Characteristics of persistent diarrhea in a community-based cohort of young US children

OBJECTIVE: The objective of the study was to define the characteristics and microbiology of persistent diarrhea (PD) in US children. METHODS: Six-month prospective cohort study of a convenience sample of 604 healthy 6- to 36-month-old children recruited by the Slone Center Office-based Research Network. RESULTS: Of 611 diarrhea episodes, 50 (8.2%) lasted < or = 14 days. The incidence of PD was 0.18 episodes per person-year, and the median duration of episodes was 22.0 days (range, 14-64 days). PD episodes were more likely than acute episodes to result in a medical visit (28.0% vs 8.2%; P = 0.0001). The most commonly used treatments were oral rehydration solution (12.0% of episodes) and antibiotics (6.0%). No bacterial or parasitic pathogens were associated with PD; but norovirus, rotavirus and sapovirus were each significantly more prevalent in PD stools compared with baseline stools, with relative risks of 12.4, 6.9 and 6.2, respectively. Fifty-nine per cent of the PD specimens tested were negative for all studied pathogens. CONCLUSIONS: PD occurs with a frequency of approximately 1 case per 5 person-years in US infants and young children. It seems to be a generally benign illness, with only 28% of cases presenting to medical care. Although viral pathogens seem to cause a minority of PD episodes in this population, most are not due to currently known infectious agents.     

Cryptosporidiosis and persistent diarrhea

OBJECTIVE: The association between cryptosporidiosis and persistent diarrhea has been studied in many countries. The aim of this study was to verify the incidence of this parasite in children with persistent diarrhea. Children infected or not with protozoan cryptosporidium were compared in relation to laboratory and clinic analysis.METHODS: Retrospective study in 70 inmate suckling at pediatrics hospital due persistent diarrhea, younger than 2 year, negative HIV, and other causes of diarrhea were ruled out. The duration of diarrhea, hospitalization, clinic modifications, preceding history of diarrhea, nutrition, d-xilosis and diet management were appraised.RESULTS: Criptosporidium sp was founded in 14 (20%) sucking and it was more frequent between children younger than 3 months (13/57, 23%). The duration of hospitalization and diarrhea were similar in both. Malnutrition was been present in 91.5% of patients, 13/14 of infected cryptosporidium children and 51/56 of not infected. The diet management was similar in both. There was a tendency to underdose xilosis of infected patients; mainly at the first year of life (15.9 +/- 8.2 and 33.8 +/- 19.9 p=0.007). CONCLUSION: Cryptosporidiosis is frequent in children with persistent diarrhea. Nevertheless, the infected patients did not differ of others if we consider theirs clinics, prognosis and therapeutics characteristics.     

Effect of glutamine supplementation on diarrhea, interleukin-8 and secretory immunoglobulin A in children with acute diarrhea

OBJECTIVE: Glutamine is an important fuel for rapidly dividing cells such as enterocytes and lymphocytes. Exogenous glutamine supplementation in catabolic states preserves intestinal mucosal structure and function, decreases bacterial translocation, and supports normal immunologic responses. This study was planned to assess the effect of glutamine supplementation on duration and severity of diarrhea and to assess its immunomodulatory effect by measuring serum interleukin-8 (IL-8) and salivary immunoglobulin A (sIgA) in children with acute diarrhea. METHODS: In this placebo-controlled, double-blind and randomized trial, 6- to 24-month-old otherwise healthy children admitted to the Diarrheal Diseases Training and Treatment Center with acute diarrhea received either 0.3 g/kg/day of glutamine (n = 63) or placebo (n = 65) for 7 days. Serum IL-8 and sIgA levels were determined on admission and 7 days later. All cases were followed until the diarrheal episode ended. Anthropometric measurements and history of subsequent infectious diseases were monitored monthly for 3 months after treatment. RESULTS: Mean duration of diarrhea in the glutamine treated group was significantly shorter than that of the placebo group (3.40 +/- 1.96 days, 4.57 +/- 2.48 days, respectively; P = 0.004). No differences in serum IL-8 and sIgA were found between groups on admission or 1 week later. During 3 month follow-up, mean weight gain and incidence of infectious diseases were similar in both groups. CONCLUSION: Duration of diarrhea was shorter in children supplemented with glutamine. The beneficial impact of glutamine supplementation seems to be through effects on gastrointestinal mucosa rather than the host immune response.     

