High detection rates of enteropathogens in asymptomatic children attending day care

Gastrointestinal Panel Performance for the Diagnosis of Acute Gastroenteritis in Pediatric Patients

BACKGROUND

Various methods are used to identify the causative organisms of acute gastroenteritis (AGE) in children. The gastrointestinal (GI) panel has the potential to detect up to 22 pathogens rapidly through the multiplex real-time PCR test. We studied the impact of the GI panel on clinical management in the pediatric population.

METHODS

A retrospective study was conducted to collect data on GI panel results and clinical details of inpatient children presenting with AGE at King Hamad University Hospital, Kingdom of Bahrain, over the course of one year.

RESULTS

One hundred nine samples were collected. The GI panel was positive in 96 samples (88.1%), with the majority detected in the toddler age group. Forty-one (42.7%) samples were positive for at least one organism. Salmonella was the most frequently encountered bacteria as a single isolate, 10/55 (18.2%), while enteropathogenic Escherichia coli was the most common co-infected organism, 16/41 (39%). Norovirus was the most common virus among the viruses. Bacterial detection peaked from July to October, while viral detection plateaued throughout the year. The GI panel and stool culture were positive for the same organism in 17 samples, versus one sample with a different organism. Sixty-two (56.9%) samples had a positive GI panel but negative stool cultures and stool analysis, and half of those detected viruses. The GI panel was positive in 86.2% of severely ill patients; the majority were bacteria. Bacterial detection was associated with a higher CRP compared to viruses.

CONCLUSION

The GI panel is an informative tool for detecting the causative pathogen of AGE in children. However, it can detect multiple organisms, indicating a possible carrier status, which points toward future studies.

Factors Associated With Actionable Gastrointestinal Panel Results in Hospitalized Children

OBJECTIVES

There is uncertainty regarding which hospitalized patients with acute gastroenteritis (AGE) benefit from gastrointestinal panel (GIP) testing. Unnecessary testing may lead to increased costs, overdiagnosis, and overtreatment. In general, AGE management and outcomes are most impacted if an actionable (bacterial or parasitic) result is obtained. We aimed to assess which clinical reasons for ordering GIP testing ("order indications") and patient factors were associated with actionable results.

METHODS

This is a cross-sectional study of pediatric patients hospitalized between 2015 and 2018 at a large pediatric health care system with diarrhea and a GIP performed. Multivariable regression analysis was used to determine associations between actionable GIP results and order indication, stool frequency, and demographics. Findings were evaluated in patients with complex chronic conditions (CCC) and non-CCC patients.

RESULTS

There were 1124 GIPs performed in 967 encounters. Non-CCC patients had more actionable results than CCC patients, and reasons for testing differed. Across both cohorts, age ≥1 year old was positively associated with actionable results. For non-CCC patients, actionable results were associated with "diarrhea with blood or pus" order indication and nonwinter season; international travel was associated with non-Clostridioides difficile bacteria and parasites. No order indications were associated with actionable results for CCC patients.

CONCLUSIONS

Patient factors and order indications that may help identify children hospitalized for AGE with actionable GIP results include older age (regardless of CCC status), as well as bloody stools and international travel in previously healthy children. Prospective validation of these findings could help improve diagnostic stewardship and decrease unnecessary testing.

Comparison of a Rapid Multiplex Gastrointestinal Panel with Standard Laboratory Testing in the Management of Children with Hematochezia in a Pediatric Emergency Department: Randomized Controlled Trial

Advances in diagnostic microbiology allow for the rapid identification of a broad range of enteropathogens; such knowledge can inform care and reduce testing. We conducted a randomized, unblinded trial in a tertiary-care pediatric emergency department. Participants had stool (and rectal swabs if stool was not immediately available) tested using routine microbiologic approaches or by use of a device (BioFire FilmArray gastrointestinal panel), which identifies 22 pathogens with a 1-h instrument turnaround time. Participants were 6 months to <18.0 years and had acute bloody diarrhea. Primary outcome was performance of blood tests within 72 h. From 15 June 2018 through 7 May 2022, 60 children were randomized. Patients in the BioFire FilmArray arm had a reduced time to test result (median 3.0 h with interquartile range [IQR] of 3.0 to 4.0 h, versus 42.0 h (IQR 23.5 to 47.3 h); difference of -38.0 h, 95% confidence interval [CI] of -41.0 to -22.0 h). Sixty-five percent (20/31) of participants in the BioFire FilmArray group had a pathogen detected-most frequently enteropathogenic Escherichia coli (19%), Campylobacter (16%), and Salmonella (13%). Blood tests were performed in 52% of children in the BioFire FilmArray group and 62% in the standard-of-care group (difference of -10.5%, 95% CI of -35.4% to 14.5%). There were no between-group differences in the proportions of children administered intravenous fluids, antibiotics, hospitalized, or who had diagnostic imaging performed. Testing with the BioFire FilmArray reduced the time to result availability by 38 h. Although statistical significance was limited by study power, BioFire FilmArray use was not associated with clinically meaningful reductions in health care utilization or improved outcomes. IMPORTANCE Advances in diagnostic microbiology now allow for the faster and more accurate detection of an increasing number of pathogens. We determined, however, that in children with acute bloody diarrhea, these advances did not necessarily translate into improved clinical outcomes. While a greater number of pathogens was identified using a rapid turnaround multiplex stool diagnostic panel, with a reduction in the time to stool test result of over 1.5 days, this did not alter the practice of pediatric emergency medicine physicians, who continued to perform blood tests on a large proportion of children. While our conclusions may be limited by the relatively small sample size, targeted approaches that educate clinicians on the implementation of such technology into clinical care will be needed to optimize usage and maximize benefits.

Molecular analysis of enteropathogenic Escherichia coli (EPEC) isolates from healthy food-producing animals and humans with diarrhoea

Enteropathogenic Escherichia coli (EPEC) is a pathogen associated with acute diarrhoea in humans. To determine whether EPEC isolated from healthy food-producing animals possesses the same virulence gene repertoire as EPEC isolated from human with diarrhoea, we compared six typical EPEC (tEPEC) and 20 atypical EPEC (aEPEC) from humans with diarrhoea and 42 aEPEC from healthy animals (swine, sheep and buffaloes), using pulsed-field gel electrophoresis (PFGE), virulence markers, serotyping and subtyping of eae and tir genes. We found that human and animal isolates shared virulence genes, including nleB, nleE and nleF, which were associated with human diarrhoea. Serogroups and serotypes identified in isolates of food-producing animals such as O26:H11, O128:H2, O76:H7, O103, O108, O111 and O145, have previously been implicated in human disease. The subtypes eae and tir were also shared between human and animal isolates, being eae-γ1 and eae-β1 the most prevalent in both groups, while the most common tir subtypes were α and β. Despite PFGE analysis demonstrating that EPEC strains are heterogeneous and there was no prevalent clone identified, EPEC isolated from humans and food-producing animals shared some characteristics, such as virulence genes associated with human diarrhoea, indicating that food-producing animals could play a role as reservoirs for those genes.

Pathophysiology of Enteropathogenic Escherichia coli-induced Diarrhea

Enteropathogenic Escherichia coli (EPEC) are important diarrheal pathogens of infants and young children. Since the availability of molecular diagnosis methods, we now have new insights into the incidence and prevalence of these infections. Recent epidemiological studies indicate that atypical EPEC (aEPEC) are seen more frequently than typical EPEC (tEPEC) worldwide, including in both endemic diarrhea and diarrhea outbreaks. Therefore, it is important to further characterize the pathogenicity of these emerging strains. The virulence mechanisms and pathophysiology of the attaching and effacing lesion (A/E) and the type-three-secretion-system (T3SS) are complex but well-studied. A/E strains use their pool of locus of enterocyte effacement (LEE)-encoded and non-LEE-encoded effector proteins to subvert and modulate cellular and barrier properties of the host. However, the exact mechanisms of diarrhea in EPEC infection are not completely understood. From the clinical perspective, there is a need for fast, easy, and inexpensive diagnostic methods to define optimal treatment and prevention for children in endemic areas. In this article, we present a review of the classification of EPEC, epidemiology, pathogenesis of the disease caused by these bacteria, determinants of virulence, alterations in signaling, determinants of colonization vs. those of disease, and the limited information we have on the pathophysiology of EPEC-induced diarrhea. This article combines peer-reviewed evidence from our own studies and the results of an extensive literature search in the databases PubMed, EMBASE, and Scopus.

