Diarrheal morbidity and mortality in children in the Central African Republic

Diarrheal morbidity and mortality in children less than 5 years old were studied in Bangui, Central African Republic, by a cluster survey. We found a high prevalence of diarrheal disease with an estimated annual incidence of 7 episodes of diarrhea per child per year. The estimated annual mortality rate for children less than 5 years old was 28.6 per 1,000 and 85.8 per 1,000 for infants; 51.6% of deaths were reported to be associated with diarrhea. During the survey, stool specimens were collected from 133 children with current diarrhea and 117 control children to study the etiologic agents of diarrheal disease in the community. An enteric pathogen was identified in 58% of diarrheal children's stools and 48% of stools of well children. A statistically significant association between diarrhea and rotavirus was found, with it being isolated from 8 of 33 (24%) of stools of infants with diarrhea compared to 0 of 25 (0%) of control infants. Isolation rates for Campylobacter jejuni, Entamoeba histolytica, pathogenic Escherichia coli, and other bacterial enteropathogens did not differ significantly between children with diarrhea and control children.     

Comparison of Manning, Rome I, II, and III, and Asian diagnostic criteria: Report of the Multicentric Indian Irritable Bowel Syndrome (MIIBS) study

Background

Attempts to diagnose and subtype irritable bowel syndrome (IBS) by symptom-based criteria have limitations, as these are developed in the West and might not be applicable in other populations.

Objectives

This study aimed to compare different criteria for diagnosing and subtyping of IBS in India.

Method

Manning's and the Rome I, II, and III criteria as well as the Asian criteria were applied to 1,618 patients (from 17 centers in India) with chronic lower gastrointestinal (GI) symptoms with no alarm features and negative investigations.

Results

Of 1,618 patients (aged 37.5 [SD 12.6] years; 71.2 % male), 1,476 (91.2 %), 1,098 (67.9 %), 649 (40.1 %), 849 (52.5 %), and 1,206 (74.5 %) fulfilled Manning's, Rome I, II, and III, and the Asian criteria, respectively. The most common reason for not fulfilling the criteria was absence of the following symptoms: “more frequent stools with onset of pain,” “loose stool with onset of pain,” “relief of pain with passage of stool,” “other abdominal discomfort/bloating,” and, in a minority, not meeting the duration criterion of 3 months/12 weeks. By stool frequency, constipation-predominant IBS (<3 stools/week) was diagnosed in 319 (19.7 %), diarrhea-predominant IBS (>3 stools/day) in 43 (2.7 %), and unclassified in 1,256 (77.6 %). By Bristol stool form, constipation, diarrhea, and unclassified were diagnosed in 655 (40.5 %), 709 (43.8 %), and 254 (15.7 %) patients, respectively. By their own perception, 462 (28.6 %), 541 (33.4 %), and 452 (27.9 %) patients reported constipation-predominant, diarrhea-predominant, and alternating types, respectively.

Conclusion

By Manning's and the Asian criteria, a diagnosis of IBS was made frequently among Indian patients with chronic functional lower GI symptoms with no alarm features; the Rome II criteria gave the lowest yield. By the stool frequency criteria, a majority of patients had unclassified pattern, unlike by the stool form and patients' perception of their symptoms.     

Frequency of recovery of Blastocystis hominis in clinical practice

We examined the frequency of isolation of Blastocystis hominis from stools of patients seen in an indigent-care teaching hospital. Over a 2-year period, 2,744 stool specimens were examined prospectively. B. hominis was found in 262 stools (9.5% of all stool specimens and 53.5% of the positive specimens). Clinical data were obtained from 80 patients with stools positive for B. hominis. B. hominis was the only parasite isolated in 39 of 47 (83%) of the adults, compared with 17 of 33 (52%) of the children (p = 0.006). All but 2 of 52 patients without concomitant parasitic infection or bacterial pathogens in stool had gastrointestinal symptoms (41 abdominal pain, 26 diarrhea, and 5 vomiting), but no association was seen with fever, peripheral leukocytosis, stool occult blood, fecal leukocytes, or endoscopic or radiologic evidence of colitis. Therefore, B. hominis was frequently recovered from stools examined in a hospital clinical parasitology laboratory. The clinical presentations of patients in our series did not suggest that B. hominis was invasive. Most patients with B. hominis probably do not require treatment since they will either have spontaneous resolution of symptoms or will be found to have an alternative explanation for their problem.     

