The seasonality of diarrheal pathogens: A retrospective study of seven sites over three years

BACKGROUND

Pediatric diarrhea can be caused by a wide variety of pathogens, from bacteria to viruses to protozoa. Pathogen prevalence is often described as seasonal, peaking annually and associated with specific weather conditions. Although many studies have described the seasonality of diarrheal disease, these studies have occurred predominantly in temperate regions. In tropical and resource-constrained settings, where nearly all diarrhea-associated mortality occurs, the seasonality of many diarrheal pathogens has not been well characterized. As a retrospective study, we analyze the seasonal prevalence of diarrheal pathogens among children with moderate-to-severe diarrhea (MSD) over three years from the seven sites of the Global Enteric Multicenter Study (GEMS), a case-control study. Using data from this expansive study on diarrheal disease, we characterize the seasonality of different pathogens, their association with site-specific weather patterns, and consistency across study sites.

METHODOLOGY/PRINCIPAL FINDINGS

Using traditional methodologies from signal processing, we found that certain pathogens peaked at the same time every year, but not at all sites. We also found associations between pathogen prevalence and weather or "seasons," which are defined by applying modern machine-learning methodologies to site-specific weather data. In general, rotavirus was most prevalent during the drier "winter" months and out of phase with bacterial pathogens, which peaked during hotter and rainier times of year corresponding to "monsoon," "rainy," or "summer" seasons.

CONCLUSIONS/SIGNIFICANCE

Identifying the seasonally-dependent prevalence for diarrheal pathogens helps characterize the local epidemiology and inform the clinical diagnosis of symptomatic children. Our multi-site, multi-continent study indicates a complex epidemiology of pathogens that does not reveal an easy generalization that is consistent across all sites. Instead, our study indicates the necessity of local data to characterizing the epidemiology of diarrheal disease. Recognition of the local associations between weather conditions and pathogen prevalence suggests transmission pathways and could inform control strategies in these settings.

Lack of an adverse effect of Giardia intestinalis infection on the health of Peruvian children

Giardia intestinalis is a common gastrointestinal protozoan worldwide, but its effects on childhood growth in developing countries are not clearly understood. The authors aimed to describe its effects on child growth. They followed 220 Peruvian children daily for diarrhea, weekly for stool samples, and monthly for anthropometry. The authors modeled the effect of nutritional status on the risk of Giardia infection and the risk of diarrhea attributable to Giardia using negative binomial regression. They modeled the effects of Giardia infection on growth using linear regression, with 85% of children becoming infected with Giardia and 87% of these becoming reinfected. In multivariable analysis, the risk of Giardia infection did not vary with weight for age (relative risk = 1.00, 95% confidence interval: 0.89, 1.12) or height for age (relative risk = 0.92, 95% confidence interval: 0.82, 1.04). Giardiasis did not affect growth at 1 or 2 months following the first infection at any age interval. The longitudinal prevalence of Giardia between 6 and 24 months of age was not associated with height gain in that interval (p = 0.981). Giardia was not associated with an increased risk of diarrhea at any age interval. Study results question the importance of Giardia as a childhood pathogen in developing countries where giardiasis is hyperendemic.

Point-of-use water treatment and use among mothers in Malawi

A national household survey was conducted in Malawi to determine awareness and use of a socially marketed water treatment product. In all, 64% of mothers were aware of the product, and 7% were using it. Both poor and rural mothers had lower awareness and use rates. Targeting promotion to rural populations could enhance program effectiveness.

[Animal and human Cryptosporidiosis in rural zone in Vietnam (Cu Chi district, Ho-Chi-Minh-City)]

A pilot study was carried out in May-June 2003 to evaluate the epidemiological situation of cryptosporidiosis in the Cu Chi district, a rural zone of Ho-Chi-Minh City Vietnam. The modified acid-fast stain of the stools revealed that 10/202 (5%) cows, 1/29 (3.5%) cattle breeders, and 2/53 (3.8%) under five year- old children with diarrhoea were infected by this germ. Unconfined cattle had a significantly higher risk of infection than penned animals (odds ratio [OR]: 8.3; 95% confidence interval [CI]: 1.06-64.7; p: 0.025).

