Diagnostic accuracy of stool assays for inflammatory bacterial gastroenteritis in developed and resource-poor countries

Relationship of Salmonella isolation with different serum and inflammatory intestinal parameters in natural fowl typhoid outbreaks from laying hens

Our study was undertaken to determine the best samples and selective-differential plating media to be used for Salmonella spp. isolation. We also compared hematological and serum biochemical values, Salmonella biovar Gallinarum (SG) detection (isolation and serological test), and inflammatory intestinal response (fecal leukocyte) in laying hens with naturally occurring fowl typhoid outbreaks. Furthermore, we looked for a biomarker of SG infection. Spleen, liver, ovarian follicle content, and bone marrow were found to be the best samples for SG isolation and the agreement between MacConkey-Salmonella Shigella agar was slight to excellent. The laying hens with SG isolation and rapid serum plate agglutination positive results showed a higher percentage of heterophils, heterophil/lymphocyte ratio and total white blood cells, and a lower percentage of lymphocytes than those with negative results. Furthermore, the positive fecal leukocyte samples had a higher percentage of heterophils, gamma-glutamyl transferase, total protein and globulin values than negative samples. Five biomarkers' cut-offs are proposed to distinguish between laying hens positive and negative to SG isolation.

Evaluation of fecal occult blood testing for rapid diagnosis of invasive diarrhea in young children

Antimicrobials are only indicated in acute childhood diarrhea if it is invasive or persistent. Rapid screening for invasive diarrhea can therefore inform treatment decisions but pathogen identification by culture is slow, expensive and cumbersome. This study aimed to assess the diagnostic utility of stool microscopy and immunochromatographic fecal occult blood test (FOBT) kits for identifying invasive or potentially invasive diarrhea in Ibadan, Nigeria. Fecal specimens from 46 children under 5 years old with diarrhea, collected as part of ongoing case-control studies, were subjected to stool microscopy for erythrocytes and leucocytes, and FOBT using the innovator's product and four locally procurable generic immunochromatographic kits, each according to manufacturers' instructions. Stool specimens were cultured for enteric bacterial pathogens using standard procedures. Presumptive pathogen isolates were identified biochemically and by PCR, and then confirmed by whole genome sequencing. Shigella, enteroinvasive Escherichia coli and Yersinia, pathogens that invariably cause invasive diarrhea, were detected in five of 46 specimens. Occult blood detection by microscopy was 55.6% sensitive and 78.4% specific, while the innovator's FOBT product was respectively 62.5% and 81.6% sensitive and specific compared to strict invasive pathogen recovery. Microscopy and FOBT testing were less sensitive in identifying specimens that contained pathogens that do not always elicit invasive diarrhea. Generic FOBT tests compared well with the innovator's product. Microscopy and FOBT testing have some value for delineating likely invasive diarrheas. They could inform treatment and serve as early warning indicators for dysentery outbreaks in resource limited settings. Inexpensive, generic FOBT kits that are locally procurable in Nigeria performed as well as the innovator's product.

Clinical Management of Infectious Diarrhea

BACKGROUND

Infectious diarrhea is the most common cause of diarrhea worldwide and is responsible for more deaths than other gastrointestinal tract diseases such as gastrointestinal cancers, peptic ulcer disease or inflammatory bowel disease. Diarrheal disease still represents the 8th leading cause of death worldwide, with more than 1,6 million attributed fatalities in 2016 alone. The majority of cases can be divided into three principal clinical presentations: acute watery diarrhea lasting 5-10 days and normally self-limiting, bloody diarrhea (dysentery), and persistent diarrhea with or without intestinal malabsorption.

METHODS

We performed an electronic search on PUBMED of the scientific literature concerning infectious diarrhea and its clinical management.

AIM

In this review article, we analyze the most important causes of infectious diarrhea and their constellation of signs and symptoms, providing an update on the diagnostic tools available in today's practice and on the different treatment options.