Etiology of diarrhea in pediatric outpatient settings

BACKGROUND: The frequency with which bacteria cause diarrhea evaluated in ambulatory settings is often unknown. We attempted to determine the microbiologic etiology of diarrhea in a private pediatric practice (site A) and a clinic serving largely immigrant children (site B) and to establish guidelines for bacterial culture. METHODS: Children with diarrhea were prospectively enrolled, and their stools were examined for diarrheagenic bacteria, viruses and parasites. RESULTS: A total of 123 and 103 children were enrolled at sites A and B, respectively. Stools from all (100%), 126 (55.8%), 104 (46.0%) and 75 (33.2%) were tested for bacterial enteric pathogens, parasites, Clostridium difficile toxin and viruses, respectively. Of the 75 patients whose stool underwent complete testing, 36 (48%) contained at least 1 definitive or plausible pathogen. Twelve stools (5.3%) tested positive for bacteria [Campylobacter jejuni (n = 7), Yersinia enterocolitica, Shigella flexneri, Shigella sonnei, Salmonella serogroup D and Salmonella Braenderup (n = 1 each)]. One contained Blastocystis hominis, 8 contained C. difficile toxin and 16 contained viruses (9 rotavirus, 5 adenovirus and 2 astrovirus). Visible fecal blood (P = 0.029), increased stool frequency (P = 0.035), abdominal tenderness (P = 0.011) and fecal white (P < 0.001) or red blood cells (P = 0.002) were associated with bacterial infection. All children with stool yielding diarrheagenic bacteria or C. difficile toxin had at least 1 of these factors, but so did 75% of children without these agents (positive predictive value, 11%; negative predictive value, 100%; sensitivity, 100%; specificity, 25%). CONCLUSIONS: The bacterial diarrhea prevalence is similar to that in other ambulatory studies, although the spectrum differs. Exclusion criteria for stool testing in diarrhea remain elusive. Studies to determine the etiology of unexplained diarrhea and cost-effective algorithms for diarrhea diagnosis, are needed.     

Potential role of adherence traits of Escherichia coli in persistent diarrhea in an urban Brazilian slum.

We examined stools from 40 children with persistent diarrhea (duration, 14 days or more), from 50 children with acute diarrhea and from 38 control children to determine infectious etiologies for persistent diarrhea in Goncalves Dias, an urban favela (slum) in Fortaleza, Ceara, Brazil. Children with persistent diarrhea and children with acute diarrhea had similar rates of isolation of routine viral, bacterial and parasitic enteric pathogens. Routine pathogens were identified in at least 20% of cultures done more than 14 days into the diarrheal illness. We examined Escherichia coli isolated from these stools for adherence potential. Enteroaggregative E. coli were isolated significantly more often from children with persistent diarrhea than from control children or children with acute diarrhea (P less than 0.05). E. coli with hemagglutination patterns suggestive of adherence pili were also isolated more often from children with persistent diarrhea than from children with acute diarrhea (38% vs. 18%; P less than 0.05). Enterotoxigenic E. coli were isolated in combination with rotavirus more often from children with persistent diarrhea than from children with acute diarrhea. E. coli which were hydrophobic or exhibited hemagglutination were also seen more often in association with Giardia in children with persistent diarrhea. These findings suggest that the etiology of persistent diarrhea in children is complex and that the aggregative E. coli are associated with prolonged diarrheal illness. Although routine diarrheal pathogens may be present for more than 14 days, combinations of pathogens, including E. coli with adherence potential, may also contribute to prolonged diarrheal disease.     

Correlation between CD4+ lymphocyte counts, concurrent antigen skin test and tuberculin skin test reactivity in human immunodeficiency virus type 1-infected and -uninfected children with tuberculosis.

