Cryptosporidiosis outbreak in a day-care center

An outbreak of diarrhea occurred in a day-care center in San Marcos, Tex, in August 1984. At the time of this study, the center was caring for 81 children aged 2 months through 5 years. A single stool specimen was collected from each of 50 children (62%). Cryptosporidium oocysts and Giardia lamblia cysts were each identified in stool specimens from 18 children. Three children had both parasites present in the same stool specimen. Echovirus 30 was identified in 19 of 25 stools cultured. Although three pathogens were circulating simultaneously in this group of children, only the presence of Cryptosporidium oocysts was associated with the occurrence of a diarrheal illness. Cryptosporidium may be a common cause of diarrhea in children who attend day-care centers.     

Role of protozoa as risk factors for persistent diarrhea

A case control study including 175 children aged 0–36 months suffering from diarrhea of ≥14 days duration was undertaken to determine whether there is an association betweenGiardia lamblia, Entamoeba histolytica orCryptosporidium infection and persistent diarrhea (PD). Subjects were identified by ongoing household surveillance and enrolled as cases. For each case two controls were selected by survey of neighbouring households—a child with acute diarrhea and one without diarrhea. Both the controls were matched with the case for age and nutritional status. Two fresh stool samples were collected from all cases and controls at enrolment and examined for trophozoites ofGiardia lamblia, Entamoeba histolytica andCryptosporidium. Giardia lamblia trophozoites were detected in a significantly higher proportion of PD cases (20.0%) than acute diarrheal and non diarrheal controls (4.6% each, p<0,0001). There were no significant differences in the proportion of cases and controls who passedE. histolytica trophozoites or cryptosporidium in their stools. There was a consistent trend towards poorer weight gain in PD cases who passed Giardia trophozoites in stool; the differences were statistically significant at days 14 and 21, after enrolment. Giardia lamblia infection is more prevalent in PD cases than in acute diarrhea or non-diarheal controls. This prevalence is not high enough to warrant routine anti-giardia therapy in patients with PD. However, as giardiasis was observed to have adverse growth impact in PD cases, stool microscopy for detection and subsequent treatment ofGiardia lamblia seems to be justified.     

Potential role of adherence traits of Escherichia coli in persistent diarrhea in an urban Brazilian slum.

We examined stools from 40 children with persistent diarrhea (duration, 14 days or more), from 50 children with acute diarrhea and from 38 control children to determine infectious etiologies for persistent diarrhea in Goncalves Dias, an urban favela (slum) in Fortaleza, Ceara, Brazil. Children with persistent diarrhea and children with acute diarrhea had similar rates of isolation of routine viral, bacterial and parasitic enteric pathogens. Routine pathogens were identified in at least 20% of cultures done more than 14 days into the diarrheal illness. We examined Escherichia coli isolated from these stools for adherence potential. Enteroaggregative E. coli were isolated significantly more often from children with persistent diarrhea than from control children or children with acute diarrhea (P less than 0.05). E. coli with hemagglutination patterns suggestive of adherence pili were also isolated more often from children with persistent diarrhea than from children with acute diarrhea (38% vs. 18%; P less than 0.05). Enterotoxigenic E. coli were isolated in combination with rotavirus more often from children with persistent diarrhea than from children with acute diarrhea. E. coli which were hydrophobic or exhibited hemagglutination were also seen more often in association with Giardia in children with persistent diarrhea. These findings suggest that the etiology of persistent diarrhea in children is complex and that the aggregative E. coli are associated with prolonged diarrheal illness. Although routine diarrheal pathogens may be present for more than 14 days, combinations of pathogens, including E. coli with adherence potential, may also contribute to prolonged diarrheal disease.     

Effects of nutritional status on diarrhea in Peruvian children

OBJECTIVES: We conducted a 4-year (1995-1998) field study in a Peruvian peri-urban community (pueblo joven) to examine the relation between diarrhea and nutritional status in 230 children <3 years of age. METHODS: We followed the birth cohort daily for diarrhea and monthly for anthropometry. We modeled diarrheal incidence with a multivariate time-to-event regression model to account for multiple episodes per child and irregular follow-up periods and diarrheal duration with a mixed-effects gamma regression model to account for disease heterogeneity across children. RESULTS: During 159,551 child-days of follow-up, we identified 1387 diarrheal episodes, which yielded an average incidence of 3.2 episodes per child-year. Diarrhea was seasonal, for example, infants had up to 8 diarrheal episodes during the summer; however, these variations decreased noticeably with age. Nutritional status was significantly associated with diarrheal incidence. The frequency of diarrhea increased by 15% per standard deviation decrease in height-for-age z score. Diarrheal episodes in children <6 months of age lasted significantly longer than episodes among older children. CONCLUSIONS: These results identify infants and children of poor nutritional status as priority risk groups for prevention efforts aimed at reducing the burden of acute childhood diarrhea.     