CONCLUSION

Even though the majority of intestinal infections are self-limiting in immunocompetent individuals, specific diagnosis and identification of the causative agent remain crucial from public health and epidemiological perspectives. Specific diagnostic investigation can be reserved for patients with severe dehydration, more severe illness, persistent fever, bloody stools, immunosuppression, and for cases of suspected nosocomial infection or outbreak and it includes complete blood count, creatinine and electrolytes evaluation, determination of leukocytes and lactoferrin presence in the stools, stool culture, together with C. difficile testing, PCR, ova and parasites' search, endoscopy and abdominal imaging. Since acute diarrhea is most often self-limited and caused by viruses, routine antibiotic use is not recommended for most adults with mild, watery diarrhea. However, when used appropriately, antibiotics are effective against shigellosis, campylobacteriosis, C. difficile colitis, traveler's diarrhea, and protozoal infections. Furthermore, antibiotics use should be considered in patients who are older than 65 years, immunocompromised, severely ill, or septic.

The importance of stool tests in diagnosis and follow-up of gastrointestinal disorders in children

Stool is not just a simple waste material. Some stool tests can be easily used in primary care in the differential diagnosis of disorders such as gastrointestinal infections, malabsorption syndromes, and inflammatory bowel diseases. Stool tests can prevent unnecessary laboratory investigations. Stool analyses include microscopic examination, chemical, immunologic, and microbiologic tests. Stool samples can be examined for leukocytes, occult blood, fat, sugars (reducing substances), pH, pancreatic enzymes, alpha-1 antitrypsin, calprotectin, and infectious causes (bacteria, viruses, and parasites). Stool should also be macroscopically checked in terms of color, consistency, quantity, shape, odor, and mucus.

Epidemiological and clinical differences between sexes and pathogens in a three-year surveillance of acute infectious gastroenteritis in Shanghai

Acute infectious gastroenteritis cases in Shanghai, reported over three years, were analyzed. Pathogens were identified in 1031 patients; of these, 725 and 306 were bacterial and viral cases, respectively. Vibrio parahemolyticus and Salmonella were the dominant bacteria, and Caliciviridae and Reoviridae were the dominant viral families in the local area. The acute gastroenteritis epidemic peaks appeared in August and January, which represented the active peak periods of bacteria and viruses, respectively. Logistic regression analyses with sex stratification showed that abdominal pain, fever and ingestion of unsafe food at restaurants were independent factors more frequently associated with bacterial gastroenteritis irrespective of sex; red cell-positive fecal matter was associated with bacterial gastroenteritis with an odds ratio (OR) of 3.28 only in males; and white blood cell count was associated with bacterial gastroenteritis with an OR of 1.02 only in females. Pathogen stratification showed that age, vomiting and red cell-positive fecal matter were associated with males with ORs of 0.99, 0.61 and 1.71, respectively, in bacterial gastroenteritis; and the migrant ratio was higher in males with an OR of 2.29 only in viral gastroenteritis. In conclusion, although bacterial and viral gastroenteritis shared many features, epidemiological and clinical factors differed between sexes and pathogens.

A Hospital-based Case-control Study of Diarrhea in Children in Shanghai

BACKGROUND

Prevention and control of childhood diarrhea is a global priority. We conducted a case-control study of childhood diarrhea in Shanghai.

METHODS

We prospectively recruited diarrheal children in an outpatient setting. Nondiarrheal controls were individually matched to cases. Rotavirus, norovirus and bacterial pathogens were examined. Clinical and epidemiologic data were obtained at enrollment and follow-up.

