Review article: infectious diarrhoea

Monocyte human leukocyte antigen-DR expression-a tool to distinguish intestinal bacterial infections from inflammatory bowel disease?

BACKGROUND

We sought to determine the quantitative expression of human leukocyte antigen-DR (HLA-DR) on monocytes in patients with acute intestinal bacterial infections and inflammatory bowel disease (IBD).

METHODS

The quantitative expression of HLA-DR on monocytes was determined by fluorescence-activated cell sorting analysis in patients with IBD, patients with acute intestinal bacterial infections (bact.), and healthy subjects (contr.).

RESULTS

The quantitative expression of HLA-DR in patients with bact. (n = 20; 90,000 molecules per monocyte; confidence interval [CI], 79,000-102,000) was significantly higher than that in patients with ulcerative colitis (n = 40, 30,000; CI, 30,000-38,000; P < 0.0001), Crohn disease (n = 80, 31,000; CI, 32,000-39,000; P < 0.0001), or in contr. (n = 28, 39,000; CI, 36,000-46,000; P < 0.0001). In patients with ulcerative colitis and Crohn disease, HLA-DR expression was significantly decreased, as compared with contr. (P < 0.05 and P < 0.01, respectively). With a cutoff point of 50,000, HLA-DR showed a sensitivity of 95% and a specificity of 92% in discriminating between bact. and active IBD.

CONCLUSION

The quantitative measurement of HLA-DR expression could serve as a valuable tool to discriminate between bact. and active IBD.

Psychometric scores and persistence of irritable bowel after infectious diarrhoea

BACKGROUND

Although previous studies have shown that psychological disturbances are frequently associated with the irritable bowel syndrome (IBS), the relation was not necessarily cause and effect. The development of chronic bowel symptoms after an episode of acute gastroenteritis has allowed us to examine prospectively the role of psychological factors.

METHODS

Seventy-five patients with acute gastroenteritis completed a series of psychometric tests soon after admission to hospital. Of these, 22 had persistent symptoms compatible with IBS after the acute illness, and in 20 of these the symptoms were still present at six months.

FINDINGS

At the time of their initial illness, patients who subsequently developed IBS had higher scores for anxiety, depression, somatization and neurotic trait than those who returned to normal bowel function. The psychometric scores had not changed when remeasured after the acute illness. Lactose malabsorption was not an important factor.

INTERPRETATION

These results support the hypothesis that psychological factors are important in IBS.

Rectal nitric oxide gas and stool cytokine levels during the course of infectious gastroenteritis

Nitric oxide (NO) is known to be an important inflammatory mediator with a potential role in gastrointestinal diseases. We prospectively studied the luminal NO levels in 51 patients with infectious gastroenteritis, 35 patients with nonenteric bacterial infections, and 11 healthy control subjects. The levels of proinflammatory cytokines were simultaneously measured in the stools of patients with gastroenteritis. Rectal gas was sampled with balloon catheters made of silicone and was analyzed for NO levels by chemiluminescence. The median rectal NO level was 2,450 ppb in the acute phase of gastroenteritis and gradually decreased to 225 ppb after 3 to 8 weeks, whereas the median NO values were 150 ppb in patients with nonenteric bacterial infections and 100 ppb in healthy control subjects. Patients with Salmonella, Shigella, and Campylobacter infections generally had more severe symptoms and a higher median NO level (17,250 ppb) than patients with Clostridium difficile-associated diarrhea (median NO value, 275 ppb). Interleukin-1 beta levels were elevated in 82% of the patients at disease onset and decreased during the convalescent phase. In contrast, gamma interferon was detected in only 16% of the patients and was predominantly collected in stool samples collected during the subacute and convalescent stages. Our data point to the possibility of using this easy, minimally invasive method for luminal NO measurement as a diagnostic tool, among others, to evaluate the degree of intestinal inflammation in patients with infectious gastroenteritis.

