Stool cultures and antimicrobial prescriptions related to infectious diarrhea

Stool cultures can be important in guiding antimicrobial therapy for diarrhea. From among 11.64 million person-years of Tennessee Medicaid enrollment data collected from 1995 through 2004, 315,828 diarrheal episodes were identified. Stool cultures were performed for only 15,820 episodes (5.0%). Antimicrobials were prescribed for 32,949 episodes (10.4%), 89.4% of which were not accompanied by a stool culture. White race and urban residence were associated with higher rates of stool culture. Frequent use of antimicrobials for diarrhea without stool culture may indicate inappropriate antimicrobial use and has critical implications for public health.     

Epidemiologic and clinical characteristics of acute diarrhea with emphasis on Entamoeba histolytica infections in preschool children in an urban slum of Dhaka, Bangladesh

The epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 Bangladeshi children (147 boys and 142 girls) 2-5 years old. The use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of Entamoeba histolytica to total diarrheal illness in this community setting. The average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average observation period of 2.8 years/child. Seventy-five percent of the diarrheal episodes were < or = 2 days in duration. Persistent diarrhea was relatively uncommon (0.2% of the children) and chronic diarrhea was observed in only one episode. Compared with malnourished and/or stunted children, better-nourished children experienced significantly fewer diarrheal episodes. The diarrheal incidence rate for children with blood group A was significantly less that that of the children with blood groups O and AB. The most frequent bacterial enteropathogens isolated from diarrheal stool specimens were enterotoxigenic Escherichia coli (9%) and Aeromonas species (9%), followed by Plesimonas shigelloides (4%) and Shigella flexneri (3.8%). Rotavirus was the most common viral agent isolated from diarrheal stool samples (5%). Giardia lamblia, Cryptosporidium parvum, and E. histolytica were identified in 11%, 8.4%, and 8%, respectively, of the diarrheal stool specimens. Dysentery was observed in 7.7% of all diarrheal episodes. The most common pathogens isolated from dysenteric stool were S. flexneri (11.6%), Aeromonas sp. (10%), E. histolytica (8.7%), Campylobacter jejunii (5.8%), P. shigelloides (4.3%), and A. caviae (4.3%). The overall incidence rate of E. histolytica-associated diarrhea was 0.08/child-year. Visible blood and hemoccult test-detected blood loss was found in 7% and 25%, respectively, of cases of E. histolytica-associated diarrhea. Children who had recovered from a diarrheal episode with E. histolytica, but not E. dispar, had half the chance of developing subsequent E. histolytica-associated diarrhea, consistent with the development of species-specific acquired immunity. In conclusion, the use of modern diagnostic tests demonstrated that E. histolytica contributed to overall morbidity from diarrheal illness. Understanding the etiology, frequency, and consequences of acute diarrhea in children from a developing country should aid in the design of interventions to improve child health.     

The Influence of Episode Severity on Caregiver Recall,Care-seeking,and Treatment of Diarrhea among Children 2–59 Months of Age in Bihar,Gujarat, and Uttar Pradesh,India

Increased diarrheal episode severity has been linked to better 2-week recall and improved care-seeking and treatment among caregivers of children under five. Using cross-sectional data from three Indian states, we sought to assess the relationship between episode severity and the recall, care-seeking, and treatment of childhood diarrhea. Recall error was higher for episodes with onset 8–14 days (31.2%) versus 1–7 days (4.8%) before the survey, and logistic regression analysis showed a trend toward increased severity of less recent compared with more recent episodes. This finding indicates that data collection with 2-week recall underestimates diarrhea prevalence while overestimating the proportion of severe episodes. There was a strong correlation between care-seeking and dehydration, fever, vomiting, and increased stool frequency and duration. Treatment with oral rehydration salts was associated with dehydration, vomiting, and higher stool frequency, and trends were established between therapeutic zinc supplementation and increased duration and stool frequency. However, state and care-seeking sector were stronger determinants of treatment than episode severity, illustrating the need to address disparities in treatment quality across regions and delivery channels. Our findings are of importance to researchers and diarrhea management program evaluators aiming to produce accurate estimates of diarrheal outcomes and program impact in low- and middle-income countries.     

Enteric infections and diarrhea in human immunodeficiency virus-infected persons: prospective community-based cohort study. Swiss HIV Cohort Study.

