Schistosome infection among pregnant women in the rural highlands of Madagascar: A cross-sectional study calling for public health interventions in vulnerable populations.

INTRODUCTION: Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa (SSA) with Madagascar being among the countries with highest burden of the disease worldwide. Despite WHO recommendations, suggesting treatment of pregnant women after the first trimester, this group is still excluded from Mass Drug Administration programs. Our study, had the objective to measure the prevalence of schistosome infection among pregnant women in Madagascar in order to inform public health policies for treatment in this vulnerable population. METHODS: Women were recruited for this cross-sectional study between April 2019 and February 2020 when attending Antenatal Care Services (ANCs) at one of 42 included Primary Health Care Centers. The urine-based upconverting reporter particle, lateral flow (UCP-LF) test detecting circulating anodic antigen was used for the detection of schistosome infections. To identify factors associated with the prevalence of schistosome infection crude and adjusted prevalence ratios and 95% CIs were estimated using mixed-effect Poisson regression. RESULTS: Among 4,448 participating women aged between 16 and 47 years, the majority (70.4%, 38 n = 3,133) resided in rural settings. Overall, the prevalence of schistosome infection was 55.9% (n = 2486, CI 95%: 53.3-58.5). A statistically significant association was found with age group (increased prevalence in 31-47 years old, compared to 16-20 years old (aPR = 1.15, CI 95%: 1.02-1.29) and with uptake of antimalaria preventive treatment (decreased prevalence, aPR = 0.85, CI 95%: 0.77-0.95). No other associations of any personal characteristics or contextual factors with schistosome infection were found in our multivariate regression analysis. DISCUSSION AND CONCLUSION: The high prevalence of schistosome infection in pregnant women supports the consideration of preventive schistosomiasis treatment in ANCs of the Malagasy highlands. We strongly advocate for adapting schistosomiasis programs in highly endemic contexts. This, would contribute to both the WHO and SDGs agendas overall to improving the well-being of women and consequently breaking the vicious cycle of poverty perpetuated by schistosomiasis.

Health Communication and Behavioral Change During the COVID-19 Pandemic.

The COVID-19 pandemic challenged the public health system to respond to an emerging, difficult-to-understand pathogen through demanding behaviors, including staying at home, masking for long periods, and vaccinating multiple times. We discuss key challenges of the pandemic health communication efforts deployed in the United States from 2020 to 2022 and identify research priorities. One priority is communicating about uncertainty in ways that prepare the public for disagreement and likely changes in recommendations as scientific understanding advances: How can changes in understanding and recommendations foster a sense that "science works as intended" rather than "the experts are clueless" and prevent creating a void to be filled by misinformation? A second priority concerns creating a culturally fluent framework for asking people to engage in difficult and novel actions: How can health messages foster the perception that difficulties of behavior change signal that the change is important rather than that the change "is not for people like me?" A third priority entails a shift from communication strategies that focus on knowledge and attitudes to interventions that focus on norms, policy, communication about policy, and channel factors that impair behavior change: How can we move beyond educating and correcting misinformation to achieving desired actions?

Misinformed by images: How images influence perceptions of truth and what can be done about it.

We organize image types by their substantive relationship with textual claims and discuss their impact on attention, comprehension, memory, and judgment. Photos do not need to be false (altered or generated) to mislead; real photos can create a slanted representation or be repurposed from different events. Even semantically related non-probative photos, merely inserted to attract eyeballs, can increase message acceptance through increased fluency. Messages with images receive more attention and reach a wider audience. Text-congruent images can scaffold the comprehension of true and false claims and support the formation of correct and false memories. Standard laboratory procedures may underestimate the impact of images in natural media contexts: by drawing all participants' attention to a message that may be ignored without an image, they inflate message effects in the control condition. Misleading images are difficult to identify and their influence often remains outside of awareness, making it hard to curb their influence through critical-thinking interventions. Current concerns about deep fakes may reduce trust in all images, potentially limiting their power to mislead as well as inform. More research is needed to understand how knowing that an image is misleading influences inferences, impressions, and judgments beyond immediate assessments of the image's credibility.

What makes narratives feel right? The role of metacognitive experiences.

Conviction Narrative Theory holds that reasoners adopt "a narrative that feels 'right' to explain the available data" and use "that narrative to imagine plausible futures" (target article, Abstract). Drawing on feelings-as-information theory, this commentary reviews the role of metacognitive experiences of ease or difficulty and highlights that fluently processed narratives are more likely to "feel right."

