Predicting Hemolytic Uremic Syndrome and Renal Replacement Therapy in Shiga Toxin-producing Escherichia coli-infected Children

Volume expansion mitigates Shiga toxin-producing E. coli-hemolytic uremic syndrome in children

BACKGROUND

Shiga toxin-producing E. coli-hemolytic uremic syndrome (STEC-HUS) is associated with high morbidity and relevant mortality. Previous small studies showed that volume expansion could improve the course and outcome of STEC-HUS. The aim of this single-center study was to evaluate the effect of volume expansion on the clinical course and outcome in STEC-HUS.

METHODS

Data of pediatric patients with STEC-HUS were analyzed retrospectively. Course and outcome of patients treated with volume expansion (VE) from 2019 to 2022 (n = 38) were compared to historical controls (HC) from 2009 to 2018 (n = 111).

RESULTS

Patients in the VE group had a significant relative median weight gain compared to HC (7.8% (3.4-11.3) vs. 1.2% (- 0.7-3.9), p < 0.0001) 48 h after admission. The need for dialysis was not reduced by VE (VE 21/38 (55.3%) vs. HC 64/111 (57.7%), p = 0.8). However, central nervous system involvement (impairment of consciousness, seizures, focal neurological deficits, and/or visual disturbances) was significantly reduced (VE 6/38 (15.8%) vs. HC 38/111 (34.2%), p = 0.039). None of the patients in the VE group died or developed chronic kidney disease (CKD) stage 5, whereas in the HC group, three patients died and three patients had CKD stage 5 at discharge.

CONCLUSIONS

This study suggests that volume expansion may be associated with the mitigation of the acute course of STEC-HUS, especially severe neurological involvement and the development of CKD. Prospective trials should lead to standardized protocols for volume expansion in children with STEC-HUS.

Factors affecting dialysis duration in children with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome

BACKGROUND

Predicting disease severity can be informative for management of HUS. Dialysis requirement, volume depletion, elevated white blood cell counts, very young age, and use of antimotility agents are known factors associated with severe HUS.

METHODS

A retrospective cohort analysis was performed to identify factors associated with dialysis duration using electronic medical record and chart review of 76 children ≤ 18 years of age at presentation with STEC-HUS identified through billing data from July 2008 to April 2020 at James Whitcomb Riley Hospital for Children, Indiana University, Indiana.

RESULTS

Novel findings associated with prolonged dialysis duration were age ≥ 6 years old at presentation (p = 0.041) and lack of drop in platelets below 60,000/mm3 anytime during the illness (p = 0.015). In addition, children with NSAID exposure trended longer on dialysis: 15 days with vs. 10 days without (p = 0.117). Known risk factors for severe disease including elevated peak white blood cell (WBC) count and higher hematocrit at presentation were also associated with longer dialysis duration: children with peak WBC > 20,000/mm3 were on dialysis for 15 vs. 9.5 days (p = 0.002) and in children on dialysis ≥ 14 days hematocrit at presentation was 29.6% vs. 24.2% (p = 0.03). Children requiring dialysis for 20 days or longer were more likely to be on anti-hypertensive medications (p = 0.025) and have chronic kidney disease at 12-month follow up (p = 0.044).

CONCLUSIONS

Age ≥ 6, elevated WBC count > 20,000/mm3, higher hematocrit at presentation, lack of drop in platelets to < 60,000/mm3, and possibly NSAID exposure during illness are associated with longer dialysis duration in STEC-HUS. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Hyperhydration to Improve Kidney Outcomes in Children with Shiga Toxin-Producing E. coli Infection: a multinational embedded cluster crossover randomized trial (the HIKO STEC trial)

BACKGROUND

Shiga toxin-producing E. coli (STEC) infections affect children and adults worldwide, and treatment remain solely supportive. Up to 15-20% of children infected by high-risk STEC (i.e., E. coli that produce Shiga toxin 2) develop hemolytic anemia, thrombocytopenia, and kidney failure (i.e., hemolytic uremic syndrome (HUS)), over half of whom require acute dialysis and 3% die. Although no therapy is widely accepted as being able to prevent the development of HUS and its complications, several observational studies suggest that intravascular volume expansion (hyperhydration) may prevent end organ damage. A randomized trial is needed to confirm or refute this hypothesis.

