Candida-associated diarrhea in hospitalized patients

Incidence of Invasive Infections Among Hemato-Oncology Patients with Significant Burden of Candida in Stool

Candidemia is a serious infection associated with increased mortality. It is unclear whether a high concentration of Candida in stool in patients with hematologic malignancies is associated with a higher risk for developing candidemia. In this observational historical study in patients hospitalized in hemato-oncology departments, we describe the association between gastrointestinal Candida colonization and the risk for candidemia and other severe outcomes. Data from 166 patients with heavy burden of Candida in stool were collected and compared to a control group of 309 patients with minimal or no Candida in stool, from 2005 to 2020. Severe immunosuppression and recent use of antibiotics were more common in heavily colonized patients. Outcomes of heavily colonized patients were worse as compared to the control group with statistical significance in 1-year mortality (53% vs. 37.5%, p = 0.001) and borderline statistical significance in candidemia rate (12.6% vs. 7.1%, p = 0.07). Risk factors for 1-year mortality were significant colonization of Candida in stool, older age and recent use of antibiotics. In conclusion, significant stool burden of Candida among hospitalized hemato-oncology patients may pose a risk for 1-year mortality and increased candidemia rate.

Small intestinal fungal overgrowth

Small intestinal fungal overgrowth (SIFO) is characterized by the presence of excessive number of fungal organisms in the small intestine associated with gastrointestinal (GI) symptoms. Candidiasis is known to cause GI symptoms particularly in immunocompromised patients or those receiving steroids or antibiotics. However, only recently, there is emerging literature that an overgrowth of fungus in the small intestine of non-immunocompromised subjects may cause unexplained GI symptoms. Two recent studies showed that 26 % (24/94) and 25.3 % (38/150) of a series of patients with unexplained GI symptoms had SIFO. The most common symptoms observed in these patients were belching, bloating, indigestion, nausea, diarrhea, and gas. The underlying mechanism(s) that predisposes to SIFO is unclear but small intestinal dysmotility and use of proton pump inhibitors has been implicated. However, further studies are needed; both to confirm these observations and to examine the clinical relevance of fungal overgrowth, both in healthy subjects and in patients with otherwise unexplained GI symptoms. Importantly, whether eradication or its treatment leads to resolution of symptoms remains unclear; at present, a 2-3-week course of antifungal therapy is recommended and may be effective in improving symptoms, but evidence for eradication is lacking.

Study of fungal isolates in patients with chronic diarrhea at a tertiary care hospital in north India

OBJECTIVE

The aim of this study was to evaluate the rate of isolation and antifungal susceptibility profile of various opportunistic yeasts in faeces of patients with chronic diarrhea.

PATIENTS

The study included 120 patients who received the consultation and treatment for the complaints of chronic diarrhea for a period of more than 15 days.

MATERIALS AND METHODS

The microscopy of samples of stool was followed by the culture on Sabourauds-dextrose agar. Isolate were tried for their sensitivity to fluconazole, flucytosine, amphotericin B and voriconazole.

RESULTS

The significant growth of fungal organism was seen in 32 (26.7%) stool specimen. These fungal isolates include five (15.6%) of C. albicans, 14 (43.8%) of C. tropicalis, five (15.6%) of C. krusei, two (6.3%) of C. famata, two (6.3%) of C. parapsilosis isolates and one isolate each of C. lusitaniae, C. guilliermondii, Stephanoascus ciferri and Trichosporon asahii (3.1% each). Most of the yeast isolates (65.6%) were found to be sensitive to all four antifungal agents i.e., fluconazole, flucytosine, amphotericin B and voriconazole. The highest resistance was seen against fluconazole in 10 (31.3%) isolates followed by flucytosine in eight (25%) isolates. No resistance to voriconazole was observed in any of the isolates. The resistance to the antifungal agents was higher among the other species of Candida compared to C. albicans.