The paucity of morality in everyday talk.

Given its centrality in scholarly and popular discourse, morality should be expected to figure prominently in everyday talk. We test this expectation by examining the frequency of moral content in three contexts, using three methods: (a) Participants' subjective frequency estimates (N = 581); (b) Human content analysis of unobtrusively recorded in-person interactions (N = 542 participants; n = 50,961 observations); and (c) Computational content analysis of Facebook posts (N = 3822 participants; n = 111,886 observations). In their self-reports, participants estimated that 21.5% of their interactions touched on morality (Study 1), but objectively, only 4.7% of recorded conversational samples (Study 2) and 2.2% of Facebook posts (Study 3) contained moral content. Collectively, these findings suggest that morality may be far less prominent in everyday life than scholarly and popular discourse, and laypeople, presume.

Prevalence and risk distribution of schistosomiasis among adults in Madagascar: a cross-sectional study.

BACKGROUND: The goal to eliminate the parasitic disease of poverty schistosomiasis as a public health problem is aligned with the 2030 United Nations agenda for sustainable development goals, including universal health coverage (UHC). Current control strategies focus on school-aged children, systematically neglecting adults. We aimed at providing evidence for the need of shifting the paradigm of schistosomiasis control programs from targeted to generalized approaches as key element for both the elimination of schistosomiasis as a public health problem and the promotion of UHC. METHODS: In a cross-sectional study performed between March 2020 and January 2021 at three primary health care centers in Andina, Tsiroanomandidy and Ankazomborona in Madagascar, we determined prevalence and risk factors for schistosomiasis by a semi-quantitative PCR assay from specimens collected from 1482 adult participants. Univariable and multivariable logistic regression were performed to evaluate odd ratios. RESULTS: The highest prevalence of S. mansoni, S. haematobium and co-infection of both species was 59.5%, 61.3% and 3.3%, in Andina and Ankazomborona respectively. Higher prevalence was observed among males (52.4%) and main contributors to the family income (68.1%). Not working as a farmer and higher age were found to be protective factors for infection. CONCLUSIONS: Our findings provide evidence that adults are a high-risk group for schistosomiasis. Our data suggests that, for ensuring basic health as a human right, current public health strategies for schistosomiasis prevention and control need to be re-addressed towards more context specific, holistic and integrated approaches.

The Gut Microbiome of an Indigenous Agropastoralist Population in a Remote Area of Colombia with High Rates of Gastrointestinal Infections and Dysbiosis.

An Indigenous agropastoralist population called the Wiwa from the Sierra Nevada de Santa Marta, in North-East Colombia, shows high rates of gastrointestinal infections. Chronic gut inflammatory processes and dysbiosis could be a reason, suggesting an influence or predisposing potential of the gut microbiome composition. The latter was analyzed by 16S rRNA gene amplicon next generation sequencing from stool samples. Results of the Wiwa population microbiomes were associated with available epidemiological and morphometric data and compared to control samples from a local urban population. Indeed, locational-, age-, and gender-specific differences in the Firmicutes/Bacteriodetes ratio, core microbiome, and overall genera-level microbiome composition were shown. Alpha- and ß-diversity separated the urban site from the Indigenous locations. Urban microbiomes were dominated by Bacteriodetes, whereas Indigenous samples revealed a four times higher abundance of Proteobacteria. Even differences among the two Indigenous villages were noted. PICRUSt analysis identified several enriched location-specific bacterial pathways. Moreover, on a general comparative scale and with a high predictive accuracy, we found Sutterella associated with the abundance of enterohemorrhagic Escherichia coli (EHEC), Faecalibacteria associated with enteropathogenic Escherichia coli (EPEC) and helminth species Hymenolepsis nana and Enterobius vermicularis. Parabacteroides, Prevotella, and Butyrivibrio are enriched in cases of salmonellosis, EPEC, and helminth infections. Presence of Dialister was associated with gastrointestinal symptoms, whereas Clostridia were exclusively found in children under the age of 5 years. Odoribacter and Parabacteroides were exclusively identified in the microbiomes of the urban population of Valledupar. In summary, dysbiotic alterations in the gut microbiome in the Indigenous population with frequent episodes of self-reported gastrointestinal infections were confirmed with epidemiological and pathogen-specific associations. Our data provide strong hints of microbiome alterations associated with the clinical conditions of the Indigenous population.

Close to the same: Similarity influences remembered distance between stimuli.