METHODS

We will conduct a pragmatic, embedded, cluster-randomized, crossover trial in 26 pediatric institutions to determine if hyperhydration, compared to conservative fluid management, improves outcomes in 1040 children with high-risk STEC infections. The primary outcome is major adverse kidney events within 30 days (MAKE30), a composite measure that includes death, initiation of new renal replacement therapy, or persistent kidney dysfunction. Secondary outcomes include life-threatening, extrarenal complications, and development of HUS. Pathway eligible children will be treated per institutional allocation to each pathway. In the hyperhydration pathway, all eligible children are hospitalized and administered 200% maintenance balanced crystalloid fluids up to targets of 10% weight gain and 20% reduction in hematocrit. Sites in the conservative fluid management pathway manage children as in- or outpatients, based on clinician preference, with the pathway focused on close laboratory monitoring, and maintenance of euvolemia. Based on historical data, we estimate that 10% of children in our conservative fluid management pathway will experience the primary outcome. With 26 clusters enrolling a mean of 40 patients each with an intraclass correlation coefficient of 0.11, we will have 90% power to detect a 5% absolute risk reduction.

DISCUSSION

HUS is a devastating illness with no treatment options. This pragmatic study will determine if hyperhydration can reduce morbidity associated with HUS in children with high-risk STEC infection.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05219110 . Registered on February 1, 2022.

Foodborne and Waterborne Illness

Safe water and food are impactful public health measures that improved significantly during the past century in the United States. But waterborne and foodborne illnesses continue to cause significant morbidity and mortality despite existing public health control measures and regulations. It was estimated that each year in the United States, 31 pathogens caused 37.2 million illnesses, with 36.4 million domestically acquired. Of those, 9.4 million were foodborne: 59% were caused by viruses, 39% by bacteria, and 2% by parasites. The pathogens that caused the most foodborne illnesses were norovirus (58%), nontyphoidal Salmonella species (11%), Clostridium perfringens (10%), and Campylobacter species (9%). Unspecified agents caused an estimated 38.4 million episodes of domestically acquired foodborne gastroenteritis, 258,033 hospitalizations, and 3,574 deaths. The estimate for illnesses caused by waterborne transmission was 7.15 million. The diseases that caused the greatest number were otitis externa (n = 4.67 million), norovirus (n = 1.33 million), giardiasis (n = 415,000), and cryptosporidiosis (n = 322,000). An important aspect of management and prevention is health-care provider reporting of foodborne and waterborne illnesses. Health-care provider reporting of reportable diseases has been inconsistent, infrequent, and delayed. Education efforts concerning reporting need to be enhanced, and physicians should report suspected cases before laboratory confirmation to enhance the timeliness of outbreak investigation and possibly prevent subsequent cases.

Interventions for Shiga toxin-producing Escherichia coli gastroenteritis and risk of hemolytic uremic syndrome: A population-based matched case control study

Background

The role of antibiotics in the treatment of Shiga toxin-producing Escherichia coli (STEC) infection is controversial.

Objectives

To evaluate the association between treatment (antibiotics, antidiarrheal agents, and probiotics) for STEC infection and hemolytic uremic syndrome (HUS) development.

Patients and methods

We performed a population-based matched case-control study using the data from the National Epidemiological Surveillance of Infectious Diseases (NESID) between January 1, 2017 and December 31, 2018. We identified all patients with STEC infection and HUS as cases and matched patients with STEC infection without HUS as controls, with a case-control a ratio of 1:5. Further medical information was obtained by a standardized questionnaire. Multivariable conditional logistic regression model was used.

