Weather variables as important clinical predictors of bacterial diarrhoea among international travellers.

BACKGROUND: Clinicians and travellers often have limited tools to differentiate bacterial from non-bacterial causes of travellers' diarrhoea (TD). Development of a clinical prediction rule assessing the aetiology of TD may help identify episodes of bacterial diarrhoea and limit inappropriate antibiotic use. We aimed to identify predictors of bacterial diarrhoea among clinical, demographic and weather variables, as well as to develop and cross-validate a parsimonious predictive model. METHODS: We collected de-identified clinical data from 457 international travellers with acute diarrhoea presenting to two healthcare centres in Nepal and Thailand. We used conventional microbiologic and multiplex molecular methods to identify diarrheal aetiology from stool samples. We used random forest and logistic regression to determine predictors of bacterial diarrhoea. RESULTS: We identified 195 cases of bacterial aetiology, 63 viral, 125 mixed pathogens, 6 protozoal/parasite and 68 cases without a detected pathogen. Random forest regression indicated that the strongest predictors of bacterial over viral or non-detected aetiologies were average location-specific environmental temperature and red blood cell on stool microscopy. In 5-fold cross-validation, the parsimonious model with the highest discriminative performance had an area under the receiver operator curve of 0.73 using 3 variables with calibration intercept -0.01 (standard deviation, SD 0.31) and slope 0.95 (SD 0.36). CONCLUSIONS: We identified environmental temperature, a location-specific parameter, as an important predictor of bacterial TD, among traditional patient-specific parameters predictive of aetiology. Future work includes further validation and the development of a clinical decision-support tool to inform appropriate use of antibiotics in TD.

Epidemiology and etiology of Traveler's diarrhea in Bangkok, Thailand, a case-control study.

BACKGROUND: Traveler's diarrhea (TD) is a common health problem among visitors from developed to developing countries. Although global and regional estimates of pathogen distribution are available, the etiology of diarrhea among non-military travelers to Thailand is largely unknown. METHODS: A prospective TD case-control study was conducted among adult travelers from developed countries at a prominent hospital in Bangkok, Thailand during 2001-2003. Stool samples were collected from acute TD cases and non-diarrheal controls and analyzed for bacterial, viral, and protozoan pathogens by microbiology, ELISA or PCR methods. Calculation of adjusted odd ratios for risk factors was performed by logistic regression using STATA statistical software. RESULTS: Stool samples were collected and analyzed from 389 TD cases and 400 non-diarrhea controls. At least one pathogen was detected in 227 (58%) cases and 124 (31%) controls. Plesiomonas (14%), Vibrio (14%), Campylobacter (14%), and norovirus (12%) were the most frequently isolated pathogens among cases and significantly associated with diarrhea at p = 0.006, p < 0.001, p < 0.001, p < 0.001, respectively. Shigella (3%) and ETEC (8%), detected in lower prevalence, also showed significant association with TD at p < 0.001 and p = 0.002, respectively. Travelers from East Asian countries had an increased risk of Vibrio infection (Crude odds ratio: 3.1, p-value = 0.001); travelers from the United States, Canada, and Europe had an increased risk of Campylobacter infection (Crude odds ratio: 2.6, p-value = 0.001); and travelers from Australia and New Zealand had an increased risk of Salmonella infection (Crude odds ratio: 3.2, p-value = 0.009). CONCLUSIONS: Etiology of TD in Thailand is mainly of bacterial origin. Plesiomonas, Vibrio, and norovirus are underappreciated diarrheagenic pathogens. In our study, the origin of the traveler plays an important role in diarrhea etiology. Understanding variations in TD severity and etiology among travelers from different regions warrants further study.

Five-year clinical outcomes of Crohn's disease: a report of 287 multiethnic cases from an International Hospital in Thailand.

