Autochthonous and imported giardiasis cases: An analysis of two decades of national surveillance data, Germany, 2002 to 2021

BackgroundGiardia duodenalis is a major cause of gastroenteritis globally, and is the most common food- and waterborne parasitic infection in Europe.AimTo describe the epidemiology of reported acute giardiasis cases in Germany and compare demographic and clinical characteristics between imported and autochthonous cases.MethodsWe conducted a descriptive analysis of giardiasis cases that fulfilled the national case definition and were reported between January 2002 and December 2021. We defined an imported case as having at least one place of exposure abroad in the 3-25 days before symptom onset. We analysed case numbers and incidence by age, sex, month reported and geographic region, both overall and stratified by autochthonous and imported cases.ResultsFrom 2002 to 2021, 72,318 giardiasis cases were reported in Germany, corresponding to a mean annual incidence of 4.4 per 100,000 population. Annual incidence gradually decreased since 2013, declining sharply during the COVID-19 pandemic in 2020-21. Of 69,345 cases reported between 2002 and 2019, 35% were imported. Incidence of autochthonous cases (overall yearly mean: 3.1/100,000) was highest in males and young children (< 5 years); imported cases were predominantly adults aged 20-39 years. We identified seasonal patterns for imported and autochthonous cases.ConclusionsGiardiasis in Germany is typically assumed to be imported. Our data, however, underline the importance of autochthonous giardiasis. Travel advice might reduce imported infections, but prevention strategies for autochthonous infections are less clear. Dietary, behavioural and environmental risk factors need to be further investigated to enhance infection prevention measures for autochthonous giardiasis.

Infectious etiology and indicators of malabsorption or intestinal injury in childhood diarrhea

INTRODUCTION

The multifactorial etiology of gastroenteritis emphasizes the need for different laboratory methods to identify or exclude infectious agents and evaluate the severity of diarrheal disease.

OBJECTIVE

To diagnose the infectious etiology in diarrheic children and to evaluate some fecal markers associated with intestinal integrity.

MATERIALS AND METHODS

The study group comprised 45 children with diarrheal disease, tested for enteropathogens and malabsorption markers, and 76 children whose feces were used for fat evaluation by the traditional and acid steatocrit tests.

RESULTS

We observed acute diarrhea in 80% of the children and persistent diarrhea in 20%. Of the diarrheic individuals analyzed, 40% were positive for enteropathogens, with rotavirus (13.3%) and Giardia duodenalis (11.1%) the most frequently diagnosed. Among the infected patients, occult blood was more evident in those carrying pathogenic bacteria (40%) and enteroviruses (40%), while steatorrhea was observed in infections by the protozoa G. duodenalis (35.7%). Children with diarrhea excreted significantly more lipids in feces than non-diarrheic children, as determined by the traditional (p<0.0003) and acid steatocrit (p<0.0001) methods. Moreover, the acid steatocrit method detected 16.7% more fecal fat than the traditional method.

CONCLUSIONS

Childhood diarrhea can lead to increasingly severe nutrient deficiencies. Steatorrhea is the hallmark of malabsorption, and a stool test, such as the acid steatocrit, can be routinely used as a laboratory tool for the semi-quantitative evaluation of fat malabsorption in diarrheic children.

Dientamoeba fragilis associated with microbiome diversity changes in acute gastroenteritis patients

This study examined the correlation between intestinal protozoans and the bacterial microbiome in faecal samples collected from 463 patients in New Zealand who were diagnosed with gastroenteritis. In comparison to traditional microscopic diagnosis methods, Multiplexed-tandem PCR proved to be more effective in detecting intestinal parasites. Among the identified protozoans, Blastocystis sp. and Dientamoeba fragilis were the most prevalent. Notably, D. fragilis was significantly associated with an increase in the alpha-diversity of host prokaryotic microbes. Although the exact role of Blastocystis sp. and D. fragilis as the primary cause of gastroenteritis remains debatable, our data indicates a substantial correlation between these protozoans and the prokaryote microbiome of their hosts, particularly when compared to other protists or patients with gastroenteritis but no detectable parasitic cause. These findings underscore the significance of comprehending the contributions of intestinal protozoans, specifically D. fragilis, to the development of gastroenteritis and their potential implications for disease management.

PGD2 and CRTH2 counteract Type 2 cytokine-elicited intestinal epithelial responses during helminth infection

Type 2 inflammation is associated with epithelial cell responses, including goblet cell hyperplasia, that promote worm expulsion during intestinal helminth infection. How these epithelial responses are regulated remains incompletely understood. Here, we show that mice deficient in the prostaglandin D2 (PGD2) receptor CRTH2 and mice with CRTH2 deficiency only in nonhematopoietic cells exhibited enhanced worm clearance and intestinal goblet cell hyperplasia following infection with the helminth Nippostrongylus brasiliensis. Small intestinal stem, goblet, and tuft cells expressed CRTH2. CRTH2-deficient small intestinal organoids showed enhanced budding and terminal differentiation to the goblet cell lineage. During helminth infection or in organoids, PGD2 and CRTH2 down-regulated intestinal epithelial Il13ra1 expression and reversed Type 2 cytokine-mediated suppression of epithelial cell proliferation and promotion of goblet cell accumulation. These data show that the PGD2-CRTH2 pathway negatively regulates the Type 2 cytokine-driven epithelial program, revealing a mechanism that can temper the highly inflammatory effects of the anti-helminth response.

Molecular analysis of cryptosporidiosis cases in Western Australia in 2019 and 2020 supports the occurrence of two swimming pool associated outbreaks and reveals the emergence of a rare C. hominis IbA12G3 subtype

Cryptosporidium is an important protozoan parasite and due to its resistance to chlorine is a major cause of swimming pool-associated gastroenteritis outbreaks. The present study combined contact tracing and molecular techniques to analyse cryptosporidiosis cases and outbreaks in Western Australia in 2019 and 2020. In the 2019 outbreak, subtyping at the 60 kDa glycoprotein (gp60) gene identified 89.0% (16/18) of samples were caused by the C. hominis IdA15G1 subtype. Amplicon next generation sequencing (NGS) at the gp60 locus identified five C. hominis IdA15G1 subtype samples that also had C. hominis IdA14 subtype DNA, while multi locus sequence typing (MLST) analysis on a subset (n = 14) of C. hominis samples identified three IdA15G1 samples with a 6 bp insertion at the end of the trinucleotide repeat region of the cp47 gene. In 2020, 88.0% (73/83) of samples typed were caused by the relatively rare C. hominis subtype IbA12G3. Four mixed infections were observed by NGS with three IdA15G1/ IdA14 mixtures and one C. parvum IIaA18G3R1 sample mixed with IIaA16G3R1. No genetic diversity using MLST was detected. Epidemiological and molecular data indicates that the outbreaks in 2019 and 2020 were each potentially from swimming pool point sources and a new C. hominis subtype IbA12G3 is emerging in Australia. The findings of the present study are important for understanding the introduction and transmission of rare Cryptosporidium subtypes to vulnerable populations.