CONCLUSION

The study could establish the relation between the opportunistic yeasts and chronic diarrhea and gives information on the antifungal sensitivity profile of the isolated yeasts.

Diarrhoeagenic Escherichia coli as a predominant cause of paediatric nosocomial diarrhoea in India

Intestinal nosocomial infections remain a major concern in paediatric wards leading to increased morbidity and mortality. This study determined the aetiological and epidemiological profile of nosocomial diarrhoea (ND) among children admitted to a hospital in India. During the period of January 2008 to June 2009, we consecutively enrolled 100 children between the age of 2 months and 14 years who developed ND as defined by the Centers for Disease Control and Prevention. A control group of patients matched for age and severity score but with no diarrhoea at admission or during their hospital stay (n=50) were also enrolled. Stool samples were cultured for various pathogens using standard protocols. Clostridium difficile toxins and rotavirus antigen were detected using commercial ELISAs. Detection of diarrhoeagenic Escherichia coli was carried out by multiplex PCR assay. All patient details were noted. In this study, males predominated (77%), and 56% children were <1 year of age and 96% were <5 years. The mean duration of diarrhoea and hospitalization in the case group was 3.2 days and 27.5 days, respectively. Malignancy and nasogastric tube usage were significant underlying factors for the development of ND. Diarrhoeagenic E. coli was the commonest agent (47%: enterotoxigenic E. coli, enteroaggregative E. coli and enteropathogenic E. coli were isolated in 22, 18 and 7% of patients, respectively). C. difficile toxin was seen in 9% of cases, whilst rotavirus was found in 8% of cases. Although rotavirus and C. difficile are major causative agents of hospital-acquired diarrhoea in the developed world, in this setting diarrhoeagenic E. coli was responsible for the majority of cases of hospital-acquired diarrhoea. ND was most common in children aged <5 years.

Yeasts in the gut: from commensals to infectious agents

BACKGROUND

Controversy still surrounds the question whether yeasts found in the gut are causally related to disease, constitute a health hazard, or require treatment.

METHODS

The authors present the state of knowledge in this area on the basis of a selective review of articles retrieved by a PubMed search from 2005 onward. The therapeutic recommendations follow the current national and international guidelines.

RESULTS

Yeasts, mainly Candida species, are present in the gut of about 70% of healthy adults. Mucocutaneous Candida infections are due either to impaired host defenses or to altered gene expression in formerly commensal strains. The expression of virulence factors enables yeasts to form biofilms, destroy tissues, and escape the immunological attacks of the host. Yeast infections of the intestinal mucosa are of uncertain clinical significance, and their possible connection to irritable bowel syndrome, while plausible, remains unproved. Yeast colonization can trigger allergic reactions. Mucosal yeast infections are treated with topically active polyene antimycotic drugs. The adjuvant administration of probiotics is justified on the basis of positive results from controlled clinical trials.

CONCLUSION

The eradication of intestinal yeasts is advised only for certain clearly defined indications.

Probiotics for the prevention of antibiotic-associated diarrhea and Clostridium difficile diarrhea

Antibiotic-associated diarrhea is a common clinical problem occurring in up to 25% of patients, with diarrhea owing to Clostridium difficile accounting for up to a quarter of cases. The clinical and economic costs of antibiotic-associated diarrhea are significant and better treatments are needed. Probiotics may offer potential effective therapy for antibiotic-associated diarrhea by restoring intestinal microbial balance. A number of different probiotics have been evaluated in the prevention and treatment of antibiotic-associated diarrhea in adults and children, including the nonpathogenic yeast Saccharomyces boulardii and multiple lactic-acid fermenting bacteria such as Lactobacillus rhamnosus GG (LGG). A careful review of the literature supports the efficacy of S. boulardii in the prevention of antibiotic-associated diarrhea recurrent C. difficile infection in adults, whereas LGG is useful in the treatment of antibiotic-associated diarrhea in children. Not enough data exist to currently support the use of other probiotic preparations in these conditions. Although generally safe and well tolerated, both S. boulardii and LGG should be used cautiously in immunocompromised patients. Further study of probiotics, including large, well-designed, randomized controlled dose-ranging trials, comparative trials, and cost-benefit analyses are necessary.

