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 had 2 or more episodes of infection. 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.

Neonatal and early postneonatal morbidity and mortality in a rural Guatemalan community: the importance of infectious diseases and their management.

We conducted a 1-year longitudinal prospective study of infants born in a traditional rural indigenous community of Guatemala. Three hundred twenty-nine infants surviving birth and the first day of life were followed during the first 3 months of life. Surveillance included routine household and well baby clinic visits and clinic visits for minor illnesses. Detection of potentially lethal illnesses depended on orientation of families and midwives to important symptoms and to the need for immediate medical evaluation if such symptoms were identified. We identified 38 episodes of lethal and potentially lethal illness. Thirty-five (92%) of these episodes were infectious diseases, principally sepsis during the neonatal period and acute lower respiratory infection in Months 2 and 3. Of all study infants, low birth weight (less than 2500 g) infants comprised 14% and premature (less than 37 weeks gestation) infants comprised 1%. Premature infants had a relative risk of lethal and potentially lethal illnesses of 11.1 (95% confidence interval, 3.6 to 34.4) compared with normal term infants, and no premature infant survived the first 3 months of life despite medical intervention. Low birth weight infants had a relative risk of 3.2 (95% confidence interval, 1.5 to 6.6), but with medical intervention all but 2 survived. Despite their lower risk, because of their much greater number normal term infants experienced 60% of lethal and potentially lethal illnesses. Among all study infants medical intervention was associated with survival of 86% of lethal and potentially lethal infectious illnesses and with a rate of neonatal mortality among study children significantly lower than rates documented in previous years in the same community.

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.

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 longitudinal 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.

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 1/2-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 less than 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 enrollement 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 less than 0.002) and in younger children (P less than 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.

Epidemiology of persistent diarrhea among Guatemalan rural children.

A prospective, longitudinal two-year study to determine the epidemiology of persistent (> or = 14 days' duration) diarrhea in rural children of Guatemala was undertaken. Three-hundred and twenty-one children aged 0-35 months were kept under surveillance by twice-a-week home visits. The overall incidence of diarrhea was 0.147 per child-week; the incidence of persistent diarrhea was 0.014 per child-week. The peak of persistent diarrhea was observed in infants below six months of age, with a continuous decline thereafter. This trend in incidence of persistent diarrhea was associated with a higher proportion (16%) of illnesses persisting for more than 13 days in children younger than six months of age as compared to children 30-35 months old (4%). Males had more diarrhea (0.156 per child-week) than females (0.139 per child week). Among children above 18 months of age, the proportion of episodes that lasted for more than 13 days was lower in females than in males.

Association of indicators of hygiene behavior with persistent diarrhea of young children.

We examined the association between water and hygiene-related behaviors and persistent diarrhea (duration > or = 14 days) among children under age three years in an indigenous rural Guatemalan community. Behavior indicators were specific aspects of the appearance of the mother, study child, other children and household that could be observed using a spot observation technique. Thirty-four percent of children had one or more episodes of persistent diarrhea during the year of study. Bivariate analyses found that a higher proportion of observations in which the anti-hygienic condition was observed was significantly associated with persistent diarrhea for 11 of 26 behavior indicators; these 11 indicators were also strongly correlated with each other. In individual logistic regression models, which included overall rate of diarrhea and other child characteristics associated with persistent diarrhea, six behavior indicators maintained significant association with persistent diarrhea: presence of toy on the ground, presence of baby bottle on the ground, the hands of the mother being dirty, presence of a fecally soiled diaper on the ground in the household compound, presence of feces in the yard, and the study child wearing a fecally soiled diaper. Three additional indicators closely approached significant association with persistent diarrhea. Excluding the three soiled diaper indicators, which might be the result rather than the cause of diarrhea, we found the six other behavior indicators to demonstrate a significant dose-response effect in increasing risk of persistent diarrhea. These findings suggest that behaviors which promote increased exposure of young children to enteric pathogens increase risk of persistent diarrhea.

Oral gentamicin is not effective treatment for persistent diarrhea.

We conducted a randomized, double-blind, placebo controlled clinical trial of oral gentamicin (10 milligrams/kilogram body weight/day for five days) in treatment of unselected cases of persistent diarrhea (duration 14-18 days at initiation of treatment) among 3-36-month-old children in a rural Guatemalan community. Following random assignment of each child to a treatment group, the appropriate dose of gentamicin or placebo was administered to the child three times daily by a study nurse; this nurse also identified the presence or absence of diarrhea on each day of treatment and for the next two days. Cure was defined as cessation of diarrhea during the five-day treatment period, sustained through at least the two days after completion of treatment. Among 92 evaluable cases who entered the clinical trial, there was essentially no difference in cure rate between gentamicin and placebo treatment groups (42% versus 43%). Enteroadherent strains of Escherichia coli were identified in 46% of children tested in this trial; no significant difference existed between treatment groups in frequency of isolation of this or any other enteropathogen. Among 40 children having successful duodenal cultures immediately prior to beginning treatment, > or = 10(4) aerobic organisms per milliliter of fluid were identified in 12 (30%); treatment groups did not differ substantially with respect to proportion of children identified with this level of duodenal microbial colonization. Failure of gentamicin treatment did not appear to be explained by emergence of resistance, although a small number of resistant enteropathogens were identified near the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Acute infectious diarrhea among children in day care: epidemiology and control.

