Prevalence of Strongyloides in Southeast Asia: a systematic review and meta-analysis with implications for public health and sustainable control strategies.

BACKGROUND: Strongyloidiasis, caused by the nematodes Strongyloides stercoralis and Strongyloides fuelleborni, is estimated to affect over 600 million individuals worldwide. The disease is endemic in Southeast Asia, where a warm-humid climate and socio-economic conditions maintain the parasite's life cycle and transmission. However, the current diagnostic methods may not be sufficiently sensitive, suggesting that the true prevalence of strongyloidiasis could be seriously underestimated in this. This study aims to determine the prevalence of strongyloidiasis in Southeast Asia through a systematic review and meta-analysis and to discuss the implications of the estimated prevalence on diagnostic approaches and control strategies. METHODS: Following PRISMA guidelines, we conducted a systematic literature search in PubMed and Google Scholar databases to identify studies reporting Strongyloides prevalence data in the 11 Southeast Asian countries up to December 2022. A random effects model was employed to estimate the pooled prevalence of S. stercoralis at both regional and country levels. RESULTS: Out of 3722 articles identified, 224 met our inclusion criteria. For S. stercoralis specifically, we found 187 articles, of which 52.4% were from Thailand. All Southeast Asian countries, except Brunei, had at least one study on Strongyloides prevalence. The estimated pooled prevalence of S. stercoralis regionally was 12.7% (95% CI 10.70-14.80%), ranging from 0.4 to 24.9% at the country level. Cambodia had the highest pooled prevalence (24.9%, 95% CI 15.65-35.38%), followed by Lao PDR (16.5%, 95% CI 9.50-24.95%). Moreover, we obtained a pooled prevalence of 10% (95% CI 7.06-13.52%) in a group comprising immigrants, workers, and veterans from Southeast Asian countries. S. stercoralis infects various host types, including nonhuman primates, domestic dogs and cats, rodents, and transport carriers such as cockroaches and vegetables. CONCLUSIONS: A high prevalence of strongyloidiasis in Southeast Asia was revealed, highlighting the importance of the region's ongoing research, surveillance, and control efforts. Factors contributing to the strongyloidiasis transmission include the role of animal hosts, the impact of global connectivity, and the significance of the co-endemicity of other Strongyloides species. Based on these findings, a multi-pronged One-Health approach is essential for sustainable intervention and control.

Prevalence of hypertension among travelers and stability of blood pressure control during travel: a cross-sectional descriptive study and prospective cohort study.

BACKGROUND: Hypertension is a common and important risk factor for cardiovascular disease which is the leading cause of death among the general population and travelers. Data on hypertension among travelers are very limited due to the scarcity of research reports in this specific population. Therefore, this study aimed to determine the prevalence of hypertension among adult travelers and the stability of blood pressure control during international trips using a mobile automated blood pressure device. METHODS: This was a cross-sectional descriptive study conducted at the Thai travel clinic, Hospital for Tropical Diseases in Bangkok, Thailand. All adult travelers completed a questionnaire which included demographic data, medical history, medication use, trip characteristics and hypertension awareness and knowledge. Standard two time blood pressure measurements were performed at the clinic to detect possible undiagnosed hypertension. Travelers with pre-existing hypertension were also invited to monitor their blood pressure level before and during their trip for a total of 14 days by using an automated blood pressure device and reporting the readings back to the study team. RESULT: During July and October 2022, a total of 1,359 adult travelers visited the Thai Travel Clinic before their international trip. The overall prevalence of hypertension was 28.8%, including those with pre-existing hypertension (6.7%) and those with newly diagnosed hypertension (22.2%). Travelers with newly diagnosed hypertension were significantly younger than travelers with pre-existing hypertension (38.5 years vs. 55.6 years, p < 0.001). Eleven travelers agreed to monitor their blood pressure, Most (90.9%, 10/11) had stable blood pressure control during their trip. One participant had > 10 mmHg higher blood pressure during the trip, however this was not clinically significant. All participants remained well, and acute symptoms secondary to hypertension were not reported. CONCLUSION: Up to 28.8% of adult travelers seen in pre-travel consultations had hypertension. Most of them were unaware of their blood pressure condition. Vital signs including blood pressure should be evaluated in all pre-travel visits in order to prevent undiagnosed severe hypertension that might lead to hypertensive crisis.