Antibiotic-associated diarrhea and pseudomembranous colitis: are they less common with poorly absorbed antimicrobials?

Diarrhea is a well-known complication of antibiotic therapy. Rates of antibiotic-associated diarrhea (AAD) vary from 5 to 25%. Some antibiotics are more likely to cause diarrhea than others, specifically, those that are broad spectrum and those that target anaerobic flora. This paper reviews the effects of antibiotics on the fecal flora as well as host factors which contribute to AAD. Clinical features and treatment of AAD are also described. Prevention of AAD rests on wise antibiotic policies, the use of probiotics and prevention of acquisition in the hospital setting. Data from clinical trials suggest that poorly absorbed antimicrobials might have a decreased risk of causing AAD and Clostridium difficile-associated disease, as concluded from studies of antibiotics used for preoperative bowel decontamination and poorly absorbed antibiotics used for traveler's diarrhea. Controlled trials would prove this but are not yet available. Probiotics may be a good adjunct to poorly absorbed antibiotics to minimize the risk of diarrhea associated with antibiotics.

A Pseudomonas aeruginosa quorum-sensing molecule influences Candida albicans morphology

Candida albicans is an opportunistic pathogen that is commonly found as a member of the human microflora. The ability of C. albicans to alter its cellular morphology has been associated with its virulence; yeast cells are more prevalent in commensal interactions whereas filamentous cells appear important in opportunistic infections. C. albicans encounters a multitude of other microbial species in the host environment and it is likely that they impact the C. albicans transition between virulent and non-virulent states. Here, we report that C. albicans morphology is significantly affected by the presence of Pseudomonas aeruginosa, another opportunistic pathogen. In a screen using a C. albicans HWP1-lacZ strain to indicate regions of filamentous growth, we identified P. aeruginosa mutants incapable of inhibiting C. albicans filamentation. Through these studies, we found that 3-oxo-C12 homoserine lactone, a cell-cell signalling molecule produced by P. aeruginosa, was sufficient to inhibit C. albicans filamentation without affecting fungal growth rates. Both microscopic analysis and real-time reverse transcription polymerase chain reaction analysis of morphology-specific markers confirmed that filamentation was suppressed by 200 microM 3-oxo-C12 homoserine lactone. Structurally related compounds with a 12-carbon chain length, e.g. C12-acyl homoserine lactone and dodecanol also affected C. albicans filamentation at similar concentrations. In contrast, other acylated homoserine lactones of different chain lengths did not affect fungal morphology. The activity of 3OC12HSL is compared with that of farnesol, a C. albicans-produced molecule also with a C12-backbone. The effects that bacteria have on the morphology of C. albicans represents one of the ways by which bacteria can influence the behaviour of fungal cells.

Candida and antibiotic-associated diarrhoea

The role of Candida in antibiotic-associated diarrhoea (AAD) has been controversial for many years. Since Candida exists physiologically in the gastrointestinal tract, the presence of small numbers of Candida organisms in stool has therefore been considered normal, and thus non-pathogenic. Increased Candida counts have been linked to the development of diarrhoea in antibiotic-treated patients. However, recent findings have not confirmed this. To date, there is no convincing evidence that Candida may cause AAD in adults.