RESULTS

Potential pathogens identified in 680 diarrheal cases and 680 controls were rotavirus (19.0% vs. 1.3%), norovirus (13.4% vs. 4.7%), nontyphoidal Salmonella (9.3% vs. 1.9%), enteropathogenic Escherichia coli (8.4% vs. 6.9%) and enteroaggregative Escherichia coli (7.2% vs. 6.2%) and Campylobacter (5.1% vs. 1.2%), enterotoxigenic Escherichia coli (1.2% vs. 0.6%), enterohemorrhagic Escherichia coli (0.3% vs. 0%) and Shigella (0.15% vs. 0%), respectively. The specificity and sensitivity of fecal leukocytes >5 per high-power field for the diagnosis of bacterial diarrhea were 94.2% and 22.8%. Salmonella were susceptible to ciprofloxacin, ceftriaxone and amoxicillin-clavulanate and showed low frequency of resistance to azithromycin. Campylobacter showed low frequency of resistance to azithromycin and high frequency of resistance to ciprofloxacin. Diarrheagenic Escherichia coli was highly susceptible to ciprofloxacin and amoxicillin-clavulanate. Contact with diarrheal patients was a risk factor for rotavirus [adjusted odds ratio (aOR): 11.7], norovirus (aOR: 7.5) and Campylobacter (aOR: 27.1) infections. Mother's education was positively associated with Salmonella infection (aOR: 2.1). Good hand hygiene was protective against rotavirus (aOR: 0.6), norovirus (aOR: 0.5) and Salmonella (aOR: 0.3) infections.

CONCLUSIONS

Rotavirus, norovirus, nontyphoidal Salmonella and Campylobacter are significantly associated with diarrhea in Chinese children. Fecal leukocytes >5 per high-power field can predict bacterial diarrhea. Target prevention and appropriate treatment of diarrhea should consider the potential pathogen and resistance pattern.

Multiplex Polymerase Chain Reaction for Detection of Gastrointestinal Pathogens in Migrant Workers in Qatar

The causes of infectious diarrhea among the migrant worker population in Qatar are not well understood. We conducted a prospective observational study to understand the demographic and clinical characteristics and infectious causes of diarrhea among migrant workers in Doha, Qatar. A total of 126 male workers presenting to the Qatar Red Crescent Worker's Health Center outpatient clinic or emergency department were studied over a 5-month period in 2015–2016. Epidemiologic surveys were administered to all subjects and the prevalence of 22 different stool pathogens was determined using multiplex polymerase chain reaction (PCR) (FilmArray^® Gastrointestinal PCR). A target pathogen was identified in 62.7% of subjects. Enteropathogenic Escherichia coli was the most prevalent pathogen and was detected in 24.6% of subjects, followed by Salmonella (22.2%), enteroaggregative E. coli (15.1%), Giardia lamblia (9.5%), and enterotoxigenic E. coli (8.7%). Multiple pathogens were identified in 49.3% of positive stool samples. In a multivariable analysis, the presence of a heart rate ≥ 90 (adjusted odds ratio [OR] = 3.7, 95% confidence interval [CI] = 1.4–10.0) and > 5 fecal leukocytes/high-power field (adjusted OR = 2.8, 95% CI = 1.2–7.0) were significant predictors of detecting an acute inflammatory pathogen by PCR. Use of multiplex PCR enabled the detection of gastrointestinal pathogens in a high proportion of cases, illustrating the utility of this diagnostic tool in epidemiologic studies of infectious diarrhea.

A scoring system for assessing the severity of acute diarrhea of adult patients

BACKGROUND

Diarrhea is frequently seen in developed and developing countries, and severe diarrhea is characterized by the high risk of death. Thus, it is very important to assess the severity of diarrhea early. We conducted a multi-center study to identify risk factors for the severity of diarrhea in adult patients and formulate an adult diarrhea state score (ADSS) for out-patient clinicians.

METHODS

A total of 219 adult patients with acute diarrhea were divided into two groups: 132 patients with mild diarrhea and 87 with severe diarrhea. Logistic regression was used to determine risk factors for the severity of diarrhea. The risk factors were assessed and an ADSS was formulated. Receiver operating characteristic (ROC) analysis was made to evaluate the diagnostic accuracy of ADSS, and the Kappa test was used to confirm the diagnostic reliability.

