A long-term survey of rotavirus infection in Japanese children with acute gastroenteritis.

Human rotavirus was detected by electron microscopic examination of the stools of 320 (63%) of 506 infants and young children hospitalized with acute gastroenteritis between December 1974 and March 1977. Serologic responses to infection with the rotavirus were revealed by the complement-fixation test in 130 (70%) of 185 patients examined. During the study period three epidemics of human rotavirus infection occurred during the winter months. The peak incidences occurred in January 1975 (88% of patients positive by serologic analysis or electron microscopy of stools), January 1976 (92%), and February 1977 (96%). Rotavirus was detected in the stools of 288 (79%) of 365 patients tested during the cooler months (December to March) and 35 (25%) of 141 during the rest of the year. In the summer (June to August), rotavirus infection occurred rarely. The frequency of human rotavirus infection was highest among patients aged six to 11 months. These results indicate that human rotavirus can be regarded as a major etiologic agent of acute gastroenteritis in infants and young children, of which wintertime epidemics are common in Japan.     

Rotavirus in travelers' diarrhea: study of an adult student population in Mexico.

The role of rotavirus in adult diarrhea was evaluated in 165 students attending a Mexican university. Students were divided into three groups: newly arrived summer students from the United Sttes, regular students from the United States, and Mexican and Venezuelan students. Ninety-one students with diarrhea and 74 corresponding, matched, asymptomatic control students were included in the study. The frequency of rotavirus in stools was determined by electron microscopy with use of the pseudoreplica technique. Twenty-five percent of those who were ill and 12% of the controls had rotavirus in their stools. A significantly (P less than 0.05) greater number of newly arrived United States summer students with diarrhea had rotavirus in their stool than did matched controls (26% vs. 3%). There was no significant difference in rate of recovery of bacterial pathogens from rotavirus-positive and rotavirus-negative stools (52% vs. 53%) from students with diarrhea. Although significantly more rotavirus was identified from ill American summer students than from controls, the role of rotavirus as a cause of diarrhea in these students could not be established in all cases since bacterial pathogens were also commonly found in stool.     

A comprehensive survey of pediatric diarrhea at a private hospital in Metro Manila.

The epidemiology of diarrhea among Filipino pediatric patients, representing a cross-section of socioeconomic strata, was investigated over a one year period. Rotavirus was detected in 33.9% of the diarrhea stools examined and was the leading cause of diarrhea in the study population. Although proportionately more rotavirus was found during the cold season, most children became infected with rotavirus during the rainy season, when diarrheal disease was at its peak in Metropolitan Manila. Enteric adenovirus types 40 or 41 were associated with only 5.4% of the diarrhea cases. Overall, one or more etiologic agents of diarrhea were detected in 67.2% of the stools examined. Many of these positive stools (21.6%) contained multiple diarrheogenic agents. Bacterial enteric pathogens were isolated from 32.3% of the cases. Nearly 70% of these patients with bacterial gastroenteritis became ill during the rainy season. Etiology specific and general risk factors associated with diarrheal illness in the study population are discussed.     

Estimating hospital admissions due to rotavirus gastroenteritis from hospital episode statistics

OBJECTIVES: To determine the proportion of hospital admissions, in children < 5 years old, coded for intestinal infectious disease or non-infectious gastroenteritis, using ICD-10 codes, that were due to rotavirus infection. To assess how many children admitted with rotavirus gastroenteritis were given the specific ICD-10 code (A080) for this disease. METHODS: Sixteen-month prospective, observational study of children < 5 years old, admitted to district general hospital with: acute gastroenteritis (> or =3 loose stools/day), proven rotavirus infection and those coded as intestinal infectious disease or non-infectious gastroenteritis. RESULTS: Four hundred and twenty children < 5 years old were admitted with acute gastroenteritis. Rotavirus was detected in 170 children's stools. Acute rotavirus gastroenteritis accounted for 81/397 (20%) children coded as having non-infectious gastroenteritis and 32/81 (40%) coded for intestinal infectious disease. Only 18 children were coded for rotavirus gastroenteritis. Potentially preventable rotavirus gastroenteritis occurred in 122 children; 78 coded as non-infectious gastroenteritis (20%) and 26 coded for intestinal infectious disease (34%). CONCLUSIONS: The proportion of children coded with diarrhoeal diseases and found to have rotavirus is less than previously estimated. Using the specific code for rotavirus infection to estimate hospital admissions would be a gross underestimate. Hospital episode statistics cannot reliably estimate the burden of disease due to rotavirus.     