Background: Crohn's disease (CD) has been relatively rare in Asian region whereas its clinical outcomes have been dominated by evidence from Caucasians in developed countries. This study reported clinical characteristics and outcomes of the multiethnic patients who visited our institution. Materials and methods: Medical records of all patients who visited our institution during 2005-2010 were reviewed. Colonoscopy and sigmoidoscopy were performed in compliance with the ASGE guidelines. Results: A total of 287 CD patients were followed up for 5.65 years on average: 41.80% Middle Eastern (ME), 29.62% Caucasian, 28.57% Asian. ME and Caucasian had higher CD prevalence than Asian (286.71, 278.66, and 43.10 per 100,000 population, respectively). Significant variation in male proportion was observed (p=0.001): 39.02% Asian, 65.83% ME, 68.24% Caucasian. The mean age was 39.46 years (ME 32.88, Asian 43.35, Caucasian 45.00; p<0.001). ME had alonger duration of symptoms (26.55 months) than Caucasian (11.98 months) and Asian (12.35 months) (p=0.0008). The proportions of perianal lesions were statistically different across ethnic origins (p=0.014): 9.76% Asian, 24.17% ME and 12.94% Caucasian. Caucasian was severely active, compared with ME (10.83%) and Asian (6.10%). Disease progression existed in 88 of 254 patients who initially had non-severe pathology: 19.63% ME, 40% Caucasian, 50.65% Asian (p<0.0001). Clinical improvement was observed in 82% of the patients. Seventy-five patients required either surgery or hospitalization with a significant ethnic variation: 37.65% Caucasian, 28.33% ME, 10.98% Asian (p<0.0001). Conclusions: Crohn's disease prevalence, gender, age, duration of symptoms, perianal lesion, pathological severity and disease progression varied across ethnic origins.

Travelers' Diarrhea in Thailand: A Quantitative Analysis Using TaqMan® Array Card.

Background: Travelers' diarrhea (TD) is a common illness experienced by travelers from developed countries who visit developing countries. Recent questionnaire-based surveillance studies showed that approximately 6%-16% of travelers experienced TD while visiting Thailand; however, a majority of TD information was limited mainly to US military populations. Methods: A TD surveillance study was conducted at Bumrungrad International Hospital in 2012-2014 in Bangkok, Thailand. Enteropathogens were identified using conventional methods and the TaqMan® array card (TAC), which uses real-time polymerase chain reaction for the simultaneous detection of multiple pathogens. Analyses to determine pathogen-disease and symptoms association were performed to elucidate the clinical relevance of each enteropathogen. Results: TAC identified more pathogens per sample than conventional methods. Campylobacter spp. were the most prevalent, followed by the diarrheagenic Escherichia coli and norovirus GII. These agents had significant pathogen-disease associations as well as high attributable fractions among diarrheal cases. A wide range of pathogen loads for Campylobacter spp. was associated with TD, while heat-labile toxin enterotoxigenic Escherichia coli was associated with an increased pathogen load. Most cases were associated with inflammatory diarrhea, while Campylobacter spp. and Shigella spp. were associated with dysentery. Conclusions: A pan-molecular diagnostic method such as TAC produces quantifiable and comparable results of all tested pathogens, thereby reducing the variability associated with multiple conventional methods. This allows better determination of the clinical relevance of each diarrhea etiologic agent, as well as their geographical relevance in Thailand.

Incidence of Campylobacter concisus and C. ureolyticus in traveler's diarrhea cases and asymptomatic controls in Nepal and Thailand.

