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.     

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.     

Case-control study of endemic diarrheal disease in Thai children

In a year-long, case-control study of endemic diarrheal disease among 1230 Thai children less than five years of age, rotavirus was detected in 20%, Campylobacter in 13%, Shigella in 13%, Salmonella in 12%, and enterotoxigenic Escherichia coli (ETEC) in 9%. The differences in detection of enteric pathogens between patients and controls was significant for rotavirus (P less than .001), Shigella (P less than .001), ETEC that produced heat-labile and heat-stable toxins (LT and ST; P = .005), and ST only (P less than .001). C. jejuni was most significantly associated with diarrhea in children less than 12 months [corrected] old (P = .037) and Salmonella in children less than three months of age (P = .003). Enteropathogenic E. coli (EPEC) that adhered in a localized pattern to HeLa cells was isolated from 7% of patients and 3% of controls less than six months of age. Only 50% of these E. coli strains were of EPEC serotypes. Enteroinvasive E. coli was isolated from 7% of patients more than two years of age, and new serotypes were identified.     

Epidemiological profile of rotavirus infection in the Republic of Korea: results from prospective surveillance in the Jeongeub District, 1 July 2002 through 30 June 2004

To facilitate future decisions regarding the usefulness of rotavirus vaccines in the Republic of Korea, active surveillance was conducted in a network of clinics, emergency departments, and hospitals serving Jeongeub District, Korea. Children with diarrhea underwent standard clinical evaluations, and stool specimens were collected to test for the presence of rotavirus. Parents were interviewed to collect demographic and family information. From 1 July 2002 through 30 June 2004, a total of 4106 children, representing 1 (50%) of every 2 children <5 years old in the study population, were evaluated for rotavirus diarrhea. Of the 2232 stool specimens obtained throughout the year, 460 (20.6%) were rotavirus positive; however, the monthly prevalence of rotavirus infection peaked at 49.5% in February 2004. Of the 460 rotavirus-positive stool specimens, 366 were obtained from children who visited outpatient clinics, and 94 were obtained from children who were hospitalized. By extrapolating the proportion of rotavirus-positive patients to all children with diarrhea in the surveillance system, we calculate that 882 children in Jeongeub District had rotavirus infection (which would predict that there would be 702 associated clinic visits and 180 hospitalizations). Genotyping of rotavirus strains showed that 39% of strains were type G9P[8], 24% were type G1P[8], 17% were type G3P[8], and 13% were type G2P[4]. The incidence of rotavirus diarrhea peaked at age 13-24 months, and 94% of cases occurred during the first 3 years of life. The annual incidence of all rotavirus disease-associated outcomes was 56.9 cases/1000 children <5 years old (95% confidence interval [CI], 51.9-62.2 cases/1000 children <5 years old). The incidence of rotavirus disease-associated hospitalizations was 11.6 cases/1000 children <5 years old (95% CI, 9.5-14.2 cases/1000 children <5 years old). In Korea, diarrhea is common during childhood, and the incidence of diarrhea due to rotavirus infection suggests that improved programs for the prevention and control of both rotavirus diarrhea and diarrhea due to other causes are needed.     

A prospective case-control study of the role of astrovirus in acute diarrhea among hospitalized young children

This study examines the importance of astroviruses as a cause of acute diarrhea in hospitalized children <10 years old during a 5-year period. Stools were screened by electron microscopy and were tested for astrovirus, rotavirus, and enteric adenovirus by EIA. During the study, 14.6% of hospitalized children had diarrhea. Astroviruses were second only to rotaviruses as etiologic agents of both community-acquired and nosocomial diarrhea. Community-acquired astrovirus infection occurred in 6.8% of patients, and nosocomial disease occurred in 16.2%. Most cases occurred from March through June, and astrovirus type 1 was the most common. The symptoms of astrovirus-infected children were similar to those of children with rotavirus infection. However, astrovirus-infected children had a lower median age, less dehydration, and lower symptom severity scores and were less likely to have been admitted for gastroenteritis than were children with rotavirus. Astrovirus, for which only rehydration therapy is required, should be considered as another common diarrheal pathogen in children <2 years old.     

