The detection of enteropathogens in acute diarrhea in a family cohort population in rural Egypt

In 8 villages of rural northeastern Egypt, a 2-year study of the etiologic agents associated with episodes of diarrhea was carried out. Stool specimens (3,243) from 3,513 episodes of diarrhea were processed for enteropathogens. The most commonly identified agents in the group with diarrhea were Giardia lamblia (44%), heat stable enterotoxin (ST)-producing enterotoxigenic Escherichia coli (ETEC) (15%), heat labile toxin (LT)-producing ETEC (12%), enteropathogenic E. coli (EPEC) (4%), rotavirus (3%), Shigella (2%) and Salmonella (1%). Isolation rates were increased in cases compared to controls for all agents except G. lamblia and EPEC strains. Rotavirus, Salmonella and ST-producing ETEC were more frequently isolated during cooler months and Shigella and LT-ETEC occurred more commonly in warmer months. Campylobacter, EPEC, Giardia and E. histolytica did not show a discernable seasonal pattern. Rotavirus was primarily associated with diarrhea in infants only. Forty-four percent of children experienced at least 1 bout of rotavirus diarrhea by the age of 3 years. Vomiting was reported in 65% of cases of rotavirus infection. Dehydration was reported in greater than 40% of those with rotavirus-, Salmonella-, Campylobacter-, LT-ETEC- and EPEC-associated illness and in those without an identifiable agent. While rotavirus was implicated in 3% of cases overall, when vomiting or vomiting plus dehydration occurred, rotavirus was identified with a rate of 10% and 12%, respectively. Dysentery was common only in Shigella cases, occurring in 24%. A decrease in occurrence of rotavirus, Campylobacter and possibly EPEC illness was seen in the infants less than 6 months of age who were breast-fed when compared to those who were not.     

Enteropathogens associated with acute diarrheal disease in urban infants in S?o Paulo, Brazil

To determine the prevalence and epidemiology of enteropathogens in acute infantile diarrhea, 500 infants less than or equal to 12 months of age with diarrhea and 500 age-matched control subjects coming to a S?o Paulo emergency room were studied. Enteropathogens were identified in 55% of case infants and 10% of controls; enteropathogenic Escherichia coli (EPEC) of classic EPEC serotypes producing EPEC adherence factor (EAF) (26% of case infants), rotavirus (14%), Salmonella species (8%), enterotoxigenic E. coli (7%), and Shigella species (5%) were associated with diarrhea. Isolation of EAF+ classic EPEC decreased with increasing age of cases and peaked in spring, whereas rotavirus was least common in early infancy and peaked in fall and winter. Bloody stool had a 36% positive predictive value for Shigella infection, EAF+ classic EPEC were highly resistant to antimicrobial drugs. Among poor S?o Paulo infants, EAF+ classic EPEC equaled or exceeded rotavirus throughout the year as a cause of diarrhea bringing children to medical attention.     

Future vaccines against enteric pathogens

A small number of bacterial agents, including enterotoxigenic Escherichia coli (ETEC), enteropathogenic E. coli (EPEC), Shigella and Vibrio cholerae 01 and one virus, rotavirus, combine to cause a major proportion of the diarrheal illness of public health importance worldwide. Salmonella typhi is by far the major cause of enteric fever. Attempts to develop safe, practical, and effective vaccines against these agents are under way. Examples of vaccine candidates include live oral vaccines against S. typhi, V. cholerae, Shigella, and rotavirus, and inactivated, submit vaccines given parentally or orally against S. typhi, V. cholerae or ETEC. Although the oral attenuated S. typhi vaccine is ready for commercial license, it will be several years before the other vaccines are proven to be practically safe and effective in children and adults.     

