Perspectives on Shiga-like Toxin Infections in Argentina (original) (raw)

Epidemiology and Characterization of Shiga Toxin-Producing Escherichia Coli of Hemolytic Uremic Syndrome in Argentina

Cureus

Argentina has one of the highest prevalence in Shiga toxin-producing Escherichia coli (STEC) and the high rate of hemolytic uremic syndrome (HUS) in the world. Though preventive steps such as food safety have been implemented as a way to reduce STEC infections, these have proven to be insufficient. STEC's pathogenesis, virulence factors, relationship with the environment, and emerging strains have been studied in the past few years in the country. Many factors that contribute to the morbidity and mortality of STEC infections include the expression of pathologic genes, alternative characteristics (inhibition of phagocytosis, invasion, cytotoxicity, and bacterial attachment), and host factors (age, immune status, treatments, medical history). However, research studies in combination with epidemiological data suggest trends of the prognosis, with the relationship between and genetic combinations of adherence, Shiga toxin (Stx) genes, and virulence genes, which significantly influence disease outcomes. This review explains the characteristics and epidemiology of STEC in Argentina. All these facts show that the application of molecular subtyping techniques in real-time is essential for detecting and controlling outbreaks. Applying molecular subtyping techniques in hemorrhagic diarrhea can avoid severe consequences caused by progression to HUS, and help the epidemiological analysis of the outbreak.

An Epidemiologic Surveillance of Shiga-like Toxin-producing Escherichia coli Infection in Argentinean Children

The Pediatric Infectious Disease Journal, 2012

Background and Aims: Shiga-like toxin (Stx)-producing Escherichia coli (STEC) infection is an ongoing health issue that can lead to serious complications, including hemolytic uremic syndrome (HUS) and death. This study assessed demographic and epidemiologic information of STEC infection among Argentinean children. Methods: A prospective surveillance of 2435 screened children (age, 0.5-15 years) presenting with watery diarrhea and/or bloody diarrhea was undertaken to evaluate the clinical course of STEC infection. Results: Prevalence of STEC infection was 4.1% among subjects presenting with watery diarrhea for Յ5 days' duration, bloody diarrhea for Յ36 hours' duration, or both. Incidence of STEC infection was significantly higher in the subjects with bloody diarrhea. Ninety-three STECϩ children underwent further evaluation, of whom 8 (8.6%) developed HUS. White blood cells, particularly neutrophils, were abnormally elevated at screening in 5 of 8 HUS subjects. Quantifiable serum Stx-2 values were noted within 24 to 48 hours after the onset of bloody diarrhea in 3 HUS subjects using a validated chemiluminescence assay, with levels quickly dissipating by HUS onset. Conclusions: Results suggest that young STEC-positive children with bloody diarrhea and exhibiting neutrophilic leukocytosis in the early course of their diarrhea are at risk for HUS progression. The observation of measurable concentrations of Stx-2 levels in the early post-bloody-diarrhea period and rapid dissipation at the time of HUS onset requires further evaluation.

Co-infection in Children With Bloody Diarrhea Caused by Shiga Toxin–Producing Escherichia coli

Journal of Pediatric Gastroenterology & Nutrition, 2014

Hemolytic-uremic syndrome (HUS) is an important cause of acute kidney injury in children often caused by Shiga toxin-producing Escherichia coli (STEC) enterocolitis. In a screening program for STEC infection in children with bloody diarrhea in northern Italy for early diagnosis of HUS, coinfection with Salmonella or Campylobacter was documented in as many as 35.6% of Shiga toxin-positive patients. It is speculated that infection by Salmonella or Campylobacter may increase the risk of STEC enterocolitis and therefore of HUS. The isolation of microorganisms (other then STEC) in HUS should not be necessarily regarded as the etiological agent for the thrombotic microangiopathy.