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.     

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.     

Evaluation of rhesus rotavirus vaccine (MMU 18006) in infants and young children

Orally administered rhesus rotavirus vaccine was evaluated in a placebo-controlled study in young children and infants (ages, eight months to 61 months). Thirteen children received the rotavirus vaccine, and ten children served as the control group. The vaccine was well tolerated. There were no significant differences between the vaccine recipients and the control group in the number of child-days with temperatures greater than or equal to 37.8 C, vomiting, diarrhea, or cough. There were significantly more child-days of rhinorrhea among the vaccine recipients than there were among the control group. The vaccine recipients under two years of age passed a larger number of stools than did the children in the control group, and vaccine recipients had significantly more semiformed and unformed stools than did the children receiving the placebo. All twelve of the children tested were positive for viral shedding. Peak viral shedding occurred on days three and five postvaccination. On day eight, over one-half of the children from whom a stool specimen was obtained were still shedding rotavirus. Children less than two years old shed more rotavirus in their stool than did children more than two years old. All 13 vaccine recipients had a fourfold or greater rise in titer of antibody as measured by plaque reduction, tube neutralization, complement fixation, and/or immune adherence hemagglutination.     

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.     

Control study of oral rehydration solution (ORS)/ORS + dioctahedral smectite in hospitalized Thai infants with acute secretory diarrhea.

Dioctahedral smectite, a non systemic antidiarrheal agent, is mucoprotective and absorbs enterotoxins and rotavirus as demonstrated in animal models. Smectite has been successfully used in various countries in children and adults with acute diarrhea. This study was to assess the efficiency of smectite associated with rehydration in infants with acute secretory diarrhea. Sixty-two hospitalized Thai infants, aged 1-24 months, with acute secretory diarrhea were randomly divided into 2 groups receiving (1) oral rehydration solution (ORS) (30 cases), (2) ORS and Smectite (3.6 g/day) (32 cases). Both groups were comparable for age, weight, nutritional status and duration of symptoms before treatment. All 62 infants received lactose free formula and chicken rice soup as the standard diet. Stool frequency, weight change and duration of diarrhea were recorded. The mean duration of diarrhea was 84.7 +/- 48.5 hours in group 1, and 43.3 +/- 25.1 hours in group 2 (p = 0.005). The number of infants with diarrhea was significantly lower in group 2 on Day 1 (p < 0.01) and Day 3 (p = 0.001); furthermore 27% of infants in group 1 and 3% in group 2 had still diarrhea on Day 5. The stool frequency and weight changes were not statistically different in the two groups. No major side effects were observed except two cases of vomiting and hardened stools. It is concluded that (1) Smectite shortens the course of acute secretory diarrhea in Thai infants; (2) smectite may reduce the occurrence of prolonged diarrhea; furthermore (3) in our study dioctahedral smectite was found to be safe in children aged 1 to 24 months.     

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.     

2011年北京地区婴幼儿病毒性腹泻病原学研究

目的了解北京地区婴幼儿病毒性腹泻的病原学特点。方法采集2011年1月-12月5岁以下腹泻患儿的粪便标本并填写个案调查表,用ELISA试剂盒检测A组轮状病毒,采用逆转录-聚合酶链反应（RT-PCR）检测人杯状病毒和星状病毒,采用PCR检测腺病毒。结果 604例粪便标本中,A组轮状病毒检出率15.89%,人杯状病毒检出率18.71%,星状病毒检出率2.98%,腺病毒检出率4.80%,病毒混合感染27例。11月份轮状病毒检出率最高,10月份人杯状病毒检出率最高。结论 A组轮状病毒和人杯状病毒为北京地区秋冬季婴幼儿腹泻的主要病原。     

Epidemiology, clinical course and impact on hospitalization costs of acute diarrhea among hospitalized children in Athens, Greece.