A comparative trial of rhesus monkey (RRV-1) and bovine (RIT 4237) oral rotavirus vaccines in young children

Heterologous live, oral rotavirus vaccines of rhesus monkey (RRV-1) and bovine (RIT 4237) origin were tested for immunogenicity, excretion of virus, and clinical reactions in six- to eight-month-old infants. Antibody response, indicating infection with the vaccine virus, was detected in 21 (88%) of 24 children receiving the RRV-1 vaccine and in 18 (75%) of 24 receiving the RIT 4237 vaccine. Excretion of virus in the stools within one week after vaccination was demonstrable in 84% of the RRV-1 and in 21% of the RIT 4237 vaccinees. RRV-1 vaccination was associated with a febrile response (over 38 C) that clustered on days 3 or 4 postvaccination in 64% of the recipient children. In addition, 20% of the RRV-1 vaccinees had watery stools on days 4 or 5. Fever on days 3 and 4 and loose stools were not seen in the RIT 4237 vaccinees. We concluded that in young children the RRV-1 (rhesus monkey) rotavirus vaccine is more immunogenic than the RIT 4237 (bovine) rotavirus vaccine, but vaccination with RRV-1 is associated with significant adverse reactions.     

Rotavirus in pediatric diarrhoea at Siriraj Hospital, Bangkok, Thailand

Between June 1982 and May 1983, rotavirus was found in 29% of 248 pediatric patients between 1 month to 5 years of age at Siriraj Hospital, Bangkok, Thailand. Among 413 household contacts, RV was detected in 9 (2%) of whom 6 developed diarrhoea. RV was not found in age-matched healthy controls. In a serological study, the serological response was 81% in rotavirus diarrhoea cases (17 out of 21) by ELISA. By the ELISA blocking test, the seroconversion rate was only 29.6% in rotavirus diarrhoea cases (8 out of 27) and in others, 2 out of 71 cases (2.6%) who also showed serological response did not have rotavirus in their stools. This study indicates role of rotavirus in causing acute diarrhoea in young children, suggests a guideline for diagnosis and management of the patients. The rotavirus immunization should be considered if the vaccine becomes available in the near future.     

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.     

The incidence of enterotoxigenic Escherichia coli, rotavirus and Clostridium perfringens from cases of diarrhea in children, in the region of Campinas, SP, Brazil

A survey for the detection of enterotoxigenic Escherichia coli (ETEC), rotavirus and enterotoxigenic Clostridium perfringens in diarrheic stools of children up to 2 years old was carried out in the region of Campinas, SP, Brazil. Twenty-seven (20.45%) faecal specimens were positive for ETEC. From these samples 41 strains of ETEC were isolated from which 40 produced only thermolabile (LT) enterotoxin, as detected by a modified radial immune haemolysis test. Among the 183 faecal specimens examined for the detection of rotavirus, 29 (15.84%) were positive when examined by polyacrilamide gel electrophoresis (PAGE) and immunoenzymatic assay (EIA) being 15 (51.7%), derived from stools collected from winter months. All strains of rotavirus belonged to group A and through the PAGE technique, it was observed that the most frequent (9 strains) electrophoretype, according to the adopted classification, was Ib, IIc, IIIb, IVa. Only 113 fecal specimens were examined for the presence of enterotoxigenic C. perfringens. For the detection of enterotoxin in culture supernatants the reverse passive haemagglutination and intravenous inoculation of mice were used. Twelve (10.61%) enterotoxigenic C. perfringens strains were found. Taking into consideration these findings the authors call the attention of the relative value of conventional coprocultures for diagnostic purposes, pointing out the important of establishing simplified methods which would render easier, the detection and identification of the groups of enteropathogenic agents studied in this research.     