Bacterial enteric pathogens in children with acute dysentery in Thailand: increasing importance of quinolone-resistant Campylobacter

Current data on pathogen prevalence and drug resistance patterns are important for treatment and vaccine-development strategies. An etiologic study of acute bacterial dysentery was conducted in children up to 12 years of age in 2 major hospitals in and around Bangkok. Stool samples or rectal swabs and clinical data were collected. Standard microbiological methods were used to detect Salmonella, Shigella, Campylobacter, Vibrio, Aeromonas and Plesiomonas. Pathogenic E. coli (ETEC, EIEC, STEC) was identified by digoxigenin-labeled probes. A total of 623 cases were enrolled: median age 11.0 months (range 1 month-12 years). At least one bacterial pathogen was isolated in 55% of cases. Campylobacter was the most common pathogen found (28%), whereas Salmonella, Shigella and ETEC were isolated from 18%, 9% and 6% respectively. EIEC, Vibrio and Plesiomonas were isolated from <1% and no STEC was detected. C. jejuni serotypes 36, 4 and 11 were the most common. The mean age of cases with Campylobacter was significantly lower than with Shigella (17.9 vs 52.8 months, p<0.001). Clinical presentations of Campylobacter and Shigella infections were compared: fever (28% vs 37%), abdominal colic (62% vs 80%, p<0.05), vomiting (38% vs 70%, p<0.001) and bloody stools (52% vs 48%). The Campylobacter isolates (80% C. jejuni, 20% C. coli) were 90% resistant to ciprofloxacin but sensitive to macrolides. All the Shigella isolates (70% S. sonnei) were sensitive to quinolones. Our study illustrates the increasing importance of quinolone-resistant Campylobacter and the decline of Shigella in the etiology of dysentery in Thailand. The clinical presentation of campylobacteriosis is similar to that of shigellosis, except that the patients may be younger and there may be less association with colic and vomiting; having fecal leukocytes will be >10/HPF. The use of macrolide antibiotics rather than quinolones would be reasonable in children <24 months of age; fluoroquinolones will be ineffective in at least half of culture-positive cases.     

Etiology of acute diarrhea in children and adults in Tunis, Tunisia, with emphasis on diarrheagenic Escherichia coli: prevalence, phenotyping, and molecular epidemiology

A total of 271 stool specimens were collected from children (diarrheagenic, n = 115 and control, n = 54) and adults (diarrheagenic, n = 73 and control, n = 29) from Tunis, Tunisia, and processed to detect bacterial enteropathogens, parasites, and viruses. Diarrheagenic Escherichia coli (DEC) were identified by their virulence genes (polymerase chain reaction) and adherence patterns (tissue culture assays). The most frequently isolated enteric pathogens from diarrheagenic children were enterotoxigenic E. coli (ETEC, 32.3%), enteroaggregative E. coli (EAEC, 11.3%), enteroinvasive E. coli (EIEC, (11.3%), adenovirus (10.4%), enterohemorrhagic E. coli (EHEC, 10.4%), and Salmonella spp. (9.5%). For children in the control group, ETEC (37%), EAEC (15%), EHEC (11.1%), and typical enteropathogenic E. coli (EPEC, 11.1%) were the most common enteric pathogens. In adults in the diarrheagenic group, Salmonella spp. (34.2%), ETEC (12.3%), adenovirus (7%), and Shigella spp. (4%) were the most common enteric pathogens. In adults in the control group, ETEC (31%) was the most common enteric pathogen. Multiple pathogens were recovered from 22% of the diarrheagenic children and 7% of the diarrheagenic adults. Escherichia coli strains showed high resistance rates to tetracycline, streptomycin, and beta-lactams. The most frequent combinations were ETEC-rotavirus and ETEC-adenovirus. Pulsed-field gel electrophoresis for DEC indicated a large number of DEC clones (five major clones) persistent in the community reservoir for a considerable period of time that caused diarrhea in the population. This suggests the confluence of small epidemics by clonally related DEC strains circulating in this region.     

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.     

A prospective study of enteropathogenic Escherichia coli in endemic diarrheal disease.

The rate of isolation of Escherichia coli belonging to the traditional serotypes enteropathogenic for infants was studied prospectively in two groups. Group 1 consisted of children with diarrhea and of controls without gastrointestinal disease who were matched for age and inpatient or outpatient status. Group 2 consisted of families entered in a prospective study of rotavirus infections. In group 1 enteropathogenic Escherichia coli were found in 13 (6%) of 220 children younger than 12 months of age and in nine (6%) of 143 children 12--35 months of age, all of whom had diarrhea. Enteropathogenic E. coli were found in only one of an equal number of matched controls (P = 0.002 and 0.004, respectively). In group 2 enteropathogenic E. coli were present in seven (18%) of 38 specimens obtained during diarrheal episodes, as compared with five (1%) of 492 specimens obtained when there was no diarrhea (P less than 0.001). The enteropathogenic E. coli isolated were not enterotoxigenic. The most common serogroup was O111, but many different O:H serotypes were detected. Thus, the association of enteropathogenic E. coli with endemic diarrhea was significant, even though no enteropathogenic mechanism was apparent.     

