Characterization of virulence factors of Aeromonas isolated from children with and without diarrhoea in Tripoli, Libya

During September 1992-August 1993, stool samples from 157 children with diarrhoea and 157 matched healthy controls were examined for the presence of Aeromonas and other enteropathogens. Aeromonas strains were tested for haemolytic activity, haemagglutination patterns, and antibiotic susceptibility. In total, 62 Aeromonas were isolated, of which 27 (17.2%) were from children with diarrhoea and 35 (22.3%) from healthy controls. Only 23 (14.6%) of the diarrhoeal children and 28 (17.8%) of the healthy controls were positive for Aeromonas; of which, 4 (2.5%) of the diarrhoeal children and 6 (3.8%) of the healthy controls showed multiple species. Aeromonas hydrophila was isolated from 5 (3.2%) children with diarrhoea and from 9 (6.4%) controls, A. veronii bv sobria from 8 (5.1%) and 7 (4.5%), A. caviae from 13 (8.3%) and 17 (10.8%), and A. schubertii from 1 (0.6%) and 2 (1.3%) respectively. No significant difference in the haemolytic activity of Aeromonas was found between diarrhoeal and healthy children. However, a significant difference (p < 0.002) was observed in mannose-resistant haemagglutination (MRHA) by diarrhoeal isolates of Aeromonas (7/27, 26%) compared to the healthy controls (1/35, 3%). Aeromonas strains were uniformly sensitive to ciprofloxacin, gentamicin, and nalidixic acid. The results of this study suggest that A. caviae strains may be associated with diarrhoea in children and MRHA may be used as one of the virulence markers for distinguishing between Aeromonas isolated from diarrhoeal children and healthy controls or environmental isolates.     

Incidence and risk factors of paediatric rotavirus diarrhoea in northern Ghana

We measured the type-specific incidence of paediatric rotavirus diarrhoea in an area of northern Ghana. Over 1 year, diarrhoea 1717 episodes were identified, of which 677 (39%) were positive for rotavirus. Risk factors for rotavirus infection included old age, wasting, high Vesikari score and the episode occurring in the dry season. Rotavirus-positive episodes tended to be more acute, causing vomiting and greater dehydration, and were more likely to require hospitalization. The incidence was 0.089 episodes per person-year for all diarrhoea, and 0.035 for rotavirus diarrhoea. The observed incidence decreased markedly with distance from the nearest health centre, suggesting a large unobserved burden. G2P[6], G3P[4] and G9P[8] made up more than half the genotypes detected, but the remainder were diverse. There is a large burden of rotavirus diarrhoea, but the effectiveness of future vaccines could be diluted by the high polymorphism of the virus, and the difficulty of reaching remote populations.     

Chronic diarrhoea in children

Chronic diarrhoea in children shows an age related spectrum. In infants and young children a major role is related to persistent intestinal infections, intolerance to specific nutrients such as cow's milk protein, and toddler's diarrhoea. In older children and adolescents, inflammatory bowel diseases are strongly increasing and nonspecific diarrhoea is also frequent. Coeliac disease is a major cause of diarrhoea throughout childhood. In neonates, congenital diarrhoea is a rare but severe syndrome that includes several highly complex diseases. In children, diagnosis should be based on noninvasive techniques. Endoscopy should be decided based on clinical criteria, but also driven by noninvasive tests to assess the digestive absorptive functions and intestinal inflammation. A stepwise approach may reduce the need of endoscopy, also in the light of its relatively limited diagnostic yield compared to adult patients. Treatment of chronic diarrhoea in children is also substantially different from what is generally done in adults and includes a major role for nutritional interventions. Therefore chronic diarrhoea in children is a complex age-specific disorder that requires an age-specific management that is in many aspects distinct from that in adults.     

Cryptosporidial diarrhoea in children

Summary By auramine and modified Ziehl-Neelsen staining, cryptosporidial oocysts were found in the stools of 31 (1.36%) out of 2,367 patients with diarrhoea. All specimens were also tested for Salmonella, Shigella, Campylobacter, Yersinia, and Rotavirus. Among these patients, 432 were children and 24 (5.5%) of them were positive for cryptosporidia. All children infected with cryptosporidia were immunocompetent. Watery diarrhoea, vomiting and abdominal pain were the most frequent symptoms. The survey showed that in patients with gastroenteritis, cryptosporidial oocysts were found more commonly in the stools of children than in those of adults, and the prevalence of infection was the highest in August and September (16 cases). The epidemiological aspects and clinical significance are discussed.