Microbial-gut interactions in health and disease. Antibiotic-associated diarrhoea

Most cases of antibiotic-associated diarrhoea (AAD) are directly or indirectly due to the alteration of gut microflora by antibiotics. 'Functional' diarrhoea, usually limited to a mild and brief change in stool frequency, is considered as the most frequent pattern of AAD. Reduced carbohydrate fermentation and impaired metabolism of bile acids have been claimed as the potential causes of this transient digestive discomfort but a critical analysis of the data supporting these theories is necessary. Alternatively, changes in the gut flora ecosystem allow pathogens to proliferate. Clostridium difficile is responsible for approximately 10% of cases of AAD and almost all cases of antibiotic-associated pseudomembranous colitis. The level of evidence which supports the potential responsibility of other candidate pathogens (Klebsiella oxytoca, enterotoxin-producing Clostridium perfringens and Staphylococcus aureus, Candida) needs to be appreciated according to the updated postulates of causality relationships between a bacterium and a disease.

Translocation model of Candida albicans in DBA-2/J mice with protein calorie malnutrition mimics hematogenous candidiasis in humans

To elucidate the mechanism of translocation of Candida albicans from the intestine to the bloodstream, we attempted to establish a murine model for hematogenous translocation of C. albicans using DBA-2/J mice with protein calorie malnutrition (PCM). PCM severely affected the development of the intestinal epithelia; thereby, the keratin and mucinous layers became very thin. Oral inoculation with C. albicans resulted in long-term colonization in the intestine of the PCM mice but not the well-nourished animals. Chemotherapy with a combination of cyclophosphamide and methotrexate, which started four days after oral inoculation of C. albicans, resulted in the systemic dissemination of C. albicans from the intestine in the PCM mice. Among systemic organs, C. albicans was first isolated from the liver, in which focal necrosis, containing fungal balls of yeast-like forms and/or hyphae, was formed. Subsequently, C. albicans was first recovered from the blood of the infected PCM mice at one day after the isolation from the liver, and thereafter, candidemia continued to increase its intensity until death. Histological study indicated that C. albicans gained entry into the systemic organs from the epithelia of the esophago-cardiac junction as well as the Ileo-cecal portions of the infected mice. The results of our present study therefore suggest that this PCM mouse model may be useful for better understanding of the chemotherapy-induced translocation by C. albicans from the gut to the systemic organs in compromised humans.

Antibiotic-associated diarrhoea and Clostridium difficile in the community

BACKGROUND

Clostridium difficile is the main cause of nosocomial infectious diarrhoea and the causative agent of antibiotic-associated colitis. The involvement of C. difficile infection in antibiotic-associated diarrhoea in the community is poorly documented.

METHODS

We studied prospectively 266 adult out-patients in the Paris (France) area who were prescribed a 5-10-day course of antimicrobial chemotherapy. Stools were screened for C. difficile before and 14 days after the start of treatment by standard culture, toxigenic culture and testing for the cytopathic effect of toxin B. Patients were requested to note daily stool frequency and consistency. Diarrhoea was defined as the passage of at least three loose stools per day.

RESULTS

Forty-six (17.5%) of the 262 assessable patients had diarrhoea during the study period. Diarrhoea was mild and self-limited in all patients, and lasted for only 1 day in 65.6% of cases. C. difficile was isolated before and after treatment from one patient, who did not develop diarrhoea. C. difficile was detected only on day 14 in 10 patients (3.8%). The isolate was toxin producing in seven patients. Four of these seven patients had mild self-limited diarrhoea. Toxin-producing C. difficile was isolated significantly more frequently from patients who had diarrhoea than from those who were diarrhoea free (8.7% vs. 1.4%, P = 0.02).

CONCLUSION

The acquisition of toxin-producing C. difficile appears to be frequent during antimicrobial chemotherapy in the community [estimated rate of 2700 (1150-5400) cases per 100 000 exposures to antibiotics]. However, C. difficile is not the main agent of mild antibiotic-associated diarrhoea in out-patients.

Elevated fecal Candida counts in patients with antibiotic-associated diarrhea: role of soluble fecal substances

To assess the role of soluble fecal substances in the elevation of fecal Candida counts in patients with antibiotic-associated diarrhea (AAD), we investigated the growth of Candida albicans in vitro in serially diluted stool fluids from patients with AAD and healthy subjects. There were significantly higher Candida albicans counts in stool fluids diluted 1:10 from AAD patients than in healthy subjects and the phosphate-buffered saline growth control, which may be due to reduced soluble Candida inhibitors and increased availability of growth factors and nutrients.