Selected commensals educate the intestinal vascular and immune system for immunocompetence

BACKGROUND

The intestinal microbiota fundamentally guides the development of a normal intestinal physiology, the education, and functioning of the mucosal immune system. The Citrobacter rodentium-carrier model in germ-free (GF) mice is suitable to study the influence of selected microbes on an otherwise blunted immune response in the absence of intestinal commensals.

RESULTS

Here, we describe that colonization of adult carrier mice with 14 selected commensal microbes (OMM¹² + MC²) was sufficient to reestablish the host immune response to enteric pathogens; this conversion was facilitated by maturation and activation of the intestinal blood vessel system and the step- and timewise stimulation of innate and adaptive immunity. While the immature colon of C. rodentium-infected GF mice did not allow sufficient extravasation of neutrophils into the gut lumen, colonization with OMM¹² + MC² commensals initiated the expansion and activation of the visceral vascular system enabling granulocyte transmigration into the gut lumen for effective pathogen elimination.

CONCLUSIONS

Consortium modeling revealed that the addition of two facultative anaerobes to the OMM¹² community was essential to further progress the intestinal development. Moreover, this study demonstrates the therapeutic value of a defined consortium to promote intestinal maturation and immunity even in adult organisms. Video Abstract.

Clinical impact of a gastrointestinal PCR panel in children with infectious diarrhoea

OBJECTIVES

Multiplex gastrointestinal PCR (GI-PCR) allows fast and simultaneous detection of 22 enteric pathogens (including Campylobacter, Salmonella, Shigella/enteroinvasive Escherichia coli (EIEC), among other bacteria, parasites and viruses). However, its impact on the management of children with infectious diarrhoea remains unknown.

PATIENTS/DESIGN

All children eligible for stool culture from May to October 2018 were prospectively included in a monocentric study at Robert-Debré University-Hospital.

INTERVENTION

A GI-PCR (BioFire FilmArray) was performed on each stool sample.

MAIN MEASURES

Data on the children's healthcare management before and after GI-PCR results were collected. Stool culture results were also reported.

RESULTS

172 children were included. The main criteria for performing stool analysis were mucous/bloody diarrhoea and/or traveller's diarrhoea (n=130). GI-PCR's were positive for 120 patients (70%). The main pathogens were enteroaggregative E. coli (n=39; 23%), enteropathogenic E. coli (n=34; 20%), Shigella/EIEC (n=27; 16%) and Campylobacter (n=21; 12%). Compared with stool cultures, GI-PCR enabled the detection of 21 vs 19 Campylobacter, 12 vs 10 Salmonella, 27 Shigella/EIEC vs 13 Shigella, 2 vs 2 Yersinia enterocolitica, 1 vs 1 Plesiomonas shigelloides, respectively. Considering the GI-PCR results and before stool culture results, the medical management was revised for 40 patients (23%): 28 initiations, 2 changes and 1 discontinuation of antibiotics, 1 hospitalisation, 2 specific room isolations related to Clostridioides difficile infections, 4 additional test prescriptions and 2 test cancellations.

CONCLUSION

The GI-PCR's results impacted the medical management of gastroenteritis for almostone-fourth of the children, and especially the prescription of appropriate antibiotic treatment before stool culture results.

Potentially Pathogenic Organisms in Stools and Their Association With Acute Diarrheal Illness in Children Aged <2 Years

BACKGROUND

Acute diarrheal illness (ADI) causes a substantial disease burden in high-income countries. We investigated associations between potentially pathogenic organisms in stools and ADI by polymerase chain reaction (PCR) in Australian children aged <2 years.

METHODS

Children in a community-based birth cohort had gastrointestinal symptoms recorded daily and stool samples collected weekly until their second birthday. Diarrhea was defined as ≥3 liquid or looser than normal stools within a 24-hour period. PCR assays tested for 11 viruses, 5 bacteria, and 4 protozoa. Detections of a new organism or of the same following at least 2 negative tests were linked to ADIs, and incidence rates and estimates of association with ADI were calculated.

RESULTS

One hundred fifty-four children provided 11 111 stool samples during 240 child-years of observation, and 228 ADIs were linked to samples. Overall, 6105 (55%) samples tested positive for a target organism. The incidence rate of 2967 new detections was 11.9 (95% confidence interval 11.4-12.3) per child-year, with 2561 (92%) new detections unrelated to an ADI. The relative risk of an ADI was 1.5-6.4 times greater for new detections of adenovirus, enterovirus, norovirus GII, parechovirus A, wild-type rotavirus, sapovirus GI/II/IV/V, Salmonella, Blastocystis, and Cryptosporidium, compared to when these were absent.

CONCLUSIONS

Wild-type rotavirus, norovirus GII, sapovirus GI/II/IV/V, adenovirus 40/41, and Salmonella were associated with ADI in this age group and setting. However, high levels of asymptomatic shedding of potential pathogens in stools from children may contribute to diagnostic confusion when children present with an episode of ADI.

High prevalence of small intestine bacteria overgrowth and asymptomatic carriage of enteric pathogens in stunted children in Antananarivo, Madagascar

Environmental Enteric Dysfunction (EED) refers to an incompletely defined syndrome of inflammation, reduced absorptive capacity, and reduced barrier function in the small intestine. It is widespread among children and adults in low- and middle-income countries and is also associated with poor sanitation and certain gut infections possibly resulting in an abnormal gut microbiota, small intestinal bacterial overgrowth (SIBO) and stunting.

We investigated bacterial pathogen exposure in stunted and non-stunted children in Antananarivo, Madagascar by collecting fecal samples from 464 children (96 severely stunted, 104 moderately stunted and 264 non-stunted) and the prevalence of SIBO in 109 duodenal aspirates from stunted children (61 from severely stunted and 48 from moderately stunted children). SIBO assessed by both aerobic and anaerobic plating techniques was very high: 85.3% when selecting a threshold of ≥10⁵ CFU/ml of bacteria in the upper intestinal aspirates. Moreover, 58.7% of the children showed more than 10⁶ bacteria/ml in these aspirates. The most prevalent cultivated genera recovered were Streptococcus, Neisseria, Staphylococcus, Rothia, Haemophilus, Pantoea and Branhamella. Feces screening by qPCR showed a high prevalence of bacterial enteropathogens, especially those categorized as being enteroinvasive or causing mucosal disruption, such as Shigella spp., enterotoxigenic Escherichia coli, enteropathogenic E. coli and enteroaggregative E. coli. These pathogens were detected at a similar rate in stunted children and controls, all showing no sign of severe diarrhea the day of inclusion but both living in a highly contaminated environment (slum-dwelling). Interestingly Shigella spp. was the most prevalent enteropathogen found in this study (83.3%) without overrepresentation in stunted children.

About 2 million children under the age of 5 suffer from stunted growth in Madagascar. Although deficient diet is the major cause of undernutrition, impaired absorption or assimilation caused by Environmental Enteric dysfunction (EED) has been proposed to play an important role in stunting. EED is widespread among children and adults in low- and middle-income countries (LMIC) and is also associated with undernutrition, poor sanitation, certain gut infections resulting in an abnormal gut microbiota and small intestinal bacterial overgrowth (SIBO) although the role of SIBO in EED remains unclear. The current study highlights the presence at high concentrations of bacterial taxa usually found in the oro-pharyngeal sphere in a high number of duodenal fluids of stunted children. This uncommon presence suggests a decompartmentalization of the gastrointestinal tract and a possible pro-inflammatory effect due to the ectopic presence of some of these bacteria in the duodenum.

The study also points to a high prevalence of enteropathogens (especially Shigella spp.) in the feces of both stunted and control children, hence preventing from proposing a direct association with stunting. This suggests that, beside combatting poverty and improving diet, environmental sanitation, quality of water sources, hygiene promotion and health education are key points to mitigate stunting and restore nutritional benefits.

Sapovirus, Norovirus and Rotavirus Detections in Stool Samples of Hospitalized Finnish Children With and Without Acute Gastroenteritis

BACKGROUND

Sapovirus, norovirus and rotavirus are major causes of childhood acute gastroenteritis (AGE) globally. Asymptomatic infections of these viruses have not been extensively studied.

AIM

To examine the prevalence and the genetic variations of sapovirus, norovirus and rotavirus in children with and without symptoms of AGE.

METHODS

We collected 999 stool samples from children under 16 years old from September 2009 to August 2011 at Tampere University Hospital, Finland. In total 442 children (44%) had symptoms of AGE and 557 patients (56%) had acute respiratory tract infection (ARTI) only. Samples were examined for sapovirus, norovirus and rotavirus using reverse transcription-polymerase chain reaction and the positive amplicons were sequenced.