Acute gastroenteritis due to Blastocystis hominis in an adolescent boy

Acute gastroenteritis with persistent vomiting, high degree fever and blood streaking stools often suggests bacterial aetiology in children. Authors report a 13-year-old boy presenting with acute watery diarrhoea with persistent vomiting, fever of 103°F, abdominal cramps and blood streaking stools who failed to show any response to parenteral third-generation cephalosporin for 72 hours. The stool examination revealed numerous cystic and amoeboid forms of Blastocystis hominis Metronidazole was started and the boy promptly responded within 24 hours. There was no recurrence of symptoms then onwards. The case highlights the crucial stool examination in case of acute diarrhoeal disease for rare aetiology.

Anguillulosis: circumstances of infestation and evolution towards the malignant form

INTRODUCTION

Anguillulosis is a ubiquitous digestive parasitosis. Rare in Tunisia, it is due to a round worm, strongyloid stercoralis, whose natural lodging is the duodeno-jejunal mucosa. Its malignant form is rare but it represents a potentially life-threatening disease.

AIM

We report a case of malignant anguillulosis occurring in a context of immunosuppression.

OBSERVATION

The case we report is about a 46-year-old man treated by a long-term corticosteroid therapy for Takayasu disease. He was hospitalized for an acute digestive syndrome. Biopsies were performed but the evolution was rapidly marked by multiorgan failure, sepsis and death of the patient. Histological analysis of the digestive biopsies concluded to an oeso-gastroduodenal anguillulosis.

CONCLUSION

Anguillulosis is a rare parasitosis but it can pose a health problem especially in its malignant form wich can be a life-threatening.

First Evidence of Teladorsagia circumcincta Infection in Sheep from Egypt

Trichostrongylid nematodes are a common cause of gastroenteritis in sheep. Despite its worldwide distribution, Teladorsagia circumcincta has not been included in reports listing the various trichostrongyles infecting sheep from Egypt. Herein, we describe the presence of 2 T. circumcincta haplotypes infecting small ruminants from Egypt. For this study, fresh fecal samples were collected from 340 sheep and 115 goats reared at 5 districts in Dakahlia governorate and its surroundings, Egypt. Trichostrongyle eggs were harvested from the samples, and then subjected to DNA isolation and analysis. Polymerase chain reaction (PCR) amplification was carried out for the second internal transcribed spacer of ribosomal DNA (ITS2 rDNA). Purified PCR products of T. circumcincta were sequenced, and the revealed sequences were subjected to the nucleotide and phylogenetic analysis. A relatively high prevalence of trichostrongyles eggs was identified in sheep (33.2%) and a lower prevalence was found in goats (14.7%). Molecular analysis revealed, for the first time, 2 sheep herds from Egypt that were infected with T. circumcincta. Both infected herds were raised by the Bedouins in rural areas of El Mahalla El Kubra city. No T. circumcincta infections were found in any of the goats. Nucleotide sequence analysis revealed 2 haplotypes (Te1 and Te2) from 7 successfully sequenced samples (5 from the first and 2 from the second herd). Te1 was the major haplotype in both herds, and Te2 was retrieved from a single sample. Phylogenetic analysis displayed that the Te1 haplotype clustered with one from Cyprus, which might have been introduced to Egypt via goats imported from Cyprus due to a program to improve meat and milk production in Egypt. The present results could be beneficial in understanding the epidemiology of T. circumcincta and other trichostrongyles in Egypt, and have implementations in the effective control strategies used in this region.

Analysis of the Cryptosporidium spp. and gp60 subtypes linked to human outbreaks of cryptosporidiosis in England and Wales, 2009 to 2017

BACKGROUND

Cryptosporidium spp. are important causes of gastroenteritis that can be transmitted from humans and animals. We elucidated the distribution of species and gp60 subtypes in human outbreaks classified by transmission vehicle.

METHODS

We used a combined database of national outbreak surveillance and reference unit data to analyse outbreaks by setting, vehicle, season, and linkage with suspected sources.

RESULTS

A total of 178 outbreaks involving 4031 laboratory confirmed cases were identified; 82 (46%) outbreaks involved recreational waters, 74 (42%) animal contact, 4 (2%) environmental contact, 4 (2%) person-to-person spread, 3 (2%) food, 2 (1%) drinking water supplies, and 9 (5%) were of unknown source. The infecting Cryptosporidium sp. was identified in 131 (74%) outbreaks; 69 were C. parvum, 60 C. hominis, and in two outbreaks cases were infected with either species. Animal contact, environmental contact, and food-borne outbreaks were exclusively C. parvum and were mainly in first half of the year. Recreational water outbreaks were predominantly C. hominis and were mainly in the second half of the year. Outbreaks attributed to person-to-person spread were exclusively C. hominis and all occurred in October. Both C. parvum and C. hominis caused drinking waterborne outbreaks. Gp60 subtypes were identified from patients in 48 C. parvum and 38 C. hominis outbreaks, revealing more subtypes among C. parvum (n = 14) than C. hominis (n = 7) outbreaks. Cryptosporidium hominis IbA10G2 predominated (30 outbreaks). Of C. parvum subtypes, IIaA15G2R1 predominated (17 outbreaks), followed by IIaA17G1R1 (12 outbreaks), IIaA19G1R1 (four outbreaks), and other subtypes caused three or fewer outbreaks each. Linkage between cases and suspected sources by gp60 subtype was established in nine animal contact, three swimming pool, and one drinking water outbreak.

CONCLUSIONS

The public health benefit of identifying infecting species and subtypes was twofold: (i) identifying and strengthening epidemiologic links between cases; and (ii) indicating possible exposures and sources to inform outbreak management. Gp60 subtype refined the epidemiological investigations, but a multilocus genotyping scheme would provide further benefit. Characterisation of Cryptosporidium spp. and subtypes needs to shift from predominantly supporting outbreak investigations to becoming nationally systematic.

Impact of Gastrointestinal Panel Implementation on Health Care Utilization and Outcomes

PCR-based multiplex gastrointestinal (GI) pathogen panels have started to replace stool culture and ova and parasite exam as a rapid and accurate means of diagnosing acute gastroenteritis. However, there are limited data on the impact of panel testing on patient outcomes. The objective of this study was to evaluate the management and health care utilization of patients following GI panel compared with conventional stool testing. We performed a retrospective comparative analysis of 9,402 patients who underwent testing with the FilmArray GI panel from March 2015 through May 2017 and 5,986 patients who underwent conventional stool testing from December 2012 through February 2015. GI panel was positive in 2,746 exams (29.2%) compared with 246 exams (4.1%) with conventional testing. Within 30 days following stool testing, compared with patients who received a conventional stool test, patients who received a GI panel were less likely to undergo any endoscopic procedure (8.4% GI panel versus 9.6% stool culture, P = 0.008) or any abdominal radiology (29.4% GI panel versus 31.7%, P = 0.002). Within 14 days following stool testing, patients who received a GI panel were less likely to be prescribed any antibiotic (36.2% GI panel versus 40.9%, P < 0.001). The implementation of multiplex PCR stool testing was associated with a reduction in the utilization of endoscopy, abdominal radiology, and antibiotic prescribing.

Plan ahead to control parasitic gastroenteritis, husk and fluke

This focus article has been prepared by Arthur Otter, deputy lead of the APHA Cattle Expert Group.