International University Students' Pre-Travel Preparation, Knowledge and Practices towards Travel Health in Thailand: A Nationwide Cross-Sectional Study.

International university students are vulnerable travellers due to their unpredictable schedules and lifestyles. As Thailand continues to see an increase in international students, evaluating their pre-travel preparation and preventive behaviours is crucial to identify areas for improvement. For this purpose, an online survey focusing on pre-travel preparation, knowledge and preventive practices related to travel health was distributed to 324 eligible international students from 14 Thai universities, with the majority being from Asia and Oceania (79.0%; n = 256). The results showed that half of the respondents (53.7%; n = 175) received professional pre-travel advice, mainly because of the mandatory health examination and vaccination requirements of the host university. The study also revealed inadequate knowledge about infectious and non-infectious health risks, with only one-third being aware that Japanese encephalitis is transmitted by mosquito bites, and less than half of the students recognising Thailand's emergency services number. Poor preventive practices were also observed, with less than half of those with new sexual partners consistently using condoms and less than half of those riding motorcycles always wearing helmets. These findings highlight the need for a new strategy to improve the standard of travel health preparation among this group of young adult travellers, particularly those from resource-limited countries.

Risk factors and prevalence of taeniasis among the Karen people of Tha Song Yang District, Tak Province, Thailand.

Taeniasis remains a prevalent public health problem in Thailand. National helminthiasis surveys report only the incidence of Taenia spp. eggs. The ability to differentiate Taenia species using morphological and molecular techniques is vital for epidemiological surveys. This study detected taeniasis carriers and other helminthic infections by Kato's thick smear technique and identified the Taenia species by multiplex PCR. The study subjects were the ethnic Karen people in Tha Song Yang District, Tak Province, Thailand, bordering Myanmar. In total, 983 faecal samples from villagers were examined for helminthiases. Interview-based questionnaires were used to gather information on possible risk factors for infection. The prevalence of helminth infections was 42.7% (420/983), including single (37.3%, 367/983) and mixed infections (5.4%, 53/983). The most common infection (19.23%, 189/983) was Ascaris lumbricoides, whereas taeniasis carriers comprised 2.8% (28/983). Multiplex PCR of Cox1 was used for species identification of Taenia tapeworms, eggs, or both in 22 taeniasis carriers. Most of the parasites (20 cases) were Taenia solium, with two cases of Taenia saginata. Taenia saginata asiatica was not found in the villagers examined. The analysis of 314 completed questionnaires showed that a statistically significant (p < 0.05) risk of taeniasis was correlated with being male, a history of being allowed to forage during childhood, a history of seeing tapeworm proglottids, and a history of raw or undercooked pork consumption. Health education programmes must seek to reduce and prevent reinfection in these communities.

TITLE: Facteurs de risque et prévalence de la téniase chez les Karens du district de Tha Song Yang, province de Tak, Thaïlande. ABSTRACT: La téniase reste un problème de santé publique répandu en Thaïlande. Les enquêtes nationales sur les helminthiases ne rapportent que l'incidence des œufs de Taenia spp. La capacité de différencier les espèces de Taenia à l'aide de techniques morphologiques et moléculaires est vitale pour les enquêtes épidémiologiques. Cette étude a détecté des porteurs de téniase et d'autres infections helminthiques par la technique de frottis épais de Kato et a identifié les espèces de Taenia par PCR multiplex. Les sujets de l'étude étaient les Karens du district de Tha Song Yang, province de Tak, Thaïlande, à la frontière du Myanmar. Au total, 983 échantillons de matières fécales provenant de villageois ont été examinés pour les helminthiases. Des questionnaires basés sur des entretiens ont été utilisés pour recueillir des informations sur les facteurs de risque possibles d'infection. La prévalence des helminthes était de 42,7 % (420/983), dont des infections uniques (37,3 %, 367/983) et mixtes (5,4 %, 53/983). L'infection la plus courante (19,23 %, 189/983) était Ascaris lumbricoides, tandis que les porteurs de téniase représentaient 2,8 % (28/983). La PCR multiplexe de Cox1 a été utilisée pour l'identification des adultes ou des oeufs de Taenia, ou des deux, chez 22 porteurs de téniase. La plupart des parasites (20 cas) étaient Taenia solium, avec deux cas de Taenia saginata. Taenia saginata asiatica n'a pas été trouvé chez les villageois examinés. L'analyse de 314 questionnaires a montré qu'un risque statistiquement significatif (p < 0,05) de téniase était en corrélation avec le fait d'être un homme, et des antécédents d'avoir été autorisé à ramasser sa nourriture pendant l'enfance, d'avoir vu des proglottis de ténia et de consommation de porc cru ou insuffisamment cuit. Les programmes d'éducation sanitaire doivent chercher à réduire et à prévenir la réinfection dans ces communautés.