Endometriosis is associated with an altered profile of intestinal microflora in female rhesus monkeys

BACKGROUND

The intestinal microflora provide a strong defence against intestinal pathogens, and may be altered in inflammatory conditions that impact the gut, such as endometriosis. Therefore, intestinal bacteria shed from rhesus monkeys with endometriosis were compared with age-matched healthy controls. A second study assessed the prevalence of intestinal inflammation in female monkeys to determine whether endometriosis is associated with an increased likelihood of intestinal inflammation.

METHODS

Differential and selective agars were used to enumerate total and Gram-negative aerobic and facultatively anaerobic bacteria, as well as Lactobacilli, from female monkeys with or without endometriosis. In addition, the prevalence of intestinal inflammation in monkeys with or without endometriosis was determined in a retrospective analysis of necropsy reports.

RESULTS

Monkeys with endometriosis had a significantly different profile of shed microflora. Endometriosis was associated with lower Lactobacilli concentrations and higher Gram-negative bacteria concentrations. Moreover, there was a higher prevalence of intestinal inflammation in monkeys with endometriosis in comparison to healthy controls.

CONCLUSIONS

Endometriosis is associated with an altered profile of intestinal microflora in rhesus monkeys. Although the exact mechanisms linking endometriosis and the microflora are unknown, it is possible that the microflora were affected by endometriosis-associated intestinal inflammation.

Infectious causes of chronic diarrhea

Chronic diarrhea can be seen in association with specific pathogens, usually parasites and occasionally some bacteria. This article reviews pathogens causing chronic diarrhea in immunocompetent individuals and provides a rational diagnostic approach.

Faecal candida and diarrhoea

BACKGROUND

Candida species are frequently isolated from stools of children with diarrhoea but are not proven enteropathogens. It is hypothesised that faecal candida causes diarrhoea.

AIMS

To determine the prevalence of faecal candida in childhood diarrhoea and the relation between faecal yeasts and diarrhoea.

METHODS

Comparison of clinical and laboratory data, including quantitative stool culture for yeasts from 107 children hospitalised with diarrhoea and 67 age matched controls without diarrhoea.

RESULTS

Yeast species, predominantly candida, were identified in the stools of 43 children (39%) with diarrhoea and 26 (36%) without diarrhoea. The concentration of candida was positively associated with recent antibiotic use (p = 0.03) and with the presence of another enteric pathogen (p < 0.005), but not with patient age, nutritional status, or duration of diarrhoea.

CONCLUSION

Candida species do not cause childhood diarrhoea in well nourished children.

Intestinal lesions associated with disseminated candidiasis in an experimental animal model

In human patients, disseminated candidiasis, a life-threatening disease for immunocompromised patients, is often associated with intestinal lesions. In this study, we demonstrate that immunosuppressed gnotobiotic (IGB) piglets orally inoculated with wild-type Candida albicans developed extensive intestinal lesions and disseminated infection. Severe ulceration of the ileal mucosa was observed overlying regions of colonization and necrosis of the gut-associated lymphoid tissue. Despite the high susceptibility of IGB piglets to many microbial pathogens, an avirulent mutant strain of C. albicans failed to produce intestinal lesions and exhibited poor dissemination, demonstrating that these effects required virulent organisms. It is likely that in IGB piglets, as in human patients, intestinal lesions provide the mechanism for escape of C. albicans from the gastrointestinal tract. Multinucleated giant cells containing fungal organisms were observed within lymph nodes and lymphatic vessels, and as with other pathogens, such cells could provide a mechanism for dissemination of C. albicans.

