Acute diarrhea in Baltimore children attending an outpatient clinic

Acute diarrheal illnesses in Baltimore children younger than 2 years of age attending an outpatient clinic were studied during a 12-month period. One in five acute care visits made to the clinic by children younger than 2 years was for diarrhea, and 5% of diarrhea cases required hospitalization. With the use of comprehensive methodology, a potential etiologic agent was identified in the stool of 105 (43%) of the 246 episodes of diarrhea in cases and in 43 (28%) of the 155 controls. Viral pathogens were found in 26% of episodes, and bacterial pathogens were found in 14%. Only rotavirus, enteric adenovirus and Salmonella were significantly associated with diarrhea. Cases were more likely to have measures of socioeconomic deprivation, such as household crowding, low maternal educational level and low birth weight, when compared to controls. Racial differences in morbidity from diarrheal illnesses were observed but could be attributed to these specific sociodemographic factors. Despite the low mortality caused by infantile gastroenteritis in the United States, it remains an important public health problem. However, even with intensive investigation the etiologies remain largely unknown.     

Enteric pathogens,intestinal permeability and nitric oxide production in acute gastroenteritis

BACKGROUND: Aboriginal children hospitalized with diarrheal disease in northern Australia have high rates of acidosis, hypokalemia and osmotic diarrhea, as well as abnormal small bowel permeability and elevated nitric oxide (NO) production. METHODS: In a study of 291 diarrheal admissions and 84 controls, we examined the relationship of diarrheal severity outcomes with specific enteric pathogens. NO production was measured by urine nitrate plus nitrite excretion on a low nitrate diet, small bowel permeability by the lactulose:rhamnose ratio on a timed blood specimen and stool pathogens by standard microbiologic investigations and PCR. RESULTS: The addition of diagnostic tests for diarrheagenic Escherichia coli to standard stool microbiologic testing increased the rate of specific diagnoses from 53% to 75%, but with multiple pathogens isolated from 34%. The most frequently isolated pathogens from diarrheal patients were enteroaggregative E. coli (28.9%), rotavirus (26.5%), enteropathogenic E. coli (17.2%), Salmonella spp. (10.7%), Cryptosporidium parvum (7.2%) and Strongyloides stercoralis (7.2%). High geometric mean permeability ratios (95% confidence intervals) occurred with rotavirus (19.6; 15.3 to 25.1), enteroaggregative E. coli (21.2; 15.3 to 29.3) and Cryptosporidium (23.0; 15.1 to 35.1) compared with 9.4 (6.8 to 13.1) for no pathogens. NO production was highest for Cryptosporidium (3.7; 2.3 to 6.1) compared with 0.6 (0.4 to 1.1) for no pathogens. Multiple regression analysis revealed significant associations (P < 0.001) for rotavirus with acidosis and osmotic diarrhea, for Strongyloides with wasting and hypokalemia and for Cryptospoidium with severe and prolonged diarrhea. CONCLUSIONS: Cryptosporidium, Strongyloides, rotavirus and enteroaggregative E. coli are important contributors to the severe manifestations of acute gastroenteritis in Australian Aboriginal children.     

Etiology of community-acquired pediatric viral diarrhea: a prospective longitudinal study in hospitals, emergency departments, pediatric practices and child care centers during the winter rotavirus outbreak, 1997 to 1998. The Pediatric Rotavirus Epidemiology Study for Immunization Study Group

OBJECTIVE: To determine the viral etiology of community-acquired diarrhea in children admitted to hospitals and presenting in emergency departments, pediatric practices and child care centers from November 1, 1997, to June 30, 1998. STUDY DESIGN: Children with diarrhea were identified in a prospective multisite cohort study and analyzed according to age, gender and duration of hospitalization. Stools were tested for rotavirus by enzyme immunoassay and for all other enteric viruses by electron microscopy. RESULTS: Of the 2524 children identified with diarrhea, stools of 1386 (55%) were tested by enzyme immunoassay for rotavirus, and of these 1365 (54%) were screened by electron microscopy for all identifiable enteric viruses. Rotavirus was found in 32% (n = 437), adenovirus in 4% (n = 55), torovirus in 3% (n = 44), Norwalk-like viruses in 2% (n = 25) and astrovirus (n = 14) and calicivirus (n = 7) in fewer than 1% of the specimens tested. The proportion of rotavirus was significantly higher in children 12 to 23 months of age (43% of tested stools, n = 159) and 24 to 35 months of age (38% of tested stools, n = 64) (P < 0.001) than in any other age group. Toroviruses were found to approximately the same extent in children > or =36 months of age (6% of tested stools, n = 19) as those <36 months of age. Rotavirus (36% of tested stools, n = 375, P < 0.0005) and torovirus (4% of tested stools, n = 43, P < 0.004) were most often found in hospitalized patients. In contrast Norwalk-like viruses (P < 0.001) and astroviruses (P < 0.01) were more commonly detected in specimens from patients who presented to physicians' offices and who were symptomatic for gastroenteritis in child care centers. CONCLUSION: This study demonstrates that although all known gastroenteritis viruses were diagnosed in symptomatic children, rotavirus was the etiologic agent in most cases of diarrhea managed in the community and in the hospital.     