RESULTS

Five risk factors for evaluating the severity of diarrhea in adults included age (P<0.05), axillary temperature (P<0.01), mean arterial pressure (P<0.01), white blood cell count (WBC; P<0.01), and WBC in stool (P<0.01). The area under the ROC curve for ADSS was 0.958 when the cut off value was 4 (a sensitivity of 0.909; a specificity of 0.874), and the Kappa value was 0.781 (P<0.05).

CONCLUSION

The risk factors associated with the pathogenic condition of diarrhea were identified, quantified and formulated into an ADSS, which has high diagnostic accuracy and reliability for the early identification of patients with severe acute diarrhea.

Diagnostic value of the Vesikari Scoring System for predicting the viral or bacterial pathogens in pediatric gastroenteritis

Purpose

To evaluate the diagnostic value of the Vesikari Scoring System (VSS) as an early predictor of pathogens in children with acute gastroenteritis (AG).

Methods

In this retrospective study, the VSS score, absolute neutrophil count (ANC), and C-reactive protein (CRP) levels were analyzed in 107 hospitalized children with AG, aged 6 months to 17 years. Patients were divided into nonspecific, viral, and bacterial groups according to the pathogens detected using a multiplex polymerase chain reaction (PCR) test.

Results

Patients in the bacterial group had significantly higher CRP values and VSS scores compared to those in the viral group and significantly higher VSS scores compared to those in the nonspecific group (P<0.05). Patients in the viral group had significantly higher VSS scores than those in the nonspecific group (P<0.05). Logistic regression analysis revealed that VSS was the most effective diagnostic tool for predicting the type of pathogen (P<0.05). The area under the receiver operating characteristics curve of VSS was significantly greater than that for ANC and CRP (P<0.05). At a cutoff point of 10 in the VSS, an acceptable diagnostic accuracy could be achieved for distinguishing between bacterial and viral pathogens in AG.

Conclusion

VSS can be considered a useful and reliable infectious marker for pediatric gastroenteritis. VSS may be a good early predictor of the type of pathogen, enabling development of a treatment plan before results from a stool culture or PCR test are available.

Etiology and Risk Factors of Acute Gastroenteritis in a Taipei Emergency Department: Clinical Features for Bacterial Gastroenteritis

BACKGROUND

The causative pathogen is rarely identified in the emergency department (ED), since the results of cultures are usually unavailable. As a result, antimicrobial treatment may be overused. The aim of our study was to investigate the pathogens, risk factors of acute gastroenteritis, and predictors of acute bacterial gastroenteritis in the ED.

METHODS

We conducted a matched case-control study of 627 stool samples and 612 matched pairs.

RESULTS

Viruses (41.3%) were the leading cause of gastroenteritis, with noroviruses (32.2%) being the most prevalent, followed by bacteria (26.8%) and Giardia lamblia (12.4%). Taking antacids (adjusted odds ratio [aOR] 4.10; 95% confidence interval [CI], 2.57-6.53), household members/classmates with gastroenteritis (aOR 4.69; 95% CI, 2.76-7.96), attending a banquet (aOR 2.29; 95% CI, 1.64-3.20), dining out (aOR 1.70; 95% CI, 1.13-2.54), and eating raw oysters (aOR 3.10; 95% CI, 1.61-5.94) were highly associated with gastroenteritis. Elders (aOR 1.04; 05% CI, 1.02-1.05), those with CRP >10 mg/L (aOR 2.04; 95% CI, 1.15-3.62), or those who were positive for fecal leukocytes (aOR 2.04; 95% CI, 1.15-3.62) or fecal occult blood (aOR 1.97; 95% CI, 1.03-3.77) were more likely to be hospitalized in ED. In addition, presence of fecal leukocytes (time ratio [TR] 1.22; 95% CI, 1.06-1.41), abdominal pain (TR 1.20; 95% CI, 1.07-1.41), and frequency of vomiting (TR 0.79; 95% CI, 0.64-0.98) were significantly associated with the duration of acute gastroenteritis. Presence of fecal leukocytes (aOR 2.08; 95% CI, 1.42-3.05), winter season (aOR 0.45; 95% CI, 0.28-0.74), frequency of diarrhea (aOR 1.69; 95% CI, 1.01-2.83), and eating shrimp or crab (aOR 1.53; 95% CI, 1.05-2.23) were highly associated with bacterial gastroenteritis. The area under the receiver operating characteristic curve of the final model was 0.68 (95% CI, 0.55-0.63).