Reovirus-like agent in acute epidemic gastroenteritis in Japanese infants: fecal shedding and serologic response.

The reovirus-like agent, sometimes referred to as duovirus or rotavirus, was visualized by electron microscopy in stool extracts from Japanese infants and young children with acute epidemic gastroenteritis. The virus particles measured 70 nm in diameter and had double-shelled capsids. One hundred ten (89%) of 124 patients with the gastroenteritis had such virus particles in stools obtained during the acute phase. The virus particles were excreted in the stools usually during the first eight days of illness. Agglutination of virus particles by antibody present in convalescent-phase sera was demonstrated by immune electron microscopy. Complement-fixing antibody was detected as early as day 3 of illness, and antibody titers peaked during the second and third weeks of the disease. The antibody appearing in the acute and early convalescent phases was sensitive to 2-mercaptoethanol. Antibody resistant to 2-mercaptoethanol was produced approximately 10 days after the onset of the symptoms. The serologic evidence suggests that a primary infection with the reovirus-like agent was responsible for the clinical attack of acute gastroenteritis.     

Hepatitis E in Hetian city. Analysis of 562 cases]

Between August and September 1987, 562 patients were hospitalized with acute non-A, non-B hepatitis. The male to female ratio was 1.4:1, and 75% of the patients was of 15-40 years of age. Jaundice developed in 87%. The overall case-fatality rate was 1.4%, but it was highest among pregnant women (5.2%) and newborn infants (24.2%). In general, the disease was self-limited with no evidence of chronic infection. Liver biopsies obtained during the acute illness showed portal inflammation and cytoplasmic cholestasis. Of 31 specimens of stool examined with a prototype ELISA for HEV antigen, 8 were found to be 'positive' and confirmed with immune electron microscopy (IEM). IEM examination of 'patients' stool revealed 27-32 nm viruslike particles. Inoculation of rhesus monkeys with patients stool containing virus-like particles produced acute hepatitis and the acute phase serum reacted with these particles in IEM, while preinoculation serum specimens were non-reactive.     

An Examination of the Reliability of Reported Stool Frequency in the Diagnosis of Idiopathic Constipation

Objectives : To investigate the reliability of reported stool frequency in the diagnosis of constipation. Methods: Our criterion for the diagnosis of idiopathic constipation was ≤3 stools per week for ≥6 months. Subjects who believed that they met this criterion were invited to participate. Daily stool frequency was recorded over a 4-wk study period, and all stools were weighed during the final week. A colon transit study and anorectal manometry were performed at the beginning and at the end of the study. Results : On review of stool diaries from 45 subjects who described chronic constipation and who completed the 4-wk study, only 22 (49%) actually satisfied our criterion for idiopathic constipation. The remaining 23 (51%) subjects, although describing constipation, had, on average, 6 stools/wk. A history of psychiatric illness was 5 times more frequent among those whose bowel symptoms correlated poorly with objective measures. Measures of difficult defecation were similar in the two groups. Mean colon transit time was significantly longer and correlated closely with stool weight only in subjects who truly were constipated (p < 0.05). Anorectal manometry was not helpful in discriminating between those who satisfied our criterion for constipation and those who did not. Conclusions : Defining constipation on the basis of a patient's reported stool frequency may prove misleading; the diagnosis of idiopathic constipation should be supported by the use of stool diaries and a colon transit study.     