[Role of Dientamoeba fragilis in human bowel infections]

During 2004, we identified 39 intestinal infections caused by Dientamoeba fragilis and 23 caused by Giardia duodenalis, on 1141 home subjects (3.4% and 2.0% respectively): D. fragilis was observed in 4.5% of O and P (29/644 subjects suffering from aspecific bowel disorders) and in 2.0% of diarrhoeas (10/497); G. duodenalis was observed in 3.1% (20/644) and in 0.6% (3/497) of cases respectively. No other pathogenic parasites were identified (only 1 case of enterobiasis in an asymptomatic child). Commensal protozoa were observed, among O and P, in 4.3% of cases (28/644). The non-pathogenic B. hominis, often associated with other protozoa, was observed in 4.1% of all 1141 cases. D. fragilis is undoubtedly more frequent in adults (36/39 cases, 92.3%) than in children (3/39, 7.7%), and is prevalent among females (24/39, 61.5%) in respect of males (15/39, 38.5%). G. duodenalis is more prevalent among adults (16/23, 69.5%) than children (7/23, 30.5%), but is more frequent among males (13/23, 56.5%) than females (10/23, 43.5%). Clinical correlations of dientamoebiasis and giardiasis are reported, seasonal and epidemiological features of these protozooses are outlined, and the authors emphasize the importance and need of Giemsa stain, among O and P and acute or prolonged diarrhoeas, on the basis of previous good direct microscopic observations of faecal specimens, for correct and complete diagnosis of intestinal infections.

Heavy cryptosporidial infections in children in northeast Brazil: comparison of Cryptosporidium hominis and Cryptosporidium parvum

Cryptosporidium is an important cause of infectious diarrhoea worldwide, but little is known about the course of illness when infected with different species. Over a period of 5 years, Cryptosporidium was identified in the stools of 58 of 157 children prospectively followed from birth in an urban slum (favela) in northeast Brazil. Forty isolates were available for quantification and 42 for speciation (24 Cryptosporidium hominis and 18 C. parvum). Children with C. hominis shed significantly more oocysts/ml of stool (3.5 x 10(6) vs. 1.7 x 10(6)perml; P=0.001), and oocyst counts were higher among symptomatic children (P=0.002). Heavier C. parvum shedding was significantly associated with symptoms (P=0.004), and symptomatic C. parvum-infected children were significantly more likely than asymptomatic children to be lactoferrin-positive (P=0.004). Height-for-age (HAZ) Z-scores showed significant declines within 3 months of infection for children infected with either C. hominis (P=0.028) or C. parvum (P=0.001). However, in the 3-6 month period following infection, only C. hominis-infected children continued to demonstrate declining HAZ score and asymptomatic children showed even greater decline (P=0.01). Cryptosporidium hominis is more common than C. parvum in favela children and is associated with heavier infections and greater growth shortfalls, even in the absence of symptoms.

[Diarrhoea-causing agents in children aged less than five in Tunja, Colombia]

OBJECTIVES

Determining the prevalence and type of infectious ADD-causing agents in a sample of children aged less than five who consulted the IPS in Tunja during 2004.

MATERIAL AND METHODS

A cross-sectional study was designed. Data was obtained by surveying 129 children younger than 5 suffering from ADD. Samples of faeces were obtained following outpatient consultation at San Rafael Hospital and SaludCoop's clinic in Tunja.

RESULTS

Rotavirus was found in 48.1% of cases, Shigella in 0.8%, E. coli in 13.9%, Campylobacter in 2.3%, Giardia lamblia in 12.4% and E. hitolytica in 7%. The causative agent could not be identified in 15.5% of cases. The statistical association grew with age for Rotavirus (p < 0.01), E. coli (p < 0.05) and campylobacter (p < 0.001).

CONCLUSION

Rotavirus is the major causative agent of ADD in children younger than one year and, generally, in children aged less than five. The prevalence found was similar to data reported in studies carried out in Facatatativá, Bogotá, Santander, Manizales and the Chocó in Colombia and studies carried out in Venezuela, Peru and Mexico.

Community-based monitoring of diarrhea in urban Brazilian children: incidence and associated pathogens

Community-based monitoring was conducted in order to investigate the occurrence of diarrhea in 'sentinel areas' of Salvador, Brazil, and to establish a preliminary profile of the most common pathogens present in children's diarrhea by screening stool samples. This report describes the results obtained from twice weekly home visits to identify and follow diarrhea episodes and testing of carer-requested stool sample collection over a 6-month period. Participants were selected from a large longitudinal study in 21 areas representing the city's poorer socioeconomic and sanitary conditions. Fecal samples were examined for the presence of pathogenic bacteria, viruses and protozoa. The mean incidence of diarrhea was 4.97 episodes per child-year, and longitudinal prevalence was 13.6 days per child-year (3.7%). Pathogens were found in 44% of the fecal samples examined. Bacteria were the most frequently encountered pathogens (isolated in 22% of samples), followed by protozoa (19.5%) and viruses (16%). Viral and bacterial pathogens were associated with episodes of severe diarrhea, while viral and protozoan pathogens were associated with longer episodes. The study demonstrated the importance of a public health monitoring system based on 'sentinel areas'.