The incidence of diarrhea among children in day care centers is highest for those under three years of age. Limited studies indicate that diarrhea occurs more frequently among children enrolled at these centers than among age-matched children cared for at home or in family day care. Most reported outbreaks have been caused by rotavirus, Giardia, Shigella, or combinations of these organisms. Children in day care centers commonly excrete enteropathogens in the absence of symptoms; the significance of this phenomenon in transmission is unknown. An association between higher rates of diarrhea and selected characteristics of centers--the most important of which is the presence of non-toilet-trained children--has been shown. The contamination of hands, communal toys, and other classroom objects as well as a lack of infection control measures play a role in the transmission of enteropathogens in outbreaks of diarrhea in day care centers. Spread of infection from non-toilet-trained children in centers to their families is common. Potential ways of dealing with this situation include education; development, implementation, and enforcement of regulations; and use of infection control measures. However, the effectiveness of specific control measures has not been systematically evaluated.

Day care homes: the "silent majority" of child day care.

Family day care--child day care provided in a private home other than the child's own--includes more children than any other mode of day care in the United States. Day care homes have traditionally cared for a large proportion of younger children, particularly infants and toddlers, who are most likely to contract and spread infectious diseases. The majority of homes are run on an informal basis and are neither licensed nor registered; a small minority of homes are regulated or operated under sponsorship of an umbrella agency. Homes generally have fewer children than do day care centers, and when children of different ages are cared for, they usually mix freely. Care givers in homes, especially in those that are not registered, are unlikely to have had child care-specific training. Parent fees in homes and centers appear roughly comparable, with fees in nonregulated homes generally lower than those in regulated or sponsored homes. It is difficult to compare the actual costs of child care in these settings. Results of the small number of studies comparing the occurrence of infectious diseases among children in day care centers, day care homes, and at home suggest that the rates of some infections may be lower in day care homes than in centers; this effect may vary by age and infections. Because of the large population of young ages of children involved in family day care, additional study and recommendations regarding infections in this setting are needed.

Intrapartum and neonatal mortality in a traditional indigenous community in rural Guatemala.

We identified high rates of intrapartum and neonatal mortality among children born in a traditional indigenous community in rural Guatemala. To examine the potential association of maternal characteristics and obstetric and newborn care practices with this mortality, we conducted a retrospective case-control study. Case were infants born in 1986 and 1987 who died during birth or in the first month of life, as identified by civil records; for each case, the next child born who survived the first month of life was selected as control. In interviews with mothers of cases and controls standardized data were collected on demographic and socioeconomic characteristics of the mother, her general obstetric history, history of the pregnancy, labor, and delivery, condition and care of the infant at birth, and morbidity and treatments of the infant after birth. Sixty-one cases and their controls were included in the study. Based on clinical condition at birth, we subcategorized cases into infants stillborn or dying in the first 24 hours of life (intrapartum cases) and those dying in the first month after day 1 (neonatal cases). Factors significantly associated with both subcategories of cases were maternal illiteracy, primagravity, failure to use "modern" prenatal care, and inter-birth interval less than 14 months. Intramuscular injection of oxytocin by the midwife during labor, and performance of greater than or equal to 3 vaginal examinations by the midwife were each significantly associated only with the intrapartum subcategory of cases. Mother's estimate of infant size as "smaller than normal" was associated with neonatal, but not with intrapartum, cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of diaper types on diaper dermatitis associated with diarrhea and antibiotic use in children in day-care centers.

Infants and toddlers in day-care centers have a relatively high frequency of diarrhea and/or oral antibiotic use, and may be at increased risk of developing diaper dermatitis when diapered. A six-month, prospective, double-blind study was conducted in day-care centers in Houston, Texas, to determine the frequency of diarrhea, antibiotic use, and diaper dermatitis in infants and toddlers wearing conventional (cellulose-only core) disposable diapers or disposable diapers with a core of absorbent gelling material (AGM) and cellulose. A questionnaire was administered weekly to the day-care staff to gather health information, and weekly visual examinations were made of children for diaper dermatitis. The frequency of diarrhea was 1.9 episodes per child-year and that of antibiotic use was 3.3 courses per child-year. Infants diapered in disposable diapers with AGM had a significantly (P 0.032) lower mean grade of diaper dermatitis during diarrhea episodes and a lower (P 0.054) mean grade during antibiotic use, compared to those diapered in conventional disposable diapers. There was no significant difference between groups with regard to isolation of Staphylococcus aureus or Candida albicans from superficial skin cultures of the diapered area. The results indicate that diarrhea and antibiotic use occur frequently in children in day-care centers, and that the severity of diaper dermatitis is less in children wearing AGM disposable diapers than those wearing conventional disposable diapers in that setting.

