Epidemiologic and clinical characteristics of acute diarrhea with emphasis on Entamoeba histolytica infections in preschool children in an urban slum of Dhaka, Bangladesh

The epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 Bangladeshi children (147 boys and 142 girls) 2-5 years old. The use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of Entamoeba histolytica to total diarrheal illness in this community setting. The average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average observation period of 2.8 years/child. Seventy-five percent of the diarrheal episodes were < or = 2 days in duration. Persistent diarrhea was relatively uncommon (0.2% of the children) and chronic diarrhea was observed in only one episode. Compared with malnourished and/or stunted children, better-nourished children experienced significantly fewer diarrheal episodes. The diarrheal incidence rate for children with blood group A was significantly less that that of the children with blood groups O and AB. The most frequent bacterial enteropathogens isolated from diarrheal stool specimens were enterotoxigenic Escherichia coli (9%) and Aeromonas species (9%), followed by Plesimonas shigelloides (4%) and Shigella flexneri (3.8%). Rotavirus was the most common viral agent isolated from diarrheal stool samples (5%). Giardia lamblia, Cryptosporidium parvum, and E. histolytica were identified in 11%, 8.4%, and 8%, respectively, of the diarrheal stool specimens. Dysentery was observed in 7.7% of all diarrheal episodes. The most common pathogens isolated from dysenteric stool were S. flexneri (11.6%), Aeromonas sp. (10%), E. histolytica (8.7%), Campylobacter jejunii (5.8%), P. shigelloides (4.3%), and A. caviae (4.3%). The overall incidence rate of E. histolytica-associated diarrhea was 0.08/child-year. Visible blood and hemoccult test-detected blood loss was found in 7% and 25%, respectively, of cases of E. histolytica-associated diarrhea. Children who had recovered from a diarrheal episode with E. histolytica, but not E. dispar, had half the chance of developing subsequent E. histolytica-associated diarrhea, consistent with the development of species-specific acquired immunity. In conclusion, the use of modern diagnostic tests demonstrated that E. histolytica contributed to overall morbidity from diarrheal illness. Understanding the etiology, frequency, and consequences of acute diarrhea in children from a developing country should aid in the design of interventions to improve child health.     

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.     

Enteropathogens associated with acute and persistent diarrhea in Bangladeshi children less than 5 years of age.

A longitudinal study of diarrhea was carried out from May 1988 to April 1989 by household surveillance of 705 children less than 5 years old in rural Bangladesh. Stool samples were examined for enteric pathogens at the beginning of each diarrheal episode. For persistent episodes, stool examination was repeated on days 15-17 of the illness. For each case of persistent diarrhea, stool samples from age-matched acute diarrheal and healthy controls were examined. Compared with healthy controls, cases of diarrhea were associated with Shigella species (P = .07) and rotavirus (P less than .05). Diffusely adherent Escherichia coli (P less than .05) and cryptosporidia (P = .07) were the only enteropathogens associated with persistent diarrhea in comparison with acute diarrhea. No more than 15% of children had the same class of pathogen identified from stool on both days 1-3 and days 15-17, indicating that persistent infection was uncommon. However, a different enteropathogen was frequently found on days 15-17, suggesting that sequential infection may be a cause of persistent diarrhea.     

Clinical trial of T-3262 on acute enteritis. Japan Research Committee of T-3262, Research Group for Acute Infectious Enteritis