Cryptosporidium parvum diarrhea in an infant with short bowel syndrome

Cryptosporidium parvum is an underdiagnosed cause of diarrhea in children. The case of a 1-year-old girl with short bowel syndrome presenting with severe dehydrating diarrhea with a protozoon named C parvum is reported. Although the resection of the small bowel in this patient seemed to cause this severe infection with C parvum, more cases are needed to include the resection of the small bowel as a risk factor for Cryptosporidium infection and/or for a more severe form of diarrhea. Awareness of this infection among clinicians will help to diagnose this infection since special acid fast staining is made on special request.

Virus diversity of acute diarrhea in tropical highlands

Infectious acute diarrhea (IAD) is an important health problem affecting a large number of Latin-American children. Several reports show that bacteria, parasites and virus are involved in the burden of this disease. Most reports reveal Rotavirus A as the responsible etiological agent, at the same time, there seems to be some correlation between IAD and seasonal weather changes. To learn about the type of microbial agents associated with IAD in children during mildly changing yearly climatic conditions, as found in a high altitude tropical city, and to identify the viral agents affecting this population, stool samples from 300 children under 5 years of age were studied throughout a one-year period. Bacteria and intestinal parasites were identified by routine methods, while viruses were detected and typed by EIA and PCR. 20.6% of the IAD studied was associated with bacteria; 9% with parasites and 40% with virus. Group C Rotavirus accounted for 20.2%, group A Rotavirus for 13% and Calicivirus 10%. During November-April (p < 0.007) more virus associated IAD was found, while bacteria (p < 0.03) or parasite (p < 0.00014) related IAD was prevalent from May to October. The mild seasonal weather changes don't seem to be associated with any other microbial agent.

Use of nitazoxanide as a new therapeutic option for persistent diarrhea: a pediatric perspective

Despite advances in the management of diarrheal disorders, diarrhea is the second most frequent illness in the world. Persistent diarrhea, common in community pediatrics, is often caused by organisms such as Giardia lamblia, Cryptosporidium parvum and, less frequently, Cyclospora, Isospora belli, and Clostridium difficile. Identifying the causative organism is often challenging, and diagnostic tests may be inaccurate and expensive and, thus, of limited benefit. Consequently, carefully chosen empiric therapy guided by a physician's clinical impressions may be a useful and cost-effective option in children with persistent diarrhea, particularly those whose signs and symptoms suggest a protozoal etiology. This article discusses the empiric use of anti-infective nitazoxanide, a thiazolide compound, in three case reports of children with persistent diarrhea, and presents an overview of the diagnostic and therapeutic issues associated with this disorder and the pharmacodynamics and pharmacokinetics of the drug.

[Cryptosporidiosis and isosporiasis in children suffering from diarrhoea in Abidjan]

A parasitological survey on intestinal coccidia, Cryptosporidium sp and Isospora belli, has been carried out in paediatric service of an teaching hospital in the district of Abidjan (Côte d'Ivoire). 130 children under 5 years old suffering from diarrhoea have been enrolled. Direct stools examination method, simplified Ritchie technique and Ziehl Neelsen modified coloration were used for analysis. Moreover, the AIDS serological status of the patients has been determined. The results show that Cryptosporidium sp and Isospora belli were found respectively with a prevalence of 7.7% and 3.9%. Only one case of mixed infestation between theses two parasites has been found. Coccidia were the most recurrent parasites found in diarrhoea after flagellates. Parasitism by coccidia was not related to AIDS serological status of the children. These results point out the necessity to make common coccidian parasitical diagnosis in children under 5 years old suffering from diarrhoea.

Disseminated cryptosporidiosis in Turkey: case report

Cryptosporidium sp is a protozoan that displays an intracellular settlement primarily in the intestinal systems of humans and can result in diarrhoea. Undernourished children and persons with immunosuppression in developing countries are especially vulnerable to infection with this parasite. A 12-month-old female presented at Ege University, Faculty of Medicine, Department of Paediatrics with complaints of fever, diarrhoea, respiratory distress and growth-development retardation was diagnosed with CD40 deficiency (Hyper IgM Type 3). During the one year investigation process of the case with chronic diarrhoea and necrotic pneumonia, Cryptosporidium sp oocysts were found in nine of the 22 faecal examinations and also in transtracheal aspiration liquid examined using the Kinyoun Acid-fast staining method. In conclusion, it is thought that cryptosporidiosis should also be considered in the distinct diagnosis of immunodeficient infants who are presented with respiratory and gastrointestinal system complaints.