RESULTS

Totally 54% and 14% of the patients in AGE and ARTI groups, respectively, tested positive. All viruses were more frequently detected in AGE patients than in ARTI patients (norovirus, 25% vs. 7.2%, respectively; rotavirus, 24% vs. 6.1%; sapovirus, 5.2% vs. 1.4%). In ARTI patients, the cases were seen most frequently during the first two years of life. Norovirus was the most detected pathogen in both groups with genogroup GII covering ≥97% of norovirus strains. Sapovirus was mostly detected in children under 18 months old without predominating genotype. Rotavirus was often detected after recent rotavirus vaccination and 18% and 88% of the strains were rotavirus vaccine-derived in AGE and ARTI groups, respectively.

CONCLUSIONS

We showed that the most common viruses causing gastroenteritis in children may be found in the stools of an asymptomatic carrier which may function as a potential reservoir for AGE.

The bacterial community of childcare centers: potential implications for microbial dispersal and child exposure

BACKGROUND

Bacterial communities within built environments reflect differences in sources of bacteria, building design, and environmental contexts. These communities impact the health of their occupants in many ways. Children interact with the built environment differently than do adults as a result of their unique behaviors, size, and developmental status. Consequently, understanding the broader bacterial community to which children are exposed will help inform public health efforts and contribute to our growing understanding of the bacterial community associated with childcare centers.

METHODS

We sampled childcare centers to survey the variation in bacterial community composition across five surfaces found inside and outside twelve classrooms and six centers using 16S rRNA marker gene amplicon sequencing. We then correlated these bacterial community analyses of surfaces with environmental and demographic measures of illumination and classroom occupant density.

RESULTS

The childcare environment was dominated by human-associated bacteria with modest input from outdoor sources. Though the bacterial communities of individual childcare centers differed, there was a greater difference in the bacterial community within a classroom than among centers. Surface habitats-fomites-within the classroom, did not differ in community composition despite differing proximity to likely sources of bacteria, and possible environmental filters, such as light. Bacterial communities did correlate with occupant density and differed significantly between high and low usage surfaces.

CONCLUSIONS

Our results suggest built environments inhabited by young children are similar to functionally equivalent built environments inhabited by adults, despite the different way young children engage with their environment. Ultimately, these results will be useful when further interrogating microbial dispersal and human exposure to microorganisms in built environments that specifically cater to young children.

From a case-control survey to a diagnostic viral gastroenteritis panel for testing of general practitioners' patients

OBJECTIVE

To evaluate the pathogenicity of a broad range of 11 possible gastroenteritis viruses, by means of statistical relationships with cases vs. controls, or Ct-values, in order to establish the most appropriate diagnostic panel for our general practitioner (GP) patients in the Netherlands (2010-2012).

METHODS

Archived stool samples from 1340 cases and 1100 controls were retested using internally controlled multiplex real-time PCRs for putative pathogenic gastroenteritis viruses: adenovirus, astrovirus, bocavirus, enterovirus, norovirus GI and GII, human parechovirus, rotavirus, salivirus, sapovirus, and torovirus.

RESULTS

The prevalence of any virus in symptomatic cases and asymptomatic controls was 16.6% (223/1340) and 10.2% (112/1100), respectively. Prevalence of astrovirus (adjusted odds ratio (aOR) 10.37; 95% confidence interval (CI) 1.34-80.06) and norovirus GII (aOR 3.10; CI 1.62-5.92) was significantly higher in cases versus controls. Rotavirus was encountered only in cases. We did not find torovirus and there was no statistically significant relationship with cases for salivirus (aOR 1,67; (CI) 0.43-6.54)), adenovirus non-group F (aOR 1.20; CI 0.75-1.91), bocavirus (aOR 0.85; CI 0.05-13.64), enterovirus (aOR 0.83; CI 0.50-1.37), human parechovirus (aOR 1.61; CI 0.54-4.77) and sapovirus (aOR 1.15; CI 0.67-1.98). Though adenovirus group F (aOR 6.37; CI 0.80-50.92) and norovirus GI (aOR 2.22, CI: 0.79-6.23) are known enteropathogenic viruses and were more prevalent in cases than in controls, this did not reach significance in this study. The Ct value did not discriminate between carriage and disease in PCR-positive subjects.

CONCLUSIONS

In our population, diagnostic gastroenteritis tests should screen for adenovirus group F, astrovirus, noroviruses GI and GII, and rotavirus. Case-control studies as ours are lacking and should also be carried out in populations from other epidemiological backgrounds.

Impact of Metronidazole Treatment and Dientamoeba Fragilis Colonization on Gut Microbiota Diversity

OBJECTIVES

The intestinal parasite Dientamoeba fragilis is a common colonizer of children in Denmark. Metronidazole has been used to reduce gastrointestinal symptoms in children colonized with D fragilis. We aimed to identify gut microbiota changes associated with D fragilis carrier status and metronidazole treatment of D fragilis-positive children.

METHODS

The fecal microbiota of 275 fecal samples from children treated with metronidazole (n = 48) or placebo (n = 48) were characterized by ribosomal DNA sequencing. Samples collected before (T1), 2 weeks after (T2), and 8 weeks (T5) after treatment were included. Seventy fecal samples from 70 age-matched parasite-negative children served as controls.

RESULTS

The abundance of 24 bacterial genera differed significantly according to D fragilis carrier status, with Flavonifractor being remarkably more abundant in children testing negative for D fragilis. Eight bacterial genera changed significantly in abundance in children losing versus keeping D fragilis after metronidazole treatment. Of these, 7 returned to pretreatment (T1) levels at T5. Meanwhile, the abundance of Flavonifractor continued to differ at T5, whereas for Ruminococcus the abundance only remained high in children who were D fragilis-negative at T2 and T5. Increases in Hungatella, Sutterella, and Streptococcus abundances observed at T2 were specific to metronidazole exposure and hence independent of D fragilis colonization.

CONCLUSIONS

This study revealed that specific bacterial genera were associated with D fragilis colonization. Metronidazole treatment had a short-term impact on the abundance of some bacterial genera, with most of these reverting to pretreatment levels 8 weeks after completed treatment.

Enteropathogenic Escherichia coli—A Summary of the Literature

Diarrheal disease is still a major public health concern, as it is still considered an important cause of death in children under five years of age. A few decades ago, the detection of enteropathogenic E. coli was made by detecting the O, H, and K antigens, mostly by agglutination. The recent protocols recommend the molecular methods for diagnosing EPEC, as they can distinguish between typical and atypical EPEC by identifying the presence/absence of specific virulence factors. EPEC are defined as diarrheagenic strains of E. coli that can produce attaching and effacing lesions on the intestinal epithelium while being incapable of producing Shiga toxins and heat-labile or heat-stable enterotoxins. The ability of these strains to produce attaching and effacing lesions enable them to cause localized lesions by attaching tightly to the surface of the intestinal epithelial cells, disrupting the surfaces of the cells, thus leading to the effacement of the microvilli. EPEC are classified on typical and atypical isolates, based on the presence or absence of E. coli adherence factor plasmids. All the EPEC strains are eae positive; typical EPEC strains are eae+, bfpA+, while atypical strains are eae+, bfpA−. No vaccines are currently available to prevent EPEC infections.

Description of Enteropathic Escherichia coli Species in Pediatric Patients at a Quaternary Children's Hospital

BACKGROUND

The epidemiology, demographics, clinical presentations, and outcomes associated with enteroaggregative Escherichia coli (EAEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) pathotypes in US children are not well understood.

METHODS

This study was a retrospective chart review of all pediatric patients with a stool sample submitted to the Children's Hospital Colorado clinical microbiology laboratory for testing with the BioFire FilmArray Gastrointestinal Pathogen Panel from October 2015 through October 2017.

RESULTS

During the study period, 5692 patient stool samples were submitted; 679 (13%) were positive for EAEC, EPEC, or ETEC. Of note, 163/232 (70%) patients with EAEC, 282/493 (57%) with EPEC, and 49/58 (85%) with ETEC had detection of at least 1 other pathogen. Of all E. coli-positive stool samples, only 158/679 (23%) were from low-risk patients who were singly infected with EAEC, EPEC, or ETEC. In this cohort, most cases were associated with acute diarrhea (50%), abdominal pain (61%), and/or cramping (49%) and presented without fever (14%), emesis (28%), or lethargy (7%). Thirteen (8%) of these 158 patients received antibiotics at the time of their initial presentation to care. Of the 145 patients who did not receive antibiotics at their initial visit, 23 (16%) returned to care due to persistence of symptoms.