Overview of rotavirus infections in Korea

Rotavirus is the most common cause of acute watery diarrhea in young Korean children. Rotavirus vaccine will soon be available, and information is urgently required about the serotype distribution of recent epidemics and clinical characteristics of rotavirus infection in Korean children before the implementation of a vaccination program against rotavirus. We reviewed published studies of the past 20 years, carried out on Korean children with rotavirus gastroenteritis. Rotavirus was estimated to be responsible for 46% of 4668 hospitalized Korean children with acute gastroenteritis. Rotavirus gastroenteritis was most prevalent among children aged 6-24 months, which accounted for 84% of all cases. Asymptomatic rotavirus infection was common. Rotavirus was one of the most commonly identified enteric pathogens in nosocomial diarrhea. Vomiting, respiratory symptoms and fever were prominent symptoms in rotavirus gastroenteritis. Transient elevation of liver enzymes, pulmonic infiltration and rarely afebrile convulsion were also observed. The epidemic peak, which occurred in November of the last 15 years, has been moving toward late winter and early spring in recent years. No apparent cause has been found to explain this alteration of peak seasonality. All serotyping studies in Korea for the past 10 years until 1997 revealed that G1 was most prevalent (45-81%). Interestingly, the predominant G serotype of the recent outbreaks in 1998 and 1999 was not G1 but G4. Approximately 95% of rotavirus isolates in recent outbreaks belonged to serotype G1, 2, 3 or 4.     

Significant prevalence and genetic diversity of norovirus infection in Irish children

Pediatric gastroenteritis places a considerable disease burden on children of the developed world. The national surveillance of gastroenteritis in Ireland is a combined virological and epidemiologic surveillance program. The objectives of this study were to characterize the norovirus (NoV) genotypes associated with viral gastroenteritis in children or=4 mo of age and determined that NoV and adenovirus infection are equally significant in children in the first 5 y of life. This group of pediatric patients reported diarrhea as their most common symptom raising the question whether Kaplan criteria are the most effective method for clinically diagnosing outbreaks of enteric infection in pediatric patients. ABBREVIATIONS::     

Rotavirus disease in young children from Hanoi, Vietnam

BACKGROUND: Pathogen prevalences and antimicrobial susceptibilities are essential for the rational development of preventive strategies for diarrheal diseases, but little recent information from Vietnam is available. We prospectively studied the prevalence of enteric pathogens in children less than 5 years of age with acute diarrhea and in nondiarrhea controls in a city hospital in Hanoi, Vietnam for 1 year. METHODS: Enteric bacteria and viruses were detected by standard culture methods, and enzyme immunoassay in 291 cases and 291 controls. RESULTS: Detection rates of viral pathogens among cases and controls were 31% and 3% for rotavirus, 12% and 1% for astrovirus and 4% and 1% for adenovirus. For bacterial pathogens, Aeromonas, Shigella, Salmonella, Campylobacter and enterotoxigenic E. coli were isolated from cases and controls in 15% and 8%, 9% and 1%, 7% and 1%, 4% and 0%, and 3% and 0%, respectively. The isolation of bacterial and viral pathogens except for adenovirus was significantly lower in controls than cases. Fluoroquinolones were effective against most bacterial enteropathogens, but resistance was observed in 27% of Campylobacter isolates. CONCLUSIONS: Viral etiologic agents especially rotavirus were the most important cause of acute diarrhea in children less than 5 years of age in Hanoi. The burden of rotavirus in young children in Hanoi warrants consideration of using the recently released rotavirus vaccine.     