BACKGROUND: Persons infected with human immunodeficiency virus (HIV) are at increased risk for diarrhea and enteric infections. We studied (1) the epidemiology of enteric pathogens associated with diarrhea, (2) the diagnostic yield of stool examination and endoscopic evaluation, (3) risks to develop diarrhea, and (4) the impact of diarrhea on patients' survival. METHODS: A total of 1933 participants in the Swiss HIV Cohort Study were prospectively followed up for a median of 25.5 months. A total of 560 diarrheal episodes were evaluated by standardized stool examination. Endoscopic evaluation was performed in 25% of patients with chronic diarrhea. RESULTS: The incidence of diarrhea was 14.2 per 100 person-years (95% confidence interval, 13.0-15.4). Among patients with CD4 cell counts below 0.05 x 10(9)/L, the probability to develop diarrhea within 1, 2, and 3 years was 48.5%, 74.3%, and 95.6%, respectively. The risk to develop diarrhea was increased among patients with severe immunodeficiency, homosexual men, and patients taking antiretroviral therapy. Pneumocystis carinii chemoprophylaxis did not reduce the risk of diarrhea. Diarrhea was an independent negative predictor of survival. Enteric pathogens were detected in 16.5% of 212 acute diarrheal episodes and in 46% of 348 chronic diarrheal episodes. The sensitivity of histological and stool examination was similar except for the diagnosis of intestinal cytomegalovirus infection and leishmaniasis, which required invasive evaluation. CONCLUSIONS: Intestinal infections were diagnosed in less than 50% of chronic diarrheal episodes. The prevalence of enteric pathogens tended to decrease during the observation period, possibly because of improved antiretroviral therapy. Endoscopic evaluation did not improve the diagnostic yield compared with stool examination except for the diagnosis of cytomegalovirus enteritis and leishmaniasis.     

Clostridium difficile-associated diarrhea and colitis in adults. A prospective case-controlled epidemiologic study

In a one-year period, 149 adult cases of Clostridium difficile-associated diarrhea and colitis were compared with 148 diarrhea-free controls. Eighty-seven percent were nosocomial and 75% were on surgical services. Endoscopy revealed pseudomembranes in 51% of the 109 cases in which stool cytotoxin was present, compared with 11% of the 40 cases that were culture-positive but cytotoxin-negative. Cases diagnosed only by stool culture showed essentially no differences from controls, 21% of whom had asymptomatic stool colonization. We estimate that only 20% of these cases had diarrhea due to C difficile. Compared with controls, cases diagnosed by the presence of cytotoxin or pseudomembranes were found to have been hospitalized longer at diarrhea onset, to have had more antecedent infections, and to have received clindamycin, multiple antimicrobials, and therapeutic antimicrobials more often than controls, but controls received prophylactic antimicrobials more frequently than cases. Cultures of the environment, patients, and personnel failed to detect a mechanism of acquisition.     

A Bayesian approach to acute infectious diarrhea in adults

Acute infectious diarrhea is a yearly occurrence for most Americans, and is associated with 1 million hospitalizations and about 6000 deaths in the United States annually. Up to 80% of acute infectious diarrhea is caused by noroviruses, which produce a clinically mild illness with a predictable short course and good outcome that make laboratory testing and antimicrobial treatment unnecessary. Most diarrhea-causing bacteria and protozoa can cause a clinical illness "like norovirus"; when they do so in healthy adults neither specialized testing nor antimicrobials is required. The presence or absence of epidemiologic evidence (such as travel, hospitalization, antibiotic use, other exposures)and clinical evidence (such as diarrhea frequency and duration, severity of abdominal pain and fever, character of stool, presence of chronic illness or immune deficiency) can change the probability of "not norovirus" from as low as 8% to as high as 100%. Such probabilities guide the use of laboratory testing and antimicrobial therapy in patients who have acute infectious diarrhea.     

Furazolidone for treatment of diarrhoeal disease

Furazolidone, a synthietic nitrofuran, is active against a broad spectrum of bacteria and Giardia lamblia. Since 1954, furazolidone has been used almost exclusively for the specific and symptomatic treatment of infectious diarrheal diseases. Diarrheal disease is the leading cause of death of children and a major contributing factor of malnutrition in the developing world. It can be avoided with proper water and waste treatment, personal hygiene, and food preparation. The most critical aspect of treating acute diarrhea is maintaining optimal hydration and electrolyte balance. Fluid and electrolyte replenishment must constitute the 1st line of therapy. Antimicrobial therapy, however, improves the outlook further. Effective antimicrobials reduce the average duration of illness and the likelihood of relapses, complications and death. The ideal antimicrobial for treating acute diarrhea is a single broad-spectrum antimicrobial agent of low toxicity that would be effective for empirical treatment of acute diarrheal disease. During 30 years of clinical use worldwide, the effectiveness of furazolidone has shown to be comparable or superior to that of other drugs used to treat these diseases. Because furazolidone has fairly low toxicity, it is a relatively safe drug. The most common reaction appears to be gastrointestinal distress, though dizziness, drowsiness, headaches, and general malaise have also been reported. A drug that acts specifically on its target is generally preferable to one with less specific activity. Furazolidone inhibits a variety of bacterial enzymes, an activity that minimizes the development of resistant organisms. Furazolidone is a single, broad-spectrum antimicrobial that is effective, relatively safe, specific, and is orally administered in tablet or suspension form.     

