Alfred V. Bartlett

Asymptomatic excretion of rotavirus before and after rotavirus diarrhea in children in day care centers

A 12-month prospective study of diarrhea in children in day care centers (DCCs) provided an opportunity to evaluate the duration of excretion of rotavirus from children before and after episodes of diarrhea caused by rotavirus. Ninety-nine episodes of rotavirus diarrhea occurred in 94 children. Asymptomatic rotavirus excretion occurred in 50% of children tested on the day before diarrhea occurred, 31% two days before diarrhea, and 9% in days 3 through 5 before diarrhea. Two children had positive specimens 11 and 13 days, respectively, before illness. During the week after cessation of diarrhea, 32% had positive specimens; 12% had positive stool specimens during the second week after diarrhea episodes. Electrophoretic testing of rotavirus RNA from stool specimens showed different electrophoretic migration patterns of the genomic RNA among the pairs tested, but the genomic RNA was the same within each pair of symptomatic and asymptomatic specimens. Excretion of rotavirus before and after diarrhea is common in children in DCCs; the role that asymptomatic excretion plays in the spread of this disease within DCCs is unknown.

Rotavirus in infant-toddler day care centers: epidemiology relevant to disease control strategies.

A 15-month prospective longitudinal study of diarrhea and rotavirus (RV) infection was conducted concurrently in infants and toddlers in day care centers (DCCs) and in a large pediatric clinic in Houston. The mean number of children in the DCCs was 223; the diarrhea rate during the first 12 months was 2.62 episodes per child-year. Rotavirus accounted for approximately 10% of the total episodes of diarrhea in the pediatric clinic and DCC populations, but 50% during the winter months. The occurrence of RV in the DCCs paralleled that seen in the pediatric clinic. The annual rate of RV infection in DCCs was 0.55 episodes per child-year, with diarrhea occurring in only 40% of the episodes (0.22 episodes per child-year). There were 45 diarrhea outbreaks in DCCs, for a mean of 3.8 per center per year; nine of these outbreaks were associated with RV. Polyacrylamide gel electrophoresis of RNA genome patterns of RV strains from eight of these outbreaks showed that in seven outbreaks a single strain was identified in children in that DCC, whereas multiple strains were identified simultaneously in the community. The age distributions of symptomatic and asymptomatic RV infections in DCC study children were not significantly different. In symptomatic RV-infected children in DCCs, 42% had RV identified in stool specimens within 2 days before diarrhea occurred. Thirty-eight DCC children had more than one episode of RV infection, but only five had two symptomatic RV infections. Diarrhea caused by RV is common in children in DCCs, often occurs in outbreaks due to the same strain, and parallels disease in the community; asymptomatic RV infection is also common in children in DCCs.

Human Calicivirus-Associated Diarrhea In Children Attending Day Care Centers

Abstract We investigated human calicivirus (HCV)-associated diarrheain children attending day care centers by using stool specimens collected in 1981–1983. We used a screening enzyme linked immunosorbent assay (ELISA) derived from reagents prepared against the Sapporostrain ofHCV and confirmed positive results with a blocking ELISA an dimmunosorbent electron microscopy. HCV was detected in 11 (2.9%) of 375 diarrheal stools and in none of 86 stools from asymptomatic contacts. This incidence ratewas half that noted for rotaviruses and higher than that noted for Campylobaeter, Salmonella, and Shigella in the original study. HCV was found in stool specimens from children in nine day care centers; HCV-associated diarrhea was sporadic, occurred with greater frequency in young children, and had a summer-fall predominance. Our results indicate that HeV is an important cause of diarrheain day care centers and that frozen stool samples can yield epidemiological data on HCV infection.

Longitudinal study of Giardia lamblia infection in a day care center population

An enzyme-linked immunosorbent assay was used to detect Giardia lamblia in stool specimens collected during a 15-month longitudinal study of diarrhea in 82 children 1 to 24 months old attending a day care center (DCC) in Houston. A total of 2727 stool specimens were collected on a weekly basis from the DCC children and were evaluated for rotavirus and Giardia. For DCC children who developed diarrhea stool specimens were also cultured for bacterial enteropathogens. During the 15-month study period, 48 episodes of Giardia infection were detected in 27 of 82 (33%) DCC children, compared with 57 episodes of rotavirus detected in 37 (45%) of these same DCC children. The duration of Giardia excretion was 2.0 ≥ 1.5 weeks (mean ≥ SD). Only 6 (7%) of the 82 DCC children, or 6 of the 27 (22%) with infection, developed symptoms attributable to Giardia. Ten of the 27 (37%) DCC children infected with Giardia was identified in the DCC in all months except June. Two Giardia outbreaks occurred in 1 of the 6 DCC rooms under study. One outbreak was associated with overcrowding. Neither outbreak was associated with the introduction of a new Giardia-positive child into the involved room. In this study Giardia infection occurred commonly in the DCC throughout the year, was rarely associated with illness and was not associated with introduction of asymptomatic carriers into the DCC rooms.