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.     

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.     

Persistent diarrhea in Vietnamese children: a preliminary report

The clinical and laboratory features of persistent diarrhea were investigated in 83 children under three years of age who were treated in the Gastroenterology Division of the Institute for the Protection of Children's Health, Hanoi from August 1988 to August 1989. The number of cases of diarrhea was highest in the children aged 4-5 months. The mean age of the children studied was 6.6 ± 3.4 months. The ratio of males to females was 2.6 and mean age of first episode of diarrhea was 4.3 ± 3.4 months; persistent diarrhea was more common in children under six months of age than in older children. Persistent diarrhea occurred in the first diarrheal episode in 66.5% of cases. Recent nonenteric infections were found in 30% of the study group. Of the 83 children studied, 36% had stool specimens positive for enteric pathogens; 24% had enterotoxigenic Escherichia coli isolated, 8% had enteropathogenic E. coli , 5% rotavirus, 6% Candida , and 4% Giardia lamblia. The duration of diarrhea was longer in children who received antibiotics than in those who did not ( p <0.01).     

Etiologic agents in acute vs persistent diarrhea in children under three years of age in peri-urban Lima, Perú

In a longitudinal study of acute and persistent diarrhea in 677 children less than three years old in a peri-urban community of Lima, Perú, during 27 months of surveillance, stools were cultured at the beginning of each diarrheal episode and on each subsequent week of illness. Analyzing stool cultures only from children who had not received antibiotic treatment in the 48 h prior to the culture, no association was found between any enteropathogen and persistent diarrhea. We did not find any increase in mixed infections in persistent diarrhea episodes as compared with acute diarrhea, controlling for age, season and anthropometric status. The isolation rate for any given enteropathogen was similar during the first, second, third or later week of illness, but when the presence of a specific enteropathogen was sought in sequential stools within a single episode, no evidence of persistent infection was found. This study shows that in developing countries with a high incidence of diarrheal diseases frequent re-infections with enteropathogens prevalent in the population are one reason for prolonged illnesses. Host factors that increase susceptibility to infection or decrease recovery from illness may also play a role. Further studies of these factors, such as micronutrient deficiencies, are needed to identify a public health intervention to control persistent diarrhea, a condition associated with mortality in many developing countries.     

Asymptomatic salmonellosis among children in day-care centers in Mérida, Yucatan, Mexico.

BACKGROUND: Child day-care centers (DCC) have become common in many lower and middle income countries, presenting new problems that may differ from those of DCC in more developed countries. Diarrhea is a common problem in DCC in the United States, but information on the prevalence of diarrhea or specific enteropathogens among children in DCC in tropical and developing countries is limited. METHODS: Because of preliminary data from newborns and DCC attendees in Mérida, Mexico, with high rates of Salmonella infection, we conducted a 12-month longitudinal surveillance study of enteropathogens in two Mérida DCC. Seventy-eight children ages 2 months to 4 years were evaluated with demographic and clinical data, and stools were cultured monthly. RESULTS: Salmonella sp. was the most common enteropathogen detected (46 of 683 specimens, 6.7%), with higher rates in children younger than 18 months (P < 0.02), but it was found in only 1 of 10 diarrhea episodes that coincided with sampling. Other common organisms identified included Giardia lamblia (21 of 683, 3.0%) and LT-producing enterotoxigenic Escherichia coli (16 of 683, 2.3%). Salmonella was recovered from as many as 19% of children in a single month, but the large multiplicity of serotypes recovered suggested multiple sources rather than a common source outbreak. Children with Salmonella tended to have more liquid stools during the preceding 2 weeks. Salmonella was also isolated from the stool of teachers in 1 of the 2 DCC in 10 of 94 specimens (10.6%), and again multiple serotypes were represented. CONCLUSION: These data indicate the presence of multiple sources of Salmonella infection in the DCC, posing a complex situation for infection control.     