CONCLUSIONS

Our results suggest that the majority of patients singly infected with EAEC, EPEC, or ETEC present with mild, self-limited, gastrointestinal (GI) complaints. Further research is needed to determine what role these pathogens might play in children who present with chronic or inflammatory GI symptoms.

Prevalence and Effect of Intestinal Infections Detected by a PCR-Based Stool Test in Patients with Inflammatory Bowel Disease

BACKGROUND

The advent of PCR-based stool testing has identified a greatly increased number of infectious agents in IBD, but their clinical significance is unknown.

AIMS

To determine the infectious agent prevalence and the clinical significance of these infectious agents in IBD patients.

METHODS

This cross-sectional study compared the prevalence of GI infections among IBD patients with active and quiescent disease versus healthy controls. Among actively inflamed patients, we compared clinical characteristics, medication use, and disease course between those with positive and negative tests.

RESULTS

Three hundred and thirty-three IBD patients and 52 healthy volunteers were included. The IBD group was divided into active Crohn's disease (CD, n = 113), inactive CD (n = 53), active ulcerative colitis (UC, n = 128), and inactive UC (n = 39). A significantly higher percentage of actively inflamed patients had positive stool tests (31.1%) compared to those with quiescent disease (7.6%, P = < 0.001) and healthy controls (13.5%, P = 0.01). In actively inflamed patients, shorter symptom duration and the use of multiple immunosuppressive agents were significantly associated with positive stool tests. Escalation of immunosuppressive therapy was less frequent in those with positive (61.3%) than with negative tests (77.7%, P = < 0.01). However, the need for surgery (13.3% vs. 18.7%, respectively, P = 0.31) and hospitalization (14.7% vs. 17.5%, respectively, P = 0.57) in 90 days was not significantly different.

CONCLUSION

GI infections are common in IBD patients with active disease. Evaluating patients for infection may help avoid unnecessary escalation of immunosuppressants, especially during an acute flare or combination immunosuppression.

Effectiveness of a hand hygiene program to reduce acute gastroenteritis at child care centers: A cluster randomized trial

We aimed to assess the effectiveness of an educational and hand hygiene program in daycare centers (DCCs) and homes on acute gastroenteritis (AGE) incidence in children attending DCCs.

METHODS

A randomized, controlled, and open study of 911 children aged 0-3 years attending 24 DCCs in Almería (Spain) with an 8-month follow-up was employed. Two intervention groups of DCCs families performed educational and hand hygiene measures, 1 with soap and water (soap and water group; n = 274), another with hand sanitizer (hand sanitizer group [HSG]; n = 339), and the control group (CG; n = 298) followed usual handwashing procedures. We compared AGE episode rates with Poisson regression model.

RESULTS

seven hundred fourteen AGE episodes were registered, significant differences between HSG and CG children were found during December and January. A multivariate model was applied and the adjusted incidence rate ratios by rotavirus vaccination found significant differences when children were previously vaccinated, the children in the soap and water group had a higher risk of AGE episodes (incidence rate ratio: 1.28, 95% confidence interval:1.0-1.64), compared with those in the HSG.

CONCLUSIONS

This study demonstrated that hand hygiene programs that included hand sanitizer were most effective in the winter months. Further, the largest reduction of AGE episodes occurred in the children that followed hand hygiene programs including hand sanitizer and educational measures for DCC staff, parents, and children, and were vaccinated for rotavirus.

How Food Affects Colonization Resistance Against Enteropathogenic Bacteria

Food has a major impact on all aspects of health. Recent data suggest that food composition can also affect susceptibility to infections by enteropathogenic bacteria. Here, we discuss how food may alter the microbiota as well as mucosal defenses and how this can affect infection. Salmonella Typhimurium diarrhea serves as a paradigm, and complementary evidence comes from other pathogens. We discuss the effects of food composition on colonization resistance, host defenses, and the infection process as well as the merits and limitations of mouse models and experimental foods, which are available to decipher the underlying mechanisms.

Norovirus transmission mediated by asymptomatic family members in households

The transmission of human norovirus excreted from infected persons occasionally causes sporadic infections and outbreaks. Both symptomatic patients and asymptomatic carriers have been reported to contribute to norovirus transmission, but little is known about the magnitude of the contribution of asymptomatic carriers. We carried out a 1-year survey of residents of a district of Bangkok, Thailand to determine the percentage of norovirus transmissions originating from asymptomatic individuals. We screened 38 individuals recruited from 16 families from May 2018 to April 2019 for GI and GII genotypes. Norovirus was detected every month, and 101 of 716 stool samples (14.1%) from individuals with no symptoms of acute gastroenteritis were norovirus-positive. The average infection frequency was 2.4 times per person per year. Fourteen genotypes were identified from the positive samples, with GII.4 being detected most frequently. Notably, 89.1% of the norovirus-positive samples were provided by individuals with no diarrhea episode. Similar to cases of symptomatic infections in Thailand, asymptomatic infections were observed most frequently in December. We detected 4 cases of NV infection caused by household transmission, and 3 of the 4 transmissions originated from asymptomatic individuals. We also identified a case in which norovirus derived from an asymptomatic individual caused diarrhea in a family member. These results suggest that asymptomatic individuals play a substantial role in both the maintenance and spreading of norovirus in a community through household transmission.

[Phylogenetic groups and virulence genes of Escherichia coli strains isolated from the children gut microbiota.]

Escherichia coli is characterized by a wide intraspecific diversity. The species includes both commensals and pathogens that cause diarrhea and extra-intestinal diseases. Pathogenic strains differ from non-pathogenic ones by the presence of virulence factors and their genes. The phylogenetic structure of the species is represented by four main groups (A, B1, B2, D), which differ in their prevalence among residents of different geographical regions. Pathogenic members of the species have been studied in detail, while non-pathogenic strains have not received such attention. This report presents the results of a study of 511 E. coli strains isolated from the gut microbiota of children without diarrhea and urinary tract infections, aged from 1 month to 17 years, living in St. Petersburg. The main phylogenetic groups were determined by PCR, and E. coli virulence genes associated with diarrhea and extra-intestinal diseases were identified. Results: population structure of E. coli is represented by the following groups: A-33.3%, B1-6.7%, B2-34.0%, D-26%. In the studied population 2.5% of strains belonded to EPEC and 4.5% to EAggEC. EPEC virulence genes were more often detected in strains of phylogroup B1, and EAggEC virulence genes in isolates of phylogroup D. The prevalence of extra - intestinal virulence genes was as follows: pap - 29.5%; sfa - 19.8%; afa - 3.3%; hly - 20.9%; cnf - 17.4%; aer-20.0%. The pap, sfa, hly, and cnf genes were detected mostly in the B2 phylogenetic group. Obtained data shows the similarity of E. coli phylogenetic groups structure in St. Petersburg with E. coli populations isolated from residents of Paris and Sydney. Analysis of the virulence genes prevalence showed the dependence of their presence on the genetic background bacteria.

Updates on Rapid Diagnostic Tests in Infectious Diseases

In the last two decades there have been dramatic advances in development of rapid diagnostic tests. Turnaround time of the assays have significantly been shortened which led to reductions in time to appropriate antimicrobial therapy and improvement of patient clinical outcomes. Molecular-based assays generally have better sensitivity than conventional methods, but the cost is higher. The results need to be interpreted cautiously as detection of colonized organisms, pathogen detection in asymptomatic patients, and false negative/positive can occur. Indications and cost-effectiveness need to be considered for appropriate utilization of rapid diagnostic tests.

Determinants of Childhood Zoonotic Enteric Infections in a Semirural Community of Quito, Ecuador

Domestic animals in the household environment have the potential to affect a child's carriage of zoonotic enteric pathogens and risk of diarrhea. This study examines the risk factors associated with pediatric diarrhea and carriage of zoonotic enteric pathogens among children living in communities where smallholder livestock production is prevalent. We conducted an observational study of children younger than 5 years that included the analysis of child (n = 306) and animal (n = 480) fecal samples for Campylobacter spp., atypical enteropathogenic Escherichia coli, Shiga toxin-producing E. coli, Salmonella spp., Yersinia spp., Cryptosporidium parvum, and Giardia lamblia. Among these seven pathogens, Giardia was the most commonly identified pathogen among children and animals in the same household, most of which was found in child-dog pairs. Campylobacter spp. was also relatively common within households, particularly among child-chicken and child-guinea pig pairs. We used multivariable Poisson regression models to assess risk factors associated with a child being positive for at least one zoonotic enteric pathogen or having diarrhea during the last week. Children who interacted with domestic animals-a behavior reported by nearly three-quarters of households owning animals-were at an increased risk of colonization with at least one zoonotic enteric pathogen (prevalence ratio [PR] = 1.56, 95% CI: 1.00-2.42). The risk of diarrhea in the last seven days was elevated but not statistically significant (PR = 2.27, CI: 0.91, 5.67). Interventions that aim to reduce pediatric exposures to enteric pathogens will likely need to be incorporated with approaches that remove animal fecal contamination from the domestic environment and encourage behavior change aimed at reducing children's contact with animal feces through diverse exposure pathways.