For the purpose of evaluation of clinical efficacy, safety and usefulness on acute infectious enteritis (bacillary dysentery, and enteritis caused by Salmonella spp., Campylobacter spp., enteropathogenic E. coli, and so on), T-3262, a newly developed pyridone-carboxylic acid derivative, was administered to a total of 136 patients and carriers. In addition, in vitro antibacterial activity of T-3262 was determined against the clinical isolates, and compared with those of nalidixic acid (NA), pipemidic acid (PPA), enoxacin (ENX), norfloxacin (NFLX) and ofloxacin (OFLX). The daily dose of 450 mg of T-3262 was administered orally three times after meals for 5 days, with the exception of 7 day administration against Salmonella enteritis. A total of 89 cases were evaluated; 23 with Shigella spp., 30 with Salmonella spp., 15 with Campylobacter spp., 6 with enteropathogenic E. coli, and 15 cases with the other pathogens or pathogen-negative. The efficacy on clinical symptoms judging from duration of fever, and duration of diarrhea and abnormal stool character was 100% in all the enteritis except enteropathogenic E. coli enteritis, in which it was 50% (n = 2). Concerning bacteriological response, elimination of the causative organisms from the feces was 100% in Shigella spp. (n = 19), Salmonella spp. (n = 30), and enteropathogenic E. coli (n = 6), although 64.3% in Campylobacter spp. (n = 14). As an adverse effect, epigastric discomfort was observed in one (0.8%) of 130 cases. Deteriorations in laboratory findings were seen in five (6.2%) of 81 cases, consisting of two with elevated GOT and GPT, two with elevated GPT, and one with increased eosinophils count, although they were all slight in degree. MICs of T-3262 which inhibited 90% of the isolates of Shigella spp, Salmonella spp., and Campylobacter spp., were 0.025, 0.05, and 0.78 microgram/ml, respectively. These values were lowest among the quinolone derivatives tested, except that the MIC90 against Campylobacter spp. was the same as that of ofloxacin.     

Enteric pathogens associated with childhood diarrhea in Tripoli-Libya

Stool samples from children < 5 years of age with diarrhea (N = 239) were examined for enteric pathogens using a combination of culture, enzyme-immunoassay, and polymerase chain reaction methods. Pathogens were detected in 122 (51%) stool samples; single pathogens were detected in 37.2% and co-pathogens in 13.8% of samples. Norovirus, rotavirus, and diarrheagenic Escherichia coli (DEC) were the most frequently detected pathogens (15.5%, 13.4%, and 11.2%, respectively); Salmonella, adenovirus, and Aeromonas were detected less frequently (7.9%, 7.1%, and 4.2%). The most commonly detected DEC was enteroaggregative E. coli (5.4%). Resistance to ≥ 3 antimicrobials was observed in 60% (18/30) of the bacterial pathogens. Salmonella resistance to ciprofloxacin (63.1%) has become a concern. Enteric viral pathogens were the most significant causative agents of childhood diarrhea in Tripoli. Bacterial pathogens were also important contributors to pediatric diarrhea. The emergence of ciprofloxacin-resistant Salmonella represents a serious health problem that must be addressed by Libyan health authorities.     

Sporadic cases of hemorrhagic colitis associated with Escherichia coli O157:H7. Clinical, epidemiologic, and bacteriologic features

During a 6-month period in 1983, Escherichia coli O157:H7 was isolated from 19 (15%) of 125 patients with grossly bloody diarrhea and 1 sibling with non-bloody diarrhea in the Calgary area. There was no clustering of the cases geographically or in time. All but 1 had clinical manifestations typical of hemorrhagic colitis associated with E. coli O157:H7. The illness appeared to be associated with consumption of hamburgers by 15 patients. The diarrheal illness was usually self-limited, but 3 children developed the hemolytic-uremic syndrome shortly after onset of illness. The organism was excreted in the stools very briefly in adults, although bacterial shedding continued for a longer period in children. All isolates produced verotoxin, and cytotoxic activities were present in stool filtrates. The results suggest that the incidence of sporadic cases of hemorrhagic colitis due to E. coli O157:H7 may be higher than has been suspected, and that patients with grossly bloody diarrhea should be studied promptly for E. coli O157:H7 infection. Specific techniques for identifying this serotype must be applied to the stool cultures. Detection of free cytotoxin in stool filtrates may be an effective diagnostic procedure.     