Giardia lamblia infections in a cohort of Bangladeshi mothers and infants followed for one year

Giardia lamblia infection in an endemic area was investigated by following a cohort of 33 lactating mothers and their infants in a semiurban community of Bangladesh for one year. Eighty-two percent of mothers and 42% of infants excreted Giardia at least once during the study period. Infants became infected as early as 3 months of age, and 86% of the infected infants had diarrhea, suggesting that the first exposure to the parasite results in disease. Only one of the infected mothers had diarrhea, indicating that with repeated exposure to Giardia, mothers in an endemic area may develop partial immunity that protects against disease but not infection. An interrelationship between maternal and infant colonization was not found. Local and systemic immune responses to Giardia correlated poorly with infection, but milk antibodies were a better reflection of infection than serum antibodies were. Infection with G. lamblia was significantly lower in infants younger than 6 months (9%), an age when many are totally breast-fed. However, we were unable to establish clear-cut protection related to human milk antibodies, and suggest that the lower infection rate in younger infants results mainly from decreased exposure to Giardia cysts.     

Hemolytic uremic syndrome and diarrhea associated with Escherichia coli O157:H7 in a day care center

Three cases of hemolytic uremic syndrome with bloody diarrhea occurred during an outbreak of diarrheal illness in children aged 4 months to 9 years who attended a day care center. Thirty-six (34%) of 107 had diarrhea (three or more loose or watery stools in 24 hours) lasting greater than or equal to 3 days. Thirty-one (48%) of 64 children younger than 4 years of age but only (12%) of 43 in the older classes became ill (relative risk 4.0, P less than 0.001). Eleven (31%) of the 36 children with diarrhea had blood in their stools. Sequential movement of illness from class to class was consistent with person-to-person spread. Ten (18%) of 56 family members of ill children but only one of 45 family members of well children younger than 4 years of age developed a diarrheal illness (P less than 0.05). Escherichia coli O157:H7 was detected in two of eight stool specimens from children who had bloody diarrhea (one with hemolytic uremic syndrome), two of seven with nonbloody diarrhea, and none of nine who remained well. All three stool specimens obtained at less than or equal to 6 days compared with one of nine obtained at greater than 6 days after onset yielded this organism (P less than 0.02). E. coli O157:H7 can cause hemolytic uremic syndrome and both nonbloody and bloody diarrhea, and can spread within families and through modes other than foodborne transmission.     

Asymptomatic giardiasis in children

Giardia lamblia infection was identified in 33 of 89 (37%) 3-month-old to 3-yr-old children who were followed with monthly stool examinations for up to 12 months in a day care center. The infection was mainly asymptomatic and usually associated with prolonged carriage of the parasite. There were no significant differences for height and weight achievements and mean hemoglobin values between Giardia-positive and Giardia-negative children. However, Giardia-positive children tended to achieve higher weight and height for age than Giardia-negative children; weight for age was above the 50th percentile in 69% of Giardia-positive vs. 40% of Giardia-negative children (alpha = 0.01). Giardia-positive children tended to have fewer symptoms related to the gastrointestinal and respiratory tracts as recorded by a weekly questionnaire. Lactase deficiency was detected by breath hydrogen testing in 8 of 26 Giardia-positive vs. only 1 of 21 Giardia-negative children (P less than 0.02). Healthy day care children with asymptomatic Giardia infection show no disadvantage and perhaps even an advantage in nutritional status and freedom from other illnesses.     

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 and etiologic agents in Mirzapur, Bangladesh

To determine the epidemiology and etiologic agents of persistent diarrhea we carried out an intensive diarrhea surveillance on children less than six years old in rural Bangladesh. From March 1987 to February 1989 we examined 363 children through diarrhea recall interviews and analyzed stool samples of all diarrhea cases for potential pathogens. Results showed that children had an average of two episodes per year and the incidence rate of diarrheal episodes denned as acute (<14 d) and persistent (14 d) varied similarly with age. The peak incidence (episodes/child/year) of acute diarrhea (2.8) and persistent diarrhea (0.8) occurred in the 6-11 months age group. The data showed that an episode tended to be prolonged if the stool was loose/mucoid or bloody at onset. Aggregative adherent Escherichia coli was found significantly more often at onset in persistent than in acute episodes, whereas Shigella, Aeromonas, Giardia and toxigenic E. coli were isolated with less frequency in persistent than acute episodes. This suggests that other factors might be more important in the development of persistent diarrhea than specific pathogens.     