Acute community-acquired diarrhea requiring hospital admission in Swiss children.

In order to ascertain the prevalence of agents that cause childhood diarrheal illness, stool specimens of 312 consecutive children with community-acquired diarrhea requiring admission were evaluated. Pathogens were detected in 166 (53%) of the 312 children (>/=2 pathogens in 28 children): Rotavirus (n=75), Salmonella spp. (n=37), Campylobacter spp. (n=24), Shigella spp. (n=5), Giardia spp. (n=4), Yersinia spp. (n=2), Aeromonas spp. (n=15), Cryptosporidium (n=15), enteropathogenic Escherichia coli (n=13), enterotoxigenic E. coli (n=7), and enterohemorrhagic E. coli (n=5). In conclusion, acute childhood diarrheal illness pathogens, such as Aeromonas, Cryptosporidium, and diarrheagenic E. coli, account for a large proportion of patients with a microbiologically positive stool specimen.     

致泻性大肠埃希菌的分布及耐药特点研究

目的监测致泻性大肠埃希菌(diarrheagenic Escherichia coli,DEC)的分布特点及耐药趋势,为流行病学研究、疫苗制备及合理使用抗生素提供依据。方法收集2002—2010年我院肠道门诊腹泻患者的大便标本,沙门-志贺菌培养基培养,筛出可疑菌落后经生化及血清学试验进一步鉴定血清型,用纸片扩散法测定抗菌药物的灵敏性。结果共分离肠道病原菌2104株,其中DEC 118株(5.61%),包括致病性大肠埃希菌(enteropathogenic E.coli,EPEC)78株(66.10%),侵袭性大肠埃希菌(enteroinvasive E.coli,EIEC)29株(24.58%),产毒性大肠埃希菌(enterotoxigenic E.coli,ETEC)11株(9.32%)。患者以男性为主,共76例(64.41%),青、中年组与儿童组无明显差异,5—9月为DEC腹泻发病高峰期。DEC在腹泻菌中比例逐年增加,构成比从2002年的0.21%上升到2010年的18.10%。DEC对氨苄西林、哌拉西林、复方磺胺甲噁唑、环丙沙星和诺氟沙星的耐药率较高,均在45%以上。多重耐药率EPEC高达69.23%、ETEC为45.45%,EIEC为37.93%。结论 DEC引起的感染性腹泻逐年增多,耐药率较高,应重视监测。     

Randomized clinical trial of norfloxacin for shigellosis.

In a randomized clinical trial, norfloxacin was compared with nalidixic acid in the treatment of acute invasive diarrhea, with particular reference to shigellosis in adults. Of 104 patients studied, 40 were positive for Shigella in stool cultures, of which 22 received norfloxacin and 18 received nalidixic acid. The patients in these two groups were comparable on admission. In the treatment of culture-positive shigellosis cases, the responses to therapy with both drugs were similar, except that the duration of fever, anorexia, and abdominal pain were less in those who received norfloxacin. Norfloxacin appeared to be superior to nalidixic acid in the treatment of shigellosis cases caused by Shigella strains resistant to nalidixic acid.     

Work-up for infectious diarrhea after allogeneic hematopoietic stem cell transplantation: single specimen testing results in cost savings without compromising diagnostic yield

BACKGROUND: Diarrhea is a common complication of allogeneic bone marrow transplantation. Microbiologic stool studies are frequently ordered to rule out infectious etiology. The utility of examining multiple stool specimens per diarrheal episode has not been examined. METHODS:. We performed a retrospective review of 169 adult and pediatric patients who underwent hematopoietic stem cell transplantation at Memorial Sloan-Kettering Cancer Center from January 1, 2000 though December 31, 2001, who had at least 1 microbiologic stool study. We report on the incidence of enteric pathogens in our population and diagnostic yield of stool studies. A diarrheal episode was defined as a 14-day period from the date of the first stool study. Cost savings analysis was based on projected savings from implementation of proposed guidelines to the study population. RESULTS: A total of 1649 stool tests were performed (mean 10.6 tests per patient). An infectious cause of diarrhea was found in 45 (28.8%) patients. Diagnostic yield was 6.2% for Clostridum difficile toxin assay, 12.9% for viral cultures, and 1.3% for rotavirus enzyme immunoassay. Bacterial cultures for enteric pathogens, examination for parasites, and rotavirus antigen assay combined had 0.5% positive yield. CONCLUSIONS: Testing of multiple specimens per diarrheal episode did not increase diagnostic yield. The estimated cost savings by implementing single testing for each type of stool study per diarrheal episode was $49,764 annually (in 2001 US dollars). Judicious use of stool tests to evaluate diarrhea results in significant cost savings without compromising diagnostic yield.     