Conduite à tenir devant une diarrhée aiguë. Étiologies

Les diarrhées aiguës constituent un problème de santé publique du fait de leur grande fréquence. Leur origine est presque toujours infectieuse et leur évolution spontanément résolutive, le plus souvent en moins de 3 jours. Seul 1 % des diarrhées nécessite d'emblée des explorations complémentaires, notamment des examens de selles, car leur présentation clinique évoque une colite aiguë sous-jacente (selles sanglantes, douleurs abdominales circonscrites), du fait d'un terrain fragile sous-jacent avec un risque immédiat pour le malade, ou d'un contexte particulier (séjour sous les tropiques…). Ces examens de selles doivent être orientés afin de guider le biologiste et améliorer la rentabilité des prélèvements, qui s'avère sinon très faible et coûteuse à l'échelle d'une population. Une antibiothérapie empirique basée essentiellement sur les fluoroquinolones est ensuite licite dans ces cas sélectionnés, en attendant les résultats des examens. Ces explorations sont aussi justifiées lorsque la diarrhée persiste au-delà de 3 jours. Enfin, lorsque l'épisode se prolonge au-delà de 5 jours, avec des prélèvements de selles négatifs, un avis spécialisé est nécessaire. Ainsi, seule une petite proportion de ces diarrhées aiguës va nécessiter une endoscopie, permettant de parler ainsi de colite ou de rectocolite. Au plan thérapeutique, la réhydratation précoce chez l'enfant reste d'actualité car elle a prouvé son efficacité en termes de mortalité depuis plus de deux décennies, principalement dans les pays en voie de développement.

The Role of Diet in the Treatment of Travelers' Diarrhea: A Pilot Study

A pilot study was performed to compare the effects of a restricted physiologic diet in 48 subjects with those of an unrestricted diet in 57 subjects on the duration and symptoms of acute travelers' diarrhea among US adults being treated with an antimicrobial agent in Mexico. Restricted physiologic diet was defined as the avoidance of certain foods during diarrheal illness, as specified in limited published literature. The mean duration of diarrhea (37 vs. 33 h) and clinical symptoms were similar between those practicing the restricted diet and those practicing unrestricted diets. These results suggest that restricting diet during treatment of travelers' diarrhea with an antimicrobial agent is not associated with improvement of clinical symptoms or with decreased duration of diarrhea. However, a much higher number of subjects would need to be studied to prove this point statistically.

Guidelines for adults on self-medication for the treatment of acute diarrhoea

Acute uncomplicated diarrhoea is commonly treated by self-medication. Guidelines for treatment exist, but are inconsistent, sometimes contradictory, and often owe more to dogma than evidence. An ad hoc multidisciplinary group has reviewed the literature to determine best practice. In general it is recognized that treatment of acute episodes relieves discomfort and social dysfunction. There is no evidence that it prolongs the illness. Self-medication in otherwise healthy adults is safe. Oral loperamide is the treatment of choice. Older anti-diarrhoeal drugs are also effective in the relief of symptoms but carry the risk of unwanted adverse effects. Oral rehydration solutions do not relieve diarrhoea, and confer no added benefit for adults who can maintain their fluid intake. Probiotic agents are, at present, limited in efficacy and availability. Antimicrobial drugs, available without prescription in some countries, are not generally appropriate for self-medication, except for travellers on the basis of medical advice prior to departure. Medical intervention is recommended for the management of acute diarrhoea in the frail, the elderly (> 75 years), persons with concurrent chronic disease, and children. Medical intervention is also required when there is no abatement of the symptoms after 48 h, or when there is evidence of deterioration such as dehydration, abdominal distension, or the onset of dysentery (pyrexia > 38.5 degrees C and/or bloody stools).

Bacterial Infections of the Colon

The colon is a common site of infection for a heterogeneous group of bacterial pathogens. The presentation of disease in the colon is generally in the form of distinct syndromes, and it is important for physicians to recognize the causative organisms, because specific treatment is highly effective. The flouroquinolones have emerged as the treatment of choice for most food-borne bacterial pathogens. Resistance to these agents is not a major issue at present except in Campylobacter. Clostridium difficile remains sensitive to both metronidazole and oral vancomycin. The majority of patients will respond to metronidazole, but oral vancomycin should be limited to severe cases of pseudomembranous colitis or treatment failures with metronidazole. Vancomycin is expensive and has the potential for the propagation of vancomycin resistance in other bacteria, notably enterococci. Patients appearing with proctitis should be screened for sexually transmitted diseases.

Oral rehydration solution therapy in the management of children with rotavirus diarrhea

Rotavirus infections are the most common cause of gastroenteritis among children younger than 3 years of age and are associated with sporadic outbreaks of diarrhea in elderly and immunocompromised patients. Oral rehydration solutions (ORS) are formulated to correct dehydration and acidosis. Currently, ORS do not promote intestinal healing; however, investigators are examining the role of nutrition in promoting intestinal healing. This article reviews the composition of several ORS in human medicine and summarizes our current knowledge of the nutritional treatment of rotavirus diarrhea and intestinal healing.