Intestinal parasites in rural communities in Nan Province, Thailand: changes in bacterial gut microbiota associated with minute intestinal fluke infection.

Gastrointestinal helminth infection likely affects the gut microbiome, in turn affecting host health. To investigate the effect of intestinal parasite status on the gut microbiome, parasitic infection surveys were conducted in communities in Nan Province, Thailand. In total, 1047 participants submitted stool samples for intestinal parasite examination, and 391 parasite-positive cases were identified, equating to an infection prevalence of 37.3%. Intestinal protozoan species were less prevalent (4.6%) than helminth species. The most prevalent parasite was the minute intestinal fluke Haplorchis taichui (35.9%). Amplicon sequencing of 16S rRNA was conducted to investigate the gut microbiome profiles of H. taichui-infected participants compared with those of parasite-free participants. Prevotella copri was the dominant bacterial operational taxonomic unit (OTU) in the study population. The relative abundance of three bacterial taxa, Ruminococcus, Roseburia faecis and Veillonella parvula, was significantly increased in the H. taichui-infected group. Parasite-negative group had higher bacterial diversity (α diversity) than the H. taichui-positive group. In addition, a significant difference in bacterial community composition (ß diversity) was found between the two groups. The results suggest that H. taichui infection impacts the gut microbiome profile by reducing bacterial diversity and altering bacterial community structure in the gastrointestinal tract.

Asymptomatic Human Paragonimiasis among the Karen People in Tak Province, Thailand: A Case Report.

During the mobile clinic activities in Tak Province, Thailand, Paragonimus sp. eggs were found in a fecal sample of a 72-year-old Karen resident. Paragonimus DNA was amplified from the stool sample and identified to P. heterotremus. The patient did not have any symptoms. Apparent pulmonary lesion was not found on the chest X-ray. The patient admitted habitual consumption of semi-cooked or roasted waterfall crabs for several years. The waterfall crabs collected from stream near the village were found negative for Paragonimus metacercariae. In northern Thailand, paragonimiasis remains as one of the public health concerns and should be ruled out for asymptomatic pulmonary patients.

"Enterocytozoon bieneusi and Cryptosporidium: a cross-sectional study conducted throughout Thailand".

BACKGROUND: Enterocytozoon bieneusi and Cryptosporidium spp. are prevalent zoonotic parasites associated with a high burden among children. To date only limited molecular epidemiological data on E. bieneusi and Cryptosporidium spp. in humans living in Thailand has been published. METHODS: PCR-based tools were used to detect and characterize E. bieneusi and Cryptosporidium spp. The internal transcribed spacer (ITS) region of the rRNA gene was used to investigate E. bieneusi, and the small subunit (SSU) rRNA gene was used to investigate Cryptosporidium spp., and 697 fecal samples from villagers and school children in rural areas in Thailand were analyzed. RESULTS: The infection rates were 2.15% (15/697) for E. bieneusi and 0.14% (1/697) for Cryptosporidium spp. The prevalence of E. bieneusi was significantly high in Loei province. Sequence analysis indicated that the Cryptosporidium isolate was C. parvum. Nine E. bieneusi genotypes were identified, EbpC, Peru12, TMH6, TMH3, TMH7, H, D, and two novel genotypes TMLH1 and TMLH2. E. bieneusi prevalence was significantly higher in male participants than in female participants, and in children aged 3-15 years than in participants aged > 15 years. CONCLUSIONS: The prevalence, genotypes, and zoonotic potential of E. bieneusi were found to vary significantly high even in one country. Transmission routes and key animal carriers of E. bieneusi may be associated with differences in hygiene, sanitation, and cultural behaviors. Further molecular studies including longitudinal studies will be required to unveil epidemiological characteristics of these opportunistic intestinal protozoa in all over the countries.