BACKGROUND: HIV-infected children are at high risk of developing tuberculosis after infection by Mycobacterium tuberculosis. Emphasis is placed on tuberculin skin testing (TST) for diagnosing tuberculosis in children; however, its value in HIV-infected children is controversial. OBJECTIVES: To determine whether concurrent antigen testing and/or CD4+ lymphocyte counts help in the interpretation of the TST in children with tuberculosis. METHODS: Children eligible for the study were diagnosed as having tuberculosis on clinical criteria. CD4+ lymphocyte counts and delayed-type hypersensitivity (DTH) test, using the CMI Multitest were performed when tuberculosis was diagnosed. RESULTS: One hundred thirty children were enrolled. Tuberculin reactivity was lower in HIV-infected children at all cutoff levels than in HIV-uninfected children (P < 0.0001). The positive predictive value of normal CD4+ lymphocyte counts in predicting tuberculin reactions of > or =5 mm (in HIV-1-infected) and > or =10 mm (in HIV-uninfected patients) were 50 and 80.3%, respectively (P < 0.0001). An intact DTH reaction to the CMI Multitest in predicting reactions of > or =5 mm and > or =10 mm to tuberculin in HIV-infected and -uninfected children were 55 and 76%, respectively (P < 0.001). Kwashiorkor was responsible for 53.3% of false-negative TST in HIV-uninfected children with normal CD4+ lymphocyte counts. CONCLUSION: TST is of limited value as an adjunct in diagnosing tuberculosis in HIV-infected children. CD4+ lymphocyte counts and concurrent DTH testing are not useful for predicting tuberculin reactivity in HIV-infected patients with tuberculosis.     

Role of protozoa as risk factors for persistent diarrhea

A case control study including 175 children aged 0–36 months suffering from diarrhea of ≥14 days duration was undertaken to determine whether there is an association betweenGiardia lamblia, Entamoeba histolytica orCryptosporidium infection and persistent diarrhea (PD). Subjects were identified by ongoing household surveillance and enrolled as cases. For each case two controls were selected by survey of neighbouring households—a child with acute diarrhea and one without diarrhea. Both the controls were matched with the case for age and nutritional status. Two fresh stool samples were collected from all cases and controls at enrolment and examined for trophozoites ofGiardia lamblia, Entamoeba histolytica andCryptosporidium. Giardia lamblia trophozoites were detected in a significantly higher proportion of PD cases (20.0%) than acute diarrheal and non diarrheal controls (4.6% each, p<0,0001). There were no significant differences in the proportion of cases and controls who passedE. histolytica trophozoites or cryptosporidium in their stools. There was a consistent trend towards poorer weight gain in PD cases who passed Giardia trophozoites in stool; the differences were statistically significant at days 14 and 21, after enrolment. Giardia lamblia infection is more prevalent in PD cases than in acute diarrhea or non-diarheal controls. This prevalence is not high enough to warrant routine anti-giardia therapy in patients with PD. However, as giardiasis was observed to have adverse growth impact in PD cases, stool microscopy for detection and subsequent treatment ofGiardia lamblia seems to be justified.     

Partially hydrolyzed guar gum-supplemented oral rehydration solution in the treatment of acute diarrhea in children

BACKGROUND: Partially hydrolyzed guar gum (Benefiber; Novartis Nutrition, Minneapolis, MN, U.S.A.) is fermented by colonic bacteria liberating short-chain fatty acids (SCFAs), which accelerate colonic absorption of salt and water. The purpose of this study was to evaluate the effect of Benefiber (BF)-supplemented World Health Organization Oral Rehydration Solution (WHO ORS) in the treatment of acute noncholera diarrhea in children. METHODS: A double-blind, randomized, controlled clinical trial was performed at ICDDR,B in 150 male children aged 4 to 18 months who had watery diarrhea of less than 48 hours' duration. After admission, children were assigned to receive either WHO ORS or BF-supplemented WHO ORS until recovery. Major outcome measures, such as duration of diarrhea and amount of stool output, were compared between the treatment groups. RESULTS: Patients receiving BF-supplemented WHO ORS had significantly reduced duration of diarrhea compared with the control group (mean +/- SD, 74 +/- 37 vs. 90 +/- 50 hours, P = 0.03). Survival analysis for duration of diarrhea also showed a reduction the BF-supplemented WHO ORS-treated group (P = 0.025, log rank test). There was also less stool output daily from days 2 through 7 in the patients treated with BF-supplemented WHO ORS compared with that in the children treated with WHO ORS; the reduction was significant on day 7 only. CONCLUSION: Benefiber added to standard WHO ORS substantially reduces the duration of diarrhea and modestly reduced stool output in acute noncholera diarrhea in young children, indicating its potential as a new antidiarrheal therapy for acute diarrhea in children.     