Fecal calprotectin as a factor that supports the pathogenicity of Dientamoeba fragilis

Calprotectin is a protein that is mostly released from neutrophils, monocytes, macrophages and submucosal epithelial cells. Fecal calprotectin (f-CP) is a marker of intestinal inflammation. There are some discussions about the pathogenicity of D. fragilis in the gastrointestinal tract. In this study, we investigated whether f-CP level is a factor supporting the pathogenicity of D. fragilis. The f-CP levels were evaluated in patients with only D. fragilis positive in comparison with healthy controls. Moreover, the levels of f-CP were investigated in fecal samples of D. fragilis negative patients with gastrointestinal complaints. The fecal samples were collected from three groups. Three groups of fecal samples were examined directly microscopy, trichrome staining, cultivation, enzyme immunoassay (EIA) and real-time PCR assay. In the first group (Group 1, n = 34), patient stool samples with gastrointestinal symptoms (without other pathogens) found only with D. fragilis were included. In the second group (Group 2, n = 31), there were patients' stool samples with gastrointestinal symptoms that D. fragilis was negative (but there may be other pathogenic agents). In the control group (Group 3, n = 23), we used fecal samples collected from healthy volunteers without any infection or gastrointestinal complaints. The collected fecal samples were stored at -20 °C until analysis. Levels of f-CP were determined by using human calprotectin ELISA kits. Total of 88 patients were enrolled in three different groups. We obtained f-CP levels as follows: 33.40 ng/mg protein in the group 1, 15.99 ng/mg protein in the group 2 and 1.54 ng/mg protein in the group 3. Statistically significant difference in f-CP levels of the group 1 and the group 2 were obtained when compared with healthy controls (p < 0.0001). However, the f-CP levels of the group 1 were not significantly different from the group 2 (p > 0.99). In conclusion, increased levels of f-CP are shown as a marker of an inflammatory disease of the lower gastrointestinal tract in infected humans. There is continues controversy about the pathogenicity of D. fragilis in symptomatic and asymptomatic patients. The findings of this study contribute to the ongoing debate about the pathogenicity of D. fragilis. In our study, the potential pathogenicity of D. fragilis is associated with increased f-CP concentrations with parasite detection in the fecal samples and therefore we assume that the parasite is not only a harmless commensal. In summary, higher levels of f-CP found in D. fragilis positive patients suggest the importance of researches that support the pathogenicity of indicated parasite.

Identification of Norovirus and Human Parechovirus in Patients With Hand, Foot and Mouth Disease Syndrome

BACKGROUND

Hand, foot and mouth disease (HFMD) is caused mostly by enteroviruses. However, other viral agents also can cause similar syndromes, and hence, the infections they cause are often misdiagnosed clinically. To determine non-enterovirus etiologic agents in HFMD-like cases, we screened enterovirus-negative samples collected from the patients who were clinically diagnosed as HFMD in China.

METHODS

Two hundred enterovirus-negative samples were collected previously in Wenzhou city of Zhejiang province, China. Both high throughput sequencing and RT-PCR were used to screen viral agents. In addition, their clinical features were analyzed.

RESULTS

Norovirus (NoV) and human parechovirus (HPeV) were identified from 22 (11.00%) and 9 (4.50%) samples, respectively. In addition, the complete genome sequences were recovered from 4 NoV-positive samples, and the VP1/3Dpol gene sequences were recovered from 5 HPeV-positive samples. Phylogenetic analyses of the NoV sequences revealed that they were closely related to those circulated in other regions of China. Notably, 4 genotypes of HPeVs, including HPeV-1, HPeV-4, HPeV-5 and HPeV-14, were found, indicating high genetic diversity of the virus. Frequent recombination between various genotypes was also observed in the HPeVs. Although most of the patients presented with the clinical features of HFMD, 4 patients infected with NoV GII.4 and 3 patients infected with HPeV-1 (1) and HPeV-4 (2) were characterized with diarrhea. Finally, tonsillitis, convulsion and granulocytopenia were observed in 1 NoV GII.4 patient, while liver dysfunction was found in 1 NoV GII.17 patient.

CONCLUSIONS

These data reveal the variety of agents in the cases clinically diagnosed as HFMD.

Variation in surface decontamination practices among Michigan child care centers compared to state and national guidelines

BACKGROUND

Environmental decontamination is one of the most effective methods to prevent transmission of infectious pathogens in child care centers (CCCs). Alongside state recommendations, national organizations-including the American Academy of Pediatrics (AAP)-offer best-practice policies. In Michigan, these sets of guidelines differ, and the extent to which CCC practices agree with either set of protocols is unknown.

METHODS

A survey of environmental decontamination practices was administered at a professional meeting of CCC directors (N = 24) in a single Michigan county. CCC practices (eg, products, locations, frequencies) were compared to state and AAP guidelines. Bivariate analyses investigated CCC characteristics as predictors of decontamination policy agreement.

RESULTS

CCC agreement with established policy was slightly higher for national AAP guidelines (66%) than Michigan standards (59%). The use of an outside child care health consultant was strongly associated with a significantly higher level of agreement with state decontamination policy (P = .01).

CONCLUSION

We noted substantial disagreement between county CCC practices and state/national guidelines, regardless of CCC size or director experience. Results highlight opportunities to improve CCC director familiarity with current state and nationally advised protocols, to consolidate state licensing and AAP guidelines, and to promote the use of child care health consultants.

Incidence and economic burden of community-acquired gastroenteritis in the Netherlands: Does having children in the household make a difference?

This study aimed at estimating gastroenteritis (GE) incidence in all age groups of the Netherlands’ general population, with special emphasis on the role of children in GE burden, and the associated costs. Monthly from November 2014 to November 2016, a random sample of 2000 residents in the Netherlands was invited to complete a questionnaire on household characteristics and health complaints. We calculated GE incidence rates standardized to the Dutch population and used multivariable logistic regression models to identify potential risk factors. We calculated the costs related to resources used within the healthcare sector, the resources used by patients and their families, and productivity losses (paid worktime) due to GE. The overall standardized incidence rate was 0.81 GE episodes/person-year, with the highest rate in children ≤4 years (1.96 episodes/person-year). GE was observed more often in households with children (≤17 years), especially if children attended out-of-home childcare services, and among individuals with non-native Dutch ethnic background. Less GE was observed among employed persons aged 25–64 years, compared with those unemployed, but the opposite was observed in persons ≥65 years. The average costs per GE episode was €191, resulting in €945 million annual total costs for GE in the Netherlands (€55 per inhabitant). The majority of costs (55%) were attributable to productivity losses of the ill or their caregivers. In conclusion, GE still poses a significant burden, particularly in preschool children and adults living in households with children. Similar to other industrialized countries, the major factor driving the costs due to GE was the loss of productivity. This study also provides up-to-date baseline GE incidence rates and associated societal costs to better contextualize the burden of the disease in support of policy making.

Comparison and Recommendations for Use of Dientamoeba fragilis Real-Time PCR Assays

Dientamoeba fragilis is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing D. fragilis in feces led to the development of real-time PCR methodologies for the detection of D. fragilis in stool samples. Prevalence studies in Europe show much higher levels of infection where a laboratory-developed real-time assay is the predominant assay for the detection of Dientamoeba fragilis than in regions that use the EasyScreen assay for detection of gastrointestinal pathogens. The aim of this study was to compare a commercially available Dientamoeba fragilis assay (Genetic Signatures EasyScreen assay) to a widely used laboratory-developed real-time PCR method. Two hundred fifty fecal samples were screened using the laboratory-developed real-time assay on four real-time PCR platforms producing a number of discrepant results. Limit-of-detection studies were undertaken to attempt to resolve sensitivity for each platform tested. The presence or absence of Dientamoeba fragilis DNA in discrepant samples was shown using PCR amplicon next-generation sequencing. Eukaryotic 18S diversity profiling was conducted on discrepant samples to identify the presence or absence of additional protozoan species in samples that may be responsible for cross-reactivity seen in these samples. The results revealed the potential for multiple false-positive results when using the laboratory-developed real-time assay across multiple real-time platforms using manufacturer default settings. This report provides recommendations to resolve these issues where possible and suggestions for future prevalence studies, and it emphasizes the EasyScreen assay as the molecular method of choice as well as the need for standardization of detection assays across all nations screening for D. fragilis.