Dietary management of acute diarrhea with local foods in a Guatemalan rural community.

A community-based, randomized trial was conducted to evaluate a locally available diet for the management of acute diarrhea (n = 99 episodes) in 90 Guatemalan children, 4-42 months of age. The Test Diet (TD), a combination of a semi-solid pap (maize flour, black beans, oil) and a liquid gruel, Incaparina (maize flour, cotton seed flour, sugar), in addition to breast-milk and other home foods (group TD, n = 45 episodes) was offered for 14 d and compared to usual home feeding (group HF, n = 54 episodes). Diarrhea episodes after admission were significantly shorter for group TD (median 2.0 d) than group HF (median 4.4 d, p = 0.003) after adjusting for potential confounders. Weight gains did not differ significantly between groups. We conclude that community-based dietary management of acute childhood diarrhea using energy-dense, locally available foods is feasible and may shorten diarrhea duration. This may encourage mothers to follow recommendations for continued feeding during diarrhea in developing country environments.

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.

Production of Shiga toxin and other cytotoxins by serogroups of Shigella.

We measured the cytotoxic activity of 119 strains of Shigella by using a quantitative [3H]thymidine-labeled HeLa cell assay. We assayed 13 strains of Shigella dysenteriae 1; 18 strains of S. dysenteriae types 2 and 3; and 88 strains of Shigella sonnei, Shigella flexneri, and Shigella boydii. Strains of S. dysenteriae 1 demonstrated high levels of cytotoxicity (geometric mean, 10(5.04) CD50/mg of protein; range, 10(3.95)-10(6.10). Cytotoxic activities of the non-type 1 strains of S. dysenteriae and of the other Shigella serogroups were approximately 1/1,000 that of the S. dysenteriae 1 strains (range, 10(1.09)-10(3.11) CD50/mg of protein). Neutralization of cytotoxicity by using rabbit antiserum to purified Shiga toxin revealed that in all strains of S. dysenteriae 1, greater than or equal to 99.5% of cytotoxic activity was attributable to Shiga toxin. In contrast, 88 of the other Shigella strains produced only nonneutralizable cytotoxic activity. Six of 18 strains of non-type 1 S. dysenteriae and 12 of 88 strains from other Shigella serogroups produced both Shiga toxin and nonneutralizable toxin.

Rotavirus gastroenteritis.

Rotaviruses have proven to be major causes of pediatric diarrheal disease morbidity and mortality worldwide. The past several years have yielded substantial new insights into these viruses, their epidemiology, and the mechanisms of host resistance to them. These insights have in turn resulted in development of several candidate rotavirus vaccine strains, bringing closer the possibility of effective protection of young children from rotavirus disease.

Diarrheal illness among infants and toddlers in day care centers. I. Epidemiology and pathogens.

We conducted a 2-year prospective study of diarrheal illness in children ages 0 to 36 months in 22 day care centers in Maricopa County, Arizona. In 7464 child-months of observation, 465 sporadic cases and 170 outbreak-associated cases of diarrhea were identified. Enteric pathogens were identified in 20% of diarrhea episodes. Giardia lamblia, rotavirus, and Campylobacter jejuni were the most common pathogens. Giardia was significantly more common in toddlers than in infants and was found in 19% of asymptomatic child contacts of symptomatic infected children. Rotavirus was significantly more common in infants than in toddlers. In outbreaks, shorter duration of child enrollment was associated with illness. Comparison of day care center characteristics revealed that only a lower score in standardized observations of hygiene and child-handling practices was associated with greater risk of diarrhea. Infectious diarrhea appears to be common in diaper-age children in day care centers, but the patterns of disease differ for different pathogens and for the infant and toddler age groups.

Diarrheal illness among infants and toddlers in day care centers. II. Comparison with day care homes and households.

During the second year of a prospective study of diarrheal illness among 0- to 36-month-old children in day care centers in Maricopa County, Arizona, we concurrently studied children of the same age in 30 day care homes and 102 households not using day care. The seasonal pattern of diarrhea, frequency of pathogen isolation, and relative frequency of individual pathogens were similar in the three settings. Giardia lamblia and rotavirus were the most common enteropathogens. Asymptomatic infection was identified in 14% to 21% of infant-toddler contacts of pathogen-positive cases of diarrhea. We compared rates of diarrhea in the three settings using five serial biweekly family-based surveys during the period of highest diarrhea rates. The incidence in infants and toddlers in DCCs (42 cases per 100 child months) was significantly higher than in DCHs (23 cases per 100 child-months) and in households not using day care (27 cases per 100 child-months); the DCH rate did not differ significantly from that in households not using day care. Among household sample children who began using day care during the survey period, the incidence of diarrhea was significantly higher than in household sample children not using day care.