Frequency and virulence properties of diarrheagenic Escherichia coli in children with diarrhea in Gabon

To investigate the presence of diarrheagenic Escherichia coli in Lambaréné, Gabon, 150 children with diarrhea were screened for enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), and enteroinvasive E. coli (EIEC) using polymerase chain reaction and an HEp-2 cell culture techniques. Isolates of EAEC were detected in 57 children, two thirds of them between six months and two years of age, and isolates of ETEC were detected in seven patients. Isolates of EPEC, EHEC, and EIEC were not present in this population. Among the EAEC, the pCVD432 plasmid, a heat stable (ST)-like (ST-like) enterotoxin (EAST), and a plasmid-encoded heat-labile toxin (PET) were detected in 19, 34, and 42 cases, respectively. Detection of pCVD432, EAST, and PET were significantly associated with EAEC identified by the HEp-2 cell assay. Although detected only in 16 patients, the presence of the fimbriae AAF I (aagA) and AAF II (aafA) were more likely to occur in EAEC than in non-EAEC (odds ratio [OR] = 4.1, 95% confidence interval [CI] = 0.5-38.6, and OR = 2.3, 95% CI = 1.0-5.3, respectively). The EAEC isolates exhibited decreased susceptibility for ampicillin, tetracycline, and trimethoprim.     

Etiology of acute diarrhea among children in Ribeirão Preto-SP, Brazil

To study the main enteropathogens causing diarrhea in the region of Ribeir?o Preto regarding serogroups and serotypes, the feces of 1836 children under 10 years old, from both sexes, attack of acute gastroenteritis, were analysed during a period of 4 years in Adolfo Lutz Institute - Ribeir?o Preto, SP. The pathogens identified by standard methods were the following: Escherichia coli, Salmonella spp., Shigella spp., Campylobacter spp., Yersinia spp., and Cryptosporidium spp. Positive samples were 22.8% (419) with 1.7% association of pathogens. Larger isolates were mainly from children 0 to 11 months old. Enteropathogenic E. coli (EPEC) was most frequent (8.7%) with predominance of serogroup O119 (40.2%), followed by Shigella (6.2%), 63.6% of which S. sonnei.     

Asymptomatic infections by diarrheagenic Escherichia coli in children from Misiones, Argentina, during the first twenty months of their lives

Diarrheagenics Escherichia coli are the major agents involved in diarrheal disease in developing countries. The aim of this study was to evaluate the time of appearance of the first asymptomatic infection by the different categories of diarrheagenic E. coli in 44 children since their birth and during the first 20 months of their lives. In all of the children studied, we detected at least one category of diarrheagenic E. coli through the 20 months of the study. 510 diarrheagenic E. coli (33.5%) were obtained from the 1,524 samples collected from the 44 children during the time of the study (31.4% EAggEC, 28.8% EPEC, 27.1% DAEC, and 12.7% ETEC). Neither EHEC nor EIEC were identified. The median age for diarrheagenic E. coli colonization was 7.5 months. The mean weaning period was 12.8 months and the mean age for introduction of mixed feeding (breast fed supplemented) was 3.8 months. A significantly lower incidence of diarrheal disease and asymptomatic infections was recorded among the exclusively breast-fed rather than in the supplemented and non breast-fed infants. For ETEC, EPEC and EAggEC the introduction of weaning foods and complete termination of breast-feeding were associated with an increase of asymptomatic infections.     

Attaching and effacing enteropathogenic Escherichia coli as a cause of infantile diarrhea in Bangkok.

To identify Escherichia coli that cause infantile diarrhea in Bangkok, Thailand, E. coli isolated in a year-long study of infantile diarrhea were examined for O and H serotypes and virulence determinants. Classic enteropathogenic E. coli (EPEC) were isolated from 28 of 509 infants with diarrhea (cases) and 11 of 509 age-matched controls (P = .009; odds ratio [OR], 2.64). Most of this difference was attributable to EPEC adherence factor (EAF)-positive EPEC that produced an attachment and effacement lesion, as identified in the fluorescence actin staining assay, isolated from 13 cases and 1 control (P = .003; OR, 13.3). EAF-EPEC was isolated from 15 cases and 10 controls (P = .418; OR, 1.52) and EAF+ non-EPEC from 17 cases and 10 controls (P = .242; OR, 1.72). EAF+EPEC that caused an attachment and effacement lesion was found in 3% of children less than 6 months old with diarrhea who were studied in an outpatient clinic in Bangkok in 1988.     