Influence of the intestinal microbiota on disease susceptibility in kittens with experimentally-induced carriage of atypical enteropathogenic Escherichia coli

Typical enteropathogenic E. coli (tEPEC) carries the highest hazard of death in children with diarrhea and atypical EPEC (aEPEC) was recently identified as significantly associated with diarrheal mortality in kittens. In both children and kittens there is a significant association between aEPEC burden and diarrheal disease, however the infection can be found in individuals with and without diarrhea. It remains unclear to what extent, under what conditions, or by what mechanisms aEPEC serves as a primary pathogen in individuals with diarrhea. It seems likely that a combination of host and bacterial factors enable aEPEC to cause disease in some individuals and not in others. The purpose of this study was to determine the impact of aEPEC on intestinal function and diarrhea in kittens following experimentally-induced carriage and the influence of a disrupted intestinal microbiota on disease susceptibility. Results of this study identify aEPEC as a potential pathogen in kittens. In the absence of disruption to the intestinal microbiota, kittens are resistant to clinical signs of aEPEC carriage but demonstrate significant occult changes in intestinal absorption and permeability. Antibiotic-induced disruption of the intestinal microbiota prior to infection increases subsequent intestinal water loss as determined by % fecal wet weight. Enrichment of the intestinal microbiota with a commensal member of the feline mucosa-associated microbiota, Enterococcus hirae, ameliorated the effects of aEPEC experimental infection on intestinal function and water loss. These observations begin to unravel the mechanisms by which aEPEC infection may be able to exploit susceptible hosts.

Investigation of Dientamoeba fragilis Prevalence and Evaluation of Sociodemographic and Clinical Features in Patients with Gastrointestinal Symptoms

BACKGROUND

Dientamoeba fragilis is a protozoan parasite of the human gastrointestinal tract and still controversial in association with gastrointestinal symptoms.

PURPOSE

We present cross-sectional study of the prevalence of D. fragilis, and sociodemographic and clinical features in the patients with gastrointestinal symptoms.

METHODS

A total of 490 fecal specimens were collected from outpatients with gastrointestinal symptoms in the Department of Parasitology, Faculty of Medicine, Ege University and Celal Bayar University, Turkey. Fecal specimens were examined with microscopy and inoculated in Robinson medium. D. fragilis-positive samples were examined for the presence of other intestinal parasites using enzyme immunoassay. Real-time PCR analysis was performed on all samples.

RESULTS

Of the 490 stool specimens examined by real-time PCR, 59 patients were positive for D. fragilis infection with prevalence rate of 12.04%. Forty-four of positive patients (74.5%) were found to be infected with only D. fragilis, while 23.7% were co-infected with Blastocystis and 1.7% were co-infected with Rotavirus. No statistically significant difference was found in all the examined patients in terms of D. fragilis positivity for all sociodemographic parameters. Loose stool consistency was associated with the presence of D. fragilis, with 18.3% (P = 0.001). When the clinical symptoms of all the patients participating in this study were examined, diarrhea was statistically more significant in patients with the presence of D. fragilis (16.3%; P = 0.001). The rate of diarrhea in D. fragilis-positive patients (84.09%; P = 0.0005) was higher than that of D. fragilis-negative patients and it was statistically significant.

CONCLUSION

This study is important for assessing the prevalence of D. fragilis and its association with other factors in symptomatic patients in a large sample group in Turkey, as well as investigating the relationship of identified symptoms with the D. fragilis pathogenicity. It is suggested that D. fragilis in this case is not a commensal parasite but a pathogenic parasite and that the most common clinical symptom is diarrhea.

Children Attending Day Care Centers are a Year-round Reservoir of Gastrointestinal Viruses

Viral gastroenteritis causes high morbidity worldwide. In this study, stool samples from 179 children aged 0–6 years attending Danish day care centers were investigated for gastrointestinal viruses. Each child was observed for one year with submission of samples and questionnaires every two months. Adenovirus, norovirus, rotavirus, and sapovirus were detected in samples using real-time PCR. A total of 229 (33%) of the 688 samples collected tested positive for at least one virus. At the first sampling point, adenovirus was shed by 6%, norovirus genotype I by 3% and genotype II by 12%, rotavirus A by 9%, and sapovirus by 21% of the 142 children included in the risk factor analyses. Increasing age was identified as a protective factor against testing positive for gastrointestinal virus, whereas nausea during the previous two months was positively associated with testing positive. Odds of shedding adenovirus were 9.6 times higher among children treated with antibiotics within the previous two months than among children who were not. Gastrointestinal viruses were shed year-round and high viral loads were observed in samples from both symptomatic and asymptomatic children, suggesting children in day care as a reservoir and a possible source of spreading of viruses into the community.

Diagnostic Interpretation Guidance for Pediatric Enteric Pathogens: A Modified Delphi Consensus Process

Background

We sought to develop diagnostic test guidance definitions for pediatric enteric infections to facilitate the interpretation of positive test results in the era of multianalyte molecular diagnostic test platforms.

Methods

We employed a systematic, two-phase, modified Delphi consensus process consisting of three web-based surveys and an expert panel face-to-face meeting. In phase 1, we surveyed an advisory panel of North American experts to select pathogens requiring diagnostic test guidance definition development. In phase 2, we convened a 14-member expert panel to develop, refine, and select the final definitions through two web-based questionnaires interspersed with a face-to-face meeting. Both questionnaires asked panelists to rate the degree to which they agreed that if the definition is met the pathogen is likely to be causative of clinical illness.

Results

The advisory panel survey identified 19 pathogens requiring definitions. In the expert panel premeeting survey, 13 of the 19 definitions evaluated were rated as being highly likely (“agree” or “strongly agree”) to be responsible for acute gastroenteritis symptoms by ≥67% of respondent panel members. The definitions for the remaining six pathogens (Aeromonas, Clostridium difficile, Edwardsiella, nonenteric adenovirus, astrovirus, and Entamoeba histolytica) were indeterminate. After the expert panel meeting, only two of the modified definitions, C. difficile and E. histolytica/dispar, failed to achieve the a priori specified threshold of ≥67% agreement.

Conclusions

We developed diagnostic test guidance definitions to assist healthcare providers for 17 enteric pathogens. We identified two pathogens that require further research and definition development.

Updated cost-effectiveness and risk-benefit analysis of two infant rotavirus vaccination strategies in a high-income, low-endemic setting

BACKGROUND AND OBJECTIVE

Since 2013, a biennial rotavirus pattern has emerged in the Netherlands with alternating high and low endemic years and a nearly 50% reduction in rotavirus hospitalization rates overall, while infant rotavirus vaccination has remained below 1% throughout. As the rotavirus vaccination cost-effectiveness and risk-benefit ratio in high-income settings is highly influenced by the total rotavirus disease burden, we re-evaluated two infant vaccination strategies, taking into account this recent change in rotavirus epidemiology.

METHODS

We used updated rotavirus disease burden estimates derived from (active) surveillance to evaluate (1) a targeted strategy with selective vaccination of infants with medical risk conditions (prematurity, low birth weight, or congenital conditions) and (2) universal vaccination including all infants. In addition, we added herd protection as well as vaccine-induced intussusception risk to our previous cost-effectiveness model. An age- and risk-group structured, discrete-time event, stochastic multi-cohort model of the Dutch pediatric population was used to estimate the costs and effects of each vaccination strategy.

RESULTS

The targeted vaccination was cost-saving under all scenarios tested from both the healthcare payer and societal perspective at rotavirus vaccine market prices (€135/child). The cost-effectiveness ratio for universal vaccination was €51,277 at the assumed vaccine price of €75/child, using a societal perspective and 3% discount rates. Universal vaccination became cost-neutral at €32/child. At an assumed vaccine-induced intussusception rate of 1/50,000, an estimated 1707 hospitalizations and 21 fatal rotavirus cases were averted by targeted vaccination per vaccine-induced intussusception case. Applying universal vaccination, an additional 571 hospitalizations and <  1 additional rotavirus death were averted in healthy children per vaccine-induced intussusception case.

CONCLUSION

While universal infant rotavirus vaccination results in the highest reductions in the population burden of rotavirus, targeted vaccination should be considered as a cost-saving alternative with a favorable risk-benefit ratio for high-income settings where universal implementation is unfeasible because of budget restrictions, low rotavirus endemicity, and/or public acceptance.

