likely to develop inflammatory TD. Further studies are needed to investigate whether nonsecretor travelers may be at less risk for developing infections with NoVs and Cryptosporidium species and PI-IBS.^

Antibiotic susceptibility and resistance among bacterial enteropathogens isolated from international travelers to Mexico, Guatemala, and India, 2006--2008

The incidence rates of travelers' diarrhea (TD) have remained unchanged for the last fifty years. More recently, there have been increasing recommendations for self-initiated therapy and even prophylactic therapy for TD. There is no recent data on the in vitro activities of commonly used antibiotics for TD therapy and whether there have been any changes in susceptibilities over the last ten years. 456 enteropathogens were isolated from adult travelers to Mexico, India, and Guatemala between the years 2006 to 2008. MICs were determined for 10 different antimicrobials by the agar dilution method. Traditional antibiotics such as ampicillin, trimethoprim/sulfamethoxazole, and doxycycline continue to show high levels of resistance. Current first line antibiotic agents including fluoroquinolones and azithromycin had significantly higher MICs when compared to 10 years ago and MIC90 levels were beyond the CSLI cutoffs for resistance. There were significant geographical differences in resistance patterns when comparing Central America with India. Entertoxigenic Escherichia coli (ETEC) isolates were more resistant to ciprofloxacin (p=0.023), and levofloxacin (p=0.0078) in India; whereas, enteroaggregative Escherichia coli (EAEC) isolates from Central America showed more resistance. When compared to MICs of isolates 10 years prior, there was a four to ten-fold increase in MIC90s for ceftriaxone, ciprofloxacin, levofloxacin and azithromycin for both ETEC and EAEC. There were no significant changes in rifaximin MICs over the last ten years, which makes it a promising agent for TD. Rising MICs over time implicate the need for continuous surveillance of susceptibility patterns worldwide and for geography specific recommendations in TD therapy.^

Numer and type of seeds introduced by footwear of travelers to Svalbard and germination success in 2008

Expanding visitation to Polar regions combined with climate warming increases the potential for alien species introduction and establishment. We quantified vascular plant propagule pressure associated with different groups of travelers to the high-Arctic archipelago of Svalbard, and evaluated the potential of introduced seeds to germinate under the most favorable average Svalbard soil temperature (10°C). We sampled the footwear of 259 travelers arriving by air to Svalbard during the summer of 2008, recording 1,019 seeds: a mean of 3.9 (±0.8) seeds per traveler. Assuming the seed influx is representative for the whole year, we estimate a yearly seed load of around 270,000 by this vector alone. Seeds of 53 species were identified from 17 families, with Poaceae having both highest diversity and number of seeds. Eight of the families identified are among those most invasive worldwide, while the majority of the species identified were non-native to Svalbard. The number of seeds was highest on footwear that had been used in forested and alpine areas in the 3 months prior to traveling to Svalbard, and increased with the amount of soil affixed to footwear. In total, 26% of the collected seeds germinated under simulated Svalbard conditions. Our results demonstrate high propagule transport through aviation to highly visited cold-climate regions and isolated islands is occurring. Alien species establishment is expected to increase with climate change, particularly in high latitude regions, making the need for regional management considerations a priority.

Ages and two-way travel times of ODP Sites 180-1109, 180-1115 and 180-1118

Synthetic seismograms are constructed from check shot-corrected velocity and density measurements collected during Ocean Drilling Program (ODP) Leg 180 at Sites 1109, 1115, and 1118. The synthetic seismograms facilitate direct correlation of a coincident multichannel seismic (MCS) profile with borehole data collected at the three sites. The MCS data and the synthetic seismograms correlate very well, with most major reflectors successfully reproduced in the synthetics. Our results enable a direct calibration of the MCS data in terms of age, paleoenvironment, and subsidence history. Seismic reflectors are time correlative within stratigraphic resolution but are often observed to result from different lithologies across strike. Our results facilitate the extrapolation of the sedimentation history into an unsampled section of Site 1118 and enable a full correlation between the three sites using all the data collected during ODP Leg 180. This study forms the foundation for regionalizing the site data to the northern margin of the Woodlark Basin, where the transition from continental rifting to seafloor spreading is taking place.

Innnovation and new business models for the regional development: travel and transportation

Regional development could present different strategies: •Relocation of industry clusters •Foreign Direct Investment attraction •Innovation based on new business models The Regional Government of Madrid (3rd largest GDP in the EU) selected strategic industries to compete & innovate: •Travel & Transportation •Aerospace •Nanotech. & •Biotech. •ICTs. •Energy

Hybrid choice model for propensity to travel and tour complexity

During the last years cities around the world have invested important quantities of money in measures for reducing congestion and car-trips. Investments which are nothing but potential solutions for the well-known urban sprawl phenomenon, also called the “development trap” that leads to further congestion and a higher proportion of our time spent in slow moving cars. Over the path of this searching for solutions, the complex relationship between urban environment and travel behaviour has been studied in a number of cases. The main question on discussion is, how to encourage multi-stop tours? Thus, the objective of this paper is to verify whether unobserved factors influence tour complexity. For this purpose, we use a data-base from a survey conducted in 2006-2007 in Madrid, a suitable case study for analyzing urban sprawl due to new urban developments and substantial changes in mobility patterns in the last years. A total of 943 individuals were interviewed from 3 selected neighbourhoods (CBD, urban and suburban). We study the effect of unobserved factors on trip frequency. This paper present the estimation of an hybrid model where the latent variable is called propensity to travel and the discrete choice model is composed by 5 alternatives of tour type. The results show that characteristics of the neighbourhoods in Madrid are important to explain trip frequency. The influence of land use variables on trip generation is clear and in particular the presence of commercial retails. Through estimation of elasticities and forecasting we determine to what extent land-use policy measures modify travel demand. Comparing aggregate elasticities with percentage variations, it can be seen that percentage variations could lead to inconsistent results. The result shows that hybrid models better explain travel behavior than traditional discrete choice models.

Surréalisme Sous-L’Eau : science and surrealism in the early films and writings of Jean Painlevé

A French biologist who moved in Surrealist circles, Jean Painlevé began making films about underwater creatures in 1927, and by 1982 had created over two hundred films on a broad range of natural, scientific, and political subjects. His underwater films remain the most ethereal and poetic works in his oeuvre, and he specifically used cinema to capture the mystery and wonder of nature.

Privy Private Eye: A Guidebook for Travelers Who Have to Go

This creative Capstone project, Privy Private Eye: A Guidebook for Travelers Who Have to Go, contains a nonfiction compendium of brief reviews of public restrooms in the Dallas, Texas area. To inform readers about facilities that are safe (and a few that should be avoided), Privy Private Eye contains reviews and ratings of restrooms in gas stations, restaurants, and retail centers. These appraisals will be featured in a full-length manuscript that may be published in the near future as a travel guide. Also contained herein, before the creative portion of the project itself, is a reflective paper describing the project, its creation, and its position within the context of published travel guides.