Easyscreen™ Enteric Protozoa Assay For the Detection of Intestinal Parasites: A Retrospective Bi-Center Study

Gastroenteritis caused by single or multiple pathogens remains a major diagnostic challenge for the laboratory, as diagnosis is achieved using different techniques with variable sensitivity and specificity. The aim of this study was to evaluate the EasyScreen™ Enteric Protozoa Detection Kit, a multiplex PCR assay for the detection and identification of the 5 most common protozoan parasites in fecal samples. A total of 632 fecal samples, submitted for routine screening to 2 centers in north-eastern Italy, was included in the study. The results of the molecular assay were compared to those of the standard diagnostic procedures, represented by microscopy and immunoassays. Out of 32 samples testing positive by conventional tools, 31 were detected as concordantly positive using the EasyScreen Kit. Additionally, 91 out of 632 samples only tested positive by the molecular test, therefore increasing the positive detection rate by 275%. Finally, the EasyScreen assay detected 14 co-infections compared to 3 co-infections identified by conventional methods. The EasyScreen Kit provided a rapid and sensitive simultaneous identification of the most important diarrhea-causing protozoa that infect humans. Additionally, this molecular assay presents several advantages compared to conventional tools, such as the standardization and near-total automation of the process. Although critical issues related to the employment of molecular assays are still evident, the system is suitable for clinical parasitological diagnosis as long as it is used in association with conventional tools.

Application of a salivary immunoassay in a prospective community study of waterborne infections

Quantifying sporadic waterborne infections in community settings can be challenging. Salivary antibody immunoassays are a promising non-invasive tool that can be used in prospective studies of common infections, especially those involving children. This study was conducted in a Massachusetts city, which uses a microbiologically contaminated river as its water source, during summer-early winter periods before and after construction of a new drinking water treatment plant. Monthly saliva samples (7480 samples from 1170 children and 816 adults) were analyzed for immunoglobulin G (IgG) responses to recombinant proteins of Cryptosporidium, one genogroup I (GI) and two GII noroviruses. Immunoconversion was defined as at least four-fold increase in specific antibody responses between two monthly samples with a post-conversion response above a flexible age-dependent cut-off. Episodes of gastroenteritis (diarrhea or vomiting or cramps) were associated with 3.2 (95% confidence limits 1.1; 9.5) adjusted odds ratio (aOR) of immunoconversion to Cryptosporidium; episodes of combined diarrhea and vomiting symptoms were associated with 3.5 (0.8; 15.0) and 4.6 (1.7; 12.6) aORs of an immunoconversion to GI and GII noroviruses, respectively. Swimming in natural water bodies or chlorinated pools was associated with 2.3 (0.4; 15.4) and 4.9 (1.6; 15.5) aORs of immunoconversion to Cryptosporidium, respectively. In a subset of study participants who did not use home water filters, consumption of at least some amount of non-boiled tap water reported in a monthly recall survey was associated with 11.1 (1.2; 100.0) and 0.6 (0.1; 2.5) aORs of immunoconversion to Cryptosporidium before and after the new water treatment plant construction, respectively. Among individuals who used home water filters, associations between non-boiled tap water consumption and Cryptosporidium immunoconversion were not significant before and after new plant construction with aORs of 0.8 (0.2; 3.3) and 0.3 (0.1; 1.6), respectively. The interaction effect of study phase and non-boiled tap water consumption on Cryptosporidium immunoconversions was statistically significant in the entire study population with aOR of 5.4 (1.1; 25.6). This was the first study that has used a salivary antibody immunoassay to demonstrate significant associations between gastrointestinal symptoms and Cryptosporidium and norovirus infections, and between water-related exposures and Cryptosporidium infections.

Detection of common diarrhea-causing pathogens in Northern Taiwan by multiplex polymerase chain reaction

Conventional methods for identifying gastroenteritis pathogens are time consuming, more likely to result in a false-negative, rely on personnel with diagnostic expertise, and are dependent on the specimen status. Alternatively, molecular diagnostic methods permit the rapid, simultaneous detection of multiple pathogens with high sensitivity and specificity. The present study compared conventional methods with the Luminex xTAG Gastrointestinal Pathogen Panel (xTAG GPP) for the diagnosis of infectious gastroenteritis in northern Taiwan. From July 2015 to April 2016, 217 clinical fecal samples were collected from patients with suspected infectious gastroenteritis. All specimens were tested using conventional diagnostic techniques following physicians' orders as well as with the xTAG GPP. The multiplex polymerase chain reaction (PCR) approach detected significantly more positive samples with bacterial, viral, and/or parasitic infections as compared to conventional analysis (55.8% vs 40.1%, respectively; P < .001). Moreover, multiplex PCR could detect Escherichia coli O157, enterotoxigenic E coli, Shiga-like toxin-producing E coli, Cryptosporidium, and Giardia, which were undetectable by conventional methods. Furthermore, 48 pathogens in 23 patients (10.6%) with coinfections were identified only using the multiplex PCR approach. Of which, 82.6% were from pediatric patients. Because the detection rates using multiplex PCR are higher than conventional methods, and some pediatric pathogens could only be detected by multiplex PCR, this approach may be useful in rapidly diagnosing diarrheal disease in children and facilitating treatment initiation. Further studies are necessary to determine if multiplex PCR improves patient outcomes and reduces costs.

The NICE-GUT trial protocol: a randomised, placebo controlled trial of oral nitazoxanide for the empiric treatment of acute gastroenteritis among Australian Aboriginal children

INTRODUCTION

Diarrhoeal disease is the second leading cause of death in children under 5 years globally, killing 525 000 annually. Australian Aboriginal and Torres Strait Islander (hereafter Aboriginal) children suffer a high burden of disease. Randomised trials in other populations suggest nitazoxanide accelerates recovery for children with Giardia, amoebiasis, Cryptosporidium, Rotavirus and Norovirus gastroenteritis, as well as in cases where no enteropathogens are found.

METHODS AND ANALYSIS

This double blind, 1:1 randomised, placebo controlled trial is investigating the impact of oral nitazoxanide on acute gastroenteritis in hospitalised Australian Aboriginal children aged 3 months to <5 years. Dosing is based on age-based dosing. The primary endpoint is the time to resolution of 'significant illness' defined as the time from randomisation to the time of clinical assessment as medically ready for discharge, or to the time of actual discharge from hospital, whichever occurs first. Secondary endpoints include duration of hospitalisation, symptom severity during the period of significant illness and following treatment, duration of rehydration and drug safety. Patients will be followed for medically significant events for 60 days. Analysis is based on Bayesian inference. Subgroup analysis will occur by pathogen type (bacteria, virus or parasite), rotavirus vaccination status, age and illness severity.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Central Australian Human Research Ethics Committee (HREC-14-221) and the Human Research Ethics Committee of the Northern Territory Department of Health and Menzies School of Health Research (HREC2014-2172). Study investigators will ensure that the trial is conducted in accordance with the principles of the Declaration of Helsinki. Individual participant consent will be obtained. Results will be disseminated via peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ACTRN12614000381684.