The role of multiplex molecular panels for the diagnosis of gastrointestinal infections in immunocompromised patients

PURPOSE OF REVIEW

An increasing number of laboratories have implemented multiplex molecular panels for the diagnosis of gastrointestinal infections. This review focuses on recent data addressing the performance of US Food and Drug Administration-cleared multiplex gastrointestinal panels and discusses the advantages and limitations of these tests in the immunocompromised population.

RECENT FINDINGS

Testing for gastrointestinal pathogens using multiplex molecular panels increases sensitivity and detection of coinfections compared with routine testing methods. Furthermore, multiplex panels reduce turnaround time and may allow for more informed decisions regarding treatment and infection control measures. However, the routine use of multiplex gastrointestinal panels has led to an increase in the detection of certain organisms, such as enteroaggregative Escherichia coli and sapovirus, which many clinical laboratories did not specifically test for in the past. This has created a degree of confusion on how to best interpret the results of multiplex panels, especially in the immunocompromised host.

SUMMARY

Multiplex molecular panels provide a rapid and sensitive tool for the diagnosis of infectious diarrhea, and may allow for more timely decisions regarding the management of immunosuppressed patients. However, there are limitations associated with multiplex panels, including the interpretation of results and the cost associated with testing. Clinical microbiologists should work closely with clinicians to develop evidence-based algorithms to guide test utilization in this area.

Syndromic Panel-Based Testing in Clinical Microbiology

The recent development of commercial panel-based molecular diagnostics for the rapid detection of pathogens in positive blood culture bottles, respiratory specimens, stool, and cerebrospinal fluid has resulted in a paradigm shift in clinical microbiology and clinical practice. This review focuses on U.S. Food and Drug Administration (FDA)-approved/cleared multiplex molecular panels with more than five targets designed to assist in the diagnosis of bloodstream, respiratory tract, gastrointestinal, or central nervous system infections. While these panel-based assays have the clear advantages of a rapid turnaround time and the detection of a large number of microorganisms and promise to improve health care, they present certain challenges, including cost and the definition of ideal test utilization strategies (i.e., optimal ordering) and test interpretation.

Evaluation of a multiplex panel for the diagnosis of acute infectious diarrhea in immunocompromised hematologic patients

Introduction

Diarrhea is a frequent complication in hematologic patients, being an infectious cause frequently suspected. Rapid and accurate detection of gastrointestinal pathogens is vital in immunocompromised hosts. The aim of this study was to compare routine diagnostic methods versus a multiplex polymerase chain reaction (PCR) assay for the diagnosis of infectious diarrhea in immunocompromised hematologic patients.

Material and methods

We conducted a prospective observational study from March 2015 to January 2016 to compare conventional methods for the diagnosis of infectious diarrhea with FIlmArray GI Panel (BioFire-bioMérieux, France). Samples from adult immunocompromised hematologic patients with acute diarrhea were collected. In cases with discordant results, a second multiplex assay was performed (Allplex, Seegene, Korea). The result was considered positive or negative when the same result was obtained by at least two of the methods.

Results

A total of 95 samples were obtained from 95 patients (median age of 52 years (46–64)). Sixty-one (64%) episodes were hospital-acquired and 34 (36%) were community-acquired diarrhea. Twenty-five (26%) patients had a positive microbiological result, being Clostridium difficile the most frequent pathogen, followed by Campylobacter spp and norovirus. The concordance between FilmArray methods was good (k = 0.79). The FilmArray GI panel showed a sensitivity of 95%, a specificity of 100% for positive results. The time required to obtain results was markedly reduced with the use of multiplex PCR methods.

Conclusions

Multiplex molecular panels provide a rapid and sensitive tool for the diagnosis of infectious diarrhea, thereby allowing more timely clinical decisions in immunocompromised hematologic patients.

Epidemiology of Diarrheal Illness in Pediatric Oncology Patients

BACKGROUND

Diarrhea is common in children with cancer, but this has not been systematically studied to date.

METHODS

Remnant stool samples collected between January 2010 and June 2011 from pediatric oncology patients with diarrhea were tested for bacterial, viral, and parasitic enteropathogens using a combination of standard-of-care (SOC) diagnostic tests, including broad-range, real-time polymerase chain reaction (PCR) assays for adenoviruses, astroviruses, and sapoviruses and 2 commercially available multiplexed PCR assays. Corresponding demographic and clinical data were abstracted from patients' medical records.

RESULTS

One hundred fourteen episodes of diarrhea in 93 patients (median age, 3.7 years; range, 0.2-18.8) were included in the study. No patients died, but morbidity was significant. A total of 158 potential pathogens were detected in 114 diarrhea episodes, with >1 organism in one third of these; the most common were Clostridium difficile, noroviruses, adenoviruses, and astroviruses. Clostridium difficile, in combination with norovirus or adenovirus, was most common when >1 pathogen was detected. When both studies were obtained, SOC and broadly multiplexed PCR tests were concordant in 64 episodes (56%). Forty-five pathogens (28%) were identified retrospectively by broadly multiplexed PCR assays only. A total of 19 (13%) were detected by SOC real-time PCR assays but not by either commercially available multiplexed PCR assay.

CONCLUSIONS

Most pediatric oncology patients in this study had 1 or more potential infectious causes for their diarrhea. Additional studies are warranted to understand the natural history of gastroenteritis in this patient population. Although broadly multiplexed PCR assays offer some advantages over conventional testing, there may be disadvantages to their use for the diagnosis of infectious gastroenteritis that are unique to pediatric oncology patients.

Clinical features and molecular epidemiology of diarrheagenic Escherichia coli pathotypes identified by fecal gastrointestinal multiplex nucleic acid amplification in patients with cancer and diarrhea

Diarrheagenic Escherichia coli (DEC) pathotypes with differing epidemiology and clinical features, are known causes of disease with worldwide occurrence. At a major cancer center in the U.S., we studied patients with cancer and diarrhea for whom a GI Biofire FilmArray multiplex GI panel (BFM) was performed. An enteropathogen was identified in 382 of 2017 (19%) samples distributed across 311 patients. Of these, 60/311(19%) were positive for DEC. Patients receiving hematopoietic stem cell transplants (HSCT) 29/60 (48%) or with a hematologic malignancy 17/60 (28%) accounted for the majority of DEC cases. Enteropathogenic E. coli (EPEC, n=35 [58%]), enteroaggregative E. coli (EAEC, n=10 [17%]) and Shiga toxin producing E. coli (STEC, n=3 [5%]) were the most common DEC identified and peaked in the summer months. Stool cultures confirmed infections in 6/10 (60%) EAEC (five typical AggR⁺), and EPEC was recovered in 8/35 (22%) samples (all atypical eaeA⁺, bfp^-). DEC was identified in 22 cases (37%) that developed diarrhea >48hours after admission suggesting health care acquisition. Chronic infections were found in 2 EPEC and 1 EAEC cases that were tested at 1month or beyond with shedding that ranged from 58 to >125days. Two patients that underwent hematopoietic stem cell transplantation carried EAEC strains resistant to multiple antibiotics including fluoroquinolones and expressed extended spectrum beta lactamases. While in some instances BFM results were not verified in culture and could represent false positives, DEC pathotypes, especially EPEC and EAEC, caused chronic infections with antimicrobial-resistant strains in a subset of immunosuppressed cancer patients.

New molecular diagnostic tools in traveller's diarrhea

Traveller's diarrhea can be caused by bacteria, protozoa, helminths and viruses. Globally, the most common causes of traveller's diarrhea are two pathotypes of Escherichia coli (enterotoxigenic and enteroaggregative) and Shigella, although there are significant variations according to the geographic area visited. While traveller's diarrhea is usually a mild, self-limiting disease, half of the travellers with traveller's diarrhea have some limitation in their activities during the journey and up to 10% present persistent diarrhea or other complications, making microbiological diagnosis necessary. The aim of this article is to describe the application of new molecular diagnostic tools mainly based on multiplex PCR, including their advantages and disadvantages as well as the current gaps that requiring further study.

Multicausal etiology of the enteric syndrome in rabbits from Mexico

Enteropathies in rabbits are difficult to diagnose; their etiology involves pathogens that act synergistically, causing damage to the intestine. The aim of the present study was isolate enteric pathogens from rabbits in Mexico. Using parasitological, bacteriological and molecular analyses, we screened 58 samples of the intestinal content of rabbits having a clinical history of enteric disease from the southeastern part of the State of Mexico. Out of the 58 samples analyzed, a total of 86 identifications were made, Eimeria spp. were found in 77.5%, followed by Aeromonas spp. in 15.5% and Escherichia coli in 8.6%, which were identified as enteropathogenic E. coli (EPEC), and the presence of the following agents was also confirmed: Salmonella spp., Klebsiella spp., Streptococcus spp., Staphylococcus aureus, Enterococcus spp., Mannheimia spp. and Rotavirus. The concurrent presence of Eimeria spp. with Aeromonas was frequent (15.5%); there was statistical significance for the presence of an association between the clinical profiles and Eimeria spp. (p=0.000), Mannheimia spp. (p=0.001), Salmonella spp., Klebsiella spp., Streptococcus spp. and Enterococcus spp. (p=0.006).