Traveler's Diarrhea in Foreign Travelers in Southeast Asia: A Cross-Sectional Survey Study in Bangkok, Thailand.

The effect of origin and destination country on traveler's diarrhea incidence rates in Southeast Asia is poorly understood, and research generally only addresses diarrhea in travelers from the developed world. This study evaluated the attack rate and effects of traveler's diarrhea by origin and destination and analyzed key risk factors. A self-administered questionnaire was provided to foreign travelers departing Southeast Asia from Suvarnabhumi Airport, Bangkok, Thailand. It evaluated traveler demographics, relevant knowledge and practices, experiences of diarrhea, and the details and consequences of each diarrheal episode. A total of 7,963 questionnaires were completed between April 2010 and July 2011. Respondents were 56% male (mean age 35) with a mean and median duration of stay of 28 days and 10 days, respectively. Most respondents were from Europe (36.8%) or East Asia (33.4%). The attack rate of traveler's diarrhea was 16.1%, with an incidence rate of 32.05 per 100 person months. Travelers' origin and destination countries significantly related to diarrhea risk. Oceanians had the highest risk (32.9%) and East Asians the lowest (2.6%). Vietnam and Indonesia were the highest risk destinations (19.3%). Other significant factors were youth, trip duration, number of countries visited, and frequently drinking beverages with ice.

Subtype distribution of Blastocystis in Thai-Myanmar border, Thailand.

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.

Wide dissemination of extended-spectrum ß-lactamase-producing Escherichia coli in community residents in the Indochinese peninsula.

Recent studies have reported a widespread distribution of extended-spectrum ß-lactamase (ESBL)-producing bacteria, not only in the nosocomial setting, but also in the community; some local communities in Southeast Asia have been reported to show a high prevalence of ESBL-producing bacteria. However, the details regarding the quantitative/qualitative state of ESBL-producing bacterial spread in Southeast Asia are currently unclear. Thus, the aim of this study was to assess the state of ESBL-producing bacterial spread in community residents from the Indochinese peninsula, as a representative region of Southeast Asia. In order to achieve this aim, local community residents in Laos and Vietnam were examined for fecal carriage of ESBL-producing Enterobacteriaceae, and the findings were compared with data from a previous study in Thailand which was conducted in the same manner as this study. Between 47.0%-70.2% of the Laotian and Vietnamese residents carried ESBL-producing CTX-M genotype Enterobacteriaceae. The most common sub-genotypes of CTX-M were CTX-M-1 (33.0%-47.5%) and CTX-M-9 (47.5%-64.1%), and these rates were similar among all three countries. Taken together, these results confirmed that ESBL-producing Enterobacteriaceae are widely disseminated in Indochinese countries, such as Thailand, Laos, and Vietnam.

Gastrointestinal parasites of dogs and cats in a refuge in Nakhon Nayok, Thailand.

We collected fecal samples from 500 dogs and 300 cats from an animal refuge in Nakhon Nayok Province, Thailand to test for gastrointestinal protozoa and helminths using a formalin-ether concentration technique. The overall prevalence of parasites in stool from dogs was 36.2% (181/500), 35.7% (177/500) had helminths and 2.8% (14/500) had protozoa. The helminths were: hookworm (30.6%), Trichuris vulpis (16.0%), Toxocara canis (6.6%), Hymenolepis diminuta (1.2%), Spirometra mansoni (0.6%), and Dipylidium caninum (0.2%). Giardia duodenalis (2.8%) was found in the stool of dogs. The overall prevalence of parasites in stool from cats was 44.3% (133/300), 43.3% (130/300) were helminths and 6.0% (18/300) were protozoa. The helminths were hookworm (34.7%), T. cati (9.7%), S. mansoni (4.0%), Platynosomum fastosum (2.7%), Strongyloides sp (0.7%), and Echinostoma sp (0.3%). Two species of protozoa, Isospora sp (5.7%) and G. duodenalis (0.3%) were found in the stool of cats. Two percent of dogs and 5.0% of cats had mixed protozoan and helminthic infections. Dogs with double, triple, and quadruple helminthic infections were found at rates of 22.0%, 2.8%, and 0.2%, respectively. Cats with double and triple helminthic infections were found at rates of 9.7% and 1.0%, respectively. Quadruple helminthic infections were not found in cats, and double protozoan infections were not found in either dogs or cats.

