Rotavirus-Associated Diarrhea in Outpatient Settings and Child Care Centers | Gastroenterology | JAMA Pediatrics | JAMA Network
[Skip to Navigation]
Sign In
June 2000

Rotavirus-Associated Diarrhea in Outpatient Settings and Child Care Centers

Author Affiliations

From the Division of Infectious Diseases, The Hospital for Sick Children (Drs Ford-Jones and Wang), and the Departments of Pediatrics (Drs Ford-Jones and Wang), Laboratory Medicine (Dr Petric), and Biostatistics (Dr Corey and Mr Moineddin), University of Toronto, and the Ontario Public Health Laboratory (Dr Fearon), Toronto, Ontario.

Arch Pediatr Adolesc Med. 2000;154(6):586-593. doi:10.1001/archpedi.154.6.586

Objectives  To determine the prevalence of rotavirus infection in outpatient and child care center (CCC) settings during the seasonal rotavirus outbreak and to describe associated health care utilization.

Design  Prospective, multisite cohort study in various ambulatory settings.

Settings and Participants  Participants were children with diarrhea (1) presenting to hospital emergency departments (EDs) and receiving intravenous (IV; n=8) or oral (n=1) hydration, (2) seen in pediatric practices (n=4), or (3) attending CCCs (n=19) between November 1, 1997, and June 30, 1998. Prospective centralized testing of stool samples for rotavirus was performed using enzyme-linked immunosorbent assay and electron microscopy. Study nurses administered follow-up parent questionnaires for rotavirus-positive children.

Main Outcome Measure  Prevalence of rotavirus-associated diarrhea.

Results  During the 8-month study, rotavirus was identified in 92 children with diarrhea: ED-IV, 20 (44%) of 45; ED-oral, 9 (47%) of 19; pediatric practices, 30 (20%) of 147; and CCCs, 33 (18%) of 186. Of 226 children with diarrhea in pediatric practices, all 5 who progressed to ED-IV hydration or hospitalization were tested, and 3 (60%) were rotavirus positive. Of 211 children in CCCs with diarrhea, 84% who required no health care visits were tested, and of these 10% were positive; of 56 who went on to require a health care visit and 8 who required ED-IV hydration or hospitalization, all were tested, and 27% and 75%, respectively, were rotavirus positive. Among 16 children with rotavirus followed up with ED-IV hydration, 4 (25%) returned and were hospitalized. Maximal health care intervention among 29 children with rotavirus enrolled in pediatric practices included 22 (76%) seeing the pediatrician only, 5 (17%) seeking further care in the ED, 1 (3%) receiving further ED-IV hydration, and 1 (3%) being hospitalized briefly. Maximal health care intervention for 33 children with rotavirus enrolled in CCCs included 13 (39%) who did not visit a physician, 11 (33%) who did, 3 (9%) who sought care in the ED, 1 (3%) who received ED-IV hydration, and 5 (15%) who were hospitalized. In CCCs, rates of diarrhea per 100 child-months of observation were as follows: ages 0 to 23 months, 6.6 episodes; ages 24 to 35 months, 1.9 episodes; and 3 years and older, 0.07 episodes; rates of rotavirus-associated diarrhea were as follows: ages 0 to 23 months, 1.1 episodes (28 of 2547); ages 24 to 35 months, 0.23 episodes (5 of 2185); and 3 years and older, 0 episodes (0 of 4124).

Conclusion  Across a variety of outpatient and CCC settings, rotavirus is an important cause of diarrhea and a major cause of health care utilization.

DATA ARE limited on the current prevalence and morbidity of rotavirus-associated diarrhea in outpatient settings and child care centers (CCCs). An estimated 30% of US children experience their first rotavirus illness in the first 2 years of life.1 An estimated 1 in 8 children will see a physician, and 1 in 73 will be hospitalized.2 A study3 using the Vaccine Safety Datalink and enrolling children from 4 health maintenance organizations estimates diarrhea hospitalization for 1 in 57 children in the first 5 years of life. A tetravalent rotavirus vaccine is now available for oral administration at ages 2, 4, and 6 months. Routine implementation of its use requires reconciliation of related economic issues, which necessitates adequate prevalence data.4

This prospective study was undertaken to determine the prevalence of rotavirus in children receiving intravenous (IV) and oral hydration for diarrhea in selected emergency departments (EDs) in recognition of the greater severity of illness that is now managed in the outpatient setting.5 In addition, the prevalence of outpatient illness was determined in 2 ambulatory care settings—pediatric practices (PP) and CCCs. Health care utilization and characteristics of childhood rotavirus infection, including demographics, course of illness, and household descriptors, were also ascertained.