Diarrhea associated with rotavirus in rural Guatemala: a longitudinal study of 24 infants and young children.

A population of 24 infants and young children followed prospectively during the first 3 years of life was studied for the occurrence of rotavirus infection by using enzyme-linked immunosorbent assay to detect virus in stools. Infection with rotavirus was associated with 26 (14.2%) of 183 selected diarrheal episodes. Twenty of the 24 infants and young children had diarrhea associated with rotavirus on at least one occasion and six had two such episodes. Rotavirus infection was documented in over 50% of the dehydrating episodes studied, thus further indicating the importance of rotavirus in this population.     

Simplified radioimmunoassay for detection of human rotavirus in stools.

A simplified radioimmunoassay (RIA) technique was developed to facilitate the diagnosis of human rotavirus in stools of infants with diarrhea. This microtiter solid-phase RIA utilizes as a critical reagent hyperimmune serum against a tissue culture-grown simian rotavirus that is immunologically closely related to the human agent. One hundred thirteen pediatric stool samples were tested. Thiry-five specimens known to be positive for rotavirus by electron microscopy were also positive by RIA. All RIA-positive reactions (36) were shown to be specific for rotavirus by means of an antibody-blocking test. Nonspecific RIA-positive reactions were not encountered. This accurate, sensitive RIA technique is practical for use in diagnostic laboratories because critical serum reagents are prepared against culture-grown virus and not against rotavirus derived from carefully selected stools of humans or experimentally infected gnotobiotic animals.     

Diagnostic studies of nosocomial diarrhea in children: assessing their use and value

During a 17-month period (01/11/85-05/31/86) 225 cases of nosocomial diarrhea were identified in a children's hospital. Diarrhea was considered to be nosocomial if it began at least 72 hours after the patient's hospital admission or within 3 days after discharge. One or more routine diagnostic studies for identification of a pathogen were performed in 195 (87%) cases. The most commonly performed test was the bacterial stool culture. None of these samples yielded a bacterial pathogen. The only pathogens detected by routine laboratory studies were rotavirus (61/137 [45%] samples were positive for rotavirus by ELISA) and Clostridium difficile (9/54 [17%] positive for toxin). Of the patients whose tests were positive for rotavirus 56 were younger than 2 years of age, and all were identified in the winter and spring. When multiple stool samples were tested by the diagnostic laboratory, rotavirus was identified in an additional 14 patients whose initial stool samples were negative for rotavirus. All patients whose tests were positive for C. difficile toxin had received antibiotics within the previous 3 months. Ova/parasites were not detected in 53 of the tested stools. We also identified enteric adenovirus in six patients. Viruses were identified in 95 (42%) of the 225 cases of nosocomial gastroenteritis. Nosocomial diarrhea is common in a children's hospital. Rotavirus is the most commonly identified pathogen. Rotavirus testing is valuable in children with nosocomial diarrhea who are younger than 2 years of age, especially in the winter and spring. Multiple samples may be necessary to identify rotavirus. C. difficile toxin assay should be considered for patients who are receiving or who have received antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)     

Parasitic, bacterial and viral pathogens isolated from diarrhoeal and routine stool specimens of urban Bangladeshi children

Few data exist in Bangladesh on longitudinal, community-based studies of bacterial or parasitic pathogens identified in routine and diarrhoeal stools of urban dwelling children. We undertook the following study on 343 children of age less than 6 years who resided in one of 51 slum settings in Dhaka, Bangladesh, between October 1984 and February 1986. Specimens from diarrhoeal episodes and from routine stools obtained at 3-monthly intervals were examined for parasites, rotavirus and pathogenic bacteria. Parasites were isolated from 509 (51%) of the 1006 routine stools and from 95 (42%) of the 225 diarrhoeal stools. Isolation rates steadily increased with age. Ascaris lumbricoides and Trichuris trichiura accounted for approximately 80% of all parasitic isolates in routine and diarrhoeal stools. Giardia lamblia was isolated from 11% diarrhoeal stools. Entamoeba histolytica was an uncommon isolate (less than 1%). Bacterial pathogens were identified in 55 (24%) of the diarrhoeal stools but were identified in only 164 (16%) of the 1028 routine stools examined (P less than 0.01). Toxigenic Escherichia coli, Shigellae and Campylobacter were the most frequent isolates from diarrhoeal and routine specimens. This pathogen profile appears to be more in keeping with that from urban settings in other developing countries than from rural Bangladesh, suggesting that extrapolations from rural-based data should not be made for urban settings.     