北京市6岁以下门诊和住院腹泻患儿腺病毒检出率及流行特征

目的 了解北京单中心门诊和住院腹泻患儿腺病毒（Ad）检出情况及流行特征。方法 收集2010年1月至2013年12月首都儿科研究所6岁以下门诊腹泻、因腹泻住院和在住院期间出现腹泻症状患儿的粪便标本,采用PCR法检测Ad基因组DNA,分析流行特征。结果 进入本文分析腹泻患儿3 357例,门诊和住院腹泻患儿分别为862和2 495例。①3 357例腹泻患儿粪便标本中Ad检测阳性341例（10.2%）,门诊和住院腹泻患儿Ad检出率分别为8.1%（70/862）和10.9%（271/2 495）;门诊腹泻患儿肠道Ad（EAd）40例,包括Ad41和40型别,非肠道Ad（NEAd）30例（42.9%）,包括Ad31和Ad2等5种型别; 住院腹泻患儿EAd 271例,包括Ad41和Ad40型别,NEAd 157例（57.9%）,包括Ad31和Ad7等11种型别;门诊和住院腹泻患儿Ad和NEAd检出率差异均有统计学意义（P分别为0.022和0.002）。②Ad在门诊腹泻男女患儿中的检出率分别为9.0%和6.5%,在住院腹泻男女患儿中的检出率分别为11.7%和9.5%,差异均无统计学意义(P分别为0.206和0.086)。男女患儿Ad检出率在住院和门诊腹泻患儿间差异均无统计学意义(P分别为0.080和0.112)。③门诊腹泻患儿~6月龄、~1岁、~2岁和~6岁的Ad检出率分别为4.4%、7.7%、11.6%和12.3%,各年龄段Ad检出率差异有统计学意义（P=0.017）。住院腹泻患儿<28 d、~6月龄、~1岁、~2岁和~6岁的Ad检出率分别为4.4%、9.4%、13.2%、12.3%和13.4%,各年龄段Ad检出率差异有统计学意义(P=0.001）。④无论是门诊亦或住院腹泻患儿,全年各月均可见Ad检出。⑤Ad合并轮状病毒感染门诊腹泻患儿8/70例(11.4%),住院腹泻患儿29/271例(10.7%),差异无统计学意义（P=0.862）。结论 北京单中心门诊和住院腹泻患儿中Ad检出率为10.2%,以EAd41型占优势,NEAd31型在儿童腹泻中的作用也不容忽视。     

Lack of impact of rapid identification of rotavirus-infected patients on nosocomial rotavirus infections

The efficacy of rapid identification of rotavirus-infected patients in the control of nosocomial rotavirus infections on an infant and young toddler ward by use of a rotavirus antigen detection test on stool from patients with diarrhea was evaluated by comparing the rate of nosocomial rotavirus infection in children during two separate 5-week periods in the winters of 1984 and 1986. In contrast to 1984 rapid rotavirus antigen testing by latex agglutination of stool from patients with diarrhea was instituted in 1986, in addition to testing for rotavirus by enzyme immunoassay, to determine whether use of rapid antigen testing resulted in an increased incidence of appropriate isolation and a decrease in nosocomial infections. In 1986 rapid identification of rotavirus resulted in an increase in hospitalization of rotavirus-infected patients in single bed rooms from 68% to 100% (P = 0.02, chi square test) but no significant increase in the use of enteric precautions for these patients. The total number of cases of nosocomial rotavirus infection in the two periods did not differ. In both periods 11 cases occurred; the nosocomial infection rate in 1984 was 18.9 cases/1000 days of exposure whereas in 1986 it was 20.2 cases/1000 days. These findings indicate that the use of rapid rotavirus antigen testing of patients with diarrhea is not of appreciable benefit in preventing the nosocomial spread of rotavirus to infants on the ward.     