Exposure to Anisakis extracts can induce inflammation on in vitro cultured human colonic cells

Anisakis spp. is a parasitic nematode whose infective third-stage larvae may be found within the flesh of fish species commonly consumed by humans. Thorough cooking or freezing should render the fish safe for consumption; furthermore, marinating solutions containing biocidal agents might have a significant action against Anisakis larvae. Some studies suggest a relationship between some parasitic infections and development of inflammatory bowel disorders, and Anisakis infection might be a risk factor for stomach or colon cancer. The aim of our study was to investigate if crude extracts (CEs) obtained from Anisakis larvae marinated in a solution with added allyl isothiocyanate (ACE-AITC) and frozen, or from frozen only Anisakis larvae (ACE), can induce an inflammatory effect on in vitro differentiated colonic Caco-2 cells exposed or not to LPS. Caco-2 exposure to the two CEs induced a marked COX-2 expression and potentiated LPS-induced COX-2 overexpression, confirming that substances present in Anisakis larvae can induce an inflammatory response in the intestinal epithelium, possibly also exacerbating the effects of other inflammatory stimuli. ACE induced a marked decrease in caspase-3 activation, while AITC-ACE increased its activation. However, LPS-induced caspase-3 activation appeared lower in cells treated with ACE and with the lower concentration of AITC-ACE. Thus, it is evident that Anisakis CEs may affect various cell pathways crucial not only in the inflammatory process but also in cell growth and death. Thus, CEs obtained from nonviable Anisakis larvae retain or are otherwise provided with noxious properties able to induce a strong inflammation response in intestinal epithelial cells. Furthermore, their influence may persist also following pretreatment with the biocidal agent AITC, indicating that the harmful substances contained in crude extracts from Anisakis larvae are resistant to the thermal or biocidal agent treatments.

Agreement between gastrointestinal panel testing and standard microbiology methods for detecting pathogens in suspected infectious gastroenteritis: Test evaluation and meta-analysis in the absence of a reference standard

Objective

Multiplex gastrointestinal pathogen panel (GPP) tests simultaneously identify bacterial, viral and parasitic pathogens from the stool samples of patients with suspected infectious gastroenteritis presenting in hospital or the community. We undertook a systematic review to compare the accuracy of GPP tests with standard microbiology techniques.

Review methods

Searches in Medline, Embase, Web of Science and the Cochrane library were undertaken from inception to January 2016. Eligible studies compared GPP tests with standard microbiology techniques in patients with suspected gastroenteritis. Quality assessment of included studies used tailored QUADAS-2. In the absence of a reference standard we analysed test performance taking GPP tests and standard microbiology techniques in turn as the benchmark test, using random effects meta-analysis of proportions.

Results

No study provided an adequate reference standard with which to compare the test accuracy of GPP and conventional tests. Ten studies informed a meta-analysis of positive and negative agreement. Positive agreement across all pathogens was 0.93 (95% CI 0.90 to 0.96) when conventional methods were the benchmark and 0.68 (95% CI: 0.58 to 0.77) when GPP provided the benchmark. Negative agreement was high in both instances due to the high proportion of negative cases. GPP testing produced a greater number of pathogen-positive findings than conventional testing. It is unclear whether these additional ‘positives’ are clinically important.

Conclusions

GPP testing has the potential to simplify testing and accelerate reporting when compared to conventional microbiology methods. However the impact of GPP testing upon the management, treatment and outcome of patients is poorly understood and further studies are needed to evaluate the health economic impact of GPP testing compared with standard methods.

The review protocol is registered with PROSPERO as CRD42016033320.

Characteristics of child daycare centres associated with clustering of major enteropathogens

Insights into transmission dynamics of enteropathogens in children attending daycare are limited. Here we aimed at identifying daycare centre (DCC) characteristics associated with time-clustered occurrence of enteropathogens in DCC-attending children. For this purpose, we used the KIzSS network, which comprises 43 DCCs that participated in infectious disease surveillance in The Netherlands during February 2010-February 2013. Space-time scan statistics were used to identify clusters of rotavirus, norovirus, astrovirus, Giardia lamblia and Cryptosporidium spp. in a two-dimensional DCC characteristic space constructed using canonical correlation analysis. Logistic regression models were then used to further identify DCC characteristics associated with increased or decreased odds for clustering of enteropathogens. Factors associated with increased odds for enteropathogen clustering in DCCs were having indoor/outdoor paddling pools or sandpits, owning animals, high numbers of attending children, and reporting outbreaks to local health authorities. Factors associated with decreased odds for enteropathogen clustering in DCCs were cleaning child potties in designated waste disposal stations, cleaning vomit with chlorine-based products, daily cleaning of toys, extra cleaning of toys during a suspected outbreak, and excluding children with gastroenteritis. These factors provide targets for reducing the burden of gastrointestinal morbidity associated with time-clustered occurrence of major enteropathogens in DCC attendees.

Frequency of Enteropathogen Detection in Suckling and Weaned Pigs with Diarrhea in Japan

Fecal samples from suckling ( n = 153) and weaned ( n = 116) piglets with diarrhea in Japan were examined for shedding of viral, bacterial, and parasitic pathogens using culture, microscopic, and polymerase chain reaction methods. In suckling piglets, diarrhea was attributed to infection with a single etiologic agent in 60.8% of cases and with combinations of agents in 22.2%. In weaned piglets, diarrhea was attributed to a single etiologic agent in 43.1% and to combinations of agents in 47.4% of cases. Rotavirus was the most prevalent agent in suckling (67.3%) and weaned (65.5%) piglets. The detection of other pathogens was associated with age of the animals examined. Coccidia were predominantly isolated from suckling piglets, whereas Escherichia coli was found predominantly in weaned piglets. Although a relationship was not observed between detection rate of rotavirus and age of piglets, a single group of rotavirus was detected in 87.5% of suckling piglets whereas multiple groups were detected in 51.6% of weaned piglets. The results of this study confirm that diarrhea in piglets can, to a variable degree, be causally associated with multiple agents. Additionally, these results suggest reasons why this syndrome can be difficult to control.

Diarrhea: Initial Evaluation and Treatment in the Emergency Department

Diarrhea generates a wide range of diagnostic considerations and has profound individual and public health significance. The setting and circumstances under which a patient presents with diarrhea drastically influences the concern brought to the encounter. Nausea, vomiting, and diarrhea are often provisionally labeled "gastroenteritis" with appropriate expectant management. In resource-poor countries, the significance of diarrhea is even greater. This review focuses on diarrhea and its initial evaluation and management in the emergency department.

Outbreaks attributed to fresh leafy vegetables, United States, 1973-2012

Leafy vegetables are an essential component of a healthy diet; however, they have been associated with high-profile outbreaks causing severe illnesses. We reviewed leafy vegetable-associated outbreaks reported to the Centers for Disease Control and Prevention between 1973 and 2012. During the study period, 606 leafy vegetable-associated outbreaks, with 20 003 associated illnesses, 1030 hospitalizations, and 19 deaths were reported. On average, leafy vegetable-associated outbreaks were larger than those attributed to other food types. The pathogens that most often caused leafy vegetable-associated outbreaks were norovirus (55% of outbreaks with confirmed aetiology), Shiga toxin-producing Escherichia coli (STEC) (18%), and Salmonella (11%). Most outbreaks were attributed to food prepared in a restaurant or catering facility (85%). An ill food worker was implicated as the source of contamination in 31% of outbreaks. Efforts by local, state, and federal agencies to control leafy vegetable contamination and outbreaks should span from the point of harvest to the point of preparation.