Identification of cryptosporidium species infecting humans in Tunisia

Prevalence and species distribution of Cryptosporidium spp. were determined among 633 immunocompetent children less than five years of age and 75 patients hospitalized for immunodeficiency who lived in northern Tunisia. Microscopy was used for initial screening to detect positive samples and a nested polymerase chain reaction and restriction fragment length polymorphism analysis was used to determine the species. Cryptosporidium spp. was identified in 2.7% of cases (19 stool samples), and there was a significant difference between samples collected from immunocompromised patients and those collected from healthy children (10.7% versus 1.7%). Prevalence was also significantly higher in diarrheal specimens than in formed specimens (6.3% versus 1.6%). Cryptosporidium hominis and C. parvum were responsible for most Cryptosporidium spp. infections (78.9%). Cryptosporidium hominis was more prevalent in children from urban areas than in those from rural areas, and C. parvum was found with similar prevalence rates in the two populations. Cryptosporidium meleagridis was identified in four children on farms.     

Clinical studies in persistent diarrhea: dietary management with green banana or pectin in Bangladeshi children

BACKGROUND & AIMS: Because of the beneficial intestinal effects of dietary fibers, we have evaluated the therapeutic effects of green banana or pectin in children with persistent diarrhea. METHODS: In a double-blind trial, 62 boys, age 5-12 months, were randomly given a rice-based diet containing either 250 g/L of cooked green banana (n = 22) or 4 g/kg pectin (n = 19) or the rice-diet alone (control, n = 21), providing 54 kcal/dL daily for 7 days. Stool weight and consistency, frequency of vomiting and purging, and duration of illness were measured. RESULTS: Most children (60%) had no pathogens isolated from stools, 17% had rotavirus, 5% Vibrio cholerae, 4% Salmonella group B, and 11% had enterotoxigenic Escherichia coli infections. By day 3 posttreatment, significantly (P < 0.001) more children recovered from diarrhea receiving pectin or banana than controls (59%, 55%, and 15%, respectively). By day 4, these proportions correspondingly increased to 82%, 78%, and 23%, respectively, the study diet groups being significantly (P < 0.001) different than controls. Green banana and pectin significantly (P < 0.05) reduced amounts of stool, oral rehydration solution, intravenous fluid, and numbers of vomiting, and diarrheal duration. CONCLUSIONS: Green banana and pectin are useful in the dietary management of persistent diarrhea in hospitalized children and may also be useful to treat children at home.     

Epidemiological and clinical characteristics of bacteraemia caused by Aeromonas spp. as compared with Escherichia coli and Pseudomonas aeruginosa

We reviewed 75 episodes of Aeromonas spp. bacteraemia observed at our institution in 1979-2002, with special reference to episodes occurring in elderly patients (> or = 65 y) and to nosocomial episodes. In addition, we compared monomicrobial bacteraemic episodes caused by Aeromonas spp. (n = 54) with those caused by Escherichia coli (n = 108) and Pseudomonas aeruginosa (n = 108), to assess differences in clinical presentation and outcome. The 75 episodes of Aeromonas spp. bacteraemia occurred mainly in males (72%), suffering from chronic liver disease (36%) or neoplasm (33%). They had an abdominal origin in 52% of cases, were recorded as primary bacteraemia in 40%, and showed a 30-d case fatality rate of 36%. 22 episodes (29%) were nosocomial, 36 (48%) occurred in elderly patients and 21 (28%) were polymicrobial infections. In comparison with Aeromonas spp., E. coli bacteraemia was more often associated with less severe underlying conditions, a community-acquired infection (74%), and a urinary tract (52%) or abdominal (27%) origin and had a 30-d case fatality rate of 24%. P. aeruginosa bacteraemia occurred mainly in patients with severe underlying conditions, was associated with nosocomial infection (69%), and had a 30-d case fatality rate of 43%. In conclusion, Aeromonas spp. bacteraemia is a serious infection that should be considered in patients with chronic liver disease or neoplasm. It may occur in the elderly and as a nosocomial infection, and differs in clinical findings from bacteraemia due to other common pathogens.     

