The effect of changing diagnostic method from culture to PCR on the number of episodes of human campylobacteriosis in Denmark: a retrospective study (2015-2022).

IMPORTANCE: This study is important because it shows the potential epidemiological silence associated with the use of culture as the primary diagnostic method for the laboratory identification of human campylobacteriosis. Also, we show how polymerase chain reaction methods are associated with a systematic increase in the number of human campylobacteriosis episodes as reported by routine disease surveillance. These findings are operationally relevant and have public health implications because they tell how crucial it is to consider changes in diagnostic methods, e.g., in the epidemiological analysis of historical data and in the interpretation of future data in light of the past. We also believe that this study highlights how the synergy between microbiology and epidemiology is essential for disease surveillance.

Imported spring onions related to the first recorded outbreak of enteroinvasive Escherichia coli in Denmark, November to December 2021.

Between November and December 2021, the first ever recorded outbreak of enteroinvasive Escherichia coli in Denmark occurred at national scale. We describe the investigation of this outbreak, which was initially recognised in early December 2021. A total of 88 cases (58 female; 30 male) with a median age of 52 years (range: 0-91) were detected by PCR-based diagnostic methods. Case ascertainment was complicated by current culture-free diagnostic procedures, with only 34 cases confirmed by culture, serotyping and whole genome sequencing. Isolates from cases grouped into two serotypes (O136:H7 and O96:H19), which was supported by whole-genome-sequence-phylogeny, also yielding two clusters. Interviews of 42 cases and traceback investigation pointed towards consumption of ready-to-eat salads as the outbreak cause. While the ready-to-eat salads comprised different vegetables, imported spring onions were the only common ingredient and thus the likely source. Environmental investigations failed to recover outbreak strains. This report highlights the value of fast typing (here O-typing) to confirm cases in an outbreak situation. Timely communication and data sharing are also important, and were facilitated by the national collaboration between relevant laboratories, the public health institute and the veterinary and food administration. High hygiene standards for imported fresh vegetables intended for ready-to-eat products are essential.

The incidence of laboratory-confirmed cases of enteric pathogens in Denmark 2018: a national observational study.

BACKGROUND: Only a subset of enteric pathogens is under surveillance in Denmark, and knowledge on the remaining pathogens detected in acute gastroenteritis is limited. Here, we present the one-year incidence of all enteric pathogens diagnosed in Denmark, a high-income country, in 2018 and an overview of diagnostic methods used for detection. METHODS: All 10 departments of clinical microbiology completed a questionnaire on test methods and provided 2018-data of persons with positive stool samples with Salmonella species, Campylobacter jejuni/coli, Yersinia enterocolitica, Aeromonas species, diarrheagenic Escherichia coli (Enteroinvasive (EIEC), Shiga toxin-producing (STEC), Enterotoxigenic (ETEC), Enteropathogenic (EPEC), and intimin-producing/attaching and effacing (AEEC)), Shigella species., Vibrio cholerae, norovirus, rotavirus, sapovirus, adenovirus, Giardia intestinalis, Cryptosporidium species, and Entamoeba histolytica. RESULTS: Enteric bacterial infections were diagnosed with an incidence of 229.9 cases/100,000 inhabitants, virus had an incidence of 86/100,000 and enteropathogenic parasites of 12.5/100,000. Viruses constituted more than half of diagnosed enteropathogens for children below 2 years and elderly above 80 years. Diagnostic methods and algorithms differed across the country and in general PCR testing resulted in higher incidences compared to culture (bacteria), antigen-test (viruses), or microscopy (parasites) for most pathogens. CONCLUSIONS: In Denmark, the majority of detected infections are bacterial with viral agents primarily detected in the extremes of ages and with few intestinal protozoal infections. Incidence rates were affected by age, clinical setting and local test methods with PCR leading to increased detection rates. The latter needs to be taken into account when interpreting epidemiological data across the country.