Ciprofloxacin or trimethoprim-sulfamethoxazole as initial therapy for travelers' diarrhea. A placebo-controlled, randomized trial

The efficacy of ciprofloxacin was compared with that of trimethoprim-sulfamethoxazole in a placebo-controlled trial of the 5-day treatment of acute diarrhea among 181 adults recently arrived in Guadalajara, Mexico. Both antimicrobial agents were significantly (p less than 0.0001) more efficacious than placebo in the treatment of diarrhea, with the average duration of diarrhea being 29, 20, and 81 hours, respectively, in the ciprofloxacin, trimethoprim-sulfamethoxazole, and placebo treatment groups. The antimicrobial agents were also more efficacious than placebo in treating diarrhea caused by enterotoxigenic Escherichia coli, invasive enteropathogens, and unknown pathogens. Both antimicrobials were effective in treating mild-to-moderate and moderate-to-severe disease, and both were well tolerated. Ciprofloxacin appears to be a logical alternative to trimethoprim-sulfamethoxazole in the initial treatment of acute travelers' diarrhea.     

Enteropathogens associated with acute and persistent diarrhea in Bangladeshi children less than 5 years of age.

A longitudinal study of diarrhea was carried out from May 1988 to April 1989 by household surveillance of 705 children less than 5 years old in rural Bangladesh. Stool samples were examined for enteric pathogens at the beginning of each diarrheal episode. For persistent episodes, stool examination was repeated on days 15-17 of the illness. For each case of persistent diarrhea, stool samples from age-matched acute diarrheal and healthy controls were examined. Compared with healthy controls, cases of diarrhea were associated with Shigella species (P = .07) and rotavirus (P less than .05). Diffusely adherent Escherichia coli (P less than .05) and cryptosporidia (P = .07) were the only enteropathogens associated with persistent diarrhea in comparison with acute diarrhea. No more than 15% of children had the same class of pathogen identified from stool on both days 1-3 and days 15-17, indicating that persistent infection was uncommon. However, a different enteropathogen was frequently found on days 15-17, suggesting that sequential infection may be a cause of persistent diarrhea.     

Hospital-based surveillance for rotavirus diarrhea in children in Yangon, Myanmar

Diarrhea is a common childhood illness in Myanmar, and rotavirus is the single most important etiological agent of diarrhea. Surveillance for rotavirus diarrhea in children <5 years of age was conducted in a tertiary pediatric hospital in Yangon, Myanmar, from January 2002 through December 2003. Stool specimens obtained from children admitted to the hospital for acute diarrhea were tested for the presence of rotavirus by use of an enzyme-linked immunosorbent assay. Diarrhea was the cause of 5671 (18%) of all hospitalizations of children <5 years of age during the 2-year study period (n = 30,869). Rotavirus was identified in 923 (53%) of the 1736 stool specimens tested, and rotavirus infection was associated with approximately 10% of all hospitalizations of children. Rotavirus diarrhea most frequently occurred in children 6-17 months of age, and it was more commonly identified in boys (62% of children with rotavirus diarrhea were boys). The seasonal pattern of rotavirus disease mimicked that of diarrheal illness due to all causes, with the peak season for rotavirus disease occurring from November through February (i.e., during the cool, dry season). During the study period, 53 of the children who were hospitalized for diarrhea died. The present study confirms the importance of the etiological role that rotavirus plays in childhood diarrhea.     

Stool electrolyte and osmolality measurements in the evaluation of diarrheal disorders

Stool osmolality and electrolyte measurements were obtained from 12 patients with diarrheal disorders. Osmolality of diarrheal stool (285 to 330 mosmol) regardless of the cause is less than the reported osmolality of normal stool. Storage of stool at room temperature can artifactually increase stool osmolality as the result of bacterial metabolism. When stool samples are fresh, a negative osmotic gap (measured osmolality - 2 X [Na + K]) is commonly associated with secretory diarrhea, whereas a high osmotic gap (greater than 160 mosmol) is seen in patients with osmotic diarrhea. In many conditions fasting does not resolve diarrhea completely, and when the stool osmotic gap is greater than 50 mosmol, the pathogenesis of diarrhea is difficult to define.     