The aim of this study was to describe the etiology, morbidity and hospitalization costs associated with acute diarrhea among hospitalized children in Greece. During 1999, 294 hospitalized children (median age 1 y) with acute diarrhea were prospectively studied. Bacterial and viral enteropathogens were detected in 100 (34%) and 37 (12.5%) patients, respectively; 17 (6%) patients had mixed infections. Isolated agents included Salmonella spp. (43 patients; 15%), rotavirus (32; 11%), Campylobacter spp. (26; 9%), enteropathogenic Escherichia coli (16; 5.5%), Shigella spp. (11; 4%), Aeromonas spp. (7; 2.5%), adenovirus (6; 2%), Yersinia enterocolitica (6; 2%), enterohemorrhagic Escherichia coli (2; 0.5%) and Giardia lamblia (1; 0.5%). Of the patients with bacterial infection, 70% were admitted between April and September 1999. A rotavirus-associated peak was noted in March. Patients with a bacterial infection were hospitalized for longer periods than those with viral infections. It is concluded that bacterial enteropathogens account for one-third of admissions due to acute diarrhea among children in Greece and are associated with significant hospitalization costs. Rotavirus is also a frequent cause of acute diarrhea necessitating hospitalization.     

Association of patterns of Escherichia coli adherence to HEp-2 cells with acute and persistent diarrhea]

In Brazil diarrhea is the cause of approximately 15% of death among infants. Enteropathogenic E coli is the most important bacterial agent causing acute diarrhea, which is defined as less than 14 days of duration. About 30% of these cases may evolve to persistent diarrhea, defined as lasting more than 14 days. In this work it was carried out a case-control study including 34 children under 2 years of age, and admitted to hospital facilities in S?o Paulo for rehydration therapy. Thirty-four age matched children hospitalized in the same facilities, and presenting no gastrointestinal symptoms were included as controls. Stool samples were analyzed for the presence of bacterial pathogens (diarrheagenic E coli, Shigella, Salmonella, Yersinia, and Campylobacter), protoparasytes, rotavirus, and enteric adenovirus. The E coli strains isolated were analyzed for their ability to adhere to HEp-2 cultured cells, in a 3 h adhesion assay. Search for homology with DNA probes for localized adherence (EAF, eaeA probes), AA (enteroagregative adherence) (AA probe), and diffuse adherence (F1845, AIDA-I probes) was carried out by the colony hybridization method. Twenty-four of the cases were acute diarrhea and 10 persistent diarrhea. Strains with localized adherence were associated with acute and persistent diarrhea. About 23.5% of E coli were associated with typical Enteropathogenic E coli strains (EAF+, eaeA+). Enteroaggregative E coli (EAggEC) (AA+) was isolated only from cases and in similar frequency for acute and persistent diarrhea. Diffusely adherent E coli (DAEC) which did not hybridize with the diffuse adherence probes were isolated among cases and controls. E coli eaeA+ with localized-like adherence was isolated from cases in a frequency three times higher than in controls, suggesting that it may really have a pathogenic potential.     

Hospital-based surveillance for rotavirus diarrhea in children in Yangon, Myanmar

Diarrhea is a common childhood illness in Myanmar, and rotavirus is the single most important etiological agent of diarrhea. Surveillance for rotavirus diarrhea in children <5 years of age was conducted in a tertiary pediatric hospital in Yangon, Myanmar, from January 2002 through December 2003. Stool specimens obtained from children admitted to the hospital for acute diarrhea were tested for the presence of rotavirus by use of an enzyme-linked immunosorbent assay. Diarrhea was the cause of 5671 (18%) of all hospitalizations of children <5 years of age during the 2-year study period (n = 30,869). Rotavirus was identified in 923 (53%) of the 1736 stool specimens tested, and rotavirus infection was associated with approximately 10% of all hospitalizations of children. Rotavirus diarrhea most frequently occurred in children 6-17 months of age, and it was more commonly identified in boys (62% of children with rotavirus diarrhea were boys). The seasonal pattern of rotavirus disease mimicked that of diarrheal illness due to all causes, with the peak season for rotavirus disease occurring from November through February (i.e., during the cool, dry season). During the study period, 53 of the children who were hospitalized for diarrhea died. The present study confirms the importance of the etiological role that rotavirus plays in childhood diarrhea.     