Impact of vitamin A on selected gastrointestinal pathogen infections and associated diarrheal episodes among children in Mexico City, Mexico

BACKGROUND: The overall effect of vitamin A supplementation on diarrheal disease in community trials may result from its effect on specific diarrheal pathogens. METHODS: We conducted a placebo-controlled, double-blind trial of the prophylactic effect of vitamin A on gastrointestinal pathogen infections and clinical symptoms among 188 children in Mexico City, Mexico, from January 1998 to May 1999. Children 6-15 months of age were randomly assigned to receive either a vitamin A supplement (for children <12 months of age, 20,000 international units [IU] of retinol; for children > or =12 months of age, 45,000 IU of retinol) every 2 months or a placebo and were followed for up to 15 months. Stool samples, collected semimonthly, were screened for enteropathogenic Escherichia coli (EPEC), enterotoxigenic E. coli (ETEC), Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), and Giardia lamblia. RESULTS: Vitamin A supplementation reduced the prevalence of EPEC infections (rate ratio [RR], 0.52 [95% confidence interval {CI}, 0.23-0.86]) and led to shorter durations of both EPEC and ETEC infections. Supplementation also reduced the prevalence of EPEC-associated diarrhea (RR, 0.41 [95% CI, 0.16-1.00]), EPEC-associated fever (RR, 0.15 [95% CI, 0.02-0.98]), and G. lamblia-associated fever (RR, 0.27 [95% CI, 0.13-0.80]). Finally, children who received vitamin A supplementation had shorter durations of EPEC-associated diarrhea than did children who did not receive supplementation but had longer durations of G. lamblia-associated diarrhea. CONCLUSIONS: These results suggest that the effect of vitamin A supplementation on clinical outcomes may be pathogen dependent.     

Clinic-based surveillance for bacterial- and rotavirus-associated diarrhea in Egyptian children

To identify enteropathogens for vaccine development, we implemented clinic-based surveillance for severe pediatric diarrhea in Egypt's Nile River Delta. Over 2 years, a physician clinically evaluated and obtained stool samples for microbiology from patients with diarrhea and less than 6 years of age. In the first (N = 714) and second clinic (N = 561), respectively, 36% (N = 254) and 46% (N = 260) of children were infected with rotavirus, enterotoxigenic Escherichia coli (ETEC), Campylobacter, or Shigella. When excluding mixed rotavirus-bacterial infections, for the first and second clinic, 23% and 10% had rotavirus-associated diarrhea, and 14% and 17% had ETEC-associated diarrhea, respectively. Campylobacter-associated diarrhea was 1% and 3%, and Shigella-associated diarrhea was 2% and 1%, respectively, for the two clinics. Rotavirus-associated diarrhea peaked in late summer to early winter, while bacterial agents were prevalent during summer. Rotavirus-associated cases presented with dehydration, vomiting, and were often hospitalized. Children with Shigella- or Campylobacter-associated diarrhea reported as watery diarrhea and rarely dysentery. ETEC did not have any clinically distinct characteristics. For vaccine development and/or deployment, our study suggests that rotavirus is of principle concern, followed by ETEC, Shigella, and Campylobacter.     

Examination of diarrheal stools in Hat Yai City, South Thailand, for Escherichia coli O157 and other diarrheagenic Escherichia coli using immunomagnetic separation and PCR method