Transmission of enteric non-A, non-B hepatitis virus in Macaca mulatta, monkeys by intraportal route: Subsequent passages of HEV virus

Macaca mulatta monkeys have been used for the transmission of enteric non-A, non-B hepatitis (HEV) virus by intraportal route. Subsequent passages of HEV virus have been completed in these monkeys. In the first passage, 2 monkeys were inoculated by intra-portal route with 27-34 nm virus-like particles (VLP) obtained from known epidemics of HEV hepatitis in India, and biochemical and serological changes in the blood, histological changes in the liver and excretion of 27-34 nm VLP in the stool were studied. Results were compared with those of 4 negative control monkeys inoculated with stool extracts from healthy individuals. The second passage of 27-34 nm VLP was carried out on 2 monkeys using pools of stool suspension positive for 27-34 nm VLP from first passaged animals. Similarly, the third passage of 27-34 nm VLP was completed intraportally in another monkey. All monkeys developed acute hepatitis, as evidenced by transient elevation of aminotransferase, histopathological changes in the liver, development of antibodies aggregating 27-34 nm VLP and excretion of 27-34 nm VLP in stools. No control monkeys developed these features.     

Prucalopride is effective in patients with severe chronic constipation in whom laxatives fail to provide adequate relief. Results of a double-blind,placebo-controlled clinical trial

BACKGROUND: Chronic constipation (CC) is common and there is a need for more effective and better-tolerated agents that normalize bowel function without affecting secretion. Prucalopride is a novel, selective serotonin(4) receptor agonist with enterokinetic properties. AIMS: Pilot study to compare the efficacy and tolerability of prucalopride and placebo in patients with severe CC referred to a tertiary centre. METHODS: After 4-weeks' run in, patients were randomized to 4 weeks' once daily, double-blind treatment with either prucalopride 4 mg (n = 27) or placebo (n = 26). A 50% dose reduction after 2 weeks' treatment was possible for patients with an excessive gastrointestinal response to the study medication (severe cramps, abdominal pain, and diarrhea). Patients assessed efficacy using a visual analogue scale (VAS) and recorded bowel function in daily diaries. The investigator assessed efficacy and total gut transit time (marker study). RESULTS: Patient VAS assessment demonstrated that prucalopride was significantly more effective than placebo in softening stools, and decreasing straining and time to first stool. Prucalopride also had a positive effect on stool frequency, feeling of complete evacuation and total gut transit time, although these differences were not statistically significant compared with placebo. The most common adverse events were gastrointestinal symptoms and headache; most were mild to moderate. There were no clinically relevant effects on cardiovascular or laboratory parameters. CONCLUSIONS: Once-daily prucalopride 4 mg for 4 weeks is effective and well tolerated in patients with severe CC. It improves whole gut transit, reducing straining, softening stools and reducing time to first bowel movement.     

Gene mutations in stool from gastric and colorectal neoplasia patients by next-generation sequencing

AIM To study cancer hotspot mutations by next-generation sequencing(NGS) in stool DNA from patients with different gastrointestinal tract(GIT) neoplasms. METHODS Stool samples were collected from 87 Finnish patients diagnosed with various gastric and colorectal neoplasms, including benign tumors, and from 14 healthy controls. DNA was isolated from stools by usingthe PSP~? Spin Stool DNA Plus Kit. For each sample, 20 ng of DNA was used to construct sequencing libraries using the Ion AmpliS eq Cancer Hotspot Panel v2 or Ion AmpliS eq Colon and Lung Cancer panel v2. Sequencing was performed on Ion PGM. Torrent Suite Software v.5.2.2 was used for variant calling and data analysis.RESULTS NGS was successful in assaying 72 GIT samples and 13 healthy controls, with success rates of the assay being78% for stomach neoplasia and 87% for colorectal tumors. In stool specimens from patients with gastric neoplasia, five hotspot mutations were found in APC,CDKN2 A and EGFR genes, in addition to seven novel mutations. From colorectal patients, 20 mutations were detected in AKT1, APC, ERBB2, FBXW7, KIT, KRAS,NRAS, SMARCB1, SMO, STK11 and TP53. Healthy controls did not exhibit any hotspot mutations, except for two novel ones. APC and TP53 were the most frequently mutated genes in colorectal neoplasms, with five mutations, followed by KRAS with two mutations.APC was the most commonly mutated gene in stools of patients with premalignant/benign GIT lesions.CONCLUSION Our results show that in addition to colorectal neoplasms,mutations can also be assayed from stool specimens of patients with gastric neoplasms.     