---

Kryptosporidien-Diarrhoe bei Kindern

Zusammenfassung Mit Hilfe einer Auramin- und einer modifizierten Ziehl-Neelsen-Färbung wurden Kryptosporidien-Oozysten in den Stühlen von 31 (1,36%) der 2367 untersuchten Patienten mit Durchfall gefunden. Alle Proben wurden daneben auf Salmonellen, Shigellen, Campylobacter, Yersinien und Rotaviren untersucht. Unter den Patienten befanden sich 432 Kinder, von denen 24 (5,5%) einen positiven Kryptosporidien-Nachweis aufwiesen. Alle mit Kryptosporidien infizierten Kinder waren immunkompetent. Die häufigsten mit einer Kryptosporidien-Infektion einhergehenden Symptome waren wäßrige Diarrhoe, Erbrechen und Abdominalschmerzen. Bei Gastroenteritis wurden Kryptosporidien-Oozysten häufiger im Stuhl von Kindern als im Stuhl von Erwachsenen gefunden. Die Inzidenz der Infektion war in den Monaten August und September (16 Fälle) am höchsten. Sowohl epidemiologische Gesichtspunkte als auch die klinische Bedeutung dieser Befunde werden diskutiert.

     

Prevalence of cryptosporidiosis in Israeli children with diarrhoea

In a prospective study, Cryptosporidium oocysts were detected in seven (3.25%) immunocompetent children with diarrhoea. The predominant clinical features were watery diarrhoea and vomiting. The patients' mean age was 19 years and infection was more common in late summer-autumn than in the rest of the year. This first survey on cryptosporidiosis in Israeli children has shown a prevalence similar to that observed in other developed countries.     

Treatment of enterotoxigenic and enteropathogenic Escherichia coli-induced diarrhoea in children with bovine immunoglobulin milk concentrate from hyperimmunized cows: a double-blind, placebo-controlled, clinical trial

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) and enteropathogenic Escherichia coli (EPEC) are important causes of diarrhoea in young children and are associated with significant mortality rates. Passive immunization with antibodies from immunized cows has previously been shown to be effective as prophylaxis against E. coli-induced diarrhoea and therapeutically against rotavirus and cryptosporidia-induced diarrhoea. METHODS: We tested the therapeutic efficacy of an oral bovine immunoglobulin milk concentrate (BIC) from cows hyperimmunized with ETEC and EPEC strains, in a randomized, placebo-controlled study in children with E. coli-induced diarrhoea. Eighty-six children between 4-24 months of age attending the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B) with E. coli-induced diarrhoea (63 EPEC/ETEC and 23 with other diarrhoeagenic E. coli) were randomly assigned to receive orally administered BIC (20 g) containing anti-ETEC/EPEC antibodies or a placebo preparation daily for 4 consecutive days. Daily stool output, intake of oral rehydration solution (ORS), stool frequency, and presence of diarrhoeagenic E. coli strains in the stool were monitored for 4 days. RESULTS: Children in the treatment group tolerated the BIC with no side effects. There were no significant differences between the two groups with regard to ORS intake, stool output, frequency of diarrhoea, or clearance of pathogen. Nor was there any significant alteration in the duration of diarrhoea. CONCLUSIONS: In contrast to the prophylactic efficacy of anti-E. coli BIC and the therapeutic efficacy of a similarly prepared anti-rotavirus BIC, antibodies from hyperimmunized cows appear to have no significant therapeutic benefit in the treatment of acute diarrhoea due to EPEC/ETEC.     

Microbial agents in stools of infants and young children with and without acute diarrhoeal disease.

A study on the microbial agents in the stools of 344 infants and young children (206 diarrhoeal and 138 nondiarrhoeal) was carried out. The diarrhoeal group comprised of 120 hospitalised cases and 86 from a community. The numbers of nondiarrhoeal subjects of matching age taken from the same hospital and community were 50 and 88 respectively. It was revealed that bacteria (50-9%), parasites (11-7%), and C. albicans (2-4%) accounted for 65 per cent of the diarrhoea cases, 6-8 per cent having mixed infections. The largest number of cases had EEC followed by P. aeruginosa, Shige-la, V. cholerae, and A, hydrophila and of the parasites G. intestinalis was followed by E. histolytica in order of frequency. Enteropathogenic bacteria and parasites were encountered in 13-0 per cent and 34.8 per cent of the nondiarrhoeal subjects respectively, 7-2 per cent having mixed infections. This group also had EEC as the commonest bacteria and A. lumbricoides was the most prevalent parasite. Except for V. cholerae, A. hydrophila and C. albicans no significant difference was observed in the microbial spectra amongst the diarrhoeal cases in the hospital or community. In the nondiarrhoeal subjects both groups showed a similar prevalence pattern. Incidence of bacterial pathogens was significantly higher in children below two years and intestinal parasites were three times more common in older children.     