Participants and methods

Study sites

Children were enrolled at selected convenience samples of EDs providing IV (n=8) and oral (n=1) rehydration, PPs (n=4), and CCCs (n=19). Patients at hospital sites were recruited through the infection control practitioners and ED staff, at PPs by a designated nurse and physician, and at CCCs by each director with the staff. Three CCCs that had initially agreed to participate did not comply with weekly provision of information to study research nurses and were excluded from further study.

Of 19 CCCs, 1 enrolled fewer than 20 children, 6 enrolled 20 to 50 children, and 12 enrolled more than 50 children. All had hand-washing and other written health guidelines, which were updated annually. Gloves were not used for diaper changes at 3 centers and were routinely used at 7 centers; glove use depended on individual staff preference at 9 centers. Action taken at the time of diarrhea included sending the child home after the second (n=11) or third (n=6) watery stool, if the diaper could not contain the stool (n=1), or if warranted by the child's appearance (n=1). Of staff preparing food, 42% (n=8) had additional child care responsibilities. Average weekly costs (Can $) for care were $185 to $246 for infants, $165 to $237 for toddlers, $140 to $215 for preschoolers, and $135 to $215 for children 5 years and older. Of 500 eligible CCC attendees at study initiation, 461 remained at closure, with 17 not consenting to participate and 22 leaving the center. There were 8856 child-months of observation, including ages 0 to 11 months, 9%; ages 12 to 23 months, 20%; ages 24 to 35 months, 25%; ages 36 to 47 months, 24%; and 4 years and older, 22%.

The study was approved by the Human Subjects' Review Committee of the University of Toronto, Toronto, Ontario, and by each hospital. Written consent for participation was provided by participating pediatricians, CCC directors, and parents of children followed up in CCCs.

Target population

Between November 1, 1997, and June 30, 1998, all children with symptoms of acute diarrhea at study sites were reported. Diarrhea was defined as the passage of 3 or more liquid or semiliquid stools or a single watery stool per day by a child. Children with chronic diarrhea, hospitalization in the preceding 7 days, or, in the ED-IV group, receiving less than 4 hours of IV rehydration were excluded.

Study setup and management

Identification of All Diarrhea Events

Designated site coordinators identified all children with diarrhea (diarrhea events), physician and child names and telephone numbers, dates of birth and presentation of diarrhea, postal codes, and whether stool samples were sent for testing. Information was forwarded on a weekly basis to the study research nurses, who initiated diarrhea event forms. Stool specimens obtained at all sites were examined in the Virology Laboratory, Department of Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario.

Identification and Enrollment of Children With Rotavirus-Associated Diarrhea

All children with stool samples that were positive for rotavirus were eligible for the study. The research nurse initiated a case report form, sought authorization to contact the family from the child's physician, and obtained telephone consent from parents and information regarding the child and the acute illness. In telephone follow-up at 1 month, information regarding the course of illness and household characteristics was obtained. Children were excluded if their physicians did not authorize parent contact, the parent(s) refused or was not available to provide consent, or a language barrier existed.

Parent Questionnaire

Information obtained at the first telephone contact included the child's date of birth, sex, history of prematurity and breastfeeding prior to the onset of diarrrhea, underlying disease, child care arrangements, duration of illness, and utilization of health care providers and hospitals for this illness. At 1-month follow-up, information was obtained regarding persistent symptoms, diarrhea in household contacts, and household descriptors, including marital status, education level, ethnicity, and income.

Strategies to maximize study compliance

Educational materials for site staff and parents, stool collection kits, and rosters for specimen pickup were provided at all sites. Recruitment at sites was enhanced through telephone liason, weekly facsimile of diarrhea events, biweekly to monthly site visits by research nurses, and a study newsletter. Unannounced visits were made on 2 occasions to a random sample of sites by a research nurse other than the one assigned to the site; a checklist was completed at each visit to confirm the availability of posters, stool containers, and information sheets and knowledge about the study. Parents of children from whom stool samples were not obtained at PPs or CCCs were provided with a stool collection kit. In addition, PP office staff placed reminder telephone calls to parents of children from whom stool samples were not obtained at the visit to encourage subsequent sample submission.