北京地区1994-2005年腹泻病原菌的分布及其耐药趋势

目的 监测我院1994-2005年与腹泻有关的肠道致病菌的分布及耐药趋势,为本地区流行病学研究、疫苗制备及临床合理用药提供依据.方法 通过常规大便培养,筛出致病菌后经生化及血清学进一步鉴定到种、群或血清型,并以纸片扩散法测定抗菌药物的敏感性.结果 12年分离到肠道病原菌8426株,患者以男性为主,儿童和青年发病为多,每年7～9月为腹泻发病高峰.病原以志贺菌属居首位(占75.11%),其次是弧菌(占12.70%),再依次为沙门菌属、气单胞菌、致病及侵袭大肠埃希菌分别占6.28%、4.43%及1.25%.6329株志贺菌中,福氏志贺菌占75.62%,其次是宋内菌群(23.98%),痢疾志贺菌及鲍氏志贺菌分别占0.22%及0.01%.12年的变化趋势是,每年肠道病原菌总数在逐渐减少,特别是志贺菌、沙门菌减少明显,而弧菌及气单胞菌相对逐渐增多.各菌属及不同的血清型对抗菌药物的敏感率有差异,福氏志贺菌和气单胞菌属多重耐药较多,而宋内志贺菌和弧菌属对多数抗菌药物敏感.结论 北京地区感染性腹泻的病原种类多,随时间的变迁病原变化明显,耐药性不同,应重视监测.     

Diarrhea etiology in a pediatric emergency department: a case control study

Background.?The etiology of childhood diarrhea is frequently unknown. Methods.?We sought Aeromonas, Campylobacter, Escherichia coli O157:H7, Pleisiomonas shigelloides, Salmonella, Shigella, Vibrio, and Yersinia (by culture), adenoviruses, astroviruses, noroviruses, rotavirus, and Shiga toxin-producing E. coli (STEC; by enzyme immunoassay), Clostridium difficile (by cytotoxicity), parasites (by microscopy), and enteroaggregative E. coli (EAEC; by polymerase chain reaction [PCR] analysis) in the stools of 254 children with diarrhea presenting to a pediatric emergency facility. Age- and geographic-matched community controls without diarrhea (n?=?452) were similarly studied, except bacterial cultures of the stool were limited only to cases. Results.?Twenty-nine (11.4%) case stools contained 13 Salmonella, 10 STEC (6 O157:H7 and 4 non-O157:H7 serotypes), 5 Campylobacter, and 2 Shigella. PCR-defined EAEC were present more often in case (3.2%) specimens than in control (0.9%) specimens (adjusted odds ratio [OR], 3.9; 95% confidence interval [CI], 1.1-13.7), and their adherence phenotypes were variable. Rotavirus, astrovirus, and adenovirus were more common among cases than controls, but both groups contained noroviruses and C. difficile at similar rates. PCR evidence of hypervirulent C. difficile was found in case and control stools; parasites were much more common in control specimens. Conclusions.?EAEC are associated with childhood diarrhea in Seattle, but the optimal way to identify these agents warrants determination. Children without diarrhea harbor diarrheagenic pathogens, including hypervirulent C. difficile. Our data support the importance of taking into account host susceptibility, microbial density, and organism virulence traits in future case-control studies, not merely categorizing candidate pathogens as being present or absent.     

Diagnosis of infectious diarrheal diseases

For many years, microbiologic examination of feces was focused on the isolation of two members of the family Enterobacteriaceae--Salmonellae and Shigellae. Over the past two decades, other enteric pathogens such as the various classes of diarrheagenic E. coli, Campylobacter, Vibrio spp., Yersinia enterocolitica, and Clostridium difficile have gained prominence. A newly recognized protozoan parasite, Cryptosporidium is now known to infect both immunocompetent and immunodeficient individuals. Added to these is the growing list of viruses incriminated in diarrheal diseases and gastritis. This article provides some of the basic information needed to allow for the isolation and identification of many of the currently recognized enteric pathogens. It also provides information on some of the currently available rapid test procedures that will speed up stool specimen testing and allow for more timely reporting to the physician.     