BACKGROUND: Campylobacter concisus and C. ureolyticus have emerged in recent years as being associated with acute and prolonged gastroenteritis and implicated in the development of inflammatory bowel diseases. However, there are limited data on the prevalence of these microorganisms in Southeast Asia. In this study, 214 pathogen-negative stool samples after laboratory examination for common enteric pathogens to include C. jejuni and C. coli by culture from two case-control traveler's diarrhea (TD) studies conducted in Thailand (cases = 26; controls = 30) and Nepal (cases = 83; controls = 75) respectively were assayed by PCR for the detection of Campylobacter 16S rRNA and two specific heat shock protein genes specific for C. concisus (cpn60) and C. ureolyticus (Hsp60) respectively. RESULTS: Campylobacter 16S rRNA was detected in 28.5% (61/214) of the pathogen-negative TD stool samples (CIWEC Travel Medicine Clinic, Kathmandu, Nepal: cases = 36, control = 14; Bamrungrad International Hospital, Bangkok, Thailand: cases = 9, controls = 2). C. consisus was identified significantly more often in TD cases in Nepal (28.9%; 24/83) as compared to controls (4%; 3/75) (OR = 9.76; 95% CI 2.80-34.02; P = 0.0003) while C. consisus was detected in only two cases (2/26; 7.7%) and none of the controls stool samples from Thailand. C. ureolyticus was detected in four cases (4.8%; 4/83) and four controls (5.3%; 4/75) and in one case (3.8%; 1/26) and one control (3.1%; 1/30) from Nepal and Thailand respectively. C. jejuni and C. coli were isolated in 18.3 and 3.4% of the cases and in 4.0 and 1.4% of the controls in stool samples from both Thailand and Nepal respectively while C. concisus nor C. ureolyticus were not tested for in these samples. CONCLUSION: These findings suggest that C. concisus potentially is a pathogen associated with TD in Nepal. To our knowledge, this is the first report of C. concisus and C. ureolyticus detected from traveler's diarrhea cases from travelers to Nepal and Thailand.

Ethnic variations in ulcerative colitis: Experience of an international hospital in Thailand.

AIM: To investigate the clinical characteristics, treatment, medication use, and treatment response in patients with ulcerative colitis (UC) across ethnic groups. METHODS: This study retrospectively analyzed medical records of all 268465 patients who visited the Bumrungrad International Digestive Disease Center during 2005-2010. The demographics, clinical characteristics, medication use, results of investigations, and medical and surgical management for patients with UC were evaluated. Evaluation included sigmoidoscopy and colonoscopy performed in compliance with the American Society of Gastrointestinal Endoscopy practice guidelines. Patient ethnicities were categorized into seven groups: Thai, Oriental, South Asian (SA), Middle Eastern (ME), Caucasian, African, and Hispanic. UC pathological severity was classified into inactive, mild, moderate, and severe. Associations between categorical variables were analyzed using the χ(2) or Fischer's exact test. Associations between categorical and interval variables were analyzed using Student's t-test and/or analysis of covariance. RESULTS: UC was diagnosed in 371 of the 268465 patients: male 56.33%; ME 42%, Caucasian 23%, and Thai 19%. Annual incidence of UC was 82 cases per 100000 with wide ethnic variation, ranging from 29 to 206 cases per 100000 in Oriental and ME patients, respectively. Of the patients with UC, 16.71% had severe UC with highest incidence among the patients from ME (20.39%) and lowest among the Caucasian population (11.90%). ME had highest proportion of pancolitis (52.90%), followed by Caucasian (45.35%) and Asian (34.40%). Only 20.93% of Caucasian patients received steroid, compared with 26.40% and 27.10% of Asian and Middle Eastern, respectively (P = 0.732). Overall, 13.72% of UC patients did not respond to steroid therapy, with non-significantly higher proportions of non-responders among Asian and Middle Eastern patients (15.22% and 15.04%, respectively) (P = 0.781). On average, 5.93% underwent surgical management with ethnic variation, ranging from 0% in African to 18% in SA. Cancer was found in three (Thai, ME, and African) cases (0.82 institution-specific incidence). CONCLUSION: Incidence, symptom duration, pathological severity, clinical manifestations, medication use, treatment response, need for surgical consultation, and cancer incidence of patients with UC potentially vary by ethnicity.

Incidence and factors associated with overweight and obesity, and hypertensive disorder, among staff in a private healthcare setting: a retrospective cohort study.