An Epidemiologic Surveillance of Shiga-like Toxin-producing Escherichia coli Infection in Argentinean Children Risk Factors and Serum Shiga-like Toxin 2 Values

Background and Aims: Shiga-like toxin (Stx)-producing Escherichia coli (STEC) infection is an ongoing health issue that can lead to serious complications, including hemolytic uremic syndrome (HUS) and death. This study assessed demographic and epidemiologic information of STEC infection among Argentinean children. Methods: A prospective surveillance of 2435 screened children (age, 0.5–15 years) presenting with watery diarrhea and/or bloody diarrhea was undertaken to evaluate the clinical course of STEC infection. Results: Prevalence of STEC infection was 4.1% among subjects presenting with watery diarrhea for 5 days' duration, bloody diarrhea for 36 hours' duration, or both. Incidence of STEC infection was significantly higher in the subjects with bloody diarrhea. Ninety-three STEC children underwent further evaluation, of whom 8 (8.6%) developed HUS. White blood cells, particularly neutrophils, were abnormally elevated at screening in 5 of 8 HUS subjects. Quantifiable serum Stx-2 values were noted within 24 to 48 hours after the onset of bloody diarrhea in 3 HUS subjects using a validated chemiluminescence assay, with levels quickly dissipating by HUS onset. Conclusions: Results suggest that young STEC-positive children with bloody diarrhea and exhibiting neutrophilic leukocytosis in the early course of their diarrhea are at risk for HUS progression. The observation of measurable concentrations of Stx-2 levels in the early post– bloody-diarrhea period and rapid dissipation at the time of HUS onset requires further evaluation.

Antibody Response to Shiga Toxins in Argentinean Children with Enteropathic Hemolytic Uremic Syndrome at Acute and Long-Term Follow-Up Periods

PLoS ONE, 2011

Shiga toxin (Stx)-producing Escherichia coli (STEC) infection is associated with a broad spectrum of clinical manifestations that include diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Systemic Stx toxemia is considered to be central to the genesis of HUS. Distinct methods have been used to evaluate anti-Stx response for immunodiagnostic or epidemiological analysis of HUS cases. The development of enzyme-linked immunosorbent assay (ELISA) and western blot (WB) assay to detect the presence of specific antibodies to Stx has introduced important advantages for serodiagnosis of HUS. However, application of these methods for seroepidemiological studies in Argentina has been limited. The aim of this work was to develop an ELISA to detect antibodies against the B subunit of Stx2, and a WB to evaluate antibodies against both subunits of Stx2 and Stx1, in order to analyze the pertinence and effectiveness of these techniques in the Argentinean population. We studied 72 normal healthy children (NHC) and 105 HUS patients of the urban pediatric population from the surrounding area of Buenos Aires city. Using the WB method we detected 67% of plasma from NHC reactive for Stx2, but only 8% for Stx1. These results are in agreement with the broad circulation of Stx2-expressing STEC in Argentina and the endemic behavior of HUS in this country. Moreover, the simultaneous evaluation by the two methods allowed us to differentiate acute HUS patients from NHC with a great specificity and accuracy, in order to confirm the HUS etiology when pathogenic bacteria were not isolated from stools.

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

Clinical Infectious Diseases

Background Shiga toxin–producing Escherichia coli (STEC) infections are leading causes of pediatric acute renal failure. Identifying hemolytic uremic syndrome (HUS) risk factors is needed to guide care. Methods We conducted a multicenter, historical cohort study to identify features associated with development of HUS (primary outcome) and need for renal replacement therapy (RRT) (secondary outcome) in STEC-infected children without HUS at initial presentation. Children aged <18 years who submitted STEC-positive specimens between January 2011 and December 2015 at a participating study institution were eligible. Results Of 927 STEC-infected children, 41 (4.4%) had HUS at presentation; of the remaining 886, 126 (14.2%) developed HUS. Predictors (all shown as odds ratio [OR] with 95% confidence interval [CI]) of HUS included younger age (0.77 [.69–.85] per year), leukocyte count ≥13.0 × 103/μL (2.54 [1.42–4.54]), higher hematocrit (1.83 [1.21–2.77] per 5% increase) and serum creatini...