Genetically distinct strains of Candida albicans with elevated secretory proteinase production are associated with diarrhoea in hospitalized children

BACKGROUND

Candida albicans has been implicated as the aetiological agent in a significant percentage of children with diarrhoea. The virulence properties of C. albicans strains associated with acute and chronic diarrhoea in hospitalized children were investigated.

METHODS

The genotypic relationships between the isolates were determined using restriction enzyme analysis and hybridization with a C. albicans-specific DNA probe, 27A.

RESULTS AND CONCLUSION

In patients with acute and chronic diarrhoea, there is evidence for selection of specific, genetically distinct strains of C. albicans. Higher levels of secretory Candida acid proteinase produced by isolates from patients with acute diarrhoea may account for the more severe symptoms. However, the lower adherence of these isolates may predispose to the rapid (within 2 to 4 days) resolution of the condition. In patients with chronic diarrhoea the lower levels of proteinase produced correlate with the less severe symptoms, while the increased adherence may account for the persistence of the infection.

Fatal diffuse invasive gastrointestinal candidiasis masking as ileus after bone marrow transplantation

High-dose cytotoxic chemotherapy has increased the incidence of candidal infections that make neutropenic patients very sick and may kill them. We report fatal invasive candidiasis involving the entire alimentary tract after autologous bone marrow transplantation in a young woman with breast cancer. Illustrated are the significance of fungal infections in this patient population, the potential for Candida albicans to invade the entire gastrointestinal tract, and the potential role of endoscopy in the early diagnosis of these often catastrophic infections. We also suggest that diffuse, invasive candidiasis should be considered in the differential diagnosis of ileus in the immunocompromised patient.

Results of culture form colonoscopically obtained specimens for bacteria and fungi in HIV-infected patients with diarrhea

BACKGROUND

The aim of our study was to determine the diagnostic yield of culture for bacteria and fungi from colonic biopsy specimens in 290 consecutive HIV-infected patients with diarrhea.

METHODS

During each colonoscopy, three biopsy specimens were homogenized and cultured on media for Salmonella and Shigella and for Campylobacter and Yersinia, on Loewenstein medium and on Sabouraud medium.

RESULTS

Cultures were found positive for one (n = 32) or two (n = 5) infectious agents in 37 cases, i.e., in 12.8% of the patients. Bacteria were isolated in 24 cases, and identified as Campylobacter jejunl-coli (n = 14), Salmonella (n = 2), Shigella (n = 1), or Pseudomonas aeruginosa (n = 7). Among the 14 patients with C. jejuni-coli intestinal infection, 11 had normal-appearing mucosa at colonoscopy, and 3 had a concomitant stool culture negative for Campylobacter. Mycobacterial cultures were positive for Mycobacterium avium intracellulare in 6 patients, who were already known as having a disseminated M. avium intracellulare infection from positive blood cultures. Fungal cultures were positive for Candida in 10 cases, without clear clinical significance.

CONCLUSIONS

The overall yield of culture for bacterial pathogens from colonic tissue in HIV-infected patients with diarrhea is low, but some individual cases of C. jejuni-coli infections may be detected from colonic tissue culture and not diagnosed by concomitant stool culture.

Nosocomial infections and nosocomial pneumonia

Nosocomial infections are a major source of revenue loss, morbidity, and even mortality to surgical patients. This review presents current issues regarding nosocomial infections and nosocomial pneumonias. This study is a literature review that presents material on nosocomial infections in general and details regarding Clostridium difficile and vancomycin-resistant enterococcus infections. Nosocomial infections, including pneumonias, are serious medical complications, and prevention by strict adherence to barrier precaution is the most important means of protecting the patient from hospital-acquired bacterial flora.