Cryptosporidiosis: A Disease of Tropical and Remote Areas in Australia

Cryptosporidiosis causes gastroenteritis and is transmitted to humans via contaminated water and food, and contact with infected animals and people. We analyse long-term cryptosporidiosis patterns across Australia (2001–2012) and review published Australian studies and jurisdictional health bulletins to identify high risk populations and potential risk factors for disease. Using national data on reported cryptosporidiosis, the average annual rate of reported illness was 12.8 cases per 100 000 population, with cycles of high and low reporting years. Reports of illness peak in summer, similar to other infectious gastrointestinal diseases. States with high livestock densities like New South Wales and Queensland also record a spring peak in illnesses. Children aged less than four years have the highest rates of disease, along with adult females. Rates of reported cryptosporidiosis are highest in the warmer, remote regions and in Aboriginal and Torres Strait Islander populations. Our review of 34 published studies and seven health department reports on cryptosporidiosis in Australia highlights a lack of long term, non-outbreak studies in these regions and populations, with an emphasis on outbreaks and risk factors in urban areas. The high disease rates in remote, tropical and subtropical areas and in Aboriginal and Torres Strait Islander populations underscore the need to develop interventions that target the sources of infection, seasonal exposures and risk factors for cryptosporidiosis in these settings. Spatial epidemiology can provide an evidence base to identify priorities for intervention to prevent and control cryptosporidiosis in high risk populations.

The parasite Cryptosporidium is a common cause of gastroenteritis worldwide. Ineffectively focused interventions are partly why the disease remains a challenge to control. In this study, we describe the geographical, seasonal and demographic characteristics of reported cryptosporidiosis in Australia from 2001–2012. We combine this analysis of illnesses with evidence published in peer review articles and state health bulletins to identify high disease risk areas and populations. We find that rates of reported cryptosporidiosis are highest in warm, remote areas and in Aboriginal and Torres Strait Islander populations’ dominated regions. Our review of the published literature and health reports highlights a focus on short term outbreaks in metropolitan areas. This negligible overlap between areas with high disease rates and areas of public health focus is of concern. Public health interventions and promotion programs to prevent and control diarrhoea need to focus on remote and Indigenous dominated Australia to reduce the currently high rates in these regions and populations.

Multiplex polymerase chain reaction tests for detection of pathogens associated with gastroenteritis

A wide range of enteric pathogens can cause infectious gastroenteritis. Conventional diagnostic algorithms are time-consuming and often lack sensitivity and specificity. Advances in molecular technology have provided new clinical diagnostic tools. Multiplex polymerase chain reaction (PCR)-based testing has been used in gastroenterology diagnostics in recent years. This article presents a review of recent laboratory-developed multiplex PCR tests and current commercial multiplex gastrointestinal pathogen tests. It focuses on two commercial syndromic multiplex tests: Luminex xTAG Gastrointestinal Pathogen Panel and BioFire FilmArray gastrointestinal test. Multiplex PCR tests have shown superior sensitivity to conventional methods for detection of most pathogens.

Parasitic gastroenteritis in lambs widespread

Parasitic gastroenteritis diagnosed in lambs by all veterinary investigation centres, Clostridium perfringens epsilon enterotoxaemia suspected in two cows, Comparative quarterly porcine reproductive and respiratory syndrome diagnoses reach a 10-year peak, Failure of an entire colony of gulls in Cumbria, Endoparasitism the predominant feature in exotic farmed animals, These are among matters discussed in the Animal and Plant Health Agency's (APHA's) disease surveillance report for September 2014.

Multilevel analysis of childhood nonviral gastroenteritis associated with environmental risk factors in Quebec, 1999-2006

Childhood nonviral gastroenteritis is a priority for various public health authorities. Given that waterborne transmission is sometimes incriminated during investigation of gastroenteritis outbreaks, the authors hypothesized that watershed characteristics may influence the occurrence of this disease and could contribute additional insights for better prevention and control. The study described here aimed to investigate watershed characteristics in relation to nonviral gastroenteritis and specifically three bacterial and parasitic forms of childhood gastroenteritis to assess their relative importance in the province of Quebec, Canada. Information on children aged 0-4 years with bacterial or parasitic enteric infections reported through ongoing surveillance between 1999 and 2006 in the province of Quebec was collected. Factors measured at the municipal and watershed levels were analyzed using multilevel models with a Poisson distribution and log link function. Childhood nonviral gastroenteritis, giardiasis, and campylobacteriosis were positively associated with small ruminants and cattle density. Childhood salmonellosis was positively associated with cattle density. Also, childhood campylobacteriosis incidence was positively associated with larger watershed agricultural surface. In addition to local agroenvironmental factors, this analysis revealed an important watershed effect.

[Changes in the heart of neonatal rats after cryptosporidial gastroenteritis of different degrees of severity]

Disturbances at the childhood age increase risk of the appearance of cardiovascular diseases decades later. The nature of this interconnection called ontogenetic programming is not completely understood. Valuable sources of knowledge about mechanisms of ontogenetic programming are data of interspecies study of biology of the body life cycles and of heart physiological capabilities. Taken into account the interspecies differences, these data allow finding the correct direction of experimental investigations. Results of studies of almost 100 homoiothermal species have shown the slow growth and a high loading on the heart at postnatal development to decrease its aerobic capability in adults. Basing on these data, we suggested that the neonatal gastroenteritis causing tachyarrhythmia, malabsorption, and the growth deceleration might lead to pathological changes in the heart. Our task was to evaluate the effect of cryptosporidial gastroenteritis of different degrees of severity on heart of the neonatal rats. By using methods of Real-Time PCR, immunocytochemistry, image analysis, and study of interatrial septum, we have established that a gradual increase of intensity of infestation with Cryptosporidium parvum oocytes causes sharp changes corresponding to the "all or nothing" response. At a weak infestation the interatrial septum was close (like in control), while significant changes in expression of isoforms of heavy chains of alpha- and beta-myosin were absent. At the intermediate and severe infestation, in the interatrial septum the foramen ovale was visualized and there were observed cardiac atrophy and a strong shift of ration of expression of myosin heavy chains toward the low-velocity beta chain. Thus, by disturbing the frequency-strength ratios and causing outflow of resources from the formed heart, the neonatal gastroenteritis produces pathological changes of the organ molecular and anatomical structures. Our results can be interest to evolutionary biologists and physicians, as they show importance of knowledge of evolutionary-comparative investigations for the search for novel risk factors of heart diseases and demonstrate interconnection between gastroenteritis, pathology of interatrial septum, and a change of composition of the main contractile proteins in cardiomyocytes.

Prevalence and characters of Entamoeba histolytica infection in Saudi infants and children admitted with diarrhea at 2 main hospitals at South Jeddah: a re-emerging serious infection with unusual presentation

In this study, Entamoeba histolytica had high prevalence and unusual presentation by affecting high proportion of infants under 1 year; severe clinical manifestations, and laboratory findings that were known to be usually encountered in invasive amebiasis as significant leukocytosis for age, neutrophilic leukocytosis for age, and positive C-reactive protein were found among more than 50% of admitted Saudi infants and children with E. histolytica infection in our locality. E. histolytica can be a re-emerging serious infection when it finds favorable environmental conditions and host factors which are mainly attributed to inadequate breastfeeding in this study. This may occur in any other area of the world with the same risk factors, so we must be ready to tackle it with effective and more powerful preventive measures.