Six preregistered studies show that the degree of similarity of two objects biases people's spatial memory of these objects. When objects are high in similarity, people remember having seen them closer together in space than when they are low in similarity. All six studies provide correlational evidence, showing that the more similar participants rated two stimuli, the smaller they remembered the distance between them. This was true for both conceptual and perceptual similarity (Study 3). Furthermore, Studies 2, 4A, and 4B provide evidence of causality by manipulating similarity experimentally. Replicating the correlational findings, highly similar stimuli were remembered as closer together than stimuli low in similarity. This pattern was found across different stimulus categories and similarity dimensions. Overall, these findings show that the similarity of stimuli influences perceivers' reconstruction of their spatial locations.

Prevalence and Molecular Characterization of Mycobacterium bovis in Slaughtered Cattle Carcasses in Burkina Faso; West Africa.

This cross-sectional study was conducted at the slaughterhouses/slabs of Oudalan and Ouagadougou in Burkina Faso, between August and September 2013. It aimed at determining the prevalence of bovine tuberculosis (bTB) suggestive lesions in slaughtered cattle carcasses and to identify and characterize the mycobacteria isolated from these lesions. A thorough postmortem examination was conducted on carcasses of a total of 2165 randomly selected cattle. The overall prevalence of bTB suggestive lesions was 2.7% (58/2165; 95% CI 2.1-3.5%). Due to the low number of positive samples, data were descriptively presented. The lesions were either observed localized in one or a few organs or generalized (i.e., miliary bTB) in 96.6% (n = 57) and 3.4% (n = 2), respectively. The identified mycobacteria were M. bovis (44.4%, n = 20), M. fortuitum (8.9%, n = 4), M. elephantis (6.7%, n = 3), M. brumae (4.4%, n = 2), M. avium (2.2%, n = 1), M. asiaticum (2.2%, n = 1), M. terrae (2.2%, n = 1), and unknown non-tuberculous mycobacteria (NTM) (11.1%, n = 5). Moreover, eight mixed cultures with more than one Mycobacterium species growing were also observed, of which three were M. bovis and M. fortuitum and three were M. bovis and M. elephantis. In conclusion, M. bovis is the predominant causative agent of mycobacterial infections in the study area. Our study has identified a base to broaden the epidemiological knowledge on zoonotic transmission of mycobacteria in Burkina Faso by future studies investigating further samples from humans and animals, including wild animals employing molecular techniques.

Implicit Bias Reflects the Company That Words Keep.

In everyday language, concepts appear alongside (i.e., collocate with) related concepts. Societal biases often emerge in these collocations; e.g., female (vs. male) names collocate with art- (vs. science-) related concepts, and African American (vs. White American) names collocate with negative (vs. positive) concepts. It is unknown whether such collocations merely reflect societal biases or contribute to them. Concepts that are themselves neutral in valence but nevertheless collocate with valenced concepts provide a unique opportunity to address this question. For example, when asked, most people evaluate the concept "cause" as neutral, but "cause" is frequently followed by negative concepts (e.g., death, pain, and trouble). We use such semantically prosodic concepts to test the influence of collocation on the emergence of implicit bias: do neutral concepts that frequently collocate with valenced concepts have corresponding implicit bias? In evaluative priming tasks, participants evaluated positive/negative nouns (Study 1) or pictures (Study 2) after seeing verb primes that were (a) strongly valenced (e.g., hate and comfort), (b) neutral in valence but collocated with valenced concepts in corpora (e.g., ease and gain), or (c) neutral in valence and not collocated with valenced concepts in corpora (e.g., reply and describe). Throughout, neutral primes with positive (negative) collocates facilitated the evaluation of positive (negative) targets much like strongly valenced primes, whereas neutral primes without valenced collocates did not. That neutral concepts with valenced collocates parallel the influence of valenced concepts suggests that their collocations in natural language may be sufficient for fostering implicit bias. Societal implications of the causal embedding hypothesis are discussed.

Sound and credibility in the virtual court: Low audio quality leads to less favorable evaluations of witnesses and lower weighting of evidence.