Epidemiology of nosocomial fungal infections

This paper briefly reviews the current knowledge of the epidemiology and modes of transmission of nosocomial fungal infections and some of the therapeutic options for treating these diseases. In the mid-1980s, many institutions reported that fungi were common pathogens in nosocomial infections. Most, if not all, hospitals care for patients at risk for nosocomial fungal infections. The proportion in all nosocomial infections reportedly caused by Candida spp. increased from 2% in 1980 to 5% in 1986 to 1989. Numerous studies have identified common risk factors for acquiring these infections, most of which are very common among hospitalized patients; some factors act primarily by inducing immunosuppression (e.g., corticosteroids, chemotherapy, malnutrition, malignancy, and neutropenia), while others primarily provide a route of infection (e.g., extensive burns, indwelling catheter), and some act in combination. Non-albicans Candida spp., including fluconazole-resistant C. krusei and Torulopsis (C.) glabrata, have become more common pathogens. Newer molecular typing techniques can assist in the determination of a common source of infection caused by several fungal pathogens. Continued epidemiologic and laboratory research is needed to better characterize these pathogens and allow for improved diagnostic and therapeutic strategies.

Infectious gastroenterocolitides in children: an update on emerging pathogens

The recognition that bacterial infections induce signal transduction responses in infected epithelial cells also provides new avenues to consider as novel forms of therapy. For example, the chemokine interleukin-8, which attracts neutrophils to sites of mucosal infection, is produced by epithelial cells of gastric and intestinal origin in response to bacterial infection. Inhibitors of chemokine production or inhibition of the biologic effects of neutrophil chemoattractants have the potential to reduce both mucosal inflammatory responses and the attendant clinical sequelae. Eukaryotic cells also respond to infection with elevations in cytosolic second messengers, including inositol triphosphate (IP3) and calcium ([Ca2+]i). In intestinal epithelium, these second messengers can mediate the diarrheal response to infection. Calcium/calmodulin inhibitors may have a beneficial effect in treating those gastrointestinal infections mediated through changes in the level of cytosolic free calcium. DuPont and colleagues showed, for example, that oral therapy with zaldaride maleate relieves symptoms of disease and shortens the duration of diarrhea in travelers with ETEC-induced diarrhea. Evaluation of additional signal transduction responses to microbial infections should provide both new insights into the pathogenesis of gastrointestinal infectious diseases and novel approaches to consider for the prevention and therapy for these human illnesses.

Methods for detection of an intestinal secretory immunoglobulin A response to Candida spp. and their preliminary application in human immunodeficiency virus-infected patients with chronic diarrhea

Six of 11 human immunodeficiency virus (HIV)-infected patients with chronic diarrhea, shedding only Candida spp. in their stools, elicited a Candida-specific secretory immunoglobulin A response. Similar responses were identified in only 1 of 10 HIV-positive patients with chronic diarrhea but without Candida spp. and in none of 10 HIV-negative subjects without diarrhea. Candida spp. may play a role in the etiology of chronic diarrhea associated with HIV infection.

Bacteria, viruses, yeasts and protozoans associated with diarrheal disease in Singapore

Labile toxin producing enterotoxic E. coli (ETEC) were the commonest pathogen isolated from diarrheal stools of hospitalized children (21%) and adults (26%) in Singapore. Salmonellas ranked a close second in children (19%). Other bacterial pathogens were isolated from less than 5% of subjects. Blastocystis hominis was detected in 4.3% of diarrheal stools when a simple sedimentation technique was used. Cryptosporidium was not detected at all. An analysis of yeast counts in smears of diarrheal and non-diarrheal stools suggested they were etiologically associated with at least 6% of diarrhea in children and 19% in adults. Testing for rotaviruses by Latex agglutination and for adenovirus by electronmicroscopy showed an association with 6 per cent and 3 per cent diarrhea respectively. The study highlighted a need for: case control studies on ETEC and B. hominis; studies on the epidemiology of diarrhea by yeasts; establishing the true incidence of adenovirus diarrhea; studies on the prevalence and seasonality of rotavirus infection in Singapore.