Sentinel surveillance and epidemiology of Clostridioides difficile in Denmark, 2016 to 2019.

BackgroundSince 2008, Danish national surveillance of Clostridioides difficile has focused on binary toxin-positive strains in order to monitor epidemic types such as PCR ribotype (RT) 027 and 078. Additional surveillance is needed to provide a more unbiased representation of all strains from the clinical reservoir.AimSetting up a new sentinel surveillance scheme for an improved understanding of type distribution relative to time, geography and epidemiology, here presenting data from 2016 to 2019.MethodsFor 2─4 weeks in spring and autumn each year between 2016 and 2019, all 10 Danish Departments of Clinical Microbiology collected faecal samples containing toxigenic C. difficile. Isolates were typed at the national reference laboratory at Statens Serum Institut. The typing method in 2016-17 used tandem-repeat-sequence typing, while the typing method in 2018-19 was whole genome sequencing.ResultsDuring the study period, the sentinel surveillance scheme included ca 14-15% of all Danish cases of C. difficile infections. Binary toxin-negative strains accounted for 75% and 16 of the 20 most prevalent types. The most common sequence types (ST) were ST2/13 (RT014/020) (19.5%), ST1 (RT027) (10.8%), ST11 (RT078) (6.7%), ST8 (RT002) (6.6%) and ST6 (RT005/117) (5.1%). The data also highlighted geographical differences, mostly related to ST1 and temporal decline of ST1 (p = 0.0008) and the increase of ST103 (p = 0.002), ST17 (p = 0.004) and ST37 (p = 0.003), the latter three binary toxin-negative.ConclusionSentinel surveillance allowed nationwide monitoring of geographical differences and temporal changes in C. difficile infections in Denmark, including emerging types, regardless of binary toxin status.

A positive diagnostic strategy is safe and saves endoscopies in patients with irritable bowel syndrome: A five-year follow-up of a randomized controlled trial.

BACKGROUND: Previously, the diagnosis of irritable bowel syndrome (IBS) required exclusion of organic causes by extensive diagnostic testing. Newer guidelines recommend IBS as a positive diagnosis based on symptoms with limited testing. We investigated the long-term safety and impact on use of health resources of a positive diagnostic strategy compared to a strategy of exclusion in patients with symptoms compatible with IBS. METHODS: In 2008-2010, primary care patients aged 18-50 years fulfilling the Rome III criteria for IBS without alarm signals were randomized to a positive diagnostic strategy (limited blood tests, n = 150) or a strategy of exclusion (extensive blood tests, fecal samples for intestinal parasites, and sigmoidoscopy with biopsies, n = 152). At five years, hospital-registered diagnoses and use of health resources including lower endoscopies were retrieved from national registries. Participants provided 5-year data on Rome III criteria for IBS, severity of symptoms, and quality of life. KEY RESULTS: Baseline mean age was 31.4 (SD 9.1) years; 79% were female. No cases of celiac disease, and gastrointestinal or gynecological cancers were diagnosed within five years. Negligible and comparable numbers were diagnosed with inflammatory bowel disease, benign gynecological conditions, and upper GI conditions in the two groups. The positive diagnosis strategy carried a higher number of lower endoscopies from year 1 to 5 (23 patients versus 13 patients in the exclusion group), but overall saved endoscopies. CONCLUSIONS & INFERENCES: A positive diagnosis of IBS was as safe as a diagnosis of exclusion in a five-year perspective and saved lower endoscopies; the study was registered at ClinicalTrials.gov numbers: NCT00659763/NCT01153295.

Multicenter evaluation of the new QIAstat Gastrointestinal Panel for the rapid syndromic testing of acute gastroenteritis.