CONCLUSIONS

Acute bacterial gastroenteritis was highly associated with season, frequency of diarrhea, frequency of vomiting, and eating shrimp or crab.

Relationship of Salmonella infection and inflammatory intestinal response with hematological and serum biochemical values in laying hens

There are few studies about the blood serum of laying hens infected with Salmonella. The differential leukocyte count and blood chemistry values are an important aid in the diagnosis of human diseases, but blood parameters in the avian species are not well known. On the other hand, invasive forms of bacterial gastroenteritis, like Salmonella, often cause intestinal inflammation so this study was undertaken to find a biomarker of Salmonella infection and inflammatory intestinal response in the hematological or serum biochemical parameters in laying hens. Furthermore, we evaluated the association of some farm characteristics with Salmonella infection and fecal leukocytes (FL). A fecal sample with at least one fecal leukocyte per field was considered positive for inflammatory intestinal response. False positive serum reactions for Salmonella infection, by serum plate agglutination (SPA) test, were reduced by heating the sample to 56°C for 30 min and then diluting it 5-fold. The range of hematological and biochemical parameter values was very wide, in addition, there was a poor agreement between the SPA and FL results. Comparison of the positive and negative samples in SPA and FL showed that 1.3% and 79.8% of the laying hens were positive and negative in both tests, respectively. Hens with a positive SPA result showed a higher percentage of monocytes than those with a negative SPA result. Hens with a positive FL test had a higher percentage of heterophils, ratio of heterophils to lymphocytes and aspartate aminotransferase values, while the percentage of lymphocytes was significantly lower (P < 0.05) than those with a negative FL test. The risk of Salmonella infection increased when the age of laying hens and the number of hens per poultry house was greater than or equal to 18 months old and 10,000 laying hens, compared to less than 18 months old and 10,000 laying hens, respectively. On the other hand, the risk of inflammatory intestinal response was higher in laying hens ≥ 18 months old than in hens < 18 months old. Despite the fact that we did not find any specific biomarker of Salmonella infection, this is the first report about the change of Salmonella infection and inflammatory response in hematological/serum biochemical values for laying hens.

Markers of intestinal inflammation for the diagnosis of infectious gastroenteritis

Infectious diarrhea is a major cause of morbidity. A rapid and inexpensive assay for the diagnosis of infectious gastroenteritis would expedite appropriate therapy and prevent unnecessary and potentially invasive testing. This article summarizes assays for the diagnosis of infectious gastroenteritis based on the host response to bacterial, viral, or parasitic infection. This includes both systemic biomarkers (such as C-reactive protein, erythrocyte sedimentation rate, and serum cytokines) and fecal biomarkers (such as lactoferrin, fecal leukocyte analysis, and calprotectin). Although some of these assays have value as adjunct diagnostics, they lack sensitivity and specificity as stand-alone tests in this setting.

[Four variants of the pathogenesis of diarrhea and its therapy]

Diarrhea is a symptom of many diseases; its pathogenesis is associated with four main mechanisms: water and electrolyte secretion into the intestinal lumen, osmolarity of the chyme, exudation, and impaired intestinal motility. The clinical manifestations, diagnosis, and therapy of bowel diseases are discussed in terms of the pathogenesis of diarrhea.