Laboratory methods

Stool specimens were labeled and stored at 40°C until transfer to the laboratory. Testing for rotavirus was performed within 1 week of collection using a commercial rotavirus enzyme-linked immunosorbent assay (IDEIA; Dako Diagnostics, Mississauga, Ontario) following the manufacturer's protocol. Specimens that were IDEIA positive were confirmed by electron microscopy in the laboratory of The Hospital for Sick Children or the Toronto Public Health Laboratory. Specimens with indeterminate results were examined by electron microscopy and excluded if no rotavirus was found. The remaining specimens were transferred to storage vials and maintained at −20°C until G typing was undertaken using monoclonal antibody and sequencing (M.P. and Raymond Tellier, MD, PhD, manuscript in preparation, 1999).

Data management

All data were entered into case report forms. All diarrhea event forms were entered into a database (Filemaker Pro; Claris Corp, Santa Clara, Calif) on a personal computer and exported for analysis using statistical software (SAS; SAS Institute Inc, Cary, NC). Each case report form for rotavirus-infected children was checked by 2 reviewers before entry into the mainframe computer; 25% were double entered. The 2 data sets of rotavirus-positive children (ie, diarrhea event forms and case report forms) were compared for consistency of birth, event, hospital admission, and discharge dates where applicable and attendance at a CCC.

Statistical analysis

Continuous measures across different groups were assessed using analysis of variance. For comparing 2 groups, t tests were used. Methods such as Fisher exact or χ2 tests were used to test the association between categorical variables. The z test or analysis of variance was used to test 2 or more proportions. The underlying assumptions for each method were checked to make sure that those assumptions were reasonably satisfied.


Identification of children with rotavirus-associated diarrhea

Diarrhea was identified in 886 children, and stool specimens of 397 (45%) were submitted for rotavirus testing. Results of testing by study site are provided in Table 1. Children from CCCs were more likely to be tested (CCCs, 88%; PPs, 65%; and EDs, 14%; P=.001).

Table 1. 
Prevalence of Rotavirus-Associated Diarrhea in Children in Outpatient Settings and Child Care Centers, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*
Prevalence of Rotavirus-Associated Diarrhea in Children in Outpatient Settings and Child Care Centers, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*

Rotavirus was identified in 92 (23%) of children tested (Table 1). Children in ED settings had the highest rates of rotavirus positivity (EDs, 45%; PPs, 20%; and CCCs, 18%). Mean ages of children testing rotavirus positive and negative, respectively, by site were as follows: ED-IV, 18.9 (n=20) and 50.4 (n=23) months; ED-oral, 42.3 (n=9) and 25.7 (n=9) months; PP, 18.2 (n=30) and 32.8 (n=117) months; and CCC, 15.1 (n=33) and 17.6 (n=157) months. Mean ages of untested children were as follows: ED-IV, 44.6 months (n=315); ED-oral, 39.5 months (n=70); PP, 31.9 months (n=79); and CCC, 18 months (n=25). In outpatient settings, more boys than girls presented with diarrhea (383 boys vs 292 girls; P=.001). In CCCs, a similar number of boys presented with diarrhea as girls (109 boys vs 102 girls; P=.63). Boys in outpatient settings, but not in CCCs, were more likely to be tested (137 boys vs 47 girls; P=.001) and to be rotavirus positive (38 boys vs 21 girls; P=.03).

Rates of diarrhea in CCCs per 100 child-months of observation were highest at ages 0 to 23 months (6.6 episodes [167 of 2547]) compared with older children aged 24 to 35 months (1.9 episodes [41 of 2185]) and 3 years and older (0.07 episodes [3 of 4124]) (P<.001). Rates of rotavirus-associated diarrhea in CCCs were also highest in this age group of 0 to 23 months (1.1 episodes [28 of 2547]) compared with older children aged 24 to 35 months (0.23 episodes [5 of 2185]) and 3 years and older (0 episodes [0 of 4124]) (P<.001). Only 2 children younger than 6 months in CCCs were identified as having rotavirus diarrhea.