Frequency and characteristics of diarrhoeagenic Escherichia coli strains isolated from children with and without diarrhoea in Rio de Janeiro, Brazil

The frequency of diarrhoeagenic Escherichia coli (DEC) strains was investigated in 253 children up to 3 years old, with (patient group, PG, 199 children) and without (control group, CG, 54 children) diarrhoea, living in Rio de Janeiro, Brazil. DEC strains were detected in 70 (27.6%) children, including 54 (27.1%) with diarrhoea and 16 (29.6%) without diarrhoea. Enteroaggregative E. coli (EAEC) was the most frequent DEC category, accounting for 14.6% of the isolates in the PG and for 11.1% in the CG. E. coli strains carrying enteropathogenic E. coli (EPEC) virulence markers showed higher incidence in the CG (12.9%) than in the PG (8.0%). E. coli strains belonging to non-classical EPEC groups that carried eae only or eae and bfpA, designated as attaching-effacing E. coli (AEEC) were the most frequent (79.1%). Simultaneous presence of multiple EPEC virulence factors (EAF/eae/bfpA) were only detected among strains isolated from the PG. Enterotoxigenic E. coli (ETEC) strains were isolated from 5.5% of the children in the CG and from 3.5% of those in the PG. Most of the ETEC isolates were LT-probe positive (70%) and none carried both LT-I and ST-I probe sequences. One enteroinvasive E. coli (EIEC) strain was recovered from a child with diarrhoea. No stx-probe positive E. coli strains were detected. Overall, DEC strains were not found to be significantly associated with diarrhoea (p>0.05). However, the higher incidence of EAEC, the most frequent DEC category, among children with diarrhoea, suggests a potential role of EAEC as an important enteric pathogen in the community investigated.     

Therapeutic methods for diarrhoea in children

Acute diarrhoea may manifest as acute watery diarrhoea or dysentery. The key to the management of acutewatery diarrhoea is correction of dehydration, proper feeding and appropriate use of antibiotic in selectedcases. Correction of dehydration may be done by oral route by using oral rehydration salts solution (ORS)recornmended by WHO/UNICEF or by intravenous administration of fluid and electrolytes, the preferredsolution being Ringer＇s lactate. Antibiotic is required for severe cholera and shigellosis. Antiparasitic drugsare required for amoebiasis or giardiasis. Use of various antidiarrhoeals is strongly discouraged. Feedingduring diarrhoea is very important. It does not worsen diarrhoea rather hastens recovery and preventsmalnutrition. Supplementation of zinc as an adjunct to rehydration therapy has also been suggested.     

Detection and characterization of human rotavirus among children with diarrhoea in Botswana

This study reports the detection, for the first time, of human rotavirus in stools of children and the molecular characterization of isolated circulating strains in Botswana. We collected 249 stool samples between 1999 and 2001 from children with diarrhoea in three health districts of Botswana and examined them for the presence of rotavirus antigens and particles. Group A rotavirus antigen was detected in 43 of 249 (17%) of the samples tested by enzyme-linked immunosorbent assay. Of the 43 children shedding rotaviruses, 37 (86%) were infants < or =2 years of age. The presence of rotavirus particles was also confirmed by direct electron microscopy. The characteristic 11 segments of the double-stranded RNA mobility pattern of rotavirus were demonstrated by polyacrylamide electrophoresis in 20 of 43 (47%) of the rotavirus-positive samples. The predominant electrophoretic pattern detected was the long (L) electrophoretype 14 of 20 (70%) followed by the short (S) electrophoretype five of 20 (25%). One strain had a mixed (L/S) pattern. Of the 26 samples subjected to subgrouping by enzyme immuno assay, eight were typed as subgroup-II specific and seven were subgroup I. The predominant VP7 genotypes detected were G1 (59%). Two mixed strains of G1 + G3 (5%) and G1 + G2 (5%) were also detected. VP4 genotypes in circulation were: P[4] (5%), P[6] (33%) and P[8] (33%). Mixed P-types P[4 + 6] (5%) and P[6 + 8] (18%) were also detected. Rotavirus strains G1 P[8] and GI P[6 + 8] were the most common cause of diarrhoea in our study area.     

Cryptosporidium among children with acute diarrhoea in the west of Ireland

During a period of 12 months beginning on 18 February 1985, 1246 specimens of faeces from 935 children aged 3 weeks to 12 years with acute diarrhoea of varying severity were examined for the presence of cryptosporidium oocysts. Twenty-six patients required admission to hospital; four of them needed intravenous rehydration. Predominant clinical features were diarrhoea, often watery, and vomiting. Diarrhoea varied in duration between 7-15 days. Cryptosporidium oocysts were found in specimens from 41 patients, an incidence of 4.3%. In four patients an additional enteropathogen was identified (Campylobacter species in two and enteropathogenic Escherichia coli in two - serotypes 0126: K71 (B16) and 018C: K77 (B12]. None of the patients had recently travelled abroad. Of the children 23 were from a farming or rural background. Eight of the farms had recently had significant outbreaks of diarrhoea among calves. There was a marked seasonal variation with 27 of the cases arising between 18 February and 18 June, an incidence during this period of 8%.     