In acute gastroenteritis (AGE), identification of the infectious agent is important for patient management. Since symptoms do not reliably identify the agent, microbiological diagnostics are important. Conventional methods lack sensitivity and often take days. Multiplex PCR panels offer fast and sensitive alternatives. Our aim was to assess the performance of the new QIAstat Gastrointestinal Panel (GIP) detecting 24 different gastroenteric pathogens from stool in Cary-Blair transport medium (Adenovirus F 40/41, Astrovirus, Norovirus GI/GII, Rotavirus A, Sapovirus, Campylobacter spp., Clostridium difficile, Plesiomonas shigelloides, Salmonella spp., Vibrio cholera, Vibrio parahaemolyticus, Vibrio vulnificus, Yersinia enterocolitica, enteroaggregative Escherichia coli, enteropathogenic E. coli, enterotoxigenic E. coli, Shiga-toxin-producing E. coli (stx1 and stx2) (including specific detection of E. coli O157), Shigella spp./enteroinvasive E. coli, Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica and Giardia lamblia). We tested both prospective (n = 163) and retrospective (n = 222) stool samples sent for routine diagnostics by the QIAstat GIP comparing it to the FDA-approved BioFire FilmArray GIP. Seegene Allplex GIP was used for discrepancy testing. After discrepancy testing, QIAstat GIP detected 447 of 455 pathogens (98.2%, 95% confidence interval (CI) 96.6-99.1%). There were eight false positive detections. Multiple pathogens were detected in 32.5% of positive samples. The QIAstat GIP detected a large range of AGE pathogens with a high sensitivity. It offers an easy-to-use system for GI pathogen detection in stool within 70 min. An advantage of the QIAstat is the availability of cycle threshold (CT) values to aid in interpretation of results.

Systematic review with meta-analyses: does the pathogen matter in post-infectious irritable bowel syndrome?

Objective: Acute gastroenteritis (AGE) is a risk factor for post-infectious irritable bowel syndrome (PI-IBS). This systematic review evaluates the prevalence and risk-factors of PI-IBS after AGE by specific pathogens. Materials and methods: Medline (1966-2019) and Embase (1974-2019) were searched for studies evaluating PI-IBS minimum 3 months after AGE with Campylobacter spp., Salmonella spp., Shigella spp., Escherischia coli, Clostridium difficile, norovirus, rotavirus, Cryptosporidium spp. or Giardia intestinalis using validated criteria for IBS. Pooled prevalence (PP), odds ratios (OR) and risk factors were determined for single pathogens, groups of bacteria, viruses and parasites, and overall for AGE caused by any pathogen. Random-effect models were used for meta-analyses. Results: A total of 34 articles were included. PP of PI-IBS after Campylobacter spp. was 12% (confidence interval 95% [CI]: 10-15%), Salmonellosis 12% (CI: 9-15%), Shigellosis 11% (CI: 8-15%), C. difficile 14% (CI: 4-29%) and E. coli spp. 12% (CI: 5-20%). OR of PI-IBS after salmonellosis was 5.5 (CI: 2.3-12.8) and after shigellosis 13.8 (CI: 4.2-45.4). Bacterial AGE overall showed OR 5.8 (CI: 4.0-8.3) and AGE caused by any pathogen OR 4.9 (CI: 3.9-6.1). Few studies exist on viral and parasitic gastroenteritis. Conclusions: Current literature show similar risks for bacterial pathogens. Studies are limited for viral and parasitic pathogens. The evaluated risk-factors for PI-IBS varied among the included studies and the existing evidence is insufficient to identify pathogen-specific risk factors.

Ceftriaxone-resistant Salmonella enterica serotype Typhi in a pregnant traveller returning from Karachi, Pakistan to Denmark, 2019.

We describe a ceftriaxone-resistant Salmonella Typhi bacteraemia in a pregnant woman returning from a family visit in Pakistan. Whole genome sequencing confirmed similarity to a Pakistani outbreak clone. Pregnancy and unawareness of this outbreak delayed appropriate antibiotic therapy. Concurrently, we detected faecal carriage of a carbapenemase-producing Escherichia coli. Awareness of the ongoing outbreak should affect empiric treatment of typhoid fever and hygiene precautions in travellers returning from Pakistan. Meropenem may be warranted in severe cases.