[High perinatal mortality associated with triple anthelmintic resistance in a German sheep flock]

High perinatal mortality, low milk yields and occasional ewe deaths were investigated in a Dorper sheep flock in Southern Germany. Parasitic gastroenteritis due to Trichostrongylus spp. associated with severe weight loss despite regular anthelmintic treatments of the flock was identified as the underlying cause. A faecal egg count reduction (FECR) test revealed zero reduction after treatment with ivermectin or albendazole, respectively, and a FECR of 57.9% following treatment with levamisole. These results indicate a lack of, or considerably reduced efficacy of substances from all three classical groups of anthelmintics and demonstrate that triple anthelmintic resistance is also present in Germany. The introduction of resistant worm populations with imported livestock, excessive use of anthelmintic drugs and under-dosing of goats have possibly led to the problem in the flock described. Veterinary advice on anthelmintic treatments and responsible parasite control programmes are therefore crucial in small ruminant flocks.

[Etiological aspects of acute gastroenteritis--a ten-year review (1.01. 2001-31.12.2010)]

Acute gastroentritis is one of the most common diseases in humans, and continues to be a significant cause of morbidity worldwide.

AIMS

To determine the bacterial pathogens associated with gastroenteritis in patients admitted to the Iasi Infectious Diseases Hospital in the last ten years.

MATERIAL AND METHODS

A total of 40481 stool samples were examined using conventional methods.

RESULTS

Bacteria were found in 7.36% of cases, and parasites in 9.64%; 83% of the cases were viral, micotic, or disbiotic. The bacterial etiology was dominated by Salmonella spp. (58.34%), Shigella spp. (27.08%), Yersinia enterocolitica 03 (8.53%), Campylobacter spp. (1.31%), other bacterial pathogens (EPEC, Aeromonas hydrophilla/caviae/sobria, Plesiomonas shigelloides, Bacillus cereus, Staphylococcus aureus, etc) being detected in 3.74% of the cases. Of the Salmonella species, group B (51.99%) followed by group D (45.23%) were most common. Shigella sonnei and Shigella flexneri were found in almost the same proportion (49.45% and 49.70%, respectively); Shigella boydii was isolated in only 0.85% of cases. The trend of gastroenteritis caused by bacterial pathogens is decreasing: from 355 cases in 2001 to 105 cases in 2010; three peaks have been recorded in 2002, 2005 (when Salmonella typhi was isolated in a patient), and 2008 (469, 409, and 252 cases, respectively). Bacterial gastroenteritis affected both sexes almost equally (122 males and 118 females). The most affected age groups were: 0 - 4 years, 15 - 24 years, 5 - 14 years and 25 - 39 years.

CONCLUSIONS

Laboratory investigations are essential in determining the etiology of gastroenteritis. Its unpredictable incidence justifies the human and material efforts aimed at controlling the spread of potentially epidemic acute gastroenteritis.

[Cardiomyocyte myosin heavy chain composition change after cryptosporidial gastroenteritis]

Cardiovascular diseases are the most common case of human death in developed countries. Thus, the discovering of their new risk factors is of primary importance. Based on epidemiology studies, vertebrate life-history traits comparison and cross-species cardiomyocyte transcriptome analysis, we suggest that one of these factors could be infectious gastroenteritis. This disease outflows recourses from cardio-vascular system and triggers pathological stimuli, like tachyarrhythmia, inflammation, malapsorption and energy depletion thereby disturbing cardiomyocyte metabolism and function. To test this hypothesis, we challenged gastroenteritis in neonatal rats with widespread human parasite Cryptosporidium parvum (Apicomplexa, Sporozoa). The results obtained by the methods of immunocytochemistry, quantitative morphometry and real-time PCR, indicate that moderate cryptosporidiosis lasting four days induces dramatic shift in myosin isoform expression ration toward isoform beta (with low ATPase activity) both at mRNA (by 1.7-4.5 folds) and protein (by 2.5-6 folds) levels. Antithetical manner of this shift and coherence between changes in mRNA and protein suggest that cryptosporidiosis affects all main steps of a complex myosin heavy chain regulatory network. Since the overexpression of myosin heavy chain beta (showing several times lower ATPase activity than myosin heavy chain alfa) is a generally accepted marker of human cardiac failure, we can consider cryptosporidial gastroenteritis as a new risk factor of cardiac contractile ability impairment. Our data can be interesting for clinicians.

Molecular characterization of viruses associated with gastrointestinal infection in HIV-positive patients

BACKGROUND

Diarrhea is a major cause of morbidity and mortality among HIV-infected patients worldwide.

OBJECTIVE

We sought to determine the frequency of viral gastrointestinal infections among Brazilian HIV-infected patients with diarrhea.

METHODS

A collection of 90 fecal specimens from HIV-infected individuals with diarrhea, previously tested for the presence of bacteria and parasite was analyzed by polymerase chain reaction and sequence analysis for the presence of enteric viruses such as astrovirus, norovirus, rotavirus groups A, B and C, adenovirus, herpes simplex virus, Epstein-Barr virus, cytomegalovirus, and human bocavirus.

RESULTS

Twenty patients (22.2%; n = 90) were infected with parasites (11 single infections and nine coinfected with virus). Enteropathogenic bacteria were not found. Virus infections were detected in 28.9% (26/90) of the specimens. Cytomegalovirus was the most common virus detected (24.4%; 22/90). Coinfections with viruses and/or parasite were observed in 10 (11.1%) samples.

CONCLUSION

Gastrointestinal virus infections were more frequent than parasitic or bacterial infections in this patient population.

[A rare gastroenteritis pathogen: Cyclospora]

Cyclospora spp. which are coccidian parasites are rare gastroenteritis pathogens. The first cyclosporiasis case in Turkey was reported in 1998 in a patient with AIDS. In this paper we report a case of Cyclospora gastroenteritis, in a patient who was admitted to our hospital and who had had diarrhea, abdominal pain and nausea for ten days. In the anamnesis it was learned that he had travelled to the Black Sea region and had drunk muddy and cloudy water. His physical examination was normal except for increased bowel sounds. There were no leukocytes or erythrocytes in the direct microscopy of the stool and bacteriologic culture did not yield any enteropathogen. Cylospora oocyysts were seen in the parasitologic exmination. The patient was treated with cotrimaxasole (2x1,160/800 mg tablet). There was no pathogen in the repeated stool examination. Our case suggests that parasitologic examination should not be neglected in longlasting diarrhea cases and occasionally Cyclospora may be the causative agent.