Of 226 children seen in PPs with diarrhea, all 5 who went on to receive ED-IV hydration or hospitalization were tested, and 3 (60%) were rotavirus positive. Of 211 children identified with diarrhea in CCCs, 84% who required no health care visits were tested, and 10% of these were positive. All 56 children who subsequently made a health care visit and 8 who subsequently received ED-IV hydration or were hospitalized were tested, and 27% and 75%, respectively, were rotavirus positive. One child receiving ED-oral therapy subsequently was admitted to the hospital. This child was rotavirus negative.

Among outpatient children, the proportion for whom information on CCC attendance was available was higher in PPs (92% [208/226]) compared with ED-IV (36% [130/360]) and ED-oral (35% [31/89]) (P=.001) and overall (55% [369/675]). The proportions of those who attended CCCs of those for whom the use of CCCs was known were as follows: ED-IV, 7% (9/130); ED-oral, 13% (4/31); and PP, 14% (30/208) (P=.11).

Seasonal variation

In the 8-month study period, rotavirus was more common at all sites from March to May inclusive, accounting for more than 60% of diarrhea in children aged 6 to 36 months tested in PPs during the peak epidemic months of April and May (Figure 1).

Proportion of rotavirus-associated diarrhea in children aged 6 to 35 months in outpatient (OP) and child care center (CCC) settings by month, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998.

Proportion of rotavirus-associated diarrhea in children aged 6 to 35 months in outpatient (OP) and child care center (CCC) settings by month, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998.

Findings in children

Five of 92 rotavirus-infected children (5%) were excluded from telephone interview because of lack of consent, inadequate communication in English, or inability to contact by telephone (ED-IV, n=4; PP, n=1). Among 87 respondents, 83% (n=72) were mothers. Response rates to questions were as follows: education, 99% (n=86); marital status, 99% (n=84); ethnicity, 99% (n=86); and household income, 78% (68). Ninety-one percent of respondents (n=79) had no difficulty answering questions and 7% (n=6) had some difficulty.

Characteristics of the children are shown in Table 2. Most children (78%) (68/87) were 6 to 35 months old. Boys comprised 61% (53/87) and girls comprised 39% (34/87) of the population. Of 28 children presenting at younger than 12 months, 96% (n=27) were born at term and 75% (n=21) were not receiving breast milk at the time that illness occurred. Of 16% (n=14) of children who reported 1 or more underlying diseases for which they regularly saw a physician or took medication, most were respiratory (n=6), dermatologic (n=4), or allergic (n=1) conditions. The majority of young children in the ED-IV, ED-oral, and PP groups for whom information was available were cared for in their own or a relative's home (83% [38/46]) (Table 2).

Table 2. 
Characteristics of Children With Rotavirus-Associated Diarrhea by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*
Characteristics of Children With Rotavirus-Associated Diarrhea by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*

Course of illness

The course of illness is shown in Table 3. There was no significant difference in rates of vomiting and fever or in duration of illness in outpatient vs CCC settings (6.1 vs 5.8 days; P=.45).

Table 3. 
Health Care of Children With Rotavirus-Associated Diarrhea After Inception by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*
Health Care of Children With Rotavirus-Associated Diarrhea After Inception by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*

Four (25%) of 16 ED-IV hydration recipients were admitted to the hospital at a subsequent visit. Of 29 children enrolled when seen in the PPs, 22 (76%) saw only the pediatrician, whereas 5 (17%) sought further care in the ED, 1 (3%) received ED-IV hydration, and 1 (3%) was hospitalized briefly. For 33 children with rotavirus from CCCs, 11 (33%) saw a physician, 3 (9%) sought care in the ED, 1 (3%) received ED-IV hydration, and 5 (15%) were hospitalized.

Children in CCCs who went on to receive ED-IV hydration or to be hospitalized did not differ significantly from those who did not with respect to any of the following variables: vomiting, 100% (9/9) vs 75% (18/24) (P=.16); fever, 89% (8/9) vs 61% (14/23) (P=.21); longer duration of illness, 6.6 (n=9) vs 5.5 (n=24) days (P=.35); younger age, 14 (n=9) vs 17.2 (n=24) months (P=.37); sex, 44% (4/9) female vs 46% (11/24) male (P=.94); prematurity, 22% (2/9) vs 0% (0/24) (P=.09); underlying disease, 11% (1/9) vs 21% (5/24) (P=.52); taking medication, 11% (1/9) vs 21% (5/24) (P=.52); and regularly seeing a physician, 11% (1/9) vs 21% (5/24) (P=.52), although comparisons are limited by sample size. There were no admissions of children to the pediatric intensive care unit, and no children died. Among those admitted to the hospital, the durations of hospital stay and of IV hydration were longest in children from CCCs.