Giardiasis associated with the use of a water slide

Although Giardia lamblia cysts are an important contaminant of surface water supplies, only one swimming pool outbreak, involving an infant and toddler swim class, has been reported. We describe an outbreak of giardiasis associated with a hotel's new water slide pool which was cleansed by both bromination and sand filtration. Among the 107 hotel guests and their visitors surveyed, 29 probable and 30 laboratory-confirmed cases of Giardia infection were found. Cases ranged from 3 to 58 years of age, with a mean age of 21 years. The 5-year modal age grouping was 5 to 10 years of age. Symptoms in the 59 cases included: diarrhea (48), cramps (38), foul smelling stools (29), loss of appetite (23), fatigue (20), vomiting (18), greasy stools (15), fever (11) and weight loss (10). Four children and 2 adults were hospitalized. Significant associations were found for staying at the hotel, using the water slide pool and swallowing pool water. A possible contributing factor was the emptying of an adjacent toddlers' wading pool, a potential source of fecal material, into the water slide pool. Transmission of Giardia can occur in water slide pools and therefore should be considered in cases of protracted diarrhea among users of such pools.     

Diarrhea associated with adherent enteropathogenic Escherichia coli in an infant and toddler center, Seattle, Washington

During November 1983, the Seattle-King County Department of Public Health investigated an outbreak of diarrhea associated with enteropathogenic Escherichia coli, serogroup 0111:K58, in an infant and toddler day-care center. Of the 25 children in the center, ranging in age from 4 to 30 months (median age 11 months), diarrhea occurred in 14 characterized by watery, greenish stools. The median duration of diarrhea was 12 days. Two of the ill children were hospitalized because of severe dehydration. Stool cultures from the children diagnosed initially did not yield the common bacterial pathogens, parasites, or rotavirus. Stool cultures from 11 of 14 ill children and two of 11 well children (P less than .005), however, yielded an E coli serogroup, 0111:K58, which was not invasive or toxigenic by standard tests. The source of the organism was not identified. Although this organism has been recognized as a cause of diarrhea in newborn nurseries, this is the first published report of a documented outbreak of enteropathogenic E coli-induced diarrhea in a day-care center in the United States.     

Intestinal parasites and lactose malabsorption

Breath-test was performed for diagnosis of lactose malabsorption in 50 Gabonese children of normal nutritional status, aged 5 to 15 years, with parasites in stools, but without diarrhoea or digestive symptoms. Control group was unparasitized and consisted of 17 children and 18 young adults living in the same area. Parasites discovered by stool examination were Ascaris lumbricoides in 76% of parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16% and Necator Americanus in 14%. Children were given a 10 g lactose load and adults 20 g. Lactose malabsorption was discovered in 64% of parasitized patients and in 63% of unparasitized. Ten of 12 (83.3%) of Giardia infected children had a lactose malabsorption (no significant difference). These data show that decrease of lactase activity in African children is not related to the presence or to the importance of intestinal parasitism, except for Giardia infestation, if nutritional status is normal.     

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.     

Efficacy of zinc-fortified oral rehydration solution in 6- to 35-month-old children with acute diarrhea

OBJECTIVE: To determine the efficacy of zinc-fortified oral rehydration salts solution (ORS) in comparison to ORS without zinc in 6- to 35-month-old urban children with acute diarrhea not sick enough to be hospitalized. DESIGN: Double-blind, randomized, controlled trial. METHODS: Children (n = 1219) with acute diarrhea were randomly assigned to one of 3 groups. The first group received a zinc syrup (15 mg zinc to 6- to 11-month-old children and 30 mg to 12- to 35-month-old children), the second group received zinc premixed with ORS (40 mg/L), and the control children received ORS only. Households were visited twice weekly until recovery. RESULTS: The total number of stools was lower in the zinc-ORS group (rate ratio, 0.83; 95% CI, 0.71-0.96), as was the proportion of children with watery stools (odds ratio, 0.61; 95% CI, 0.39-0.95), compared with the control group; there was no significant effect on diarrheal duration. ORS intake and proportion of children with vomiting were not significantly different between the zinc-ORS and control groups. The zinc syrup group had lower diarrheal duration (relative hazards, 0.89; 95% CI, 0.80-0.99) and total stools (rate ratio, 0.73; 95% CI, 0.70-0.77) than control children. CONCLUSIONS: Zinc-ORS was moderately efficacious in reducing the severity of acute diarrhea without increasing vomiting or reducing ORS intake.