Fecal IgA antibody against rotavirus and clinical manifestations of acute viral gastroenteritis in children

We determined the presence or absence of rotavirus antigen by the enzyme-immunoassay in 126 fecal specimens obtained from infants with acute gastroenteritis, and also measured IgA antibody titers against rotavirus in stool samples. Rotavirus-positive specimens amounted to 72. Thirty-five specimens in 126 stool samples were found to contain the IgA antibody against rotavirus. The IgA antibody against rotavirus was detected in 21% and 44% of fecal specimens obtained from age groups of less than 3 years and 3 years or more, respectively, showing a significant difference between these 2 groups. The geometric mean titer of specific IgA antibody was also higher in the latter group than in the former. This specific IgA antibody was detected in 32% and 22% of boys and girls, respectively, showing a tendency of high incidence among boys. The detection rate of specific IgA antibody was significantly higher in rotavirus-negative fecal specimens (41%) than in rotavirus-positive fecal specimens (18%). As for infants having the rotavirus antigen in their feces, their symptoms were severe in many of the infants at the age of less than 3 years, while many of the infants at the age of 3 years or more only had mild symptoms. There was a significant difference between the 2 age groups. When these infants were analyzed according to the presence or absence of specific IgA antibody in their feces, no difference in scores of severity of clinical symptoms was seen between the 2 groups. However, IgA antibody-negative infants more frequently had fever, over 39 degrees C and significantly more developed whitish and watery stool in comparison with IgA antibody-positive infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Factors associated with the frequency of stool examination: effect on incidence of reported rectal bleeding

BACKGROUND: Rectal bleeding is an important presenting symptom of colorectal cancer. The presentation and investigation of patients with rectal bleeding may be delayed if people do not regularly inspect their stool or toilet paper. AIM: To determine how frequently stool or toilet paper is inspected, factors associated with the frequency of inspection, and whether this affects the reported prevalence of rectal bleeding. METHODS: A questionnaire on the frequency of stool inspection and the occurrence of various gastrointestinal symptoms and diseases was developed, validated and sent to 2149 subjects chosen from four general practice lists in south-west London. RESULTS: There was a 79% response rate. Four hundred and forty-two of 1611 subjects (27%) examined both their stool and toilet paper every time. One hundred and two (6%) never examined either. Those who always examined their stool and toilet paper were more likely to report rectal bleeding compared to those who never examined either (23% vs 4%). They were also more likely to be male, to open their bowels more than three times per day, to have watery stools, to experience urgency, and have a history of piles. CONCLUSION: Many people examine their stools and toilet paper infrequently. The possibility that this may contribute to delayed diagnosis of colorectal cancer deserves further evaluation.     

A double blind, randomized, placebo-controlled phase II study to assess the safety and efficacy of orally administered SP-303 for the symptomatic treatment of diarrhea in patients with AIDS

OBJECTIVE: The aim of this study was to investigate the safety and effectiveness of orally administered SP-303 in patients with AIDS and diarrhea. METHODS: This is a multicenter, phase II, randomized, double blind, placebo-controlled study. HIV-positive subjects with a history of a CD4 count <200 or an AIDS-defining illness were admitted to an inpatient study unit and screened for diarrhea defined as at least three abnormal (i.e., soft or watery) stools and >200 g of abnormal stool weight over a 24-h period. Subjects discontinued all antidiarrheal agents >24 h before enrollment. Stool samples were studied for routine pathogens. Subjects received 500 mg p.o. of SP-303 or placebo every 6 h for 96 h (4 days). Stool frequency and weights were recorded. Subjects were monitored for symptoms and side effects and were seen 1 wk later in follow-up. RESULTS: A total of 26 subjects received SP-303, and 25 received placebo. There were no significant demographic differences between treatment arms. A total of 41 subjects (80%) were receiving antiretroviral therapy and 39 subjects (77%) were receiving at least one protease inhibitor. Stool studies revealed no pathogens in 48 of 51 patients (94%). There were no serious adverse events or laboratory abnormalities. The SP-303 treatment group demonstrated a mean reduction from baseline stool weight of 451 g/24 h versus 150 g/24 h with placebo on day 4 of treatment (p = 0.14), and a mean reduction in abnormal stool frequency of three abnormal stools in 24 h versus two in 24 h in the placebo group (p = 0.30). Daily measures analysis over 4 days of treatment demonstrated that SP-303 subjects had a significant reduction in stool weight (p = 0.008) and abnormal stool frequency (p = 0.04) when compared to placebo-treated subjects. CONCLUSIONS: SP-303 is safe and well tolerated. These results suggest that SP-303 may be effective in reducing stool weight and frequency in patients with AIDS and diarrhea.     