Evaluation and treatment of colonic symptoms

Important considerations for constipation include: 1. Initial evaluation should evaluate for fecal incontinence, fecal impaction, medication side effects, concerning symptoms, underlying medical or metabolic issues and irritable bowel syndrome. 2. History and examination should be used to determine if a defecatory disorder is most likely. a. If defecatory disorder is likely, testing with balloon expulsion or anal manometry can be considered and, if confirmed, treatment with biofeedback (if testing not available, it is reasonable to trial fiber and laxatives because many patients have a mixed disorder). b. If it is unlikely, proceed with trial of fiber and/or osmotic laxatives. 3. If continued symptoms, consider trial of newer agent (lubiprostone or linaclotide). 4. If ineffective, consider testing for colon transit time and referral to gastroenterology.

The undernourished neonatal mouse metabolome reveals evidence of liver and biliary dysfunction, inflammation, and oxidative stress

Undernutrition contributes to half of all childhood deaths under the age of 5 y, and confers upon survivors a life-long predisposition to obesity, type 2 diabetes, and cardiovascular disease. Mechanisms underlying the link between early nutrient deprivation and noncommunicable diseases are unknown. Using outbred CD1 neonatal mice, we measured metabolic profile differences between conventionally reared mice given unrestricted access to nursing, the control group, and undernourished mice subjected to protein-calorie deprivation through timed separation from lactating mothers. After 11 d of undernutrition, urine, plasma, liver, ileal fluid, cecal fluid, and stool were harvested from 8 pools of 4 neonatal mice per group. The metabolome was identified using a multiplatform mass spectrometry-based approach, and random forest metrics were used to identify the most important metabolites that distinguished the undernourished from the control group. Our data reveal striking metabolic changes in undernourished mice consistent with the known mammalian response to starvation, including evidence of muscle and fat catabolism and increased reliance on the tricarboxylic acid cycle for energy. However, we also revealed evidence of liver and biliary injury, anomalies in bile acid metabolism, oxidative stress and inflammation, accelerated heme breakdown, and altered regulation of DNA methylation. Among the metabolites that most strongly distinguished the 2 groups were 2-hydroxyisobutyrate, increased 3-fold in plasma of undernourished mice (P = 2.19 × 10(-11)); urobilinogen, increased 11-fold in urine of undernourished mice (P = 4.22 × 10(-7)); deoxycholate, decreased 94% in stool of undernourished mice (P = 3.0 × 10(-4)); and 12 different products of the enzyme γ-glutamyltransferase, increased in all 6 compartments of undernourished mice. This model of the undernourished neonatal metabolome illustrates the wide range of pathways disrupted by undernutrition in early development, and suggests mechanistic links between early starvation and persistent metabolic diseases.

Characterization and factors associated with diarrhoeal diseases caused by enteric bacterial pathogens among children aged five years and below attending Igembe District Hospital, Kenya

INTRODUCTION

Diarrhoea remains a major public health problem in East African nations such as Kenya. Surveillance for a broad range of enteric pathogens is necessary to accurately predict the frequency of pathogens and potential changes in antibiotic resistance patterns.

METHODS

A cross sectional study was conducted in Igembe District Hospital in Meru County to determine the burden and factors associated enteric bacterial infection among children aged five years and below. Stool samples were collected between March and July 2012. Bacterial pathogens were identified and antibiotic susceptibility of bacterial isolates was ascertained. Questionnaire was administered to the 308 study participants to identify the modifiable risk factors. Data was entered and analyzed using Epi Info version 3.5.3.

RESULTS

The study recruited 308 children. The mean age was 27.25 months, median of 26.0 months and age range between 2-60 months. The bacterial isolation rates were ETEC 9.1%, EPEC 6.8% and EAEC 12.3%, Salmonella paratyphoid (10.4%), Shigella flexineri (1.9%) and Shigella dysentriae (0.9%). Over 95%, of the isolates were resistance to amoxicillin, sulphinatozole, cotrimoxazole. Six factors were independently associated with diarrhoeal diseases, occupation of the parent/ guardian (miraa business) (OR=1.8, CI:1.44-4.99),care taker not washing hands after changing napkins (OR= 1.6, CI:1.2-19.7), child drank untreated water from the river (OR= 2.7, CI:2.4-9.9) child not exclusively breastfed (OR= 2.4, CI:2.1-10.5),child did not Wash hands before eating (OR=2.2, CI:1.91-16.3) and after visiting toilet (OR=3.7,CI:2.8-39.4). Eating of mangoes was found to be protective against diarrhoea (OR=0.5, CI:0.03-0.89).