Review article: travellers' diarrhoea

In this review we will briefly consider the important aetiological agents and clinical expressions in travellers' diarrhoea, then we will review the prevention and therapy of the illness.

Secretory diarrhea

Diarrhea, defined as loose stools, occurs when the intestine does not complete absorption of electrolytes and water from luminal contents. This can happen when a nonabsorbable, osmotically active substance is ingested ("osmotic diarrhea") or when electrolyte absorption is impaired ("secretory diarrhea"). Most cases of acute and chronic diarrhea are due to the latter mechanism. Secretory diarrhea can result from bacterial toxins, reduced absorptive surface area caused by disease or resection, luminal secretagogues (such as bile acids or laxatives), circulating secretagogues (such as various hormones, drugs, and poisons), and medical problems that compromise regulation of intestinal function. Evaluation of patients with secretory diarrhea must be tailored to find the likely causes of this problem. Specific and nonspecific treatment can be valuable.

Acute diarrhea: a practical review

This review provides a practical, simple, and logical approach to the diagnosis and management of patients with acute infectious diarrhea, one of the most common diagnoses in clinical practice. Diarrhea in the immunocompromised host, traveler's diarrhea, and diarrhea in the hospitalized patient are also discussed. Most episodes of acute diarrhea are self-limited, and investigations should be performed only if the results will influence management and outcome. After an adequate history and physical examination, the clinician should be able to classify the acute diarrheal illness, assess the severity, and determine whether investigations are needed. Most patients do not require specific therapy. Therapy should mainly be directed at preventing dehydration. Various home remedies frequently suffice in mild, self-limited diarrhea. However, in large-volume, dehydrating diarrhea, oral rehydration solutions should be used, as they are formulated to stimulate sodium and water absorption. Antidiarrheal agents can be useful in reducing the number of bowel movements and diminishing the magnitude of fluid loss. The most useful agents are opiate derivatives and bismuth subsalicylate. Antibiotic therapy is not required in most patients with acute diarrheal disorders. Guidelines for their use are presented.

Efficacy of SF 68 in the treatment of acute diarrhea. A placebo-controlled trial

BACKGROUND

The therapeutic value of Bioflorin, a preparation containing Enterococcus SF 68 strain, was evaluated in adult patients with acute diarrhea.

METHODS

In a double-blind randomized trial we compared the effect of SF 68 strain in a dose of 150 x 10(6) colony-forming units three times a day for 5 days compared with placebo on the duration of diarrhea in 211 adults.

RESULTS

Patients receiving SF 68 had a reduced duration of diarrhea compared with placebo, with a highly statistically significant difference between treatments. The proportion of patients with continuing diarrhea during the 2nd day of treatment was 61% in patients receiving SF 68 and 96% in those receiving placebo (P < 0.01). During the 3rd day diarrhea was still present in 8% of patients given SF 68, compared with 66% of those given placebo (P < 0.01). The mean (+/-SD) duration of diarrhea was 1.69 days (0.6) in patients given SF 68 compared with 2.81 days (0.9) in those given placebo. When pathogens were found in the first stool culture, they could not be detected at post-treatment examination. No adverse reactions were observed.

CONCLUSIONS

Oral bacteriotherapy with SF 68 strain shortens the duration and the severity of diarrhea in adults and represents a safe and effective approach to re-establishing a balanced microbial flora in this condition.

'The tropics in our bathroom': chronic diarrhoea after return from the tropics

Interest in imported tropical diseases has increased with the rising number of travellers to the tropics. This is especially true in the case of tropical gastroenterologic disorders. The causative organisms of chronic diarrhoea are different from those causing acute diarrhoea. Bacteria are relatively unusual; parasites, e.g. Entamoeba histolytica or Giardia lamblia or an opportunistic parasitic infestation associated with an HIV infection are more likely. Furthermore, non-infectious causes, such as postinfective tropical malabsorption, lactase deficiency or coeliac disease have to be considered. Today, elderly people often undertake a journey to the tropics; in these cases the diarrhoea may be associated not only with an increased susceptibility to tropical bowel infections but also with causes previously present, such as diverticulosis, carcinoma or inflammatory bowel disease. The classification of chronic diarrhoea following a visit to the tropics is essentially the same as that for acute diarrhoea: diarrhoea with and without fever and with and without blood. In addition, malabsorption is an important feature of chronic diarrhoea.