Does Co-Infection with Giardia Lamblia Modulate the Clinical Characteristics of Enteric Infections in Young Children?

BACKGROUND

Giardia lamblia (G. lamblia) is a prevalent enteric pathogen causing both asymptomatic carriage and diarrheal illness among children worldwide. In this study we examined the hypothesis that G. lamblia may modulate the effect of other enteric pathogens during concurrent infection.

METHODS

Bedouin (n = 238) infants were followed from birth to ages 18-23 months. Morbidity was ascertained by weekly home interviews and infant's stools were collected fortnightly. The risk for and severity of diarrheal disease were compared between episodes caused by enteric pathogens other than G. lamblia alone and G. lamblia-mixed episodes.

RESULTS

In 59 of 293(20.1%) diarrhea episodes two or more pathogens were detected. In two thirds of the mixed episodes G. lamblia was involved. Neither the incidence of diarrhea nor the mean diarrheal episode duration differed between follow up months in which G. lamblia was or was not detected, when age specific or age adjusted values were compared. There were no differences in severity of episodes for single or G. lamblia-mixed infections except for rotavirus. Episodes with rotavirus alone were more severe as compared to episodes where co-infection with G. lamblia was found.

CONCLUSIONS

The results of this study do not confirm the hypothesis that G. lamblia modulates the clinical effect of infection with other enteric agents. However, the findings of the change in severity of infection with rotavirus suggest that this question warrants further investigation.

[Enteropathogens associated with diarrheal disease in infants (< 5 years old) in a population sample in Greater Metropolitan Criciúma, Santa Catarina State, Brazil]

Enteropathogens were investigated in 94 children with diarrhea and 45 age-matched controls, 0 to 5 years old, attending an outpatient unit in Criciúma, Santa Catarina State, Brazil. Cryptosporidium (85.1%) topped the list of parasite isolates, followed by Entamoeba histolytica (56.4%) and Giardia lamblia (4.3%). Four samples contained enteropathogenic Escherichia coli (4.3%). Samonella and Shiguella were not detected. Only one sample contained rotavirus (1.1%).

Coccidian parasites as a cause of watery diarrhoea among protein energy malnourished and other immunocompromised Egyptian children

The role of coccidian parasites in the pathogenesis of watery diarrhea was studied among children with protein energy malnutrition (PEM), immunocompromised due to causes other than PEM and immunocompetent diarrheic of matched age and sex, as controls. The results showed that the prevalence of infection was 15.48%, Cryptosporidium was the most prevalent and showed 14.19% (18.3%, 17.5% and 7.3% in PEM, immunocompromised and immunocompetent cases respectively). Cyclospora oocysts were detected only among 2 cases (1.29%) of PEM group. Isospora oocysts were not detected in any of the studied groups. Modified Ziehl-Neelsen (Z.N.) technique was found to be the most reliable technique for identification of coccidian protozoa infection in stool. Giardia lamblia cysts were found in 10.97% and Entamoeba histolytica in 5.16% of cases. Mixed infection (G. lamblia and E. histolytica) was found in 2.58% of the cases. The duration of diarrhoea was more prolonged in Cryptosporidium and Cyclospora infections among PEM and immunocompromised cases. Cryptosporidium is one of the important casuses of watery diarrhoea in infants and children in PEM and immunocompromised patients. Therefore, it is indicated to use modified Z.N. technique as a routine test for stool examination and immunocompromised patients must avoid contaminated water.

Cryptosporidiosis in a tertiary care hospital

BACKGROUND

Cryptosporidium, an important cause of diarrhoea, has been reported worldwide both in immunocompetent and immunocompromised individuals and has emerged as a serious public health problem. This study was undertaken to assess the present status of cryptosporidiosis in children and adults with diarrhoea who attended the Nehru Hospital, Chandigarh which is a tertiary care hospital.

METHODS

Routine stool examination was done using saline and iodine stained preparations for various parasites. Modified Ziehl-Neelsen and rapid safranin-methylene blue techniques were used to detect Cryptosporidium in 2000 stool samples (1645 adults, 355 children) from March to November 1998.

RESULTS

Of the 2000 samples, 205 (10.2%) were positive for various parasites. Five (1.4%) children were positive for Cryptosporidium and one child was positive for human immunodeficiency virus. In adults, Cryptosporidium was found in only one patient (0.06%). Giardia lamblia was the commonest parasite detected both in adults (4%) and children (15.2%).