Results

7760 patients with STEC infection were registered in the NESID. 182 patients with HUS and 910 matched controls without HUS were selected. 90 patients with HUS (68 children and 22 adults) and 371 patients without HUS (266 children and 105 adults) were included in the main analysis. The matched ORs of any antibiotics and fosfomycin for HUS in children were 0.56 (95% CI 0.32–0.98), 0.58 (0.34–1.01). The matched ORs for HUS were 2.07 (1.07–4.03), 0.86 (0.46−1.61) in all ages treated with antidiarrheal agent and probiotics.

Conclusions

Antibiotics, especially fosfomycin, may prevent the development of HUS in children, while use of antidiarrheal agents should be avoided.

Why antibiotics should not be used to treat Shiga toxin-producing Escherichia coli infections

PURPOSE OF REVIEW

There has been much debate about treating Shiga toxin-producing Escherichia coli (STEC) infections with antibiotics. No data convincingly demonstrate that antibiotics are better than no antibiotic treatment at all, and many studies suggest antibiotics increase the risk of developing the hemolytic uremic syndrome (HUS). This topic is timely, because emerging technology enables rapid identification of STEC-infected patients, and we anticipate questions about management will increase. This review is designed to familiarize readers with the series of observations that underlie our recommendations.

RECENT FINDINGS

The long debate over antibiotics in STEC infections appears resolved by gradually accruing information that show that antibiotics do not benefit infected patients. In fact, they are associated with an increased likelihood of developing HUS. A meta-analysis published in 2016 demonstrated that low risk of bias studies find a clear association between antibiotic use and development of HUS. Subsequent publications do not refute these findings.

SUMMARY

In high-income countries, antibiotics should not routinely be given to patients with acute diarrhea unless testing demonstrates a pathogen for which antibiotics are indicated, and STEC infection has been excluded. Future work to prevent HUS should focus on preventing primary infections, and mitigating extraintestinal consequences of STEC gut infections.

Hemoglobinuria for the early identification of STEC-HUS in high-risk children: data from the ItalKid-HUS Network

Hemolytic uremic syndrome (HUS) represents one of the main causes of severe acute kidney injury in children. The most frequent form of HUS is caused by Shiga toxin-2 (Stx2)-producing Escherichia coli. Hemoglobinuria and hematuria are markers of glomerular damage, but their use has never been validated in HUS. We retrospectively analyzed the presence of hemoglobinuria/urinary red blood cells (RBCs) in children with Stx2-positive bloody diarrhea (BD) or with already ongoing STEC-HUS with the aim of validating its role in early identifying HUS. We reviewed all the pediatric patients with Stx2+ BD (group 1) and with ongoing HUS (group 2) referred to our center from 2010 to 2019. A total of 100 children were eligible for the study. In group 1, 22 patients showed hemoglobinuria/hematuria, while 41 remained negative. In 15/22 positive patients (68.2%), blood tests ruled in HUS, while in 7 (31.8%), HUS was excluded. Among the 41 patients persistently negative for hemoglobinuria/hematuria, no one developed HUS. The 37 STEC-HUS children (group 2) all had hemoglobinuria/RBCs at admission.Conclusion: Hemoglobinuria/hematuria for the diagnosis of HUS in children with Stx2+ BD showed a sensitivity of 100% and a specificity of 85%. We strongly recommend patients with BD carrying Stx2 in stools to be closely monitored with urine dipstick/urinalysis to early identify HUS. What is Known • Children with bloody diarrhea secondary to Shiga toxin 2 are at high risk of hemolytic uremic syndrome, thus have to be carefully monitored for the development of the disease, in order to early be hospitalized and treated. What is New • Urine dipstick for hemoglobinuria can be used as an easy, inexpensive, and repeatable tool to early diagnose children with bloody diarrhea secondary to Shiga toxin 2 to have developed hemolytic uremic syndrome, with no risk of false-negative results.