Household findings

Diarrhea in household members in the 2 weeks before and after the child's illness was more likely in children younger than 3 years in all settings (Table 4) (<3 years, 65%; 3-18 years, 43%; and >18 years, 35%; P=.03). Most outpatient and CCC children had married mothers (75% and 63%, respectively; P=.35), with respondents reporting that they received some or all of a high school (21% vs 15%, respectively; P=.78) or university (66% and 58%, respectively; P=.56) education. Household incomes of $20,000 to $60,000 were reported for 28% of outpatient families vs 33% of CCC families (P=.81) and of more than $60,000 for 55% of outpatient families vs 56% of CCC families (P=.95).

Table 4. 
Household Characteristics of Children With Rotavirus-Associated Diarrhea by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*
Household Characteristics of Children With Rotavirus-Associated Diarrhea by Site, Greater Toronto, Ontario, Area/Peel Region, November 1, 1997, to June 30, 1998*

Ethnicity was highly diverse, with whites representing 60% of outpatient and 64% of CCC families and the remainder divided among black, Asian, East Indian, and other groups. At least 1 member of the household was employed full-time in 76% of families from outpatient settings and 88% from CCCs (P=.07).

Recovery from rotavirus illness

For outpatient and CCC settings, there was no difference in mean duration of illness (6.1 vs 5.8 days; P=.50) or return to previous health by 1 month (94% vs 97%). Of outpatient children, 83% (44/53) had returned, 6% (3/53) almost had returned, and 11% (6/53) had not returned to their previous body weight, whereas 97% (31/32) of those in CCCs had returned and 3% (1/32) almost had returned to their previous body weight.


We provided the contemporary prevalence of rotavirus-associated diarrhea in a sample of outpatient and CCC settings during the epidemic season. Given the absence of cases in November and June, it is likely that we captured the epidemic period and most cases occurring at these sites for the year. The proportional frequency of rotavirus in PPs and CCCs (20% and 18%, respectively) was lower than that in the ED-IV group (44%) or in children from PPs and CCCs who progressed to more severe disease requiring hospitalization or ED-IV hydration (60% and 75%, respectively). This compares with an overall prevalence of 37% found in a concurrent study of presumably sicker hospitalized children, which increased to more than 70% in peak months in children aged 6 to 36 months.6 Rotavirus is known to cause the majority of severe diarrhea illness in young children.7,8

With high-intensity surveillance for diarrhea and effective communication with designated personnel at each site on a weekly basis, we tested for the presence of rotavirus in many but not all children with diarrhea. The study includes a relatively small number of children in each group, and the sample is not population based. The best rate of testing was obviously at the site where previously well children were incepted, the CCC. Diarrhea is often substantially diminished by the time a child is medically evaluated or simply does not occur during the brief encounter with the health care system in the ambulatory care setting. Although parents were provided with stool collection kits and telephone reminders in PPs, there are a variety of plausible reasons why testing was still not possible. Furthermore, discharge diagnoses were not evaluated, and it is likely that some children identified on inception but not tested had other causes for their diarrheal illness, including urinary tract infections.

Characteristics of children with rotavirus-associated diarrhea were unremarkable, with few having a history of premature birth or underlying disease. There were high rates of diarrheal illness in household members, especially those younger than 3 years. With most having married parents, with a broad profile of education, income, and ethnicity, and in the absence of information about uninfected children, it is not possible to characterize a group at high risk of disease. The spectrum of health care utilization was captured by inception at these sites. It has been reported elsewhere2 that the cumulative incidence of rotavirus illness by age 5 years approaches 0.8 episodes. Physician visits occur in 1 in 8 children, and 1 in 73 will be hospitalized for rotavirus diarrhea compared with 1 in 25 for diarrhea in general.2 The limited information about children receiving ED-IV hydration has not previously defined the number still requiring hospitalization later in the illness, which we found to be 25%. Similarly, 23% of children seeing pediatricians for rotavirus-associated diarrhea required additional ED or hospital care. Conversely, 39% of the rotavirus illness incepted in CCC attendees did not require a health care visit. Whether this is because of milder disease or the effect of prompt oral therapy advised by the CCC or during telephone contact with a physician is not known. Child care center attendance previously has been found9 to increase the risk of clinic visits for diarrhea caused by rotavirus.