Diagnostic accuracy of the 1,3-ß-D-glucan test for pneumocystis pneumonia in a tertiary university hospital in Denmark: A retrospective study.

1,3-ß-D-glucan (BG), a cell-wall component of most fungi including Pneumocystis (PC), is recommended by international guidelines for screening for pneumocystis pneumonia (PCP) in hematologic patients. We retrospectively validated the BG test in our tertiary university hospital. Forty-five patients (median age 53 years, 33% female) tested for PC by polymerase chain reaction (PCR) and/or immunoflourescence (IF)-microscopy with a stored blood sample within ±5 days of the PC test were tested by the Fungitell (cutoff <60 and >80 pg/ml). Cases had symptoms and radiology compatible with PCP and positive IF-microscopy (proven PCP, n = 8) or positive PCR (probable PCP, n = 10). Controls had no compatible symptoms/radiology and negative tests for PC on conventional testing (no PCP, n = 24), or positive PCR/IF-microscopy (colonized, n = 3). Median BG-levels were 1108 pg/ml (proven PCP), 612 pg/ml (probable PCP), 29 pg/ml (colonized), and 48 pg/ml (controls, P < 0.001). Compared to the PCP case/control classification, the BG test showed sensitivities of 83-89% and specificities of 64-74%, positive likelihood ratio (LR) of 3.2 and negative LR of 0.23 at recommended cutoff and moderate agreement between tests. Optimal cutoff was ≥73 pg/ml. In PCR-positive cases, the agreement between the BG test and IF-microscopy was 78-89% with fair/moderate agreement. Elevated BG levels were seen in controls with probable invasive fungal infections (n = 4), hemodialysis, bacterial infections and/or betalactams. To conclude, 11% of patients with PCP would be missed if the BG test had been used for diagnosing PCP. Specificity was moderate. Among PCR-positive patients, the BG test identified more cases than IF-microscopy. BG testing is potentially helpful but sensitivity is insufficient to exclude PCP.

Antibiotics: a risk factor for irritable bowel syndrome in a population-based cohort.

OBJECTIVES: Use of antibiotics affects the composition of the gut microbiome. The microbiome is thought to play a role in development of irritable bowel syndrome (IBS), but antibiotics as a possible risk factor for IBS has not been clarified. We aimed to explore if antibiotics is a risk factor for IBS by investigating use of antibiotics and development of IBS in a cohort from the Danish background population. MATERIALS AND METHODS: An internet-based web panel representative of the Danish background population was invited to participate in a survey regarding the epidemiology of IBS in 2010, 2011 and 2013. A questionnaire based on the Rome III criteria for IBS were answered at all three occasions. In 2013, a question regarding use of antibiotics in the past year was included. RESULTS: In 2013, use of antibiotics was reported by 22.4% (624/2781) of the population. A higher proportion of individuals with IBS reported use of antibiotics compared with asymptomatic controls [29.0% (155/534) vs. 17.9% (212/1,184), p < .01]. For asymptomatic respondents in 2010 and 2011 (n = 1004), the relative risk of IBS in 2013 related with use of antibiotics was 1.9 [95% confidence interval (CI): 1.1-3.1]. Adjusting for sex by logistic regression, development of IBS was predicted by use of antibiotics with an odds ratio of 1.8 (95% CI: 1.0-3.2). CONCLUSIONS: Antibiotics is a risk factor for IBS in asymptomatic individuals. Possible mechanisms should be investigated in future studies.

Characteristics of the bacterial microbiome in association with common intestinal parasites in irritable bowel syndrome.