Small intestinal transit, absorption, and permeability in patients with AIDS with and without diarrhoea

BACKGROUND: Diarrhoea in AIDS is associated with anorexia and weight loss. The importance of gastrointestinal transit in such symptoms has not been addressed. AIMS: To assess jejunal to caecal transit times in subjects with AIDS related diarrhoea and weight loss and correlate these with measures of absorptive capacity and intestinal permeability. METHODS: Jejunal to caecal transit times were assessed in 20 seronegative controls and 60 HIV seropositive subjects from serum analysis of 3-O-methyl-D-glucose and sulphapyridine after ingestion of the monosaccharide and sulphasalazine in aqueous solution. The method also allows an estimation of gastric emptying times for liquids. Intestinal absorptive capacity and permeability were assessed by a combined test using 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose. RESULTS: Gastric emptying was significantly delayed in all groups of patients with AIDS. Mean jejunal to caecal transit times were not significantly different between controls (246 (62) minutes) and patients without diarrhoea (AIDS, well: 278 (103) minutes; AIDS, wasting: 236 (68) minutes), cytomegalovirus colitis (289 (83) minutes), pathogen negative diarrhoea (192 (100) minutes), or microsporidiosis (190 (113) minutes), although 30% of patients had values below the control range. Patients with cryptosporidiosis differed significantly from controls (135 (35) minutes, p<0.0001), seven of 10 having rapid transit times. Absorptive capacity was reduced and intestinal permeability significantly increased in AIDS, but did not correlate significantly with transit times. CONCLUSION: Small bowel transit is accelerated in many patients with AIDS, particularily in protozoal diarrhoea, but is not the sole explanation for malabsorption of monosaccharides.     

Bacteriological study of traveller's diarrhoea. 4) Isolation of enteropathogenic bacteria from patients with traveller's diarrhoea at Osaka Airport Quarantine Station during 1984-1991]

During the last 8 years (1984 to 1991), 16,639,233 overseas travellers were quarantined at Osaka Airport Quarantine Station and 38,326 travellers reported that they were (or had been) suffering from diarrhoea. Bacteriological examination of stools from 12,573 persons revealed the following results. 1) Various enteropathogenic bacteria were isolated from 3,669 cases (29.2%) examined. The predominant species of bacteria isolated were as follows: Salmonella, 1049 cases; Plesiomonas shigelloides, 1030 cases; Vibrio parahaemolyticus, 789 cases; Shigella, 607 cases; enterotoxigenic Escherichia coli, 422 cases; Vibrio cholerae non-O1, 212 cases. 2) There were no apparent seasonal variations in the isolation rate of these pathogens. 3) The suspected regions for infection with these pathogens were as follows: a) Salmonella, Enterotoxigenic E. coli and Plesiomonas, mainly South-East and South-West Asia. b) Shigella, South-West Asia, especially India (59.8%). c) V. parahaemolyticus and V. fluvialis, mainly South-East and East Asia. d) V. cholerae non-O1, V. mimicus, almost restricted to Asia, mainly South-East Asia. 4) 22 strains of V. cholerae O1 were isolated and 19 were Ogawa, E1 Tor. Of these strains, 13 were cholera toxin-producing strains and 9 were non-toxigenic strains. 5) Several pathogens (mixed infection) were isolated simultaneously from 670 cases. 6) The 1247 Salmonella strains were identified into 98 serovars. 7) Of 624 Shigella strains isolated, 57.9% were S. sonnei, 29.2% were S. flexneri, 8.6% were S. boydii, 4.3% were S. dysenteriae. 8) The most predominant serovar of V. parahaemolyticus was O4:K8. Of 1,247 strains isolated, 9.8% were not producing thermostable direct hemolysin (TDH). 9) 570 (91.3%) of 624 Shigella strains and 409 (32.8%) of 1,247 Salmonella strains isolated were resistant to any one of the drugs tested (SM. CP. TC. KM. ABPC. NA. OFLX). The resistance rate and the number of multiple drug-resistance strains increased year by year. 10) Enterotoxigenic E. coli was isolated from 422 cases (10.7%) of 3,939 cases. Cases with enterotoxigenic E. coli strains producing ST (heat-stable), LT (heat-labile) or both ST and LT were 53.8%, 24.2% and 14.2% respectively. The others were cases with mixed types of enterotoxin production.