Among children younger than 36 months from outpatient settings with rotavirus-associated diarrhea, only 9% attended CCCs. A review10 of child care arrangements in Canada for 1996 found that 11% of children aged 0 to 17 months with mothers in the paid labor force attended regulated, center-based child care, and these numbers increased to 14% for children aged 18 to 36 months and 32% for those aged 3 to 6 years. In a telephone survey of random households of preschoolers in the study census tracts, 15% of respondents indicated that their children younger than 6 years attended CCCs. Although one might speculate that the ongoing monitoring of attendees' health by day care workers and prompt exclusion of symptomatic children means less transmission, earlier attention to appropriate rehydration, and a reduced risk of hospitalization, a larger study is required to confirm this.

As for rates of diarrhea in infants and toddlers in CCCs, our rates are slightly lower than those reported by Black et al11 with the introduction of a hand-washing program, at 9.8 and 2.6 per 100 child-weeks in children aged 6 to 17 months and 18 to 29 months, respectively. The compliance of our centers with practices known to reduce rates of diarrhea, eg, strong hand-washing programs, preparation of own manual, and prompt exclusion of ill children, should be noted. Also, many centers have participated in our earlier studies,12-16 since 1992, suggesting that their staff might be more knowledgeable about infectious diseases and particularly well administered, with uniquely strong infection control programs and thus lower rates of diarrhea. Generalization of our findings to other centers with less stringent practices might not be appropriate. Diarrhea rates in CCCs (42 cases per 100 child-months), family child care homes (23 cases per 100 child-months), and households not using child care (27 cases per 100 child-months)17 are all much higher than our rate of 6.6 episodes per 100 child-months of observation. Rotavirus has been implicated in 6% to 24% of cases of gastroenteritis and in 20% to 40% of outbreaks in CCCs.18

We have, across a variety of outpatient and CCC settings, defined the prevalence of rotavirus-associated diarrhea. Rotavirus is a major cause of diarrhea and increased health care utilization in children in outpatient and CCC settings. The American Academy of Pediatrics has recently withdrawn rotavirus vaccine from usage.19 The decision to use future approved vaccines will be based on expected reduction in moderate and severe rotavirus infection and the predicted cost-effectiveness of such a proposed program.

Author Contributors

The following members of The Greater Toronto Area/Peel Region Pediatric Rotavirus Epidemiology Study for Immunization (PRESI) Study Group contributed as authors, meeting the International Committee of Medical Journal Editors qualifications for authorship: The Hospital for Sick Children, Toronto, Ontario: E. Lee Ford-Jones, MD; Lisa Palmerino; Renee Freeman; Glenn Urbshott; Elaine Wang, MD; Martin Petric, PhD; Saul Greenberg, MD; Mort Goldbach, MD; Moshe Ipp, MD; Norm Saunders, MD; and Susan Skull, MD; Department of Biostatistics, University of Toronto, Toronto: Paul Corey, PhD, and Rahim Moineddin, MSc; Wyeth-Ayerst Canada Inc, North York, Ontario: Leslie Shane, PharmD; Karen Thompson, PhD; and Edward C. Y. Wang, PharmD; Mt Sinai Hospital: Allison McGeer, MD; Children's Hospital of Eastern Ontario, Ottawa: Noni MacDonald, MD; Laboratory Services, Ontario Ministry of Health: Margaret Fearon, MD.

Other Members of the PRESI Study Group

Virology Laboratory, The Hospital for Sick Children: Karen Siu; Department of Biostatistics, University of Toronto: Vartouhi Jazmaji; The Research Sciences Unit, Laboratory Services, Ontario Ministry of Health: Joan Stubberfield; City of Toronto Public Health: Jane Urquhart and Karen Wark; MDS Laboratory: Tom Gilder; MedChem Health Care Ltd: Aubrey Pancer; Department of Microbiology, Mt Sinai Hospital: Lisa Landry and Ellie Goldenberg; Ministry of Community and Social Sciences: Michael Bates; Center for Urban and Community Services, University of Toronto: Martha Friendly; Statistics Canada: Linda L'Estrange and Paul Franceur; Quantum Leap Computer Consulting: Scott Apted; and Public Health: Howard Beatty; B. Kawa, MD; Elizabeth Rea, MD; B. Yaffe, MD; and R. Shahin, MD.