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.     

Acute diarrhoea in adults: aetiology, clinical appearance and therapeutic aspects

A prospective study of acute diarrhoea was performed during 15 months 1981/1982 and included 731 patients and 240 controls. 43% had been infected abroad. A cluster of travellers with bacterial pathogens was diagnosed in July-August. The following pathogens were found: Campylobacter (18%), enterotoxigenic E. coli (6%), Salmonella spp. (5%), rotavirus (4%), Yersinia enterocolitica (3%), Giardia lamblia (3%), Shigella spp. (2%), Clostridium difficile (2%), enteroviruses (2%) and Entamoeba histolytica (less than 1%). More than 90% of the bacterial or parasitic enteropathogens were detected in the first stool sample. Only 10% of the patients needed hospital treatment and for 97% oral fluids were sufficient. The median duration of diarrhoea was 9 days. No fatal cases occurred and only 2 cases of chronic bowel disease were detected.     

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.     

Symptomatic and asymptomatic Cryptosporidium infections in children in a semi-urban slum community in southern India

Cryptosporidium is a leading cause of childhood diarrhea in developing countries. We investigated symptomatic and asymptomatic cryptosporidiosis in 20 children less than two years of age in a semi-urban slum in southern India. All surveillance (conducted every two weeks) and diarrheal samples from 20 children (n = 1,036) with cryptosporidial diarrhea previously identified by stool microscopy were tested by polymerase chain reaction-restriction fragment length polymorphism for species and subgenotype determination. Thirty-five episodes of cryptosporidiosis were identified in 20 children, of which 25 were diarrheal. Fifteen episodes were associated with prolonged oocyst shedding. Multiple episodes of cryptosporidiosis occurred in 40% of the children. Most infections were with C. hominis, subtype Ia. Children with multiple infections had significantly lower weight-for-age and height-for-age Z scores at 24 months but had scores comparable with children with a single episode by 36 months. Multiple symptomatic Cryptosporidium infections associated with prolonged oocyst shedding occur frequently in this disease-endemic area and may contribute to the long-term effects of cryptosporidiosis on physical growth in these children.     

Molecular characterization of diarrheagenic Escherichia coli from Libya

Diarrheagenic Escherichia coli (DEC) are important enteric pathogens that cause a wide variety of gastrointestinal diseases, particularly in children. Escherichia coli isolates cultured from 243 diarrheal stool samples obtained from Libyan children and 50 water samples were screened by polymerase chain reaction (PCR) for genes characteristic of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorrhagic E. coli (EHEC), and enteroinvasive E. coli (EIEC). The DEC were detected in 21 (8.6%) children with diarrhea; 10 (4.1%) cases were identified as EAEC, 3 (1.2%) as EPEC, and 8 (3.3%) were ETEC; EHEC, and EIEC were not detected. All DEC were grouped phylogenetically by PCR with the majority (> 70%) identified as phylogenetic groups A and B1. The EAEC isolates were also tested for eight genes associated with virulence using PCR. Multi-virulence (≥ 3 virulence factors) was found in 50% of EAEC isolates. Isolated EAEC possessed different virulence traits and belonged to different phylogenetic groups indicating their heterogeneity.     