Acute diarrhoea in children treated in an outpatient setting in Athens, Greece.

OBJECTIVE: To describe the epidemiology and aetiology of acute diarrhoea among children treated exclusively in an outpatient setting in Greece. METHODS: During 1999, children with acute diarrhoea who attended the emergency department of our hospital were prospectively studied. Patients requiring hospitalization were excluded. Stool specimens were tested microscopically, for bacterial enteropathogens by standard and selective medium cultures and for rotavirus and adenovirus by latex agglutination test. RESULTS: One hundred and thirty-two children (median age: 2 years) were included in the study; an enteropathogen was detected in 63 (48%) of them. Isolates included rotavirus (19 patients), Salmonella sp (12), Campylobacter sp (10), Aeromonas sp (9), enteropathogenic Escherichia coli (6), adenovirus (6), Giardia lamblia (4), Yersinia enterocolitica (2) and Shigella sp (1). Half of the bacterial cases occurred from August to October, and two rotavirus-associated peaks occurred during February and August. Acute diarrhoea caused by viruses affected exclusively children under six years of age, mainly those attending day care centres. Macroscopic blood in stools was reported only among patients with a bacterial infection. Socioeconomic characteristics were not helpful in differentiating disease due to specific enteropathogens. CONCLUSIONS: Bacterial enteropathogens account for a significant proportion of acute diarrhoea in children treated in the outpatient setting in Greece. Rotavirus is also a frequent cause affecting mostly younger children and those attending day care centers. The presence of blood in stools and the seasonality of bacterial infections may enable their presumptive diagnosis.     

Rotavirus infections in newborns: an epidemiological and clinical study

An outbreak of rotavirus infections among newborns at Karolinska Hospital, Stockholm, which has been going on for greater than 2 years has been followed with clinical and epidemiological investigations. About one third of the babies born in the hospital were infected at the age of 3 days. The clinical symptoms were mild, 8.8% of the rotavirus positive babies had loose stools compared to 1.9% of those who did not excrete the virus. An epidemiological survey in the neonatal intensive care unit suggested that rotavirus was introduced into the unit by babies admitted from the obstetric wards. The main reservoir of rotavirus was the babies and rotavirus was not found among staff or mothers. In the beginning hygienic measures seemed to be effective but after some weeks the colonization rate again increased. Electropherotyping of samples collected during different periods showed that one single rotavirus electropherotype belonging to the subgroup 1 of human rotavirus was found throughout the outbreak.     

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

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

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.     

改良粪便K-ras突变检测方法及在胰腺癌筛选中的应用

目的：通过改良粪便DNA提取方法,探讨粪便K－ras突变检测在胰腺癌选中的意义,方法：病例来自我院1994－2000年住院和门诊患者共127例,正常对照60例,通过改良酚－氯仿抽提法提取粪便DNA,通过PCR0－RFLP方法,检测K－ras基因第一外显子12密码子的突变,结果：粪便K－ras的扩增成功率为89．8％（168／187例）,胰腺癌患者粪便K－ras突变率为88．0％（66／75例）,胰腺良性疾病（包括腺瘤,慢性胰腺炎和内分泌瘤）为51．1％（24／47例）,正常对照组为19．6％（9／46例）,结论：通过改良粪便DNA是取方法,可明显提高PCR扩增成功率,粪便K－ras突变检测可用于胰腺癌的筛选。