Hemolytic uremic syndrome with mild renal involvement due to Shiga toxin-producing Escherichia coli (STEC) O145 strain

Revista Argentina de microbiología

Hemolytic uremic syndrome (HUS) is a disorder characterized by the presence of the classic triad: microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury. HUS without acute renal failure can be confused with other hematologic diseases. An infantile HUS caused by a Shiga-toxin-producing Escherichia coli (STEC) O145 strain carrying genotype stx2, ehxA, eae subtype β1 is herein reported. The infant did not require dialysis during the acute stage of HUS, evolved favorably, maintained normal blood pressure and normal renal function and had no recurrence until the last control. This could be due to several factors, such as the characteristics of infecting STEC strain and a reduction in host susceptibility to renal injury. This report highlights the regional participation of non-O157 STEC in childhood diseases and the importance of performing active surveillance for all forms of HUS.

Haemolytic uraemic syndrome and Shiga toxin-producing Escherichia coli infection in children in France

Epidemiology and Infection, 2000

We conducted a study to determine the incidence of haemolytic uraemic syndrome (HUS) in children in France and to assess the role of Shiga-toxin-producing Escherichia coli (STEC) infection in the aetiology of HUS. In collaboration with the Socie! te! de Ne! phrologie Pe! diatrique we undertook a retrospective review of all cases of HUS hospitalized from January 1993 to March 1995 and a 1-year prospective study (April 1995-March 1996 of epidemiological and microbiological features of cases of HUS. The polymerase chain reaction (PCR) procedure was used to detect stx, eae, e-hlyA genes directly from case stool samples. Serum samples from cases were examined for antibodies to lipopolysaccharide (LPS) of 26 major STEC serogroups. Two hundred and eighty-six cases were reported. The average incidence per year was 0n7\10& children 15 years and 1n8\10& children 5 years. During the prospective study, 122\130 cases were examined for evidence of STEC infection using PCR and\or serological assays and 105 (86 %) had evidence of STEC infection. Serum antibodies to E. coli O157 LPS were detected in 79 (67 %) cases tested. In conclusion, this study showed that STEC infection is an important cause of HUS in children in France, with a high proportion related to the O157 serogroup.

Hemolytic uremic syndrome caused by Shiga toxin–producing Escherichia coli in children: incidence, risk factors, and clinical outcome

Pediatric Nephrology, 2020

Background Hemolytic uremic syndrome (HUS) is a multisystemic disease. In a nationwide study, we characterized the incidence, clinical course, and prognosis of HUS caused by Shiga toxin (Stx)-producing Escherichia coli (STEC) strains with emphasis on risk factors, disease severity, and long-term outcome. Methods The data on pediatric HUS patients from 2000 to 2016 were collected from the medical records. STEC isolates from fecal cultures of HUS and non-HUS patients were collected from the same time period and characterized by whole genome sequencing analysis. Results Fifty-eight out of 262 culture-positive cases developed verified (n = 58, 22%) STEC-HUS. Another 29 cases had probable STEC-HUS, the annual incidence of STEC-HUS being 0.5 per 100,000 children. Eleven different serogroups were detected, O157 being the most common (n = 37, 66%). Age under 3 years (OR 2.4), stx2 (OR 9.7), and stx2a (OR 16.6) were found to be risk factors for HUS. Fifty-five patients (63%) needed dialysis. Twenty-nine patients (33%) developed major neurological symptoms. Complete renal recovery was observed in 57 patients after a median 4.0 years of follow-up. Age under 3 years, leukocyte count over 20 × 10 9 /L, and need for dialysis were predictive factors for poor renal outcome. Conclusions Age under 3 years, stx2, and stx2a were risk factors for HUS in STEC-positive children. However, serogroup or stx types did not predict the renal outcome or major CNS symptoms.