OBJECTIVES: Recent virtual court proceedings have seen a range of technological challenges, producing not only trial interruptions but also cognitive interruptions in processing evidence. Very little empirical research has focused on how the subjective experience of processing evidence affects evaluations of trial participants and trial decisions. Metacognitive research shows that the subjective ease or difficulty of processing information can affect evaluations of people, belief in information, and how a given piece of information is weighted in decision making. HYPOTHESES: We hypothesized that when people experienced technological challenges (e.g., poor audio quality) while listening to eyewitness accounts, the difficulty in processing evidence would lead them to evaluate a witness more negatively, influence their memory for key facts, and lead them to weigh that evidence less in final trial judgments. METHOD: Across three experiments (total N = 593), participants listened to audio clips of witnesses describing an event, one presented in high-quality audio and one presented in low-quality audio. RESULTS: When people heard witnesses present evidence in low-quality audio, they rated the witnesses as less credible, reliable, and trustworthy (Experiment 1, d = 0.32; Experiment 3, d = 0.55); had poorer memory for key facts presented by the witness (Experiment 2, d = 0.44); and weighted witness evidence less in final guilt judgments (Experiment 3, ηp² = .05). CONCLUSION: These results show that audio quality influences perceptions of witnesses and their evidence. Because these variables can contribute to trial outcomes, audio quality warrants consideration in trial proceedings. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A cluster randomized controlled trial for assessing POC-CCA test based praziquantel treatment for schistosomiasis control in pregnant women and their young children: study protocol of the freeBILy clinical trial in Madagascar.

BACKGROUND: Mass drug administration (MDA) of praziquantel is one of the main control measures against human schistosomiasis. Although there are claims for including pregnant women, infants and children under the age of 5 years in high-endemic regions in MDA campaigns, they are usually not treated without a diagnosis. Diagnostic tools identifying infections at the primary health care centre (PHCC) level could therefore help to integrate these vulnerable groups into control programmes. freeBILy (fast and reliable easy-to-use-diagnostics for eliminating bilharzia in young children and mothers) is an international consortium focused on implementing and evaluating new schistosomiasis diagnostic strategies. In Madagascar, the study aims to determine the effectiveness of a test-based schistosomiasis treatment (TBST) strategy for pregnant women and their infants and children up until the age of 2 years. METHODS: A two-armed, cluster-randomized, controlled phase III trial including 5200 women and their offspring assesses the impact of TBST on child growth and maternal haemoglobin in areas of medium to high endemicity of Schistosoma mansoni. The participants are being tested with the point of care-circulating cathodic antigen (POC-CCA) test, a commercially available urine-based non-invasive rapid diagnostic test for schistosomiasis. In the intervention arm, a POC-CCA-TBST strategy is offered to women during pregnancy and 9 months after delivery, for their infants at 9 months of age. In the control arm, study visit procedures are the same, but without the POC-CCA-TBST procedure. All participants are being offered the POC-CCA-TBST 24 months after delivery. This trial is being integrated into the routine maternal and child primary health care programmes at 40 different PHCC in Madagascar's highlands. The purpose of the trial is to assess the effectiveness of the POC-CCA-TBST for controlling schistosomiasis in young children and mothers. DISCUSSION: This trial assesses a strategy to integrate pregnant women and their children under the age of 2 years into schistosomiasis control programmes using rapid diagnostic tests. It includes local capacity building for clinical trials and large-scale intervention research. TRIAL REGISTRATION: Pan-African Clinical Trial Register PACTR201905784271304. Retrospectively registered on 15 May 2019.

Molecular Evidence for Flea-Borne Rickettsiosis in Febrile Patients from Madagascar.

Rickettsiae may cause febrile infections in humans in tropical and subtropical regions. From Madagascar, no molecular data on the role of rickettsioses in febrile patients are available. Blood samples from patients presenting with fever in the area of the capital Antananarivo were screened for the presence of rickettsial DNA. EDTA (ethylenediaminetetraacetic acid) blood from 1020 patients presenting with pyrexia > 38.5 °C was analyzed by gltA-specific qPCR. Positive samples were confirmed by ompB-specific qPCR. From confirmed samples, the gltA amplicons were sequenced and subjected to phylogenetic analysis. From five gltA-reactive samples, two were confirmed by ompB-specific qPCR. The gltA sequence in the sample taken from a 38-year-old female showed 100% homology with R. typhi. The other sample taken from a 1.5-year-old infant was 100% homologous to R. felis. Tick-borne rickettsiae were not identified. The overall rate of febrile patients with molecular evidence for a rickettsial infection from the Madagascan study site was 0.2% (2/1020 patients). Flea-borne rickettsiosis is a rare but neglected cause of infection in Madagascar. Accurate diagnosis may prompt adequate antimicrobial treatment.