多重感染致儿童急性腹泻病的多中心临床研究

目的 观察急性腹泻患儿中单一感染与混合感染的发病率,比较单一和多个病原体感染患儿的临床表现.方法 采用回顾性研究方法,选择年龄1个月～14岁诊断急性腹泻病的患儿4728例作为观察对象.单一感染组和混合感染组患儿均进行大便常见病原体检测,包括轮状病毒(rotavirus,RV)、肠道腺病毒(enteric adenovirus,EAdV)、诺如病毒(norovirus,NV)抗原以及常见肠道致病菌的培养、分离鉴定.同时观察患儿病情的严重程度,包括腹泻持续时间和频率,发热、呕吐持续时间以及脱水的程度.结果 4 728例患儿中有一种及一种以上病原体感染的有3 595例(76.0％),实验室检测未发现病原体感染的患儿有1 133例(24.0％).其中RV感染有1 889例(40.0％),EAdV有412例(8.7％),NV感染有309例(6.5％),大肠埃希菌(VTEC) 274例(5.8％),沙门菌属276例(5.8％),肺炎克雷伯菌感染123例(2.6％),志贺菌78例(1.6％),金黄色葡萄球菌70例(1.5％)和产气荚膜杆菌126例(2.7％).其中1370例(29.0％)腹泻患儿存在混合感染,以RV合并NV感染150例(3.2％)及RV与产气荚膜菌混合感染127例(2.7％)为最常见.混合感染所致的儿童急性腹泻较单一感染临床表现更加严重,差异有统计学意义(P＜0.05).结论 轮状病毒仍是儿童急性腹泻最常见的病原体,其次为NV、EAdV、沙门菌属及VTEC.混合感染中轮状病毒合并诺如病毒感染最常见.在病毒与细菌混合感染时,VTEC与各类病毒合并感染发生率最高.多种病毒感染与单一病毒感染腹泻患儿比较,呕吐持续时间和脱水程度较严重,而发热及腹泻持续时间、腹泻频率则无明显差异.病毒合并细菌感染与单一病毒感染和单一细菌感染腹泻患儿的临床表现比较,混合感染患儿发热、呕吐及腹泻持续时间长,腹泻、脱水程度都更加严重.     

Astrovirus,adenovirus, and rotavirus in hospitalized children: prevalence and association with gastroenteritis

BACKGROUND: Agents of viral gastroenteritis such as astrovirus, rotavirus, and adenovirus are common pediatric pathogens accounting for many physician visits, hospital admissions, and nosocomial infections. Previous hospital-based prevalence studies have examined mainly symptomatic children. PURPOSE: To evaluate the prevalence of astrovirus, rotavirus, and adenovirus infections among hospitalized children less than 6 years of age, regardless of symptoms, and determine association with gastroenteritis. METHODS: From September 1998 to June 2000, stool specimens were collected twice weekly from children less than five years of age admitted to two wards in a tertiary-care children's hospital. A total of 480 samples were obtained from 309 hospitalizations. Stools were examined using antibody-based ELISA for astrovirus, rotavirus, and adenovirus. Clinical data was abstracted from patient records. RESULTS: Twenty one percent of the children had gastroenteritis symptoms at some point during their hospitalizations (43% were hospital acquired). Astrovirus was detected in 5.2% of all children compared to 6.8% with rotavirus and 0.8% with adenovirus serotypes 40 or 41. Nosocomial acquisition was common. Seventy five percent of astrovirus infections and 90% rotavirus infections were symptomatic. Astrovirus infections were significantly more likely to occur in younger infants and in children with compromised immunity. Rotavirus infections were significantly more likely to cause dehydration. In a three-year passive surveillance of gastroenteritis at the hospital, astrovirus and rotavirus infections peaked simultaneously in winter months. CONCLUSIONS: Rotavirus and astrovirus are common symptomatic infections on pediatric wards and contribute greatly to inpatient morbidity. Adenoviruses played a limited role in gastroenteritis in hospitalized children in this study.     

Fecal adenoviruses from a longitudinal study of families in metropolitan Washington, D.C.: laboratory, clinical, and epidemiologic observations

During a 29-month period, we studied enteric infection in 70 families from a pediatric practice in suburban Washington, D.C. Fecal adenoviruses were detected in stools of 18 patients by tissue culture and electron microscopic procedures. From 6 through 11 months of age, the incidence of fecal adenoviruses associated with enteritis was seven per 100, and of confirmed enteric adenoviruses (EAds), three per 100 individuals per year. All EAds belonged to subgenus G (type 41). All three patients with EAds had diarrhea; two had vomiting and one had fever, but none required hospitalization. Ten of the 15 patients with non-EAds were younger than 2 years, and 60% had diarrhea, 40% had vomiting, and 20% had fever. Combined gastrointestinal and respiratory symptoms occurred more often in those who shed non-EAds (three of 11) than in matched controls (two of 48, P = 0.04). An adenovirus was detected in approximately 6% of gastroenteritis episodes, and confirmed EAds were present in approximately 2% of episodes of gastroenteritis in children younger than 2 years of age. None of the contacts of patients with non-EAds shed such virus in their stools. None of nine family contacts of those with EAd appeared to shed adenovirus in stool. In contrast, rotavirus spread readily to exposed adults (25% of 65) and children (56% of 62) when a child in similar families had rotavirus infection.     