Constipation in early childhood: patient characteristics, treatment, and longterm follow up.

Little is known about chronic constipation in infants, toddlers, and preschool children and longterm outcome after treatment. The symptoms of 174 children < or = 4 years of age, who were evaluated for chronic constipation, are reported in this study together with the long-term outcome in 90 of them. Initial symptoms were infrequent bowel movements in 58%, painful bowel movements in 77% often with screaming, and severe stool withholding manoeuvres in 97%. The treatment of chronic idiopathic constipation consisted of education, faecal disimpaction, prevention of future impaction, and promotion of regular bowel habits with dietary fibre and milk of magnesia, and finally toilet training of the preschool child. Longterm outcome could be evaluated in 90 patients (52%) (mean (SD) 6.9 (2.7)) years after initial evaluation. Fifty seven children (63%) had recovered, defined as no soiling with > or = 3 bowel movements per week, while not receiving treatment. The recovery rate of children < or = 2 years of age was significantly higher than in children > 2 to 4 years of age. Thirty three children (37%) had not recovered. Constipation recurred as soon as laxatives were discontinued in 31 (94%) of them. Laxatives were still used by 33% of the children who had not recovered, 39% had < 3 bowel movements per week, 48% had faecal soiling, 45% had stool withholding, 27% complained of abdominal pain, 73% passed large stools, and 45% still on occasions clogged the toilet with their large stools. Symptoms of chronic constipation persisted in one third of our patients, 3-12 years after initial evaluation and treatment. Children who had not recovered deserve continued follow up, to reinforce and adjust treatment and to prevent faecal soiling.     

Comparison of stool immunoassay with standard methods for detection of Helicobacter pylori infection in patients with upper-gastrointestinal bleeding of peptic origin

OBJECTIVE: To assess the accuracy of the determination of Helicobacter pylori infection by a stool immunoassay in patients with upper-gastrointestinal bleeding (UGB) of peptic origin, in comparison with the routine histological study, serology, rapid urease and 13C-breath tests. METHODS: Sixty-eight patients with endoscopically proven UGB of peptic origin were included. The presence of H. pylori was considered when observed on histology or, if negative, by the positive indications of two of the remaining tests (serology, rapid urease,13C-breath test). The accuracy of stool immunoassay was estimated according to results obtained with other diagnostic methods. RESULTS: Lesions causing gastrointestinal bleeding were 49 duodenal ulcers, 11 gastric ulcers, six pyloric channel ulcers, 13 acute lesions of the gastric mucosa, and 16 erosive duodenitis. H. pylori infection was present in 59 (86.76%) patients. Forty-one patients had received nonsteroidal anti-inflammatory drugs. The sensitivity and specificity of the diagnostic methods were 47.5% and 100% for the rapid urease test, 93% and 87.5% for the breath test, 86.4% and 77.7% for serology, 89.4% and 100% for histology, and 96.6% and 33.3% for the stool test. CONCLUSIONS: The detection of H. pylori antigen in stools in patients with UGB of peptic origin has a good sensitivity (96.6%) but a low specificity (33.3%) for the diagnosis of H. pylori infection, which probably makes this test an inadequate tool in this setting if utilized alone.     

'Alarm Symptoms' in Patients with Dyspepsia: a Three-year Prospective Study from General Practice