Serology- and Blood-PCR-Based Screening for Schistosomiasis in Pregnant Women in Madagascar-A Cross-Sectional Study and Test Comparison Approach.

This work was conducted as a cross sectional study to define the disease burden of schistosomiasis in pregnant Madagascan women and to evaluate serological and molecular diagnostic assays. A total of 1154 residual EDTA blood samples from pregnant Madagascan women were assessed. The nucleic acid extractions were subjected to in-house real-time PCRs specifically targeting S. mansoni complex, S. haematobium complex, and African Schistosoma spp. on genus level, while the EDTA plasma samples were analyzed using Schistosoma-specific IgG and IgM commercial ELISA and immunofluorescence assays. The analyses indicated an overall prevalence of schistosomiasis in Madagascan pregnant women of 40.4%, with only minor regional differences and differences between serology- and blood PCR-based surveillance. The S. mansoni specific real-time PCR showed superior sensitivity of 74% (specificity 80%) compared with the genus-specific real-time PCR (sensitivity 13%, specificity 100%) in blood. The laborious immunofluorescence (sensitivity IgM 49%, IgG 87%, specificity IgM 85%, IgG 96%) scored only slightly better than the automatable ELISA (sensitivity IgM 38%, IgG 88%, specificity IgM 78%, IgG 91%). Infections with S. mansoni were detected only. The high prevalence of schistosomiasis recorded here among pregnant women in Madagascar calls for actions in order to reduce the disease burden.

Global Reports of Well-Being Overestimate Aggregated Daily States of Well-Being.

Researchers can characterize people's well-being by asking them to provide global evaluations of large parts of their life at one time or by obtaining repeated assessments during their daily lives. Global evaluations are reconstructions that are influenced by peak, recent, and frequently occurring states, whereas daily reports reflect naturally occurring variations in daily life. The present research compared the averages of individual global evaluations and corresponding aggregated daily states from an ordinary two-week period and used a range of well-being measures (life satisfaction, meaning in life, and affect) and related constructs (searching for meaning in life and nostalgia). Across all measures, global reports were significantly higher than aggregated daily states. That is, life is considered more satisfying, more meaningful, and is characterized to a greater extent by more intense positive and negative emotions when reflecting on life in general than when reflecting on daily life in real time.

Grounded procedures in mind and society.

Our commentators explore the operation of grounded procedures across all levels of analysis in the behavioral sciences, from mental to social, developmental, and evolutionary/functional. Building on them, we offer two integrative principles for systematic effects of grounded procedures to occur. We discuss theoretical topics at each level of analysis, address methodological recommendations, and highlight further extensions of grounded procedures.

"That's bitter!": Culture-specific effects of gustatory experience on judgments of fairness and advancement.

[Retraction notice: A retraction for this article was reported in Vol 150(6) of Journal of Experimental Psychology: General (see record 2021-94347-001). The following article is being retracted: Xu, J., Wan, F., & Schwarz, N. (2020, October 29). "That's bitter!": Culture-specific effects of gustatory experience on judgments of fairness and advancement. Journal of Experimental Psychology: General. Advance online publication. http://dx.doi.org/10 .1037/xge0000985 A user of the open science data sets accompanying the article noticed confounds between culture condition or treatment condition and sex of participants in studies 3, 4, and 5. What caused these confounds could not be fully reconstructed. The first and second authors, who handled data collection, assume that the confounds resulted from a confluence of two decisions. First, students were recruited through campus advertisements and encouraged to bring friends, which resulted in the arrival of mostly same-sex groups. Second, in deviation from standard protocol, the administration of the taste tests was simplified in these studies by administering the same treatment to all participants who arrived together. Hence, the authors asked for a retraction.....] In English, unfair treatment and social injustice are often described as "bitter" experiences, whereas "eating bitterness" refers to endurance in the face of hardship in Chinese. This suggests that bitter taste may ground experiences of adversity in both cultures, but in culture-specific forms. We tested this possibility by assessing Canadian and Chinese participants' responses to fairness and achievement scenarios after incidental exposure to bitter or neutral tastes. Tasting something bitter increased self-reported motivation and intention to invest effort for Chinese participants, but not Anglo-Canadian participants (Studies 1, 4, 5). Tasting something bitter decreased perceived fairness for Anglo-Canadian participants (Studies 1-3) but not Chinese participants living in China (Study 2). The fairness judgments of Chinese participants living in Canada shed light on adaptation to the host culture: Bitter taste decreased these participants' fairness judgments after living in Canada for 4 years or more (Study 4), provided they were tested in English (Studies 3-4), but exerted no influence when they were tested in Chinese (Study 4). The observed cultural differences are compatible with a relatively higher emphasis on self-improvement in China versus self-enhancement in Canada. Supporting this conjecture, the fairness judgments of Chinese students in Canada followed the Anglo-Canadian pattern when primed with a self-enhancement motive and the effort judgments of Anglo-Canadian students followed the Chinese pattern when primed with a self-improvement motive (Study 5). This suggest that a universal aversive experience (bitter taste) grounds thought about adversity in ways compatible with cultural orientations and reflected in culture-specific metaphors. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Prospective, observational study to assess the performance of CAA measurement as a diagnostic tool for the detection of Schistosoma haematobium infections in pregnant women and their child in Lambaréné, Gabon: study protocol of the freeBILy clinical trial in Gabon.