CONCLUSION

The bacterial pathogens were found to be a significant cause of diarrhoea in the study participants. We established higher resistance to several commonly prescribed antibiotics. Several factors were significantly association with diarrhoea illness. We recommend multifaceted approach that acknowledges the public health aspects that would reduce the burden of diarrhoea infections as identified in this study.

Funktions- und Laboruntersuchungen

Zur Analyse abgeatmeter Gase muss endexspiratorische Luft gewonnen werden, ohne Vermischung mit frühexspiratorischer Luft (sonst Korrektur mit Messung des CO2-Partialdrucks, s. unten). Ältere Kinder blasen nach Anhalten der Atmung über 15 s durch tiefe Ausatmung über einen Strohhalm endexspiratorische Luft in ein Glasröhrchen, das dann luftdicht verschlossen wird (Vacutainer), oder über ein Mundstück oder eine Maske direkt in ein H2-Messgerät oder in Beutel. Bei Säuglingen und Kleinkindern kann mit einer Maske oder einer Sonde, die bis zum nasopharyngealen Übergang vorgeschoben wird, mit einer Spritze atemsynchron exspiratorische Luft abgesaugt und in Vacutainer oder direkt in das Messgerät eingegeben werden. In Vacutainern sind Proben über mehr als 30 Tage stabil und können auch zur Analyse verschickt werden.

Fecal leukocytes in children infected with diarrheagenic Escherichia coli

The purpose of this study was to determine the presence and quantity of fecal leukocytes in children infected with diarrheagenic Escherichia coli and to compare these levels between diarrhea and control cases. We analyzed 1,474 stool samples from 935 diarrhea episodes and 539 from healthy controls of a cohort study of children younger than 2 years of age in Lima, Peru. Stools were analyzed for common enteric pathogens, and diarrheagenic E. coli isolates were studied by a multiplex real-time PCR. Stool smears were stained with methylene blue and read by a blinded observer to determine the number of polymorphonuclear leukocytes per high-power field (L/hpf). Fecal leukocytes at >10 L/hpf were present in 11.8% (110/935) of all diarrheal episodes versus 1.1% (6/539) in controls (P < 0.001). Among stool samples with diarrheagenic E. coli as the only pathogen isolated (excluding coinfection), fecal leukocytes at >10 L/hpf were present in 8.5% (18/212) of diarrhea versus 1.3% (2/157) of control samples (P < 0.01). Ninety-five percent of 99 diarrheagenic E. coli diarrhea samples were positive for fecal lactoferrin. Adjusting for the presence of blood in stools, age, sex, undernutrition, and breastfeeding, enterotoxigenic E. coli (ETEC) isolation as a single pathogen, excluding coinfections, was highly associated with the presence of fecal leukocytes (>10 L/hpf) with an odds ratio (OR) of 4.1 (95% confidence interval [CI], 1.08 to 15.51; P < 0.05). Although diarrheagenic E. coli was isolated with similar frequencies in diarrhea and control samples, clearly it was associated with a more inflammatory response during symptomatic infection; however, in general, these pathogens elicited a mild inflammatory response.

An update on management of severe acute infectious gastroenteritis in children

This article focuses on clinical and diagnostic aspects relevant to severe acute infectious gastroenteritis in children and will update treatment strategies focused on, although not limited to, anti-infective therapy. For the purposes of this article we will consider severe acute infectious gastroenteritis as follows: watery diarrhea accompanied by, or at high risk for, moderate to severe dehydration due to abrupt onset of vomiting that reduces oral intake, and/or frequent emission of liquid stools, or moderate to severe dysenteric/bloody diarrhea with moderate to high-grade fever. The article will not include food poisoning associated with bacterial toxins and will only briefly discuss oral rehydration strategies and intravenous solutions. The article will also briefly discuss current preventive measures against rotavirus gastroenteritis through vaccination, a topic that has been extensively discussed elsewhere.