Clinical evaluation of the addition of lyophilized, heat-killed Lactobacillus acidophilus LB to oral rehydration therapy in the treatment of acute diarrhea in children

BACKGROUND: Addition of a medication to the World Health Organization protocol for treatment of acute diarrhea in children is controversial. In this trial, the clinical efficacy of a medication (Lactéol Fort sachets; Laboratoire du Lactéol du Docteur Boucard, Houdan France) containing lyophilized heat-killed Lactobacillus acidophilus LB was assessed as an adjunct to oral rehydration therapy. METHODS: Children aged 3 to 24 months with acute diarrhea and mild or moderate dehydration were enrolled in the study. Children received oral rehydration therapy for the first 4 hours. After this first rehydration phase, undiluted milk formula or breast milk was fed alternately with oral rehydration solution. Children were fed rice gruel as tolerated. They received either one sachet containing 10 billion of lyophilized heat-killed L. acidophilus LB or placebo at admission and at 12-hour intervals for five doses. RESULTS: Seventy-three children (37 L. acidophilus LB, 36 placebo) were enrolled, of whom 40 (17 L. acidophilus LB, 23 placebo) received an antibiotic before inclusion. Rotavirus was identified in approximately 50% of the children in each group. After 24 hours of treatment, the number of rotavirus-positive children with watery stools was significantly lower (p = 0.012) in the L. acidophilus LB group. Mean duration of diarrhea was decreased (p = 0.034) with L. acidophilus LB (43.4 hours) versus placebo (57.0 hours). This decreased duration was particularly marked in children with no antibiotic therapy before inclusion (31.1 hours): 42.9 hours for the L. acidophilus LB group versus 74.0 hours for the placebo group (p = 0.016). CONCLUSIONS: Addition of L. acidophilus LB to oral rehydration therapy was effective in the treatment of children with acute diarrhea by decreasing the duration of diarrhea.     

Conjunctival impression cytology in children with persistent diarrhea as indicator of pre-clinical vitamin A deficiency

Children with persistent diarrhea may be at a higher risk of developing vitamin A deficiency. Impression cytology of the conjunctiva has been shown to be a simple and objective diagnostic test for detection of early, physiologically significant vitamin A deficiency. We studied, changes in conjunctival impression cytology using millipore HAWG filter paper in 25 children aged less than 5 years suffering from persistent diarrhea, who had no ocular manifestations of vitamin A deficiency (Group I). Twenty five age matched healthy children constituted the control group (Group II). Seventeen of the 25 children with persistent diarrhea (68%), showed the following abnormalities: (i) the shape of the epithelial cells were abnormal, and (ii) goblet cells were absent. The study could be repeated after 2 weeks of administration of vitamin A in 7 children. Reappearance of PAS-positive mucous glycoproteins and presence of normal epithelial cells was demonstrated in all 7 children retested. This test can prove to be of significant value in assessment of response to vitamin A therapy. This study shows that children with persistent diarrhea appear to be at high risk for developing vitamin A deficiency, which can be detected by the technique of conjunctival impression cytology. This is a cheap and reliable method of detecting preclinical vitamin A deficiency which can be performed by a pediatrician in the office laboratory.     