Background: Ten percent of patients consulting a general practitioner (GP) because of dyspepsia report one or more alarm symptom(s): anemia, black stools, blood in stools, dysphagia, jaundice, weight loss. We observed the consequence of such symptoms prospectively over 3 years. Methods: Postal questionnaires were sent to GPs to obtain recorded information from patients who had consulted the GP because of dyspepsia. Mortality and gastrointestinal morbidity per 1000 person years were studied in two cohorts of patients, one presenting with, the other without, alarm symptoms and compared to expected rates from the general population. The incidence of ulcers was compared between the two cohorts. The predictive value of alarm symptoms for the development of cancer and ulcer was calculated. Results: Compared to the general population, dyspeptic patients without alarm symptoms had an insignificant increase in mortality (OR = 1.5 (0.9-2.4)) and a significant increase in gastrointestinal (GI) cancers (OR = 2.4 (1.1-7.1)), whereas in patients with alarm symptoms both mortality (OR = 2.3 (1.7-3.2)) and GI cancers (OR = 6.3 (3.6-11.0)) were significantly raised. In dyspeptic patients, the presence of alarm symptoms increased the risk of developing peptic ulcers significantly (OR = 5.3 (3.1-9.1)) and gastrointestinal cancer insignificantly (OR = 1.9 (0.9-4.1)). Positive predictive values for development of cancer and ulcer were 4% and 14%, respectively. During 3 years of observation, patients with alarm symptoms were diagnosed with a malignancy in 4%, ulcers in 11% and minor gastrointestinal diseases in 25% of cases. Conclusion: Although the presence of alarm symptoms predicts a bad prognosis, the positive predictive values were low and negative predicted values high, reflecting low incidences of the diseases in the population at risk. The majority of patients who developed cancer or ulcer did not present with alarm symptom(s) at the initial consultation.     

Hepatitis A antigen particles in liver, bile, and stool of chimpanzees.

Virus-like hepatitis A antigen (HA Ag) particles, presumably hepatitis A virus, were isolated from the liver, bile, and stool of three chimpanzees that had been infected with stool filtrates containing HA Ag particles. Specimens of serum, stool, liver biopsy material, and bile were obtained at selected intervals during the experiment. The animals developed mild hepatitis 19-21 days after inoculation, and antibody to HA Ag appeared de novo in their convalescent-phase serum. During acute illness, virus-like particles similar to the HA Ag particle were seen in liver cell cytoplasm by electron microscopy. HA Ag particles were detected by immune electron microscopy and a new radioimmunoassay in isopycnically banded samples of liver, bile, and stool. HA Ag particles were found at densities of 1.29-1.39 g/cm3, but the major peak density for antigen particles in samples of liver, bile, and stool was approximately 1.34 g/cm3. The fact that HA Ag particles can be recovered from chimpanzee liver, bile, and stool makes these potentially important sources of infectious and antigenic materials.     

'Alarm symptoms' in patients with dyspepsia: a three-year prospective study from general practice

BACKGROUND: Ten percent of patients consulting a general practitioner (GP) because of dyspepsia report one or more alarm symptom(s): anemia, black stools, blood in stools, dysphagia, jaundice, weight loss. We observed the consequence of such symptoms prospectively over 3 years. METHODS: Postal questionnaires were sent to GPs to obtain recorded information from patients who had consulted the GP because of dyspepsia. Mortality and gastrointestinal morbidity per 1000 person years were studied in two cohorts of patients, one presenting with, the other without, alarm symptoms and compared to expected rates from the general population. The incidence of ulcers was compared between the two cohorts. The predictive value of alarm symptoms for the development of cancer and ulcer was calculated. RESULTS: Compared to the general population, dyspeptic patients without alarm symptoms had an insignificant increase in mortality (OR = 1.5 (0.9-2.4)) and a significant increase in gastrointestinal (GI) cancers (OR = 2.4 (1.1-7.1)), whereas in patients with alarm symptoms both mortality (OR = 2.3 (1.7-3.2)) and GI cancers (OR = 6.3 (3.6-11.0)) were significantly raised. In dyspeptic patients, the presence of alarm symptoms increased the risk of developing peptic ulcers significantly (OR = 5.3 (3.1-9.1)) and gastrointestinal cancer insignificantly (OR = 1.9 (0.9-4.1)). Positive predictive values for development of cancer and ulcer were 4% and 14%, respectively. During 3 years of observation, patients with alarm symptoms were diagnosed with a malignancy in 4%, ulcers in 11% and minor gastrointestinal diseases in 25% of cases. CONCLUSION: Although the presence of alarm symptoms predicts a bad prognosis, the positive predictive values were low and negative predicted values high, reflecting low incidences of the diseases in the population at risk. The majority of patients who developed cancer or ulcer did not present with alarm symptom(s) at the initial consultation.     