Prospective multicenter study evaluating fecal calprotectin in adult acute bacterial diarrhea

BACKGROUND

Every year, about 2.2 million deaths occur worldwide due to diarrhea. Reliable diagnosis of patients with acute infectious diarrhea remains a formidable challenge to the clinicians. This is the first study reporting use of fecal calprotectin in diagnosing acute diarrhea. The aim was to compare the diagnostic accuracy of fecal calprotectin, fecal lactoferrin, and guaiac-based fecal occult blood test in a diverse group of consecutive patients with acute diarrhea in which routine bacterial stool cultures and cytotoxins for Clostridium difficile were performed.

METHODS

This was a prospective case-control multicenter study from January 2004 until October 2007 in 2383 consecutive patients with acute diarrhea. They provided stool samples for performing cultures. Patients with positive cultures and an equal number of matched controls with negative cultures underwent fecal occult blood test and calprotectin and lactoferrin assays.

RESULTS

Calprotectin, lactoferrin, and fecal occult blood tests demonstrated sensitivity and specificity of 83% and 87%, 78% and 54%, and 38% and 85%, respectively, for diagnosing acute bacterial diarrhea.

CONCLUSIONS

Calprotectin showed high correlation with bacteriologically positive infectious diarrhea compared with lactoferrin and fecal occult blood test. It may potentially revolutionize management algorithm for patients with acute diarrhea. As a screening test, calprotectin can generate results within hours to support presumptive diagnosis of infectious diarrhea, which can decide suitability of stool samples for culture.

Diagnostic approach to acute diarrheal illness in a military population on training exercises in Thailand, a region of campylobacter hyperendemicity

High rates of Campylobacter fluoroquinolone resistance highlight the need to evaluate diagnostic strategies that can be used to assist with clinical management. Diagnostic tests were evaluated with U.S. soldiers presenting with acute diarrhea during deployment in Thailand. The results of bedside and field laboratory diagnostic tests were compared to stool microbiology findings for 182 enrolled patients. Campylobacter jejuni was isolated from 62% of the cases. Clinical and laboratory findings at the time of presentation were evaluated to determine their impact on the posttest probability, defined as the likelihood of a diagnosis of Campylobacter infection. Clinical findings, the results of tests for inflammation (stool occult blood testing [Hemoccult], fecal leukocytes, fecal lactoferrin, plasma C-reactive protein), and the numbers of Campylobacter-specific antibody-secreting cells in peripheral blood failed to increase the posttest probability above 90% in this setting of Campylobacter hyperendemicity when these findings were present. Positive results by a Campylobacter-specific commercial enzyme immunoassay (EIA) and, less so, a research PCR were strong positive predictors. The negative predictive value for ruling out Campylobacter infection, defined as a posttest probability of less than 10%, was similarly observed with these Campylobacter-specific stool-based tests as well the fecal leukocyte test. Compared to the other tests evaluated, the Campylobacter EIA is a sensitive and specific rapid diagnostic test that may assist with diagnostic evaluation, with consideration of the epidemiological setting, logistics, and cost.

Infectious diarrhea in developed and developing countries

Diarrhea from gastrointestinal infection remains a common problem. In industrialized countries, management is aimed at reducing morbidity and defining groups that may benefit from further investigation. Most infectious diarrhea is self-limiting and only requires supportive management. Viral agents are increasingly recognized as causative agents of epidemic and sporadic diarrhea. In developing countries, diarrhea is a major cause of mortality in children. Oral rehydration therapy, guided by a clinical assessment of the degree of dehydration, is cheap, simple, and effective and remains the mainstay of management of infant diarrhea. Controversies focus on the optimal formulation of oral rehydration solution. A vaccine against rotavirus has the potential to save millions of lives worldwide.