A total of 493 stool samples from diarrheal patients in Songklanagarind Hospital, in southern Thailand, were examined for Escherichia coli O157 by the culture method combined with an immunomagnetic separation (IMS) technique. E. coli O157 was not found, although the IMS-based method could detect 10(2)-10(3) CFU of artificially inoculated O157/g of stool samples. Polymerase chain reaction was also used for the detection and identification of diarrheagenic E coli from 530 stool samples. The target genes were eae for enteropathogenic E. coli (EPEC), stx for enterohemorrhagic E. coli (EHEC), elt and est for enterotoxigenic E. coli (ETEC), ipaH for enteroinvasive E. coli (EIEC), and aggR for enteroaggregative E. coli (EAggEC). Fifty-eight diarrheagenic E. coli strains were detected in 55 stool samples (10%) from 32 children and 23 adults. These included 31 EAggEC strains (5.8%), 13 ETEC strains (2.5%), 13 EPEC strains (2.5%), and one EIEC strain (0.2%). EHEC was not detected. The diarrheagenic E. coli strains were found mainly in children under 2 years of age (24 of 32 children). EAggEC strains and ETEC strains were susceptible to several antibiotics whereas the EPEC strains exhibited resistance to these antibiotics.     

Incidence of rotavirus in the Menino Jesus Pediatric Hospital (SP): ELISA--a practical and efficient method for its detection

Seventy infants and children with age from 2 months to 4 years old were admitted to "Hospital Infantil Menino Jesus", in S?o Paulo, Brazil, in the period from March 1983 to June 1984 with acute diarrhea. Feces from these patients were analysed in the search of rotavirus and enteropathogenic bacteria (Shigella, Salmonella and E. coli), for the purpose of defining the role of rotavirus as an agent of acute diarrhea in infants and young children in this country. ELISA (Enzyme-linked Immuno Sorbent Assay) was the method of choice for the search of rotavirus, because of its simplicity of management and the high sensitivity of the results. Rotavirus alone was imputed as the cause of acute diarrhea in 12 patients (17.7%), with ages from 2 months to 3 years old and in 2 patients in association with Shigella. All but one of the patients with rotavirus were undernourished and none of the infants had been breast fed before the disease.     

Aetiological studies of diarrhoeal diseases in infants and young children in Iran

The aetiology of diarrhoeal diseases was investigated among 715 patients admitted to four Children's Hospitals in Tehran, during February 1986 to March 1987, and also among 443 patients attending the central Out-Patient Clinic in Sanandaj, State of Kordestan, during October 1986. Enteropathogenic Escherichia coli (EPEC) were the most common pathogens found in both areas. Almost 26.7% of the patients in Tehran and 20.1% of the patients in Sanandaj were infected with EPEC. Enterotoxigenic E. coli (ETEC) were the next most frequent groups found (17.1% both in Tehran and Sanandaj), with heat-stable enterotoxin (ST)-producing strains being dominant. Of 122 ETEC strains isolated in Tehran, 94 (77%) strains produced ST, 15 (12.3%) strains produced heat-labile enterotoxin (LT) and 13 (10.7%) strains produced both LT and ST. Almost the same pattern of toxigenicity was observed among ETEC strains isolated in Sanadaj. Of the 76 ETEC strains isolated in this area, 70 (92.1%) strains were ST producers, followed by those producing both LT and ST (five strains) and LT only (one strain). One strain of enteroinvasive E. coli (EIEC) was also isolated from a patient in Tehran. The rates of salmonella and shigella isolation were 8.8 and 5.7% in Tehran and 3.8 and 4% in Sanandaj respectively. Enterohaemorrhagic E. coli, Vibrio cholerae and V. parahemolyticus were not isolated but a mixture of two or more pathogens was found in 59 patients (8.2%) in Tehran and in 20 patients (4.5%) in Sanandaj. These findings suggest that diarrhoegenic E. coli are the most important cause of diarrhoeal diseases in infants and young children in these areas in Iran.     

The incidence and the valuation of eaeA gene of enteropathogenic Escherichia coli (EPEC) or aggR gene of enteroaggregative E. coli (EAggEC) in the strains isolated from patients in sporadic diarrhea cases