Sentinel hospital surveillance for rotavirus diarrhea in Taiwan, 2001-2003

We examined the epidemiological profile of rotavirus infection among children hospitalized for diarrhea in Taiwan, to assess the burden of this disease. From 1 April 2001 through 31 March 2003, children <5 years old with gastroenteritis admitted to 4 sentinel hospitals were enrolled in a surveillance study and had stool specimens tested for the presence of rotavirus, enteric adenovirus, and the bacterial pathogens for which routine screening is performed. For 52% of patients, a recognized enteric pathogen was identified, including rotavirus (43% of patients), bacteria (11%), enteric adenovirus (2.5%), and a mixture of pathogens (3.9%). Rotavirus was detected year-round, but great month-to-month variability made it difficult to identify a distinct seasonal pattern. Rotavirus disease was most common among children 7-23 months old, but the rate of rotavirus detection varied little between the youngest and oldest age groups. The novel strain P[8]G9 was detected most commonly (37% of strains), followed by strains P[8]G1 (31%), P[4]G2 (10%), P[8]G3 (9.3%), and P[8]G4 (3.7%). Rotavirus infection is the most important cause of diarrhea among hospitalized children in Taiwan, and a rotavirus vaccination program for young children might significantly reduce this problem.     

Gastroenteritis in children: a two-year review in Manitoba. I. Etiology.

During two years, 1,217 children hospitalized with gastroenteritis at the Children's Centre in Winnipeg, Manitoba, Canada were studied. Bacterial pathogens were present in 25% of these children: enteropathogenic Escherichia coli in 120, Shigella in 139, Salmonella in 24, and multiple pathogens in 18. Rotavirus was detected in 54 (11%) of 472 patients examined. Rotavirus and enteropathogenic E. coli were the most common pathogens in infants, and Shigella was the most common in older children. Bacterial diarrhea occurred more commonly in summer, whereas rotavirus infection occurred more commonly in winter. Among 276 children screened, enterotoxigenic E. coli was found in three, and Aeromonas shigelloides that produced a similar toxin in two others. Enteroinvasive E. coli was not detected in 70 children. Organisms producing toxins "cytotoxic" to HeLa cells were isolated from three of 90 children. Screening for enterotoxigenic or enteroinvasive organisms was not productive of a significant number of pathogens, and, although screening for rotavirus did improve the number of etiologic diagnoses, the etiology of the majority of cases of diarrhea remained unknown.     

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.     

Incidence of severe rotavirus diarrhea in New Delhi, India, and G and P types of the infecting rotavirus strains

A total of 62,475 children <5 years old from a defined population of approximately 500,000 children and adults from slums in New Delhi, India, were assessed for 1 year by means of passive surveillance, to identify children who were hospitalized for diarrhea. The incidence of severe rotavirus diarrhea was estimated, and the G and P types of the infecting rotavirus strains were determined and were correlated with the clinical severity of diarrhea. Of 584 children who were hospitalized with diarrhea, 137 (23.5%) had rotavirus detected in stool specimens (incidence of rotavirus diarrhea-associated hospitalizations, 337 hospitalizations/100,000 children <5 years of age). Most cases of diarrhea (98%) occurred during the first 2 years of life, peaking at 9-11 months of age. Rotavirus-associated diarrhea occurred year-round but was predominant in winter. Among the strains that could be G-typed, G1 was the most common serotype, followed by G9 and G2; 10% of cases of diarrhea were due to mixed G-type infections. Common strains identified in the present surveillance study were P[8]G1, P[4]G2, P[8]G9, P[6]G1, P[6]G9, and P[6]G3. Children infected with G1 strains had a greater risk of developing more-severe cases of diarrhea than did children infected with other rotavirus strains (odds ratio, 2.95; 95% confidence interval, 1.3-6.67).