OBJECTIVE: A low prevalence of intestinal parasites has been identified in individuals with irritable bowel syndrome (IBS), but potential associations with alterations in the bacterial microbiome remain largely unexplored. We aimed to investigate the relationship between parasites and bacteria in individuals with IBS in order to identify potential trans-kingdom microbial characteristics. DESIGN: Stool samples were collected from the Danish background population classified into IBS (n = 119), unspecific gastrointestinal (GI) symptoms (n = 114), and asymptomatic controls (n = 186) based on the Rome III criteria for IBS. Bacterial (16S) and eukaryotic (18S) ribosomal DNA was sequenced, and 18S data were merged with data from conventional parasite laboratory tests. The bacterial microbiome was analyzed according to symptom group and parasite colonization status. RESULTS: Bacterial richness and diversity were similar for IBS and controls but higher in those with unspecific GI symptoms. A higher abundance of Bacteroides and a lower abundance of Faecalibacterium were detected in individuals with IBS and unspecific GI symptoms compared with controls. Principal component analyses indicated differences in bacterial composition related to parasite colonization rather than symptom group. Parasites were detected at the lowest frequency in the IBS group (39%) and in samples dominated by Bacteroides. Higher bacterial richness and diversity were found in parasite-positive samples from controls and those with unspecific GI symptoms but not in individuals with IBS. CONCLUSION: Parasite colonization, rather than bacterial composition, differed between individuals with IBS and healthy controls. Parasite colonization was associated to a rich and diverse bacterial microbiome; however, this association was altered in IBS.

Laribacter hongkongensis: clinical presentation, epidemiology and treatment. A review of the literature and report of the first case in Denmark.

BACKGROUND: Laribacter hongkongensis is an emerging pathogen related to gastroenteritis that can cause invasive and even fatal disease. The aim of this review is to describe the clinical presentation, epidemiology, treatment options and implications for the clinical microbiology laboratory. METHODS: We searched Pubmed using the term Laribacter hongkongensis with limitations human and language English, and identified 35 publications with eight reports on human cases. RESULTS: We describe our first case of prolonged, travel-related gastroenteritis where Laribacter hongkongensis was isolated as the sole pathogen. Our review suggests that L. hongkongensis causes non-bloody acute diarrhoea with potential for invasive disease, since three cases of bacteraemia and one case of dialysis related peritonitis have been described previously. L. hongkongensis has primarily been described in Asia, but reports from Europe, North America and Australia suggests a worldwide distribution. Broad culturing with subsequent identification by the MALDI-TOF is the current strategy for detection of L. hongkongensis. Phenotypic susceptibility testing is necessary to guide the treatment choice. Few resistance genes have been described in L. hongkongensis. CONCLUSION: L. hongkongensis should be considered a potential cause of acute and prolonged diarrhoea. Clinicians must be aware of the test methods in the local clinical microbiology laboratory, since L. hongkongensis is difficult to detect and easily overlooked.

Danish national guideline: Diagnosis and treatment of Irritable Bowel Syndrome.

National Danish guidelines for the diagnosis and treatment of irritable bowel syndrome (IBS) in adult patients in secondary and tertiary care have been approved by the Danish Society for Gastroenterology and Hepatology. IBS can be a positive diagnosis in patients fulfilling the Rome III criteria for IBS with no alarm signals, a normal physical examination and a normal CRP and hemoglobin. In patients < 40 years with IBS and diarrhea, a normal fecal calprotectin excludes inflammatory bowel disease with a high probability. Patients with IBS and diarrhea should be tested for celiac disease. Endoscopy is not routinely recommended. The therapeutic gain of various treatment modalities is small and most likely overestimated in older studies. However, side effects are usually mild which may justify empirical treatment. The choice of therapy based on IBS subtyping is pragmatic and there are only few trials as guidance. The significance of previous failure with another treatment modality is unclear. There is a lack of long-term treatment trials. The generalizability of the trials is poor, mainly due to selection bias.

Cryptosporidium infections in Denmark, 2010-2014.