Etiology and outcome of diarrhea after marrow transplantation: a prospective study

BACKGROUND/AIMS

Acute diarrhea after marrow transplant is usually ascribed to acute graft-vs.-host disease (GVHD) or infection, with a reported 40%-50% incidence of infection. The aim of this study was to determine the incidence of acute diarrhea after transplantation, its causes, and its outcome.

METHODS

Two hundred ninety-six patients were followed up; patients with diarrhea were studied using standard evaluation of stool plus immunoelectron microscopy; assays for astrovirus, picobirnavirus, and Norwalk virus; and gene-probe methods for toxin-producing Escherichia coli. In 38 patients with diarrhea, intestinal biopsy specimens and duodenal fluid were also analyzed.

RESULTS

One hundred fifty acute diarrheal episodes developed in 126 patients (an incidence of 43%). Intestinal infection was found in 20 of 150 episodes: viruses (astrovirus, adenovirus, cytomegalovirus, and rotavirus) in 12 patients, nosocomially acquired bacteria (Clostridium difficile and Aeromonas) in 7 patients, and mixed infection in 1 patient. Acute GVHD was responsible for 72 of 150 episodes (48%). Clinical signs and symptoms of infection and GVHD were similar. In 58 of 150 episodes (39%), no clear etiology could be found for self-limited diarrhea.

CONCLUSIONS

Intestinal infection accounted for 13% and acute GVHD for 48% of diarrheal episodes. The most common infecting organisms were astrovirus, C. difficile, and adenovirus. Most cases of diarrhea after marrow transplant are not caused by infection.

Osmotic diarrhea induced by sugar-free theophylline solution in critically ill patients

It is widely accepted that early enteral nutrition is beneficial to critically ill patients. Diarrhea is a common problem in this setting and is often erroneously ascribed to enteral feedings. More often medications cause the diarrhea. Multiple cases of severe diarrhea associated with the use of a sugar-free theophylline solution (SFTS) were discovered by a nutrition support team. SFTS may induce an osmotic diarrhea because it contains sorbitol. A 55-year-old man admitted for a dissecting aneurysm was started on isotonic formula enteral feedings and within a day of starting SFTS developed severe diarrhea. The sorbitol-induced osmotic diarrhea persisted for 36 of his 83 days of hospitalization with direct cost for the evaluation of this diarrhea being $4,250. His prolonged hospitalization cost $166,200. A retrospective review of 20 consecutive patients receiving SFTS revealed that 15 patients had diarrhea for 2 or more consecutive days compared with 20 patients receiving iv aminophylline, of whom only two patients had diarrhea. Furthermore, SFTS was administered to healthy volunteers and a prominent breath hydrogen response was noted. The polyalcohol sorbitol is used as a sweetner in "sugar-free" products and not quantified on labeling because it is considered an inactive ingredient. Nutritionists should be aware that medicinal solutions can contain enough sorbitol to create a laxative effect which is an easily reversible cause of diarrhea in enterally fed patients.

Role of candida in pathogenesis of antibiotic-associated diarrhoea in elderly inpatients

The part that candida plays in antibiotic-associated diarrhoea was investigated in 24 elderly inpatients (mean age 74 years) who tested negative for Clostridium difficile toxin and other intestinal pathogens. 7 had intestinal overgrowth of Candida species (greater than or equal to 10(5) cfu/ml). None of the 24 matched, antibiotic-treated controls without diarrhoea had candida overgrowth. All 5 patients with diarrhoea and candida overgrowth treated with oral nystatin responded with resolution of diarrhoea and lowering of faecal counts to less than 10(4) cfu/ml within 7 days of start of antifungal therapy despite continuation of antibacterial therapy. In the other 2 patients with candida overgrowth, the diarrhoea subsided spontaneously and faecal candida counts returned to normal (less than 10(4) cfu/ml) after antibacterial agents were withdrawn. In patients without candida overgrowth, diarrhoea persisted until antibiotics were withdrawn, at a mean of 16 days after study entry.