Epidemiology and impact of rotavirus diarrhoea in Poland

Hospital and laboratory data were analysed in three hospitals to estimate rotavirus disease burden in 1994-96. Community acquired gastroenteritis was diagnosed in 757 children of whom 41% tested positive for rotavirus. A total of 196 children had rotavirus nosocomial infections (39% of all rotavirus community-acquired and nosocomial cases) Infants less than 24 months old and children less than 3 months old comprised 74% and 11.9% of admissions for rotavirus, respectively. Almost 94% of children with rotavirus infection had severe gastroenteritis (score 11). The annual rate of rotavirus associated hospitalization in Poland in 1996 was 3.1/1000 children under the age of 60 months and 5.2/1000 infants under 24 months of age. The mean hospital stay was 9.5 d (±9.8 d). We estimated that 8918 children under 60 months of age were hospitalized for rotavirus gastroenteritis in 1996; they accounted for 84899 inpatient days. We conclude that rotavirus is a leading aetiological agent of severe gastroenteritis in young children in Poland and that the Burden of this infection is significant. Rotavirus vaccine could significantly decrease the hospitalization rate and the financial impact of rotavirus Gastroenteritis in Poland. □ Acute diarrhoea, disease burden, epidemiology, gastroenteritis, rotavirus     

Rotavirus gastroenteritis among children under five years of age in Izmir, Turkey

Little is known about the epidemiology of rotavirus infection in Turkey. The aim of the study was to determine the incidence and clinical significance of rotavirus gastroenteritis, in view of the potentially available prevention by rotavirus vaccination. The study also sought to determine possible risk factors for rotavirus gastroenteritis. Therefore, 920 children under five years of age with acute gastroenteritis admitted to three pediatric hospitals in Izmir were studied. Rotavirus was identified in 39.8% of the children. Most children with rotavirus gastroenteritis (80.7%) were younger than two years of age. Marked seasonality of rotavirus gastroenteritis was observed, with a peak incidence from January to March. A total of 91% of rotavirus strains that were typed were of serotypes G 1-4. There was no significant difference among rotavirus-positive and rotavirus-negative patients with regard to family income. Compared with children who were exclusively breast-fed, those who were not exclusively breast-fed were at a two-fold greater risk of rotavirus diarrhea. Rotavirus gastroenteritis was significantly more severe than non-rotavirus gastroenteritis; 69% of children with rotavirus infection had severe gastroenteritis (score > or = 11). In conclusion, rotavirus is the most common cause of severe gastroenteritis among children under five years of age in Izmir. A new potent rotavirus vaccine, when available, will provide effective protection against severe rotavirus infection. Promotion of breast-feeding would augment the impact of rotavirus vaccines in preventing severe childhood diarrhea.     

Epidemiology and impact of rotavirus diarrhoea in Poland

Hospital and laboratory data were analysed in three hospitals to estimate rotavirus disease burden in 1994-96. Community acquired gastroenteritis was diagnosed in 757 children of whom 41% tested positive for rotavirus. A total of 196 children had rotavirus nosocomial infections (39% of all rotavirus community-acquired and nosocomial cases). Infants less than 24 months old and children less than 3 months old comprised 74% and 11.9% of admissions for rotavirus, respectively. Almost 94% of children with rotavirus infection had severe gastroenteritis (score > or =11). The annual rate of rotavirus associated hospitalization in Poland in 1996 was 3.1/1000 children under the age of 60 months and 5.2/1000 infants under 24 months of age. The mean hospital stay was 9.5 d (+/-9.8 d). We estimated that 8918 children under 60 months of age were hospitalized for rotavirus gastroenteritis in 1996; they accounted for 84899 inpatient days. We conclude that rotavirus is a leading aetiological agent of severe gastroenteritis in young children in Poland and that the burden of this infection is significant. Rotavirus vaccine could significantly decrease the hospitalization rate and the financial impact of rotavirus gastroenteritis in Poland.     

Intestinal damage in rotavirus and adenovirus gastroenteritis assessed by d-xylose malabsorption.