Isolation of enteropathogenic microorganism from patients with infection of the digestive tract during 1976 to 1988 in Tenri Hospital]

Enteropathogenic microorganisms isolated from feces of 9,393 patients with diarrhea or enteritis in our hospital between 1976 and 1988 were analyzed. As the result of the examination of 5,443 outpatients, 1,811 strains of pathogens were isolated from 1,686 cases (31.0%). Several species including Salmonella spp., Escherichia coli serotype, Vibrio parahaemolyticus, were isolated before 1978, and the incidence of pathogens was low (14.8%). For the 10-year period since 1979, the incidence markedly increased to 34.4%, and the number of pathogens isolated also increased to about twice that before 1978. The main cause of the increase was Campylobacter species. The major pathogens detected since 1979 were Campylobacter spp., E. coli serotype, Salmonella spp., V. parahaemolyticus, etc., but Rota virus, Clostridium difficile, Aeromonas spp., Vibrio fluvialis, etc. have also been detected, showing an increase in the number and diversity of the detected pathogens. As the result of the examination of 3,950 inpatients, 835 strains of pathogens were isolated from 800 cases (20.3%). The incidence of C. difficile was the highest, 423 of 800, followed by E. coli serotype, Salmonella spp., Campylobacter spp., V. parahaemolyticus and Aeromonas spp., in that order. All the inpatients from whom C. difficile was isolated manifested diarrhea or enteritis after administration of antimicrobial agents. The pathogens causing communicable disease were Salmonella spp. serovar Typhi, Salmonella spp. serovar Paratyphi A, Shigella flexneri, Shigella sonnei and Entamoeba histolytica, which were isolated from 5, 1, 3, 2 and inpatients, respectively.     

Microbiologic and clinical study of acute diarrhea in children in Aswan, Egypt

Children with diarrhea presenting to a Government Rehydration Center in Aswan, Egypt, were investigated to determine the etiology and clinical presentation of acute childhood diarrhea in southern Egypt. Among 126 outpatients and 25 inpatients with diarrhea (mean age 18 months), enterotoxigenic Escherichia coli (ETEC) (17% of cases), Cryptosporidium (9%), Salmonella spp. (7%), Campylobacter jejuni/coli (7%), and Shigella spp. (5%) were the most common enteropathogens identified during the high incidence season of July. Enteropathogens were isolated as often from inpatients as outpatients, except for Salmonella spp. and Cryptosporidium, which were recovered more often from inpatients. Salmonella-infected children, in particular, were more ill, feverish, and dehydrated on presentation than other children, resulting in more frequent hospitalization. Except for Salmonella-infected children, children with acute diarrhea usually presented without severe dehydration, which may have been due to frequent initiation of oral rehydration therapy (ORT) by mothers trained by local health care providers. A potential environmental source of ETEC was identified in clay water storage containers commonly used in this area.     

Studies on bacterial agents in acute diarrheal disease (1985-1987)

A three-year epidemiological study (from January 1985 to December 1987) was carried out on sporadic cases of acute diarrhea. A total of 2889 fecal specimens in Cary-Blair transport medium were examined for bacterial enteric pathogens, and 832 strains of fifteen species were isolated from 739 specimens, 73 patients having two or more pathogens. C. jejuni shared 51.7%, Salmonella spp. 18.3%, V. parahaemolyticus 10.3%, and Aeromonas spp. 15.7% of total fecal specimens. Isolation rates of C. jejuni and Salmonella spp. in children under the age of fifteen years (19.3%, 6.4%) were higher than those of older years (9.8%, 3.9%), respectively. Isolation of C. jejuni decreased to 24% (12/50) during 2-4 days storage at room temperature in Cary-Blair transport medium, which showed the necessity of rapid plating for isolation of C. jejuni from fecal specimens. Incidence of A. caviae in children up to ten years of age was significantly higher as compared with those of other Aeromonas species. Desoxycholate-hydrogen sulfide-xylose-agar (DHXA) was used for direct plating technique and for plating after enrichment with alkaline peptone water (without NaCl), which was found suitable as an enrichment medium for Aeromonas spp. Enterohemorrhagic E. coli (EHEC) O157:H7 was isolated from 3 patients by using desoxycholate-hydrogen sulfide-sorbitol-agar (DHSA).