OBJECTIVE: To determine the incidence and factors associated with overweight and obesity, and hypertensive disorder, among staff in a private healthcare setting. MATERIAL AND METHOD: The present retrospective cohort study examined the computerized data of Bumrungrad International (BI) Hospital staff that had undergone pre-employment and annual/bi-annual check-ups, between January 2000 and June 2006. RESULTS: Data for the 3,678 staff surveyed comprised 7,338 visits, with a median follow-up time of 1.9 years; 81.9% were females, and the mean age (SD) was 27.1 (6.8) years. On their first visit, 8.5% could be classified as overweight or obese (Body Mass Index-[BMI] of 25.0+ kg/m2). The overall incidence of these conditions was 22.2/1,000 person-years (95%; Confidence Interval [CI] = 18.8-26.1). Cox's regression analysis revealed that incidence increased with age (Relative Hazard [RH] = 4.4 for age 20-44 years [95% -CI 1.6-12.2], and RH = 8.2 [95% CI 2.4-27.5] for age > or = 45 years, reference: < 20 years), but decreased among the registered nurses and ancillary professional staff (RH = 0.3, 95% CI 0.2-0.6). At cohort entry, 41.0% could be classified as pre-hypertensive (blood pressure 120-139/> 80-89 mmHg) and 1.9% as stages I and II hypertension. The overall incidence of hypertensive disorder was 16.9/1,000 person-years (95%; CI 13.6-20.9). Baseline pre-hypertensive (RH 4.9, 95%; CI 2.6-9.3), males (RH 1.7, 95%; CI 1.1-2. 7), age > or = 45 years (RH3.2, 95%; CI 1.0-10.5), and BMI (RH ranges 3.3-6 4) were identified as independent risk factors for incident hypertension. In addition, 2.5% were HBsAg-positive, and 33.3% had HBsAb antibody CONCLUSION: The present retrospective cohort study was instituted in a private healthcare setting, information generated resulted in changes to the health-promotion programs of the organization.

PFGE, Lior serotype, and antimicrobial resistance patterns among Campylobacter jejuni isolated from travelers and US military personnel with acute diarrhea in Thailand, 1998-2003.

BACKGROUND: Campylobacter jejuni is a major cause of gastroenteritis worldwide. In Thailand, several strains of C. jejuni have been isolated and identified as major diarrheal pathogens among adult travelers. To study the epidemiology of C. jejuni in adult travelers and U.S. military personnel with acute diarrhea in Thailand from 1998-2003, strains of C. jejuni were isolated and phenotypically identified, serotyped, tested for antimicrobial susceptibility, and characterized using pulsed-field gel electrophoresis (PFGE). RESULTS: A total of 312 C. jejuni isolates were obtained from travelers (n = 46) and U.S. military personnel (n = 266) in Thailand who were experiencing acute diarrhea. Nalidixic acid and ciprofloxacin resistance was observed in 94.9% and 93.0% of the isolates, respectively. From 2001-2003, resistance to tetracycline (81.9%), trimethoprim-sulfamethoxazole (57.9%), ampicillin (28.9%), kanamycin (5.9%), sulfisoxazole (3.9%), neomycin (2.0%), and streptomycin (0.7%) was observed. Combined PFGE analysis showed considerable genetic diversity among the C. jejuni isolates; however, four PFGE clusters included isolates from the major Lior serotypes (HL: 36, HL: 11, HL: 5, and HL: 28). The PFGE analysis linked individual C. jejuni clones that were obtained at U.S. military exercises with specific antimicrobial resistance patterns. CONCLUSIONS: In summary, most human C. jejuni isolates from Thailand were multi-resistant to quinolones and tetracycline. PFGE detected spatial and temporal C. jejuni clonality responsible for the common sources of Campylobacter gastroenteritis.

Diarrhea among children admitted to a private tertiary-care hospital, Bangkok, Thailand: a case series.