Genetic Variation and Population Genetics of Taenia saginata in North and Northeast Thailand in relation to Taenia asiatica.

Taenia saginata is the most common human Taenia in Thailand. By cox1 sequences, 73 isolates from four localities in north and northeast were differentiated into 14 haplotypes, 11 variation sites and haplotype diversity of 0.683. Among 14 haplotypes, haplotype A was the major (52.1%), followed by haplotype B (21.9%). Clustering diagram of Thai and GenBank sequences indicated mixed phylogeny among localities. By MJ analysis, haplotype clustering relationships showed paired-stars-like network, having two main cores surrounded by minor haplotypes. Tajima's D values were significantly negative in T. saginata world population, suggesting population expansion. Significant Fu's F s values in Thai, as well as world population, also indicate that population is expanding and may be hitchhiking as part of selective sweep. Haplotype B and its dispersion were only found in populations from Thailand. Haplotype B may evolve and ultimately become an ancestor of future populations in Thailand. Haplotype A seems to be dispersion haplotype, not just in Thailand, but worldwide. High genetic T. saginata intraspecies divergence was found, in contrast to its sister species, T. asiatica; among 30 samples from seven countries, its haplotype diversity was 0.067, while only 2 haplotypes were revealed. This extremely low intraspecific variation suggests that T. asiatica could be an endangered species.

Non-encapsulated Trichinella spp., T. papuae, diminishes severity of DSS-induced colitis in mice.

BACKGROUND: Helminths use various mechanisms to avoid host immunity and protect themselves from being eliminated. Despite evading host immune responses, immunosuppression and regulation mechanisms elicit functions that diminish the adverse effects of unrelated inflammatory diseases. OBJECTIVE: We investigated whether helminthic infections can ameliorate inflammatory diseases. METHODS: Mice were infected with Trichinella papuae and then subjected to induced colitis through the oral administration of dextran sulfate sodium (DSS). Macroscopic and microscopic examinations measured weight loss, stool consistency, gross bleeding, colon length, and tissue inflammation. In addition, cytokine expression was observed in colon tissue by SYBR real-time RT-PCR to investigate the Th1, Th2, and regulatory cytokines. RESULT: The results showed that T. papuae infection decreased the severity of DSS-inducedcolitis, including weight loss, bloody diarrhea, shortening of colon, and colon tissue damage in mice (p <0.05). The expression level of IL-4 was high in the colons of DSS-treated mice without helminthic infection, while infected mice with DSS treatment had lower IL-4 levels (p <0.05). Uninfected DSS-treated mice failed to produce IL-10 mRNA in colon tissue, which may cause more severe colitis. In contrast, prior T. papuae infection DSS-treated mice had IL-10 levels in the colon significant lower than the normal and infected control groups. CONCLUSION: Our data provide the evidence that prior T. papuae infection can ameliorate DSS-induced colitis in mice and may be considered for a novel therapeutic strategy against immunological diseases in the future.

Human monoclonal antibodies to neutralize all dengue virus serotypes using lymphocytes from patients at acute phase of the secondary infection.

The global spread of the four dengue virus serotypes (DENV-1 to -4) has made this virus a major and growing public health concern. Generally, pre-existing neutralizing antibodies derived from primary infection play a significant role in protecting against subsequent infection with the same serotype. By contrast, these pre-existing antibodies are believed to mediate a non-protective response to subsequent heterotypic DENV infections, leading to the onset of dengue illness. In this study, we prepared hybridomas producing human monoclonal antibodies (HuMAbs) against DENV using peripheral blood mononuclear cells (PBMCs) from patients in the acute phase (around 1 week after the onset of illness) or the convalescent phase (around 2weeks after the onset of illness) of secondary infection. Interestingly, a larger number of hybridoma clones was obtained from patients in the acute phase than from those in the convalescent phase. Most HuMAbs from acute-phase infections were cross-reactive with all four DENV serotypes and showed significant neutralization activity to all four DENV serotypes. Thus, secondary DENV infection plays a significant role in stimulating memory cells to transiently increase the number of antibody-secreting plasma cells in patients in the early phase after the secondary infection. These HuMAbs will enable us to better understand the protective and pathogenic effects of DENV infection, which could vary greatly among secondarily-infected individuals.