BACKGROUND: Schistosoma antigen detection in urine is a valuable diagnostic approach for schistosomiasis control programmes because of the higher sensitivity compared to parasitological methods and preferred sampling of urine over stool. Highly accurate diagnostics are important in low Schistosoma transmission areas. Pregnant women and young children could particularly benefit from antigen testing as praziquantel (PZQ) can be given to only confirmed Schistosoma cases. This prevents the unborn baby from unnecessary exposure to PZQ. We present here the protocol of a diagnostic study that forms part of the freeBILy project. The aim is to evaluate the accuracy of circulating anodic antigen (CAA) detection for diagnosis of Schistosoma haematobium infections in pregnant women and to validate CAA as an endpoint measure for anti-Schistosoma drug efficacy. The study will also investigate Schistosoma infections in infants. METHODS: A set of three interlinked prospective, observational studies is conducted in Gabon. The upconverting phosphor lateral flow (UCP-LF) CAA test is the index diagnostic test that will be evaluated. The core trial, sub-study A, comprehensively evaluates the accuracy of the UCP-LF CAA urine test against a set of other Schistosoma diagnostics in a cross-sectional trial design. Women positive for S. haematobium will proceed with sub-study B and will be randomised to receive PZQ treatment immediately or after delivery followed by weekly sample collection. This approach includes comparative monitoring of CAA levels following PZQ intake and will also contribute further data for safety of PZQ administration during pregnancy. Sub-study C is a longitudinal study to determine the incidence of S. haematobium infection as well as the age for first infection in life-time. DISCUSSION: The freeBILy trial in Gabon will generate a comprehensive set of data on the accuracy of the UCP-LF CAA test for the detection of S. haematobium infection in pregnant women and newborn babies and for the use of CAA as a marker to determine PZQ efficacy. Furthermore, incidence of Schistosoma infection in infants will be reported. Using the ultrasensitive diagnostics, this information will be highly relevant for Schistosoma prevalence monitoring by national control programs as well as for the development of medicaments and vaccines. TRIAL REGISTRATION: The registration number of this study is NCT03779347 ( clinicaltrials.gov , date of registration: 19 December 2018).

Surveillance of enteropathogenic bacteria, protozoa and helminths in travellers returning from the tropics.

Diarrhoea is a frequent symptom associated with travelling to tropical regions, but the cause is often not found. Epidemiology was assessed including up-to-date real-time PCR approaches.We analysed datasets of 528 patients who presented at the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, between 2006 and 2010 for screening purposes or because of diarrhoea. Stool samples were obtained and investigated by microscopy, bacterial culture, two PCR assays targeting Entamoeba histolytica, Entamoeba dispar, Giardia duodenalis, and Cryptosporidium parvum, or Salmonella spp., Shigella/EIEC spp., Campylobacter jejuni, and Yersinia spp.Among patients with gastrointestinal symptoms, 51% tested positive for bacteria or parasites, of which 66% had a known enteropathogenic potential. In patients without diarrhoea, 53% (n = 80) were positive, and 33% of these cases harboured agents of pathogenic potential. Association with clinical symptoms was primarily found for bacterial infections. Blastocystis hominis, however, was more frequent in asymptomatic than in symptomatic travellers.In conclusion, the study stresses the etiological relevance of bacterial gastroenteritis in travellers returning from the tropics, the need for molecular approaches to increase diagnostic sensitivity and demonstrates that asymptomatic carriage of enteropathogens after prolonged stays in the tropics is similarly frequent compared with symptomatic infections in travellers.