Persistent diarrhea as a cause of childhood mortality in rural Bangladesh

To determine the importance of persistent diarrhea in childhood mortality a multiple-step verbal autopsy method was used to study 1934 deaths in Matlab, Bangladesh. We found that most of the deaths from acute watery diarrhea occurred in infancy, whereas the peak of non-watery diarrhea deaths was in children over 12 months of age. Children suffering from persistent diarrhea and malnutrition were at highest risk of dying during their third year of life. Children with infectious diseases have a two to four times higher risk of dying if they are malnourished, and for diarrhea the risk is 17 times as high. Forty-nine percent of the diarrheal deaths were in children with malnutrition associated with persistent diarrhea. These results imply that fluid and dietary management are key aspects in the treatment of diarrhea, particularly for those episodes which persist. We conclude that attempts to reduce diarrhoeal deaths with vertical ORT programmes will not have a major impact unless other interventions are directed to the persistent diarrhoea-malnutrition complex.     

小儿迁延性、慢性腹泻病83例临床分析

目的 分析小儿迁延性、慢性腹泻病的病因、临床特点及治疗现状.方法 对2002年10月-2007年10月住院并诊断为迁延性、慢性腹泻病83例患儿的临床资料进行回顾性分析.结果 主要病因包括食物过敏29例(85.3%),乳糖不耐受61例(73.5%),免疫功能低下55例(66.3%),感染35例(42.2%)等.长时间腹泻患儿多伴有营养不良,不同程度的离子紊乱、微量元素缺乏、肠道菌群失调等,部分患儿合并其他脏器受累(如心肌、肝脏等).针对病因治疗,同时辅以支持疗法和对症治疗,取得了良好的效果.结论 迁延性、慢性腹泻的病因并不都是感染;其临床表现多样,并发症多;经不同途径联合治疗,可从各个不同环节阻断病情发展,减少并发症,从而缩短病程,提高治愈率.[临床儿科杂志,2009,27(10):930-934]     

Epidemiology of postshigellosis persistent diarrhea in young children

BACKGROUND: Dysentery accounts for 20% of the 4.6 million diarrhea-associated deaths among children in developing countries, with the risk from death in dysenteric persistent diarrhea 10-fold higher than that in acute dysentery. Although Shigella accounts for the majority of dysenteric episodes, very little is known about the epidemiology of postshigellosis persistent diarrhea. METHODS: Rural Bangladeshi children younger than 5 years of age (n = 1,756) were followed for 1 month after exposure to sentinel cases of Shigella dysentery. The likelihood of an acute diarrheal episode becoming persistent was assessed. RESULTS: Diarrhea caused by Shigella was significantly associated with an increased risk of persistent diarrhea (age-adjusted relative risk, 1.83; 95% confidence interval, 1.19 to 2.81). Despite the use of nalidixic acid in dysenteric episodes, persistent diarrhea occurred in 23% of children with shigellosis. Infection by multiply antibiotic-resistant Shigella isolates (age-adjusted relative risk, 3.76; 95% confidence interval, 1.51 to 9.36) and occurrence of shigellosis during infancy were observed to be risk factors for initiation of Shigella diarrhea persistence. However, 88% of the persistent shigellosis episodes occurred in older children, 50% were associated with nondysenteric shigellosis and 79% were caused by Shigella species other than Shigella dysenteriae 1. CONCLUSIONS: These data demonstrate the importance of Shigella as a cause of persistent diarrhea and indicate that strategies to prevent postshigellosis persistent diarrhea must be broad-based, with a focus on older children as well as infants, management of nondysenteric as well as dysenteric disease and prevention of diarrhea caused by multiple Shigella species.     

Epidemiology of persistent diarrhea among Guatemalan rural children

A prospective, longitudinal two-year study to determine the epidemiology of persistent ( 14 days'duration) diarrhea in rural children of Guatemala was undertaken. Three-hundred and twenty-one children aged 0-35 months were kept under surveillance by twice-a-week home visits. The overall incidence of diarrhea was 0.147 per child-week; the incidence of persistent diarrhea was 0.014 per child-week. The peak of persistent diarrhea was observed in infants below six months of age, with a continuous decline thereafter. This trend in incidence of persistent diarrhea was associated with a higher proportion (16%) of illnesses persisting for more than 13 days in children younger than six months of age as compared to children 30-35 months old (4%). Males had more diarrhea (0.156 per child-week) than females (0.139 per child week). Among children above 18 months of age, the proportion of episodes that lasted for more than 13 days was lower in females than in males.     