Diarrhea in children newly enrolled in day-care centers in Houston

Diarrhea is a common illness among children in day-care centers (DCC). We hypothesized that the incidence of diarrhea was greater among children in their first 1 or 2 months after enrollment in a DCC than in any subsequent period in day care. We followed 442 children younger than 2 years of age enrolled in 13 randomly selected DCCs for the occurrence of diarrhea during a 14-month period. Parents completed standardized baseline questionnaires and research nurses visited the DCC twice weekly to record the occurrence of diarrhea and to collect stool specimens. Incidence rates, rate ratios, chi square statistics and 95% confidence intervals were calculated for crude and stratified analyses. The diarrheal incidence rate of 4.4 cases/child-year in the first 4 weeks in the centers was significantly (rate ratio, 1.6; confidence interval, 1.3 to 2.1; P < 0.01) higher than the 2.7 cases/child-year incidence rate of diarrhea in subsequent weeks. The effects of gender, ethnicity, age, DCC size, previous DCC attendance and season were examined and did not account for the association observed between recent enrollment and risk of diarrheal illness. Rotavirus was identified in 18% of cases of diarrhea, but no association was seen with recent enrollment in DCC. A significantly higher incidence of diarrhea occurred in males compared with females (P < 0.002) and in younger children (P < 0.001) compared with older children. Diarrhea is common in children in DCCs and occurs significantly more frequently in children during their first 4 weeks in a DCC.

Asymptomatic human calicivirus infection in a day care center.

Human caliciviruses (HCVs) are little known, recently recognized viruses associated with gastroenteritis. We identified HCV infection in an outbreak of gastroenteritis which occurred in one room of a day care center (DCC) participating in a longitudial study of diarrhea. Utilizing an enzyme-linked immunoassay and immunosorbent electron microscopy to detect HCV, we tested specimens from all children in attendance during the period of the illness outbreak and during prior and subsequent weeks. HCV infection was documented in 14 children, 11 of whom were asymptomatic. Thirteen of the 14 HCV-infected children were 8 months of age or younger. New cases of HCV infection occurred during a 4-week period. Forty percent of children less than 1 year of age were infected with HCV during the period of investigation. Few documented HCV infections have been reported. This may be related to a high attack rate of predominantly asymptomatic infections in early life, resulting in a high prevalence of antibody to HCV by 4 years of age.

Infection, diarrhea, and dysentery caused by Shigella species and Campylobacter jejuni among Guatemalan rural children.

To examine the factors that may influence the outcome of infections by Shigella spp. and Campylobacter jejuni we followed for 24 consecutive months 321 rural Guatemala children 0 to 35 months old. Home visits were made to determine child morbidity patterns with emphasis on diarrhea and dysentery. Fecal samples for microbiologic studies were obtained from the participants when they were ill and during healthy periods. Shigella spp. were isolated from 9.8 and 4.0% of ill and healthy children, respectively; the figures for C. jejuni were 12.1% and 8.1%. Shigella flexneri 1, 2 and 6 and Shigella sonnei accounted for 70% of all Shigella isolates. Twenty-four percent of Shigella spp. and 7% of C. jejuni infections resulted in dysentery. Shigella dysenteriae and Shigella flexneri were more likely to induce dysentery than the other species. The incidence of dysentery was 0.84 of 100 child weeks. Age, gender, nutritional status and feeding habits of the children did not affect the outcome of Shigella infection. Fat consumption favored the development of dysentery caused by C. jejuni. The development of dysentery seems to be associated with microbial factors and not with host variables, although specific Shigella serotype protection against symptomatic infection may be functional for prolonged periods after natural exposure.

Clinical and pharmacokinetic evaluation of ticarcillin disodium plus clavulanate potassium in adolescent patients with malignancies

T he antipseudomonal penicillins have proved to be useful components of antimicrobial therapy in episodes of infection in adults and children with malignancies. Addition of the beta-lactamase inhibitor clavulanic acid to ticarcillin promises to expand this usefulness. We evaluated the clinical efficacy, safety, and pharmacokinetits of ticarcillin disodium plus clavulanate potassium in episodes of presumed infection among adolescent patients with malignancies.

SURVEILLANCE AND TRANSMISSION OP ROTAVIRUS IN CHILDREN IN DAY CARE CENTERS (DCC) IN HOUSTON

258 children < 24 months of age in 12 DCC were randomly enrolled in a prospective study of rotavirus (RV) infection. A case control study in non-DCC children was conducted simultaneously. Stool specimens were collected from every child in the DCC weekly and when diarrhea occurred. Stools were analyzed for all enteropathogens; RV was detected by a monoclonal antibody based ELISA. In the community study RV was identified in 41 of 267 children (15%) with diarrhea and 6 of 250 control children (2%). In the DCC study there were 467 episodes of diarrhea during the 2, 108 child months of study (22.6 episodes/100 child months). There were 89 RV infections (4.3 cases/100 child months); 60% were asymptomatic. There were 37 DCC diarrhea outbreaks; rotavirus was identified in 8 (22%). In 42% of children with symptomatic RV infection, RV was identified in stool specimens 1-2 days before diarrhea. During the 10 month study there were 251 new entries (97% turnover rate). New entry children experienced significantly (p <0.001) higher rates of diarrhea during the first 8 weeks (4.11 cases/child year), than other children in DCC (2.4 cases/child year). Analysis of stool specimens by polyacrylamide gel electrophoresis showed similar patterns in RV strains from children in the same outbreak. RV infections occur commonly in children in DCC, are readily transmitted, often are asymptomatic. Peak rates occur simultaneously in DCC and in the community. This information is important for appropriate implementation of intervention modalities such as vaccines.

Campylobacter Jejuni Repeated Infections in Children from Rural Guatemala

In Guatemala, as in many other developing countries, diarrhoeal diseases continue to be the most important public health problem, with a high incidence and a heavy toll in childhood mortality. Among the many causes of diarrhoea, C. jejuni 1 is seldom reported in the routine search for pathogens due to the special conditions it requires for isolation and growth. This infection has been associated with mild, acute or persistent diarrhoea1. In Guatemalan children, seven percent of the C. jejuni infections result in acute dysentery2. As C. jejuni is only susceptible to erythromycin, it is crucial to make the differential diagnosis from dysentery caused by Shigellae or by Entamoeba histolytica, in order to prescribe the appropriate treatment3.