The absorption of D-xylose infused into the duodenum was assessed in infants with acute gastroenteritis. 1-hour blood-xylose levels were low in 6 patients found to harbour rotavirus in the small intestinal aspirate. Normal levels (greater than 1-26 mmol/l) were obtained in the absence of virus particles in the small intestine in a further 6 patients: in 3 of these adenovirus or rotavirus was recovered from the stools. Three patients with adenovirus in the small intestinal juice and ill with acute gastroenteritis also had low xylose levels. This finding supports earlier epidemiological studies that adenovirus may be a causative agent of acute infantile gastroenteritis. The association between virus in the small intestine and xylose malabsorption may indicate mucosal damage. Formal proff of this is awaited.     

Molecular epidemiology of viral gastroenteritis in Asia

Acute gastroenteritis is one of the most common diseases in humans, and continues to be a significant cause of mortality and morbidity worldwide. Recently the estimates of mortality associated with diarrhea declined, however the majority of deaths still occur in developing countries and thus urgent intervention is needed for the prevention of these diseases. In Asian countries it is very important to study the distribution, transmission and characteristics of prevalent viruses in order to produce viral vaccines. The viruses which cause gastroenteritis are primarily from four distinct families - group A rotaviruses, caliciviruses, enteric adenoviruses and astroviruses. Rotavirus is a common virus that causes severe gastroenteritis in children <5 years of age. The reassortant viruses with animal virus, or directly animal viruses are isolated in humans. The future development of a safe and effective vaccine against rotavirus, along with the expansion of understanding of the distribution of types in Asia and an availability of rapid diagnostic tests, could reduce mortality and might be able to prevent severe gastroenteritis. Calicivirus is a causative virus of acute gastroenteritis in children and has been known to contaminate food causing viral outbreaks affecting people of all ages. Recently, the understanding of calicivirus and the improvement of detection techniques has increased the total frequencies of diarrheal viruses. For the future control and prevention of diarrheal diseases it is necessary to examine the molecular epidemiology of caliciviruses as well as rotaviruses.     

Risk factors associated with nosocomial rotavirus infection

A prospective study of hospital-acquired rotavirus infection was undertaken on an infant and young toddler floor to assess the incidence of infection and risk factors associated with nosocomial transmission. During the seven-month study period, gastroenteritis accounted for 60 of 663 admissions, 23 (38%) of which were due to rotavirus. In spite of enteric isolation of 21 (91%) of 23 patients with community-acquired cases, 36 infants developed nosocomial rotavirus infections. The attack rate of hospital-acquired infection was 12.8%, ranging each month from 2% to 21%. Approximately three fourths of both community-acquired cases (17/23) and nosocomial cases (27/36) occurred during the late winter and early spring. Prolonged stays in the hospital were associated with an increased attack rate of rotavirus infection. The risk of nosocomial rotavirus infection was not significantly enhanced by room contact with a rotavirus-infected patient or by the sharing of staff. However, only 47% (17/36) of patients with nosocomial infections were appropriately isolated, despite symptoms of gastroenteritis in all cases. These findings indicate that hospital acquisition of rotavirus is common, and indicate that failure to isolate patients with nosocomial rotavirus infections could be an important factor in hospital transmission.     

Nosocomial rotavirus infections in a general pediatric ward: epidemiology, molecular typing and risk factors]

OBJECTIVES: Nosocomial rotavirus infections induce difficult problems for pediatric wards during winter epidemics. This prospective study was carried out to measure their incidence in a general pediatric ward by using epidemiological tools, clinical and molecular methods, and to examine the main factors increasing the risk of cross contamination. MATERIAL AND METHODS: The study was carried out on children, younger than three years old, hospitalized between 15 November 1996 and 1 March 1997. We examined the feces of all children for rotavirus on admission and during their hospital stay if they had developed diarrhea. The strains were typed by RNA electrophoresis. A cohort study was done to identify the factors of exposure to risk. RESULTS: Three hundred twenty-six of the 415 hospitalized infants were studied. One hundred and five were hospitalized for gastroenteritis, including 39 (37.1%) with rotavirus infection. Among 221 infants admitted without diarrhea, 11 (5.0%) had an asymptomatic community infection and nine (4.3%) developed nosocomial gastroenteritis. The only significant predisposing factor (P = 0.003) for nosocomial infection was the distance between the hospital rooms and the nurses station. Despite the low level of typing (51%), the molecular study suggested a wide diversity of nosocomial and community strains. CONCLUSION: The relatively low incidence of nosocomial infections found may be due to routine assignment to individual rooms, the isolation of infants admitted with acute diarrhea, and the policy of routine detection of asymptomatic carriers with the use of similar isolation measures for these children.