INTRODUCTION: The incidence of cryptosporidiosis in Denmark is unknown. Here, we present the number of cases detected in the 2010-2014 period along with data on species and subtypes. METHODS: Complete national data retrieved from the Danish Microbiology Database and Statens Serum Institut (SSI) comprised test results on cryptosporidia detected by microscopy or polymerase chain reaction (PCR) between 1 January 2010 and 30 April 2014. Samples that tested positive at the SSI were submitted to species and subtype analysis by conventional PCR and sequencing of ribosomal and gp60 genes, respectively. RESULTS: A total of 689 Cryptosporidium-positive stool samples were submitted by 387 patients. Limiting case episodes to two months (60 days), a total of 388 case episodes representing 387 patients were identified. Cryptosporidiosis was most common among infants and toddlers. Moreover, a peak in incidence was observed among younger adults aged 23-24 years. In 43 Cryptosporidium-positive faecal samples, identification was performed to species and subtype level. Cryptosporidium parvum was found in 34 samples, C. hominis in eight, and C. meleagridis in one sample; C. parvum subtypes IIaA15G2R1 (n = 10) and IIaA16G3R1 (n = 5) were predominating. CONCLUSION: Cryptosporidia are a significant cause of diarrhoea in Denmark. Outbreaks may not be detected due to continued use of diagnostic tests of limited sensitivity and due to lack of surveillance. With molecular methods now being introduced in many Danish laboratories, we propose establishing national surveillance of cryptosporidiosis. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

The prevalence of intestinal parasites is not greater among individuals with irritable bowel syndrome: a population-based case-control study.

BACKGROUND & AIMS: The parasites Dientamoeba fragilis and Blastocystis have been detected in feces from patients with irritable bowel syndrome (IBS), therefore these parasites may be involved in IBS pathogenesis. We proposed that a higher prevalence of the parasites in IBS subjects compared with asymptomatic controls would support such a mechanism. We aimed to determine the prevalence of these parasites in IBS subjects (cases) and controls and to identify risk factors associated with parasite carriage. METHODS: We performed a population-based, case-control study of an adult population from an internet-based research institute in Denmark. In January 2010, subjects completed a questionnaire based on the Rome III criteria for IBS and answered questions on factors associated with parasite carriage. Respondents (n = 483) were asked to submit fecal samples for parasite testing; samples were analyzed from 124 cases and 204 controls. RESULTS: A greater proportion of controls than cases carried the parasites (50% vs 36%; P = .01). D fragilis was detected in a greater proportion of fecal samples from controls than cases (35% vs 23%; P = .03), as was Blastocystis (22% of controls vs 15% of cases; P = .09), and a greater percentage of controls carried more than 1 species of parasite (16% of controls vs 8% of cases; P = .05). D fragilis infection was associated with having children 5 to 18 years old in the household and Blastocystis infection was associated with high income (≥600,000 Danish Kroner/y, approximately $100,000 US dollars/y), no animals in the household, and drinking bottled water. CONCLUSIONS: D fragilis and Blastocystis were detected in a greater proportion of fecal samples from the asymptomatic background population in Denmark than from subjects with IBS symptoms. These findings indicate that these parasites are not likely to have a direct role in the pathogenesis of IBS. Longitudinal studies are required to understand their role in gastrointestinal health.

[Diagnostic strategy in patients suspected of irritable bowel syndrome]. / Udredning af patienter med symptomer på colon irritabile.

Irritable bowel syndrome, a very common condition with a high use of health-care costs especially related to diagnostic testing, is traditionally approached by a diagnostic strategy of exclusion. However, data from clinical studies support a positive diagnostic strategy based on symptom-based criteria, absence of alarm signals and, if needed, a few simple blood tests in young patients presenting in primary care. For older patients, and for patients not fulfilling symptom-based criteria or presenting with alarm signals, more thorough investigations are needed, directed by the symptomatology.

Screening instruments for anxiety and depression in patients with irritable bowel syndrome are ambiguous.