[Gastrointestinal giardiasis associated with Helicobacter pylori]

The study involved 160 patients with chronic cholecystitis associated with chronic gastroduodenitis. Obtaining biopsy specimens of gastric mucosa and bile samples allowed to compare the microbial picture and the morphological structure of gastric mucosa in the same patient, to identify patterns of colonization of the stomach, 12 duodenal ulcer and gall bladder various microorganisms. At cytological examination was detected in the gall bladder G. lamblia in 47.5 +/- 3.95% of cases in the stomach--in 29.09 +/- 6.12% of cases. The frequency of H. pylori detection in biopsy of gastric mucosa amounted to 98.18 +/- 1.8% of cases, in 12-duodenum--93.75 +/- 1.9%, in the gall bladder--to 54.38 +/- 3.94%, in the bile duct--in 54.38 +/- 3.94%. It was found strict association between the detection of H. pylori and G. lamblia in the stomach--100% of H. pylori-infection combined with giardiasis. Morphological changes of gastric mucosa in the form of lymphoid infiltration detected mainly in the mixed-infection H. pylori and G. lamblia.

Association of Blastocystis subtype 3 and 1 with patients from an Oregon community presenting with chronic gastrointestinal illness

Chronic gastrointestinal illness of unknown etiology is a significant problem in the United States. Using a real-time LightCycler PCR assay we detected Blastocystis in nine patients from a metropolitan area of Corvallis, Oregon who presented with diarrhea, abdominal pain, fatigue, joint pain, skin rash and psychiatric co-morbidity. Phylogenetic analysis identified six infections with Blastocystis sp. subtype 3, and one with subtype 1, using the standard Stensvold nomenclature. Most patients with subtype 3 had previously tested negative with conventional parasitological diagnostics, had been symptomatic for over 4 years, and reported antibiotic failure.

Protein profile and morphometry of cultured human Blastocystis hominis from children with gastroenteritis and healthy ones

A total of 180 children of age group 5-12 years old in both sexes, of whom 90 were symptomatic and negative for other parasites, rotavirus or pathogenic bacteria. Another 90 children were asymptomatic, but with B. hominis in stools. Direct smear, formaline-ethyl acetate sedimentation concentration, kinyon carbol-fuchin stain, stool culture, enzyme immunoassay, culturing, morphometric study, gel electrophoresis and experimental infection of mice were done. The results showed that the central body cysts (CB), granular and multivacuolar forms isolated from symptomatic patients were larger than those from asymptomatic ones. The CB form was common compared to other forms and isolated from 104 cases. B. hominis infection was prevalent among males rather than females (60.5% versus 39.5%). The clinical data showed that diarrhea was the most common symptom (58.9%). The infection intensity had a direct relation with illness duration. The polyacrylamide gel electrophoresis showed that isolates from symptomatic and asymptomatic patients ranged between 24-130 kDa. All isolates showed similar banding patterns. Only minor differences was in low MW (30, 50 kDa) and in high MW (118 kDa) in samples from symptomatic patients. The histopathological examination of caecum, colon and small intestine of B. hominis mice infected from symptommatic patients showed infiltration with inflammatory cells and tissue invasion by the parasite.

Correlation between the presence of symptoms and the Giardia duodenalis genotype

Clinical manifestations of Giardia duodenalis infection vary from asymptomatic infection to chronic diarrhoea. We study the correlation between the presence of symptoms and the G. duodenalis genotype in 108 patients with giardiasis. Patient age ranged from 2 to 72 years old. We found a correlation between assemblage AII and symptomatic infections, and between assemblage B and asymptomatic infections in the overall patient group and in patients less than five years of age. Nevertheless, if only patients of more than five years of age were considered, no statistically significant relationship between assemblage and symptomatic or asymptomatic Giardia infections was found. In these patients, host factors may affect the presence of clinical manifestations more than Giardia assemblage.

An outbreak of gastroenteritis associated with intestinal parasites

Intestinal protozoa are one of the leading causes of waterborne outbreaks. Stool samples of 196 residents from a village of Izmir, using the public water supply, were collected during an outbreak of gastroenteritis. Patients were asked to fill out a questionnaire reporting on gender, age, gastrointestinal symptoms, whether or not there was a toilet in the house, their hygiene practices, and similar symptoms in the household members. Of the patients who had gastrointestinal symptoms (74.5%), diarrhea was observed in 69.5% whereas bloody and mucoid stools were observed in 20.4 %. The stool samples were examined for intestinal parasites by wet mount and trichrome stain and were also cultured in the Robinson medium. Pathogenic parasites were detected in 11 samples (5.6%) as follows: Giardia intestinalis in 7, Hymenolepis nana in 1 and Blastocystis hominis in 4. Entamoeba histolytica/dispar was not detected by direct wet mount in any of 8 patients who had E. histolytica/E. dispar in culture whereas it was detected in the trichrome stained slides of 3 patients. Amoeba prevalence in the 15-44 age-group was significantly high when compared with the 0-14 age group. The prevalence of pathogenic parasites was high among the people who had a toilet outdoors. Drinking water was thought to be a principal source of this outbreak.

[Diagnosis of intestinal-protozoa in patients with immune deficiency]

In our study, we tried to detect gastroenteritis causing intestinal protozoa in patients with immune deficiency and who suffered from diarrhea. We also tried to determine which laboratory methods should be used in detecting intestinal protozoon in these patients. Thirty-six immune deficient patients who had had diarrhea for more than 10 days and 44 immune deficient patients without diarrhea were included in the study. In stool samples taken from all cases, intestinal protozoa were detected using the conventional diagnostic methods including direct wet mount, trichrome and modified acid fast staining as well as serologic diagnostic methods such as ELISA, direct fluorescent antibody (DFA)] and the molecular method of polymerized chain reaction. In our study, we found that intestinal protozoan such as G. intestinalis; C. parvum, B. hominis and E. histolytica could be responsible for the long term diarrhea in patients with immune deficiency. If a pathogen is not detected in the feces by native Lugol (NL), DFA and MAF are suitable techniques for Cryptosporidium spp while ELISA or trichrome staining are suitable methods for E. histolytica. It was concluded in the study that the simple and inexpensive NL method is sufficient in the diagnosis of G. intestinalis and serological or molecular methods are unnecessary. Neutropenia in patients with immune deficiency did not enhance the frequent occurrence of intestinal protozoan infections; and also, in the cases with immune deficiency, it was found that the administration of steroid treatment was not a risk factor in intestinal protozoan disease.

Detection of Cryptosporidium spp and other intestinal parasites in children with acute diarrhea and severe dehydration in Rio de Janeiro

The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3%) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7%) samples examined via the direct or Ritchie methods. Other parasites identified were Ascaris lumbricoides (4.2%), Blastocystis hominis (1.4%), Entamoeba coli (0.9%), Entamoeba histolytica/Entamoeba dispar (0.5%), Endolimax nana (0.5%), Trichuris trichiura (0.5%) and Enterobius vermicularis (0.5%).