Mortality associated with acute watery diarrhea, dysentery and persistent diarrhea in rural North India

Mortality associated with diarrhea was investigated in a longitudinally followed cohort of children under six years of age in rural North India. During the follow-up, 1663 episodes of diarrhea and 23 diarrhea related deaths were recorded in 1467 children followed up for 20 months. The case fatality rate was 0.56% for acute watery diarrhea, 4.27% for dysentery and 11.94% for non-dysenteric persistent diarrhea. Most of the episodes lasted less than a week; 5.2% became persistent (duration > 14 days). The case fatality rate was similar in episodes of one and two weeks'duration (0.64% and 0.8%) and increased to 13.95% for persistent episodes. Of the total 86 persistent episodes, 22.1% were dysenteric; the case fatality rate for such dysenteric persistent episodes was 21.1% and for watery persistent diarrhea 11.4%. Diarrheal attack rates were similar among different nutritional groups, but diarrheal case fatality rates progressively increased with increasing severity of malnutrition, these were 24 times higher in children with severe malnutrition (7.48%) compared to those normally nourished (0.31%). With availability and use of oral rehydration therapy, dysentery and persistent diarrhea emerge as major causes of diarrhea related mortality, with underlying malnutrition as a key associated factor.     

Clinical consequences of replacing milk with yogurt in persistent infantile diarrhea]

Persistent diarrhea is an episode of diarrhea that begins acutely but lasts longer than expected for this usually self-limited disease. Treatment of this ill-defined syndrome is not well standardized but immediate intervention is required to minimize the risk of malnutrition with its various consequences. This randomized clinical trial was undertaken to evaluate the clinical efficacy of substituting yogurt for milk, as the only treatment. After a one to two-day observation period during which a standard milk diet was given, 78 children aged 3 to 36 months with confirmed persistent diarrhea of more than 15 days but less than one month duration and negative tests for fecal blood were fed either milk (infant formula) or yogurt (infant formula fermented with Lactobacillus bulgaricus and Streptococcus thermophilus). At inclusion both groups were comparable for age, nutritional status, diarrhea, and lactose hydrogen breath test results. Clinical treatment failure (weight loss greater than 5% in one day or persistent diarrhea after 5 days) was significantly less common in children fed yogurt (15 +/- 6%) than in children fed milk (45 +/- 8%). The beneficial effects of feeding yogurt were apparent within 48 hours in 67 +/- 8% of infants. In conclusion, these data confirm the clinical efficacy of substituting yogurt for milk in young children with persistent diarrhea. They also suggest that yogurt may be a good alternative for the initial treatment of persistent diarrhea.     

食物特异性IgG抗体检测在儿童慢性腹泻中的应用价值

目的：儿童慢性腹泻病因复杂,难以明确病因,常给治疗带来很大困难,目前认为食物过敏可能是儿童慢性腹泻的重要病因,特别是IgG介导的迟发型变态反应起主要作用。该文就食物特异性IgG与儿童慢性腹泻的相关性进行分析研究,探讨食物特异性IgG检测对儿童慢性腹泻病因诊断和治疗的价值。方法：采用ELISA法,检测患儿血清中食物特异性IgG抗体浓度,根据IgG浓度分为4级：0级,+1级,+2级,+3级。其中 0级采取“安全进食”, +1级采取“轮替”进食,+2级、+3级采取“忌食”的健康饮食指导,并观察患儿腹泻症状改善情况。结果：82例慢性腹泻患儿中,79例有1~11种不等的食物特异性IgG升高,阳性率96.2%,而对照组阳性率仅为26.7%,慢性腹泻组中对2~5种食物过敏的比例最高占58.5%。其中对牛奶、蛋清/黄敏感性最高,分别为68.3%、62.2%,而针对鸡肉和猪肉的特异性IgG升高者较少,分别为2.4%和0%。79.3%病人经过健康饮食指导治疗后疗效显著。17例（20.7%）病人症状在3个月内无明显缓解,其中5例大便培养有细菌感染,6例家属或患儿未严格执行健康饮食指导,6例原因不明。结论：食物过敏是引起儿童慢性腹泻的重要原因,根据食物特异性IgG抗体检测结果对患儿进行健康饮食指导是治疗儿童过敏性慢性腹泻的最好方法。     