Prevalence of and risk factors associated with faecal carriage of CTX-M ß-lactamase-producing Enterobacteriaceae in rural Thai communities.

OBJECTIVES: To determine the prevalence of CTX-M ß-lactamase-producing Enterobacteriaceae and to study the risk factors associated with faecal carriage in asymptomatic rural Thai people. METHODS: In all, 417 stool samples were obtained from rural Thai people and screened for extended-spectrum ß-lactamases (ESBLs) using MacConkey agar supplemented with 2 mg/L cefotaxime. Results were confirmed using cefotaxime and ceftazidime with and without clavulanic acid. The bla(CTX-M) genes were identified and genotyped using PCR with bacterial DNA samples. Multivariate analysis was performed to investigate risk factors associated with the faecal carriage of CTX-M producers. RESULTS: The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae was 65.7%. The CTX-M-9 group (60.6%) was dominant, followed by the CTX-M-1 group (38.7%). Most of the bacteria were Escherichia coli (85.4%) and Klebsiella pneumoniae (4.7%). Of a total of 234 E. coli strains, 48.7% belonged to phylogenetic group A, 28.6% to group B1, 15.8% to group D and 6.8% to group B2. Most CTX-M producers were susceptible to carbapenems and amikacin, but resistant to tetracycline and gentamicin. In a multivariate logistic regression model, better education status (OR 2.245; 95% CI 1.297-3.884), history of hospitalization (OR 1.643; 95% CI 1.036-2.603) and the use of antibiotics within the last 3 months (OR 1.883; 95% CI 1.221-2.903) were independently associated with faecal carriage. CONCLUSIONS: Faecal carriage of CTX-M-type ESBL-producing Enterobacteriaceae among asymptomatic individuals in rural Thailand remains alarmingly high, and previous antibiotic use and a history of hospitalization may contribute to its dissemination.

Awareness, practices, and health problems of backpackers traveling during flooding in Thailand during 2011.

During late 2011, Thailand experienced its worst flooding in 50 years with over 4.6 million people directly affected. During the flooding we conducted a cross sectional survey of backpackers in the Khao San Road area of Bangkok to determine awareness, practices, and their incidence of health problems during the flooding. A total of 422 subjects completed questionnaires which were analyzed. Seventy percent were European and 12.3% were North American. The overall median age was 27 years and the median stay in Thailand was 22 days. Most of the backpackers were aware of the flooding in Thailand; some had sought travel health information prior to their trip from various sources including the internet, their family physician or a travel clinic. However, even in travel clinics specific health advice related to flooding, such as leptospirosis risk/prevention, was rarely given to travelers. Fifteen point four percent of subjects (65/422) had come into contact with floodwater; 30.8% of those (20/65) washed their feet/legs afterward. Our findings indicate most backpackers were inadequately aware of potential health hazards, such as leptospirosis, during the floods.

The first workshop towards the control of cestode zoonoses in Asia and Africa.

The first workshop towards the control of cestode zoonoses in Asia and Africa was held in Asahikawa Medical University, Japan on 15 and 16 Feb 2011. This meeting was fully supported by the Asian Science and Technology Strategic Cooperation Promotion Programs sponsored by the Special Coordination Funds for Promoting Science and Technology, the Ministry of Education Japan (MEXT) for 3 years from 2010 to Akira Ito. A total of 24 researchers from 9 countries joined together and discussed the present situation and problems towards the control of cestode zoonoses. As the meeting was simultaneously for the establishment of joint international, either bilateral or multilateral collaboration projects, the main purposes were directed to 1) how to detect taeniasis/cysticercosis infected patients, 2) how to differentiate Taenia solium from two other human Taenia species, T. saginata and T. asiatica, 3) how to evaluate T. asiatica based on the evidence of hybrid and hybrid-derived adult tapeworms from Thailand and China, 4) how to evaluate T. solium and T. hyaenae and other Taenia species from the wild animals in Ethiopia, and 5) how to detect echinococcosis patients and 6) how to differentiate Echinococcus species worldwide. Such important topics are summarized in this meeting report.