Quality Improvements in Management of Children with Acute Diarrhea Using a Multiplex-PCR-Based Gastrointestinal Pathogen Panel

Conventional methods for etiologic diagnoses of acute gastroenteritis (AGE) are time consuming and have low positive yield leading to limited clinical value. This study aimed to investigate quality improvements in patient management, antibiotic stewardship, and in-hospital infection transmission prevention using BioFire^® FilmArray^® Gastrointestinal Panel (GI Panel) in children with acute diarrhea. This was a prospective study recruiting children < 19 years old with new onset diarrhea during the study period, and a matched historical cohort study of children diagnosed with AGE during the 4 years prior. Patients in the prospective cohort underwent stool testing with GI Panel and conventional methods. A total of 182 patients were included in the prospective cohort, of which 85.7% (n = 156) had community-onset and 14.3% (n = 26) had hospital-onset diarrhea. A higher pathogen positivity rate for community-onset diarrhea was observed by the GI Panel (58.3%, n = 91) compared to conventional studies (42.3%, n = 66) (p = 0.005) and historical cohort (31.4%, n = 49) (p < 0.001). The stool tests reporting time after admission was 25 (interquartile range, IQR 17-46) hours for the GI Panel, and 72 (IQR 48-96) hours for the historical cohort (p < 0.001). A significant reduction in antibiotic use was observed in the prospective cohort compared to historical cohort, 35.3% vs. 71.8%; p < 0.001), respectively. Compared to the GI Panel, norovirus ICT was only able to detect 4/11 (36.4%) patients with hospital-onset and 14/27 (51.8%) patients with community-onset diarrhea. The high positivity rate and rapid reporting time of the GI Panel had clinical benefits for children admitted for acute diarrhea, especially by reducing antibiotic use and enabling early adequate infection precaution and isolation.

Predicting Adverse Outcomes for Shiga Toxin-Producing Escherichia coli Infections in Emergency Departments

OBJECTIVE

To assess the performance of a hemolytic uremic syndrome (HUS) severity score among children with Shiga toxin-producing Escherichia coli (STEC) infections and HUS by stratifying them according to their risk of adverse events. The score has not been previously evaluated in a North American acute care setting.

STUDY DESIGN

We reviewed medical records of children <18 years old infected with STEC and treated in 1 of 38 participating emergency departments in North America between 2011 and 2015. The HUS severity score (hemoglobin [g/dL] plus 2-times serum creatinine [mg/dL]) was calculated using first available laboratory results. Children with scores >13 were designated as high-risk. We assessed score performance to predict severe adverse events (ie, dialysis, neurologic complication, respiratory failure, and death) using discrimination and net benefit (ie, threshold probability), with subgroup analyses by age and day-of-illness.

RESULTS

A total of 167 children had HUS, of whom 92.8% (155/167) had relevant data to calculate the score; 60.6% (94/155) experienced a severe adverse event. Discrimination was acceptable overall (area under the curve 0.71, 95% CI 0.63-0.79) and better among children <5 years old (area under the curve 0.77, 95% CI 0.68-0.87). For children <5 years, greatest net benefit was achieved for a threshold probability >26%.

CONCLUSIONS

The HUS severity score was able to discriminate between high- and low-risk children <5 years old with STEC-associated HUS at a statistically acceptable level; however, it did not appear to provide clinical benefit at a meaningful risk threshold.

Hemoconcentration and predictors in Shiga toxin-producing E. coli-hemolytic uremic syndrome (STEC-HUS)

BACKGROUND

Hemoconcentration has been identified as a risk factor for a complicated course in Shiga toxin-producing E. coli-hemolytic uremic syndrome (STEC-HUS). This single-center study assesses hemoconcentration and predictors at presentation in STEC-HUS treated from 2009-2017.

METHODS

Data of 107 pediatric patients with STEC-HUS were analyzed retrospectively. Patients with mild HUS (mHUS, definition: max. serum creatinine < 1.5 mg/dL and no major neurological symptoms) were compared to patients with severe HUS (sHUS, definition: max. serum creatinine ≥ 1.5 mg/dL ± major neurological symptoms). Additionally, predictors of complicated HUS (dialysis ± major neurological symptoms) were analyzed.