Acute diarrhea in children less than 3 years of age: Enteropathogens isolated in patient's stools, compared with a control group

OBJECTIVES: To observe the occurrence of different etiological agents of acute diarrhea (AD) in stool specimens of patients and children in a control group. MATERIAL AND METHODS: 100 children less than three years of age with AD were studied as well as 100 controls, between November 1993 and May 1994. Stool specimens were collected in both groups and the following enteropathogens were searched for: Rotavirus, Escherichia coli (EPEC, ETEC, EIEC, EHEC), Salmonella sp, Shigella sp, Campylobacter jejuni, Campylobacter coli, Yersinia enterocolitica, Cryptosporidium sp, Giardia lamblia, Entamoeba histolytica. Statistical analysis using the exact Fisher test (at significance level p<0,05) was done. The mean age was 12,5 months, with more cases in patients less than 6 months (35%). Children were seen at the emergency section on an average fifth day after the start of the diarrhea. Most came from homes with basical sanitary conditions. Watery diarrhea was more frequent than bloody diarrhea with mucus, at a proportion of 4:1. RESULTS: Rotavirus was the most frequent agent: 21% in the AD group and 3% in the control group (p= 0,0001). Shigella sp was isolated in 7% of the AD group and none of the control group (p= 0,0140). EPEC was detected in 13% of AD cases and 7% in the control group (p= 0,2381) but the classical subgroups O55, O111, O119 were only isolated from the patients with AD. The other enteropathogens were infrequently detected or in equal proportion in both groups. Rotavirus and EPEC were the more frequently isolated agents in watery diarrhea, while Shigella sp was the predominant agent found in bloody stools with mucus. CONCLUSIONS: Rotavirus was the most common causative agent in AD. The detection of Rotavirus and Shigella sp nearly exclusively in patients with AD confirms the high patogenicity of these etiological agents when compared to the others. Escherichia coli (EPEC) diagnosed by polyvalent sera does not confirm its respective diarrheogenic property due to isolation in the same proportion among patients with AD and controls. Monovalent antisera made possible the detection of classical subgroups of EPEC O111, O119, O55 isolated only from AD patients, confirming the already known high patogenicity of these strains.     

Oxidative stress is not enhanced in non-malnourished infants with persistent diarrhea.

Increased concentrations of reactive oxygen species (ROS) and depleted antioxidant defences have been implicated in a cycle of infection, malabsorption and malnutrition, leading to persistent diarrhea. In order to determine whether in non-malnourished children oxidative stress predisposes to the development of persistent diarrhea, infants with acute diarrhea (< 7 days) (n = 39) were compared to infants with persistent diarrhea (> 14 days) (n = 38). Lipid peroxidation was assessed by the TBARs assay and expressed as malondialdehyde equivalent content (nmol MDA/ml plasma), and levels of plasma antioxidants vitamin A and vitamin E were determined. In infants with acute and persistent diarrhea nutritional status, as assessed by weight/height and height-for-age, hemoglobin levels, serum albumin and immunoglobulin levels, did not differ between groups. Serum vitamin A and vitamin E levels did not differ in infants with acute or persistent diarrhea. TBARs, expressed as nmol MDA/ml plasma did not differ between infants with acute or persistent diarrhea and furthermore did not differ from levels in a healthy, similar age, control group. Non-malnourished infants with persistent diarrhea do not exhibit plasma antioxidant depletion or enhanced lipid peroxidation. In these infants, oxidative stress, as reflected in plasma, does not play a role in the pathogenesis of persistent diarrhea.