Pediatric Practices

Norman Saunders, MD: Melanie Fallis, Barb Fallis, Sally Chalmers, Judy Godbold, and Cathy Beattie; Saul Greenberg, MD: Karen Fabro and Moshe Ipp; and Morton Goldbach, MD: Suzanne Stewart, Diana Cohen, and Patricia Long; Centenary Health Centre, Scarborough, Ontario: Roland Beaulieu, MD; Peggy Perkins; Barbara Mater; Janice L. Pound; and Tom Stavro-Sholdoff, MD; The Hospital for Sick Children: Helen Heurter; Karen Sui; John Nishikawa; Raymond Tellier; Nia Davies; Jonathan Pirie, MD; Anne Matlow, MD; Stan E. Read, MD; Julie Jeffery; Luba Komar, MD; Christopher Gillies; Anna Jarvis, MD; Rosanne Jabbour; Bebi Wali; and Rob Teteruck; North York General Hospital, North York, Ontario: Diane White; Marilyn Abraham; Jonathan Tolkin, MD; Tim Rutledge, MD; Elma McLeod; Elizabeth King; Mary Davies; Sue Dempsey; and Mary-Ann Pinch; Credit Valley Hospital, Mississauga, Ontario: Elizabeth Van Horne; Colleen Butler; Pamela Coates, MD; Marilyn Sarina; and Derek McNally; Toronto East General Hospital: Pauline Fallis; Anthony Duke, MD; Irene Andress; Eric Fonberg, MD; Lufti Haj-Assaad; P. DaCamara, MD; Maggie Bruneau; Jeanne Brown; and Lois Bishop; Humber River Regional Hospital, Finch Ave and Church St sites: Delena Bragg; Terri Rybacki-Anisko; Peggy Marcinko; Lynn Tughan; Heather Watts; Gilbert Miller, MD; Don Campbell, MD; Rheney Castillo; Art Kushner, MD; and Linda Kostrzewa; and St Joseph's Health Centre: Sandy Foster; Ana Avila; Wendy Yarranton; Lynn Jones; Pat Brown; JoAnn Kieller; Mark Feldman, MD; Dilip Mehta, MD; Avro Kuld, MD; Sigmund Krajden, MD; Clency Hian-Chedng; Mary Simone; and Cora Babida.

Child Care Centers

Bellevue Child Center: Barb Klein and Laurie Stanfield; Casa Loma Child Care Center: Moira Bell; Danforth Child Care Center: Kim Bosilac; Douglas E. Light Child Care Center: Linda Mikulka; Hydrokids Day Care: Gail Tummon; North Yonge Infant Nursery and Preschool: Lynn Belanger; Davenport-Perth Child Care Center: Cynthia Thorpe, Margaret Lamont, Cathy Stevens, and Bama Thillawatuan; Kensington Day Care Center for Toronto: Christine Taylor; O'Connor Community Center: Michelle Button, Tamara Mehta, and Linda Brown; Regent Park Child Care Center: Nicole Warner; Ryerson Early Learning Center: Katrina Hugnes; YTV Child Care Network: Wilma Morrison; WinHarris Day Nursery: Elaine Levy, Kim Fritz, and Deborah Young; Sunnybrook Creche: Carolyn Crum; University Settlement Recreation Center: Ida Bertolini; Village Nursery: Sandra Vella; Esther Exton Child Care Center: Particia Chorney Rubin; Upper Yonge Village Child Care Center: Josie Greco; WaterPark Place Child Care Centre: Beth Stockton; and Riverdale Child Care Center: Anna Yu.

Accepted for publication December 1, 1999.

This study was supported by unrestricted grants from Wyeth-Lederle Laboratories Inc, Pearl River, NY, and Wyeth-Ayerst Canada Inc, North York, Ontario.

Presented as a poster at the 38th Intersciences Conference on Antimicrobial Agents and Chemotherapy, San Diego, Calif, September 25, 1998.