To clarify the pathogenic role of enteropathogenic Escherichia coli (EPEC) or enteroaggregative E. coli (EAggEC), the possession of eaeA gene of EPEC or aggR gene of EAggEC in the strains isolated from 525 patients in sporadic diarrhea cases during 3 years (1998-2000) in Tama, Tokyo was investigated by a PCR method. The eaeA-positive E. coli strains were confirmed from 23 cases including 5 cases detected verotoxin-producing E. coli (VTEC), and those except VTEC strains (18 cases, 3.4%) were the 5th predominant enteropathogen following rotavirus, Campylobacter, adenovirus, and Salmonella. By age, 17 eaeA-positive cases were from children < 10 years of age, and noticeably, of which 9 were from infants < 24 months of age. On the other hand, although aggR-positive E. coli strains were detected from 11 cases (2.1%), of which 6 also were from infants < 24 months of age. Clinical symptoms of patients whom eaeA or aggR gene-positive E.coli was isolated as the only potential enteric pathogen were similar, showing a mild gastroenteritic features. Only one strain of eaeA-positive E. coli and 4 of aggR-strains were typed with the commercial O-antisera, which were O55, and O86, O111 or O126. In antibiotic sensitivity tests for 9 agents, 22% of eaeA-strains and 91% of aggR-strains showed resistant, especially 10 aggR-strains had resistant to ABPC. These findings suggest that these organisms are a significant causative agents of infantile diarrhea and the PCR method is a useful procedure for the diagnosis of EPEC or EAggEC infectious disease.     

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.     

Outbreak caused by Escherichia coli in Chalco,Mexico

OBJECTIVE: To identify the etiologic agent responsible for a disease outbreak following an overflow of sewage water in Valle de Chalco, Mexico. MATERIAL AND METHODS: A retrospective cross-sectional study was carried out. Rectal samples were collected from the population of Chalco valley, who suffered from diarrhea and vomiting during a natural disaster that took place on May 31, 2000. The Instituto de Diagnóstico y Referencia Epidemiológicos (Epidemic Reference and Diagnosis Institute, InDRE, Ministry of Health), received 1521 rectal swab samples from diarrhea cases, to test for E. coli strains. Statistical analysis was performed to find a difference of proportions between cases and non-cases (chi-squared test). ETEC, EIEC, EPEC and EHEC pathogenic E. coli groups were hybridized by colony blot. RESULTS: Strains isolated were ETEC (62.2%), EIEC (0.84%), EPEC (0.84%), and EHEC non-O157:H7 (0.08%); there was no hybridization in 36.02% of E. coli strains. Other isolated microorganisms were Salmonella spp (0.45%) and Shigella spp (0.06%). CONCLUSIONS: Enterotoxigenic E. coli was the most likely etiologic agent. Sanitary control strategies should be targeted to preventing outbreaks caused by this pathogenic agent. The English version of this paper is available at: http://www.insp.mx/salud/index.html.     

Etiology and epidemiology of diarrhea in children in Hanoi, Vietnam.

OBJECTIVES: This paper provides a preliminary picture of diarrhea with regards to etiology, clinical symptoms, and some related epidemiologic factors in children less than five years of age living in Hanoi, Vietnam. METHODS: The study population included 587 children with diarrhea and 249 age-matched healthy controls. The identification of pathogens was carried out by the conventional methods in combination with ELISA, immunoseparation, and PCR. The antibiotic susceptibility was determined by MIC following the NCCLS recommendations. RESULTS: Of those with diarrhea, 40.9% were less than one year old and 71.0% were less than two years old. A potential pathogen was identified in 67.3% of children with diarrhea. They were group A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis, with prevalences of 46.7%, 22.5%, 4.7%, and 7.3%, respectively. No Salmonella spp or Vibrio cholerae were isolated. Rotavirus and diarrheagenic E. coli were predominant in children less than two years of age, while Shigella spp, and enterotoxigenic B. fragilis were mostly seen in the older children. Diarrheagenic E. coli and Shigella spp showed high prevalence of resistance to ampicillin, chloramphenicol, and to trimethoprim/sulfamethoxazole. Children attending the hospitals had fever (43.6%), vomiting (53.8%), and dehydration (82.6%). Watery stool was predominant with a prevalence of 66.4%, followed by mucous stool (21.0%). The mean episodes of stools per day was seven, ranging from two to 23 episodes. Before attending hospitals, 162/587 (27.6%) children had been given antibiotics. Overall, more children got diarrhea in (i) poor families; (ii) families where piped water and a latrine were lacking; (iii) families where mothers washed their hands less often before feeding the children; (iv) families where mothers had a low level of education; (v) families where information on health and sanitation less often reached their households. CONCLUSIONS: Group A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis play an important role in causing diarrhea in children in Hanoi, Vietnam. Epidemiological factors such as lack of fresh water supply, unhygienic septic tank, low family income, lack of health information, and low educational level of parents could contribute to the morbidity of diarrhea in children.