Intestinal microsporidiosis in diarrheal patients infected with human immunodeficiency virus-1 in Addis Ababa, Ethiopia

Intestinal microsporidiosis is most commonly associated with persistent diarrhea in advanced AIDS cases. To determine the prevalence and clinical manifestations of this infection in HIV/AIDS patients, a single fresh stool sample and blood were collected from 243 (214 HIV-positive and 29 HIV-negative) diarrheal patients. The presence of intestinal microsporidiosis in the stool was determined by Uvitex-2B staining and a PCR-based detection method. HIV screening was done by using ELISA, and reactive samples were confirmed by Western blotting. The CD4+ cell count was analyzed using FACScan. Out of 243 diarrheal patients, 39 (16.0%) cases were positive for intestinal microsporidial infection by either of the methods used. Of the 39, only 18 cases positive by microscopy were also positive by PCR. Based on PCR and microscopic analyses the microsporidial parasites were identified as Enterocytozoon bieneusi (30), Ecephalitozoon intestinalis (6), and double infections (3). All microsporidia-positive cases were HIV-positive, and 92.3% had diarrhea for over 4 weeks. The diarrhea was watery in 79.5% of the patients. Weight loss >10% was recorded in 37 (94.9%) cases. The CD4+ cell count was <100 cells/mm(3) in 84.4% of subjects, and 59.4% of the patients had a CD4+ cell count of < or =50 cells/mm(3), with a mean of 22.8 cells/mm(3). This study revealed that intestinal microsporidiosis is a common cause of chronic diarrhea and severe weight loss in advanced AIDS patients in Ethiopia. This condition is attributable mainly to E. bieneusi. Thus, early diagnosis of intestinal microsporidiosis in HIV/AIDS patients would certainly be helpful in the understanding and management of diarrheal illness.     

Behavior of urban based child caretakers in the home treatment of diarrheal diseases

Behaviors of low income urban mothers and child caretakers in the treatment of childhood less than 5 year diarrhea were analysed from a surveillance study conducted between August 1988 and July 1989. Help seeking behaviors of mothers and caretakers for 412 episodes of child diarrhea were as follows: investigators 37.1%, drug stores 18.2%, wait and see or self treatment 17.0%, private clinics 12.6%, near by hospital 10.2%, and local health center 4.9%. Major treatment practices included ORT alone (54%) and ORT plus antibiotics and/or antidiarrheal drug (22%). Overall ORT usage was 76%. Twelve percent of diarrheal episodes no treatment was given to the children. Antimicrobials were believed to be essential in addition to ORT especially when diarrhea was associated with fever, vomiting and bloody stools. Thirty-six percent of invasive diarrhea cases (Shigella, Salmonella, Campylobacter) were treated with antibiotics. Only 18.2% of noninvasive diarrhea received antibiotics, most of this antibiotic use being in rotavirus diarrhea where vomiting and some fever are prominent. Availability of oral rehydration salts (ORS) and good experience with ORT were the key to the extensive use or ORT in this study. A surprisingly small number of mothers and child caretakers (4.9%) sought help from the local health center when their children had diarrhea.     

Diarrhea in a non-hospitalized rural Salvadoran population: the role of enterotoxigenic Escherichia coli and rotavirus

To determine the role of rotavirus, enterotoxigenic Escherichia coli and enteropathogenic E. coli in diarrheal disease of non-hospitalized children and adults living in rural El Salvador, stool specimens were collected from 156 persons with diarrhea and 134 age- and sex-matched controls over a 1-year period. Enterotoxigenic Escherichia coli (ETEC) were isolated as frequently from controls (13.4%) as from diarrhea cases (12.2%). Enteropathogenic E. coli were isolated from 13 cases (8.3%) and 10 (7.7%) controls. Rotavirus was demonstrated in only five of the 129 specimens from cases examined; the five persons infected were less than or equal to 3 years of age. No invasive E. coli were found. Serotyping of ETEC revealed serogroups of ETEC previously associated with enterotoxigenicity but was not helpful in separating infection from disease. The etiology of diarrhea in this rural, non-hospitalized population was complex. Isolation of a known pathogen did not prove etiology. The rotaviruses, which have been isolated frequently from hospitalized persons, were rare. Further laboratory and epidemiologic studies in such populations are needed to identify those factors that determine pathogenicity.