Experimental infection of chimpanzees with hepatitis A virus.

The susceptibility of chimpanzees to viral hepatitis type A was examined with immine electron microscopy. Of four seronegative infant chimpanzees, two were inoculated with a hepatitis A acute-phase stool filtrate rich in 27 nm virus-like hepatitis A antigen (HA Ag) particles, and two were inoculated with an HA Ag-negative preinfection stool filtrate. One of each pair of chimpanzees was inoculated intravenously, the other orally. One month later both chimpanzees that had received the HA Ag-positive filtrate developed biochemical, histologic, and clinical evidence of acute viral hepatitis. HA Ag particle (27 nm) were detected in their stools by immune electron microscopy; particle shedding followed a pattern similar to that in human volunteers. Immune electron microscopy also showed that antibody HA Ag had developed in the convalescent-phase sera of the infected chimpanzees. Control animals remained free of illness at this time but did develop hepatitis three to five weeks after exposure to the two infected chimpanzee-. The infectious inoculum was titrated in two additional seronegative chimpanzees. It was concluded that hepatitis a can be successfully transmitted to seronegative chimpanzees. Moreover, these studies provide further evidence that the 27-nm virus-like HA Ag particle is the etiologic agent of viral hepatitis type A.     

How well does stool form reflect colonic transit?

BACKGROUND: Watery stools are equated with rapid and hard stools with slow intestinal transit; however, the relation between stool form and transit through specific regions of the gut is not clear cut. In addition, more information is needed on interindividual variability of these measurements. AIM: To examine the relations between stool form and gastric emptying, small bowel and colonic transit. METHODS: Regional gut transit was assessed scintigraphically and segmental colonic transit was also quantified by radio-opaque markers. On two occasions, 32 healthy volunteers (12 men, 20 women) were studied, women during the follicular and luteal phases of menstruation, men twice within a similar four week period. Diets were standardised and stool form was recorded on a seven point scale. RESULTS: Women had significant harder stools; hard stools were correlated significantly with slow transit and loose stools with fast transit through the colon. CONCLUSIONS: Stool form could not be related to gastric emptying or small bowel transit.     

Diarrhea,CD4 counts and enteric infections in a community-based cohort of HIV-infected adults in Uganda

OBJECTIVES: To examine relationships between diarrhoea, CD4 cell counts and stool pathogens in a community-based cohort of HIV-infected adults in Uganda. PATIENTS AND METHODS: Stool specimens, obtained between October 1995 and December 1997, were linked to patients' symptoms and laboratory results. The relationship between CD4 counts and symptoms was tested using the Wilcoxon rank-sum test and those between organisms and diarrhoea using first a univariate Mantel-Haenszel analysis and then a logistic regression model adjusted for CD4 count and multiple organisms. RESULTS: 1,213 HIV-infected individuals (70% women, median CD4 cell count at enrollment 215 cells/microl) were followed for 1,224 person years of observation (pyo). 484 stool samples were examined, 357 from patients with diarrhoea. The rate of diarrhoea was 661 episodes per 1,000 pyo. CD4 counts were significantly lower in individuals with diarrhoea than those without (P < 0.001, Wilcoxon rank-sum test). Forty-nine percent of diarrhoeal stools and 39% of stools from asymptomatic patients contained enteric pathogens. The most frequent isolates were helminths (29.5% of all stools), followed by bacteria (19.2%) and then protozoa (8.9%). Rates of isolation of diarrhoea-associated pathogens were 29% from diarrhoeal stools and 17% from asymptomatic stools (P = 0.01, chi(2) test). The association between diarrhoea and infection with bacteria or protozoa was weak and there was no association with helminths.Cryptosporidium parvum infection alone was associated with low CD4 counts. CONCLUSIONS: Diarrhoea was common and most strongly associated with low CD4 counts. Bacteria were frequently found, even in stools from asymptomatic individuals. Over two-thirds of diarrhoeal episodes were undiagnosed, suggesting that unidentified agents or primary HIV enteropathy are important causes of diarrhoea in this population.