RESULTS

Sixteen of one hundred seven (15%) patients had mHUS. Admission of patients with sHUS occurred median 2 days earlier after the onset of symptoms than in patients with mHUS. On admission, patients with subsequent sHUS had significantly higher median hemoglobin (9.5 g/dL (3.6-15.7) vs. 8.5 g/dL (4.2-11.5), p = 0.016) than patients with mHUS. The product of hemoglobin (g/dL) and LDH (U/L) (cutoff value 13,302, sensitivity 78.0%, specificity of 87.5%) was a predictor of severe vs. mild HUS. Creatinine (AUC 0.86, 95% CI 0.79-0.93) and the previously published score hemoglobin (g/dL) + 2 × creatinine (mg/dL) showed a good prediction for development of complicated HUS (AUC 0.87, 95% CI 0.80-0.93).

CONCLUSIONS

At presentation, patients with subsequent severe STEC-HUS had a higher degree of hemoconcentration. This underlines that fluid loss or reduced fluid intake/administration may be a risk factor for severe HUS. The good predictive value of the score hemoglobin (g/dL) + 2 × creatinine (mg/dL) for complicated HUS could be validated in our cohort. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Farm animal contact is associated with progression to Hemolytic uremic syndrome in patients with Shiga toxin-producing Escherichia coli - Indiana, 2012-2018

Background

Hemolytic uremic syndrome (HUS) is a life-threatening complication of Shiga toxin-producing Escherichia coli (STEC) infection. The relationship between STEC exposure and severity of clinical outcomes is not well documented. We examined whether direct contact with farm animals increased the likelihood of HUS among Indiana residents diagnosed with STEC.

Methods

Exposure data for laboratory-confirmed STEC cases among Indiana residents during 2012–2018 were retrieved. Logistic regression and mediation analysis were performed to determine the extent to which a history of direct contact with farm animals was associated with post-diarrheal HUS independent of age and mediated by stx2 gene presence.

Results

A total of 784 STEC cases were retrieved. Of these, 46 (6%) developed HUS. Complete exposure data were available for 600 (77%) cases. A total of 24 (52%) HUS patients reported direct contact with farm animals, while 114 (21%) STEC patients who did not develop HUS reported this exposure. Among all STEC cases, HUS was associated with direct farm animal contact after adjusting for age (OR = 3.40, 95% CI: 1.81, 6.40). Detection of stx2 genes mediated 12% of the association between farm animal contact and HUS.

Conclusions

Direct farm animal contact was a risk factor for development of HUS among laboratory-confirmed STEC cases, independent of stx2 presence. Direct farm animal contact should be considered a potential predictor of progression to HUS when patients present for care and the mechanism for its effect on virulence investigated.

•

Independent of stx2 presence, contact with farm animals is a risk factor for the development of HUS.

•

Stx2 gene detection mediated 12.2% of the association between farm animal contact and HUS.

•

Exposure source may impact virulence of STEC and thus the severity of clinical outcomes.

An outbreak of Shiga toxin-producing Escherichia coli O157:H7 linked to a mud-based obstacle course, England, August 2018

In August 2018, Public Health England (PHE) was made aware of five probable cases of Shiga toxin-producing Escherichia coli (STEC) O157:H7 among individuals reporting participation in a mud-based obstacle race. An additional four cases, identified via routine whole-genome sequencing, were subsequently linked to the same event. Two of the nine cases were due to secondary household transmission. Despite an agreement between the event organizers and the local authority, to ensure that all livestock were removed from the site 28 days before the event, sheep were observed grazing on some of the routes taken by the runners 2 days prior to the race taking place. A retrospective review of incidents reported to PHE between 2015 and 2018 identified 41 cases of gastroenteritis associated with muddy assault course events. Of these, 25 cases were due to infection with STEC O157:H7, of which all but one were associated with outbreaks. Due to the environment in which such events take place, it is impossible to entirely remove the risk of exposure to potentially pathogenic zoonoses. However, race organizers should ensure that livestock are removed from the course 28 days before the event. They should also ensure that participants are made aware of the risk of contracting gastrointestinal disease from the environment, and to stress the importance of hand hygiene post-event and the risk of secondary transmission, particularly to children who are at risk of developing haemolytic uraemic syndrome.

Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence

Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) −0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI −87.8%, −2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.