We report here a case series of pediatric diarrhea cases admitted to a private tertiary-care hospital in Bangkok, Thailand. Retrospective data were collected from computerized medical records of 2,001 children with diarrhea (80.9% Thai), ages birth to 14 years, admitted to our facility during 2000-2005. The most common symptom leading to admission was vomiting (34.6%), while the most common sign was dehydration (63.6%). The largest proportion was comprised of toddlers (45.4%), followed by infants (24.2%). Of the total 2,564 admissions, 1,874 (73.1%) stool samples were collected and examined for red blood cells (RBC) and white blood cells (WBC); 57.1% and 70.6% were negative for RBC and WBC, respectively. Of the 1,878 blood specimens collected for electrolytes, 21.6% show acidosis. Of 1,793 stool specimens collected, the majority revealed normal flora (72.9%). Enteropathogenic Escherichia coli (EPEC) were seen in 10.8%. Campylobacter jejuni was found in only 2.9% of specimens, while of 1,065 specimens tested for rotavirus antigen, 23.9% were positive. In addition to bacterial cultures and their anti-microbial sensitivities, factors associated with rotavirus infection, C. jejuni, and metabolic acidosis, were also explored in this study. Rotavirus infections were more likely to be associated with children older than toddlers (3-14 years old), being admitted within the first day of the symptoms, those who were more acidotic, and was more common in the first 3 months of each year. Our data were little different from community-acquired infections reported among the general population.

Intussusception in a private tertiary-care hospital, Bangkok, Thailand: a case series.

This was a retrospective case series study of patients with intussusception at a private tertiary-care hospital in Bangkok, Thailand. The computerized hospital records of all 94 children aged 0-14 years diagnosed with intussusception from 2000 to 2005 were reviewed. About half (51.1%) were males, 23.4% were less than 1 year old. Most (78.7%) were Thai nationals. The highest case frequency was in August (n=12, Poisson means = 7.8, 95% confidence interval 6.3-9.6). Of these, none had the classical triad of vomiting, colicky pain, and mucous bloody stools. Only 12.8% had fever; abdominal mass was detected in 4.3%, and 4.3% had increased bowel sounds, while 34.0% had no specific signs. The most frequent site of intussusception was the ileocolic (62.6%). Stool cultures for bacteria and stool for rotavirus antigen obtained in some cases revealed no significant findings. Of the cases, 10 (10.6%) had spontaneous reduction, 84 (89.4%) underwent barium enema intervention, 10 of the latter (11.9%) required further surgical intervention. There were no mortalities during the observation period. There were 10 recurrent events in this series. The 7-day recurrence-free probability was 84.9% (95% CI 49.2, 96.3%). This study provides baseline data regarding intussusception in Thailand which may be useful for future epidemiological and/or clinical studies.

The dominance of pandemic serovars of Vibrio parahaemolyticus in expatriates and sporadic cases of diarrhoea in Thailand, and a new emergent serovar (O3 : K46) with pandemic traits.

Vibrio parahaemolyticus is a major cause of gastroenteritis worldwide. A total of 95 V. parahaemolyticus isolates belonging to 23 different serovars were identified in a case-control study of expatriates and Thai adults from 2001 to 2002 in Thailand. Fifty-two per cent of isolates (49/95) were resistant to ampicillin and sulfisoxazole, but all isolates were susceptible to ciprofloxacin and trimethoprim-sulfamethoxazole, two antibiotics commonly used to treat traveller's diarrhoea. All isolates were positive for the species-specific toxR gene, and 91 and 5 were positive for the thermostable direct haemolysin (tdh) gene and the tdh-related (trh) gene, respectively. Sixty-five isolates were assigned to the pandemic group of V. parahaemolyticus by a group-specific PCR and the presence of the orf8 gene. The pandemic isolates belonged to three recognized serovars (O3 : K6, O1 : K25, O1 : KUT) and a new serovar, O3 : K46. This new serovar harboured pandemic traits. PFGE analysis revealed that all pandemic isolates including serovar O3 : K46 were closely related and clearly distinct from the non-pandemic isolates. In summary, three well-known serovars of pandemic V. parahaemolyticus isolates were identified as a major cause of diarrhoea in Thailand and a new V. parahaemolyticus isolate, serovar O3 : K46, with pandemic traits was detected.