An outbreak of cryptosporidiosis suspected to be related to contaminated food, October 2006, Sakai City, Japan

On October 17, 2006, the Sakai City Public Health Center received a report of acute gastroenteritis among 4 members from the same company who had eaten raw meat dish called "Yukke: Korean-style beef tartar" and raw liver at a rotisserie in Sakai City on October 7. Based on information from interviews, the median incubation period was 5.5 (range, 5-7 days), and the median length of illness was 7 days (range, 4-10 days). The illness was characterized by a prolonged incubation period, non-bloody watery diarrhea, reduced vomiting, and light fever, which led us to suspect an enteric protozoan infection. Stool specimens obtained from 3 of the 4 symptomatic patients were positive for Cryptosporidium oocysts. They, along with 2 food workers, were negative for food poisoning bacteria or Norovirus. Genotyping of the Cryptosporidium isolates by direct sequencing of PCR products revealed that all the isolates were the C. parvum genotype II (bovine) and the subgenotype of IIa with 100 % homology with respective 18S rRNA and Cpgp40/15 genes. Positive implementation of tests for enteric protozoa including Cryptosporidium is necessary in the differential diagnosis of suspected foodborne gastroenteritis, particularly when it is characterized by a prolonged incubation period and severe watery diarrhea. In fact, we were able to diagnose the illness as cryptosporidiosis without waiting for the results of bacteriological and virological examinations, and thus prevented the possible occurrence of a secondary infection through an ill patient who works as cooking personnel in the company.

Molecular characterization of human isolates of Giardia duodenalis from Ethiopia

Giardia duodenalis, a flagellated protozoan, represents a common cause of gastroenteritis in Ethiopia, however very little information is available on the epidemiology and transmission routes of this pathogen, and a genetic characterization of the parasite has never been attempted in this country. The aim of this study was the genetic analysis of human isolates of G. duodenalis collected in different localities across the country, both from urban and rural areas. A fragment of the beta-giardin gene was amplified by nested PCR and analyzed by restriction and sequence analyses. Of the 59 isolates examined, 31 (52%) were typed as assemblage A and 13 (22%) as assemblage B. A strong correlation between the presence of symptoms and infection with assemblage B was observed. The remaining 15 (25%) isolates were typed as mixed infections by PCR-RFLP, specifically, A+F (in seven isolates) and A+B (in eight isolates). Sequencing of the A+F products confirmed the presence of assemblage F in three isolates, whereas the remaining four were identified as assemblage A. The detection of assemblage F, a cat-specific assemblage that to date has not been associated with human infections, was not able to be confirmed by the analysis of two commonly used markers (small subunit ribosomal RNA and triosephosphate isomerase). The analysis of the one isolate that was successfully amplified with the glutamate dehydrogenase primers unambiguously identified it as G. duodenalis, yet it was distinct from the established A and F sequences; thus the exact genetic identity of these isolates remains unclear.

Outbreak of waterborne cryptosporidiosis associated with low oocyst concentrations

Water treatment plants in the United Kingdom at significant risk of cryptosporidiosis and using conventional filtration methods have been required to install 24-h monitoring systems since April 2000. No major waterborne outbreaks have been described since 2001. Small outbreaks have been associated with water. This paper describes such an outbreak. Data from a local multi-agency surveillance system was used to describe the outbreak, including mapping cases against water supply zones. A case-control study investigated hypotheses raised. All cases were genotype 1. Early cases were in the supply zone of a surface water-treatment plant that had met treatment standards. Later cases included residents in a different supply zone that temporarily received water from the implicated plant. Cases reported more consumption of domestic mains water than controls. Descriptive and analytical epidemiology thus supported drinking water as a source of cryptosporidiosis from a plant meeting regulatory requirements. The evidence for setting drinking-water standards needs review.

[The Giardia epidemic in 2004 and out-of-hours service in Bergen]

BACKGROUND

From October to December 2004, 1,300 individuals were infected with Giardia lamblia in Bergen, Norway. The aim of this study was to explore this epidemic from the perspective of an accident and emergency department in Bergen.

MATERIAL AND METHODS

Patient files from 2004 were searched retrospectively in Bergen accident and emergency department, for patients with a diagnosis of infectious gastroenteritis or with the word Giardia: in the laboratory section of their files. Information from the files where Giardia tests had been done, was collected and analysed.

RESULTS

A total of 1,603 patients with infectious gastroenteritis were found. The number of patients with gastroenteritis more than doubled six weeks before the Giardia epidemic was recognized. 420 patients had been tested for Giardia, and 200 of them had positive tests. Most of the patients with positive Giardia tests were in their twenties. Symptoms and findings of the gastroenteritis patients with positive Giardia tests were unspecific and not very alarming.

INTERPRETATION

The Giardia epidemic probably started six weeks before it was recognized as such. Giardia infection is difficult to recognize on clinical grounds alone.

[An outbreak of giardiasis in a child day-care centre in Trondheim]

BACKGROUND

The prevalence of Giardia in Norway is considered to be low, but the infection is probably under-diagnosed. In other countries, child day-care centres have turned out to be major sites of Giardiasis contamination and outbreaks. We report the first giardiasis-outbreak registered in Norway.

MATERIALS AND METHODS

The outbreak occurred in a child day-care centre in Trondheim, Norway in 2004. Out of 12 microbiologically verified cases, 9 had clinical gastroenteritis. Stool samples were collected from all children and staff in the day-care centre, and from all household members of identified carriers. All carriers were treated with metronidazole and responded well to treatment. The environment of the child day-care centre was assessed, and all affected households were interviewed by telephone. Preventative measures were implemented.

RESULTS AND INTERPRETATION

The outbreak may have started in November 2003 and lasted until July 2004. It was limited to one of the day-care centre's five sections and 44% were infected. The source of infection was not identified, but there are several possibilities: staff who changed nappies and helped with going to the toilet also prepared and served food. Washbasin taps in kitchens and nappy-changing rooms were hand-operated. Cups used for drinking were exposed to potential contamination. These conditions are regarded as important routes for infections.

A computer model to simulate control of parasitic gastroenteritis in sheep on UK farms

A computer model that simulates the population dynamics and epidemiology of three major species of parasitic nematodes of sheep found in the UK (Telodorsagia [Ostertagia] spp., Haemonchus spp. and Trichostrongylus spp.) is described. The model has been developed as a tool for veterinarians and advisors to aid in the implementation of integrated parasite control strategies designed to optimise anthelmintic usage and delay the development of resistance on UK farms. The model represents the parasite life cycle, flock dynamics and the response of individuals with different susceptible and resistant genotypes to the major broad-spectrum classes of anthelmintic available in the UK. Where possible, UK data have been used for the model parameters. The model allows worm control simulations on individual UK farms. Inputs include environmental and farm management variables which impact on the epidemiology of the disease, e.g. regional weather data; flock stocking rates; initial pasture larval contamination levels and species proportions; lambing dates; timing of flock movements to clean pastures; and removal of lambs during the year. Farm management data, as well as nematode egg outputs and grass larval counts, were collected from eight UK farms over a 1-year period for initial validation of the model outputs. The management data for each farm were used as inputs for each model run and model outputs for nematode egg counts from ewes and lambs were compared to the observed data for each farm. Statistical analysis of results shows a positive correlation for observed and simulated counts and regression analysis suggests an acceptable fit between the data. Comparison of observed and simulated outputs for resistance were possible for only one farm due to low numbers of worms developing in the laboratory tests. Additional studies will be necessary before resistance data can be reliably compared. Further validation studies are proposed to ensure that the model is robust and applicable across a diverse range of farm types. The model will be used to demonstrate the advantage, in terms of delaying resistance development, of current guidelines for anthelmintic use and management practices for worm control in sheep.