We acknowledge the helpfulness of all of the nursing and medical staff in the emergency units and pediatric practices, the staff at the child care centers, and the laboratory personnel at the hospitals.

Reprints: E. Lee Ford-Jones, MD, Division of Infectious Diseases, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8 (e-mail:

Kapikian  AZHoshino  YChanock  RMPerez-Schael  I Efficacy of a quadrivalent rhesus rotavirus-based human rotavirus vaccine aimed at preventing severe rotavirus diarrhea in infants and young children.  J Infect Dis. 1996;174(suppl)S65- S72Google ScholarCrossref
Glass  RIKilgore  PEHolman  RC  et al.  The epidemiology of rotavirus in the United States: surveillance and estimates of disease burden.  J Infect Dis. 1996;174(suppl)S5- S11Google ScholarCrossref
Parashar  UHolman  RCBresee  JS  et al.  Epidemiology of diarrheal disease among children enrolled in four west coast health maintenance organizations.  Pediatr Infect Dis J. 1998;17605- 611Google ScholarCrossref
Committee on Infectious Diseases, Academy of Pediatrics American, Prevention of rotavirus disease: guidelines for use of rotavirus vaccine.  Pediatrics. 1998;1021483- 1491Google ScholarCrossref
Issenman  RM Oral rehydration therapy: have we made progress?  Pediatr Child Health. 1997;2311- 312Google Scholar
Ford-Jones  ELWang  EPetric  MCorey  PMoineddin  RFearon  Mfor The Greater Toronto Area/Peel Region PRESI Study Group, Hospitalization for community-acquired, rotavirus-associated diarrhea: a prospective, longitudinal, population-based study during the seasonal outbreak.  Arch Pediatr Adolesc Med. 2000;154578- 585Google ScholarCrossref
Brandt  CDKim  HWRodriguez  JO  et al.  Pediatric viral gastroenteritis during eight years of study.  J Clin Microbiol. 1983;1871- 78Google Scholar
Matson  DOEstes  MK Impact of rotavirus infection at a large pediatric hospital.  J Infect Dis. 1990;162598- 604Google ScholarCrossref
Reves  RR Child care increases the risk of clinic visits for acute diarrhea and diarrhea due to rotavirus.  Am J Epidemiol. 1993;13797- 107Google Scholar
Friendly  M Status of Day Care in Canada 1995 & 1996: A Review of the Major Findings of the National Child Care Study 1995 & 1996.  Ottawa, Ontario Human Resource Development Canada1997;
Black  RDyles  AAnderson  K  et al.  Handwashing to prevent diarrhea.  Am J Epidemiol. 1981;113445- 451Google Scholar
Ford-Jones  ELKitai  ICorey  M  et al.  Seroprevalence of toxoplasmosis in Toronto women.  Can J Infect Dis. 1996;7326- 328Google Scholar
Ford-Jones  ELKitai  IDavis  L  et al.  Cytomegalovirus infection in Toronto day care centers: a prospective study of viral excretion in children and seroconversion among day care providers.  Pediatr Infect Dis J. 1996;15507- 514Google ScholarCrossref
Kellner  JFord-Jones  ELthe Toronto Child Care Center Study Group, Streptococcus pneumoniae carriage in children attending 59 child care centers.  Arch Pediatr Adolesc Med. 1999;153495- 502Google ScholarCrossref
Kellner  JDMcGeer  ACetron  MS  et al.  The use of Streptococcus pneumoniae nasopharyngeal isolates from healthy children to predict features of invasive disease.  Pediatr Infect Dis J. 1998;17279- 286Google ScholarCrossref
Law  BFitzsimon  CFord-Jones  L  et al.  Cost of chicken pox in Canada, I: cost of uncomplicated cases.  Pediatrics. 1999;1041- 6Google ScholarCrossref
Bartlett  AV Diarrheal illness among infants and toddlers in day care centers: comparison with day care homes and households.  J Pediatr. 1985;107503- 509Google ScholarCrossref
Wald  E Infections in day care environments. Feigin  RCherry  Jeds. Textbook of Pediatric Infectious Diseases. Vol 24th ed. Philadelphia, Pa WB Saunders Co1998;2826- 2841Google Scholar
Not Available, Rotavirus vaccine put on hold in USA after intussusception reports [news]  Lancet. 1999;354309Google Scholar