INTRODUCTION: Psychiatric disorders are common among patients with irritable bowel syndrome (IBS) which may make a psychiatric evaluation appropriate. The Hospital Anxiety and Depression Scale (HADS) has been recommended internationally for screening. The Common Mental Disorder Questionnaire (CMDQ) is a novel Danish instrument recommended for use in general practice, but it lacks validation. The objective of this study was to test the reliability and the convergent validity of the anxiety and depression subscales of the CMDQ and the HADS in patients with IBS. MATERIAL AND METHODS: A total of 149 patients with IBS completed the CMDQ and the HADS twice in a year. Data were analysed with respect to internal consistency (Cronbach's alpha), agreement on case identification (κ) and correlation between scores (Spearman's rank correlation coefficient). RESULTS: All subscales showed satisfactory internal consistency. Cases identified by the CMDQ's anxiety and depressions subscales differed considerably from those identified with the HADS with only fair-moderate agreement, while the correlation between the scores on the CMDQ and the HADS was only moderate for both anxiety and depressions. CONCLUSION: The subscales for anxiety disorder and depression on the CMDQ showed internal consistency, but only fair to moderate agreement and correlation, which yielded an unsatisfying convergent validity compared to the HADS. More studies in different populations and research on the cut-off values for possible cases could make the CMDQ more useful. FUNDING: Danish Council for Independent Research; Region Zealand's Health Sciences Research Foundation; Councils for Quality Assurance in Primary Care in Region Zealand. TRIAL REGISTRATION: NCT00659763.

Prevalence, incidence, and risk factors of intestinal parasites in Danish primary care patients with irritable bowel syndrome.

The gut microbiota may be involved in the aetiopathogenesis of irritable bowel syndrome (IBS). We studied the role of intestinal parasites by describing the epidemiology and risk factors for infection in primary care patients aged 18-50 y with IBS. One hundred and thirty-eight patients at baseline and 78/116 patients returning 1 y later, submitted faecal samples that were examined by microscopy, culture for Blastocystis, and real-time PCR for Dientamoeba fragilis, Entamoeba (dispar and histolytica), Cryptosporidium spp., and Giardia intestinalis. Overall, 42-45% of patients harboured intestinal parasites (baseline and follow-up, respectively): D. fragilis carriage was 35-41%; Blastocystis 14-20%. Incidence rates for D. fragilis and Blastocystis were 10 and 4 per 100 person-y, respectively. Blastocystis carriage increased the odds for carrying D. fragilis. Clinical comparisons showed D. fragilis to be associated with a low frequency of defecation. Further, D. fragilis was associated with having children aged 5-18 y and Blastocystis with increasing age.

The epidemiology of irritable bowel syndrome in Denmark. A population-based survey in adults ≤50 years of age.

OBJECTIVE: Our aims were to investigate the prevalence and subtype distribution of irritable bowel syndrome (IBS) according to the Rome III criteria in Denmark, to describe the difference in symptom reporting between those with gastrointestinal (GI) symptoms not fulfilling Rome III for IBS compared to those classified as IBS, and furthermore to describe the proportion of consulters and formally diagnosed subjects. MATERIAL AND METHODS: A web-based survey was carried out in January 2010. Questionnaires were emailed to a web panel (n = 19,567) representative of the general Danish population aged 18-50 years on gender, age, and geography. IBS and subtypes were estimated by the Rome III criteria. RESULTS: Of 6112 responders, 979 (16%) fulfilled the Rome III criteria for IBS and had no organic diagnosis likely to explain their symptoms. Subtypes were: mixed IBS 36%, IBS with diarrhea 33%, IBS with constipation 18%, and unsubtyped IBS 11%. Those with GI symptoms, not fulfilling Rome III for IBS, had symptoms very similar to those classified as IBS, but symptoms were less frequent and of shorter duration. Of IBS subjects, 180/978 (18.4%) had consulted a doctor for GI symptoms within the past 3 months, but only 7.9% were diagnosed with IBS. CONCLUSION: Symptoms compatible with IBS according to Rome III are highly prevalent in Denmark. A high proportion of sufferers are undiagnosed.