Higher atypical enteropathogenic Escherichia coli (a-EPEC) bacterial loads in children with diarrhea are associated with PCR detection of the EHEC factor for adherence 1/lymphocyte inhibitory factor A (efa1/lifa) gene

Background

Typical enteropathogenic Escherichia coli (t-EPEC) are known to cause diarrhea in children but it is uncertain whether atypical EPEC (a-EPEC) do, since a-EPEC lack the bundle-forming pilus (bfp) gene that encodes a key adherence factor in t-EPEC. In culture-based studies of a-EPEC, the presence of another adherence factor, called EHEC factor for adherence/lymphocyte activation inhibitor (efa1/lifA), was strongly associated with diarrhea. Since a-EPEC culture is not feasible in clinical laboratories, we designed an efa1/lifA quantitative PCR assay and examined whether the presence of efa1/lifA was associated with higher a-EPEC bacterial loads in pediatric diarrheal stool samples.

Methods

Fecal samples from children with diarrhea were tested by qPCR for EPEC (presence of eae gene) and for shiga toxin genes to exclude enterohemorrhagic E. coli, which also contain the eae gene. EPEC containing samples were then tested for the bundle-forming pilus gene found in t-EPEC and efa1/lifA. The eae gene quantity in efa1/lifA-positive and negative samples was compared.

Results

Thirty-nine of 320 (12%) fecal samples tested positive for EPEC and 38/39 (97%) contained a-EPEC. The efa1/lifA gene was detected in 16/38 (42%) a-EPEC samples. The median eae concentration for efa1/lifA positive samples was significantly higher than for efa1/lifA negative samples (median 16,745 vs. 1183 copies/µL, respectively, p = 0.006).

Conclusions

Atypical enteropathogenic E. coli-positive diarrheal stool samples containing the efa1/lifA gene had significantly higher bacterial loads than samples lacking this gene. This supports the idea that efa1/lifA contributes to diarrheal pathogenesis and suggests that, in EPEC-positive samples, efa/lifA may be a useful additional molecular biomarker.

Dientamoeba fragilis, a Commensal in Children in Danish Day Care Centers

Dientamoeba fragilis is an intestinal protozoan of debated clinical significance. Here, we present cross-sectional and longitudinal observations on D. fragilis in children aged 0 to 6 years from a 1-year multi-day-care-center cohort study set in Copenhagen, Denmark. The inclusion period for the cohort was 2009 through 2012. Stool samples collected from the children were accompanied by questionnaires completed by the parents or guardians of the children. Using real-time PCR, D. fragilis was detected in the first stool sample from 97 of 142 (68.3%) children. We evaluated the associations between seven plausible risk factors (age, sex, having siblings, having domestic animals at home, having had infant colic, recent history of intake of antibiotics, and recent history of travel abroad) as well as six reported symptoms (lack of appetite, nausea, vomiting, abdominal pain, weight loss, and diarrhea) and testing positive for D. fragilis The final multivariable model identified being >3 years old and having a history of recent travel abroad as risk factors for testing positive for D. fragilis Moreover, univariable analyses indicated that having siblings was a risk factor. There was no statistical association between a recent history of gastrointestinal symptoms and testing positive for D. fragilis Among the 108 children who were represented by ≥2 samples and thus included in the longitudinal analysis, 32 tested negative on the first sample and positive later, and the last sample from each of the 108 children was positive. The results are in support of D. fragilis being a common enteric commensal in this population.

Dientamoeba fragilis colonization is not associated with gastrointestinal symptoms in children at primary care level

BACKGROUND

Dientamoeba fragilis is commonly identified in children in primary care and is suspected to cause gastrointestinal disease.

OBJECTIVE

To determine the association between D. fragilis colonization and gastrointestinal symptoms in children.

METHODS

We performed a cross-sectional study with children who presented in primary care with gastrointestinal symptoms. The associations between D. fragilis colonization and specific symptoms were explored by means of logistic regression analyses. Asymptomatic siblings of these cases were invited as control subjects for a case-control analysis, where we explored the association between D. fragilis and gastrointestinal symptoms with conditional logistic regression analysis.

RESULTS

In the cross-sectional study, 107 children were included. Their median age was 9 years (interquartile range = 6-12) and 38 (35.5%) were boys. Colonization of D. fragilis was present in 59 children (55.1%). The absence of D. fragilis was associated with soft to watery stool [odds ratio (OR) = 0.29; 95% confidence interval (CI) = 0.10-0.85], chronic diarrhoea (OR = 0.42; 95% CI = 0.18-0.97) and fatigue (OR = 0.45; 95% CI = 0.20-0.99). The case-control analyses included 44 children in each group. Dientamoeba fragilis colonization was not observed more often in cases than in controls after adjustment for age and sex (OR = 1.02; 95% CI = 0.28-3.65).

CONCLUSION

Dientamoeba fragilis is a common parasite in children with and without gastrointestinal symptoms. The anomalous finding of the association between the absence of D. fragilis with soft to watery stools, chronic diarrhoea and fatigue are inexplicable. Our study suggests that D. fragilis colonization does not increase the risk for gastrointestinal symptoms.

ESBL/AmpC-producing Enterobacteriaceae in households with children of preschool age: prevalence, risk factors and co-carriage

OBJECTIVES

ESBL/AmpC-producing Enterobacteriaceae are an emerging public health concern. As households with preschool children may substantially contribute to the community burden of antimicrobial resistance, we determined the prevalence, risk factors and co-carriage of ESBL/AmpC-producing bacteria in preschool children and their parents.

METHODS

From April 2013 to January 2015, each month 2000 preschool children were randomly selected from Dutch population registries. The parents were invited to complete an epidemiological questionnaire and to obtain and send a faecal sample from the selected child and from one parent. Samples were tested for ESBL/AmpC-producing bacteria. Logistic regression was used to identify risk factors for ESBL/AmpC carriage in children and parents, and findings were internally validated by bootstrapping.

RESULTS

In total, 1016 families were included and ESBL/AmpC prevalence was 4.0% (95% CI 3.2%-5.0%); 3.5% (95% CI 2.5%-4.8%) in children and 4.5% (95% CI 3.4%-6.0%) in parents. Attending a daycare centre (DCC) was the only significant risk factor for children (OR 2.1, 95% CI 1.0-4.3). For parents, the only significant risk factor was having one or more children attending DCCs (OR 2.2, 95% CI 1.2-4.8). For parents of ESBL/AmpC-positive children the OR for ESBL/AmpC carriage was 19.7 (95% CI 9.2-42.4). Co-carriage of specific ESBL/AmpC genotypes in child and parent occurred more often than expected by chance (14.6% versus 1.1%, P < 0.001).

CONCLUSIONS

In this study, intestinal carriage with ESBL/AmpCs was detected in ∼4% of households with preschool children. DCC attendance was a risk factor in both children and parents and co-carriage of specific genotypes frequently occurred in child-parent pairs. These findings suggest household transmission or/and family-specific exposure to common sources of ESBL/AmpC-producing bacteria.

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.

Reassuringly low carriage of enteropathogens among healthy Swedish children in day care centres

OBJECTIVES

Infectious gastroenteritis is one of the most common diseases among children and has a considerable impact on health and socio-economy. Day care centres are high-risk environments for infections. The aim of this study was to investigate if asymptomatic preschool children constitute a reservoir for potential enteropathogens.

STUDY DESIGN

In total, 438 individual diapers were collected from day care centres in Uppsala, Sweden, during spring and autumn, and molecular techniques were used to estimate the prevalence of asymptomatic carriage of multiple enteropathogens.

METHODS

Faecal samples were analysed with multiplex polymerase chain reaction (PCR) (xTAG^® Gastrointestinal Pathogen Panel; Luminex Corporation, Toronto, Canada) targeting 21 different pathogens. Samples with a median fluorescence intensity above threshold were re-analysed with a second PCR assay.

RESULTS

Sixteen of the 438 samples were positive for enteropathogens, 1.6% for enteric adenovirus, 0.7% for Campylobacter spp., and 0.7% for norovirus.

CONCLUSIONS

Preschool children in Uppsala constitute a limited reservoir for potential enteropathogens.