Incidence and impact of travelers' diarrhea among foreign backpackers in Southeast Asia: a result from Khao San road, Bangkok.

BACKGROUND: Travelers' diarrhea is the most common disease reported among travelers visiting developing countries, including Southeast Asia, a region visited by large numbers of backpackers each year. Currently, the knowledge of travelers' diarrhea among this group is limited. This study aimed to determine the incidence and impact of travelers' diarrhea in this group. METHOD: Foreign backpackers in Khao San road, Bangkok, Thailand, were invited to fill out a study questionnaire, in which they were queried about their demographic background, travel characteristics, pretravel preparations and actual practices related to the risk of travelers' diarrhea. For backpackers who had experienced diarrhea, the details and impact of each diarrheal episode were also assessed. RESULTS: In the period April to May 2009, 404 completed questionnaires were collected and analyzed. Sixty percent of participants were male; overall, the median age was 26 years. Nearly all backpackers (96.8%) came from developed countries. Their main reason for travel was tourism (88%). The median stay was 30 days. More than half of the backpackers (56%) carried some antidiarrheal medication. Antimotility drugs were the most common medications carried by backpackers, followed by oral rehydration salts (ORS), and antibiotics. Their practices were far from ideal; 93.9% had bought food from street vendors, 92.5% had drunk beverages with ice-cubes, and 33.8% had eaten leftover food from a previous meal. In this study, 30.7% (124/404) of backpackers had experienced diarrhea during their trip. Most diarrhea cases (88%) were mild and recovered spontaneously. However, 8.8% of cases required a visit to a doctor, and 3.2% needed hospitalization. Longer duration of stay and drinking beverages with ice-cubes were associated with higher risk of diarrhea. CONCLUSIONS: About one third of the foreign backpackers in Southeast Asia had experienced diarrhea during their trip. Their current practices related to the risk of travelers' diarrhea were inadequate and should be improved.

Analysis of risk factors for a high prevalence of extended-spectrum {beta}-lactamase-producing Enterobacteriaceae in asymptomatic individuals in rural Thailand.

The prevalence of and risk factors associated with extended-spectrum ß-lactamase (ESBL)-producing micro-organisms have not been well studied in healthy individuals. The aim of this study was to determine this in healthy individuals in Thailand. Stool samples and questionnaires obtained from 445 participants from three provinces in Thailand were analysed. The antimicrobial susceptibility of the isolates was assessed using phenotypic and genotypic methods. PCR analysis was performed to detect and group the bla(CTX-M) genes. The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae in the three provinces was as follows: 29.3 % in Nan (43/147), 29.9 % in Nakhon Si Thammarat (43/144) and 50.6 % in Kanchanaburi (78/154) (P<0.001). Of the 445 samples, 33 (7.4 %), 1 (0.2 %) and 127 (28.5 %) isolates belonged to the bla(CTX-M) gene groups I, III and IV, respectively. Escherichia coli was the predominant member of the Enterobacteriaceae producing CTX-M-type ESBLs (40/43, 39/43 and 70/78 isolates in Nan, Nakhon Si Thammarat and Kanchanaburi, respectively). No statistically significant association was observed between the presence of ESBL-producing bacteria and gender, age, education, food habits or antibiotic usage. However, the provinces that had the highest prevalence of ESBL-producing Enterobacteriaceae also had the highest prevalence of use and purchase of antibiotics without a prescription. Thus, this study revealed that faecal carriage of ESBL-producing Enterobacteriaceae is very high in asymptomatic individuals in Thailand, with some variations among the provinces. This high prevalence may be linked to antibiotic abuse.

Abnormal Taenia saginata tapeworms in Thailand.

Sixty-eight residents of Ban Luang and Ban Pang Kae villages, in Nan Province, northern Thailand, visited our mobile field station in September 2006 and March 2007, seeking treatment for taeniasis. After treatment, 22 cases discharged tapeworm strobila in their fecal samples and 17 scolices were recovered. Among these, 3 were morphologically abnormal, with six suckers on the scolex. To confirm the species of these tapeworms, the mitochondrial cytochrome c oxidase subunit I (COI) gene was used as a molecular marker. The partial COI sequences (800 bp) of the abnormal tapeworms were identical to the sequences of Taenia saginata deposited in Genbank.