CONCLUSION

The present study highlights the importance of Cryptosporidium as a cause of diarrhoea, especially in children. Thus, there is a need for specific staining techniques to detect Cryptosporidium in routine diagnostic laboratories.

Significance of Cryptosporidium in acute diarrhoea in North-Eastern India

In a hospital-based study, stool samples from 2095 patients of all ages were examined for different fungal, protozoal and bacterial enteropathogens over a period of 2 years (July 1994-June 1996). Cryptosporidium was detected in 151 specimens (7.2%) and was the third commonest pathogen found. The highest prevalence of this organism was in the group aged 16-45 years and during the rainy months (July-Oct.). Diarrhoea caused by the protozoon was of mild to moderate severity and features of dysentery were absent. Amongst other enteropathogens, Candida albicans was the most frequently isolated, followed by enteropathogenic and enterotoxigenic Escherichia coli, Salmonella spp., Campylobacter jejuni, Entamoeba histolytica, Giardia duodenalis (lamblia), Shigella spp., Vibrio cholerae and Aeromonas spp.

Role of protozoa as risk factors for persistent diarrhea

A case control study including 175 children aged 0-36 months suffering from diarrhea of > or = 14 days duration was undertaken to determine whether there is an association between Giardia lamblia, Entamoeba histolytica or Cryptosporidium 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 enrollment and examined for trophozoites of Giardia lamblia, Entamoeba histolytica and Cryptosporidium. 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 passed E. 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 enrollment. Giardia lamblia infection is more prevalent in PD cases than in acute diarrhea or non-diarrheal 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 of Giardia lamblia seems to be justified.

[Incidence of Cryptosporidium in Zaragoza: an 8-year study (1989-1996)]

BACKGROUND

To study the incidence of Cryptosporidium infections over an eight year period in an urban area, together with the patients background and the season of the year.

MATERIALS AND METHODS

From January 1989 to December 1996, all 32,733 stool samples from 13,639 patients: children and immunocompromised adults, with presumed infective diarrhoea, were investigated for Cryptosporidium oocysts by the Department of Microbiology, Miguel Servet Hospital, Zaragoza (Spain).

RESULTS

Cryptosporidial infection was identified in a 3% of the total children, been the positivity rate highest in the 2-year old group. We visualized oocysts in the 8% of the immunocompromised patients, all of them HIV-positive. The prevalence was higher in winter (February-March).

CONCLUSIONS

According to these findings we conclude that Cryptosporidium should be systematically searched by clinical laboratories, specially in children and in immunocompromised patients suffering from infectious diarrhoea.

In vivo and in vitro efficacy of octreotide for treatment of enteric cryptosporidiosis

Previous evidence suggested a role of enterotoxin in the pathophysiology of cryptosporidiosis. If so, antisecretory drugs should be effective in reducing diarrhea. We evaluated the in vivo and in vitro efficacy of octreotide, which possesses antisecretory effects, for cryptosporidial diarrhea. Two children with severe cryptosporidial diarrhea were treated with octreotide. The volume modifications and chemical composition of stools were determined. Fecal supernatant was added to Caco-2 cell monolayers mounted in Ussing chambers with or without serosal octreotide and electrical parameters were monitored. Octreotide was effective in reducing the stool volume and fecal Na+ concentration. Fecal supernatant induced an enterotoxin-like increase in transepithelial potential difference. Octreotide induced a dose-dependent decrease in basal potential difference, consistent with an absorptive effect. In cells pretreated with octreotide, fecal supernatant induced an increase in the potential difference, whose magnitude and duration were significantly reduced compared to untreated cells. These results provide in vivo and in vitro evidence for the secretory nature of cryptosporidial diarrhea and for the efficacy of octreotide through a direct interaction with the enterocyte.

Epidemiological study on infectious diarrheal diseases in children in a coastal rural area of Kenya

Diarrheal diseases are major causes of morbidity and mortality among children in developing countries. We have analyzed the causative agents of diarrhea in children under five years of age who resided in rural environments but attended a hospital in Malindi, a coastal town in Kenya. Bacterial diarrhea was found in 239 (27.7%) of 862 patients with diarrhea. Diarrheagenic Escherichia coli, including enteropathogenic, enterotoxigenic, and enterohaemorrhagic strains, was isolated from 119 (13.8%) patients, followed by Salmonella spp. (63 cases, 7.3%) and Shigella spp. (56 cases, 6.5%). Intestinal parasites were found in 109 (12.6%) of the patients. Entamoeba histolytica and Giardia lamblia were found in 67 (7.8%) and 42 (4.9%) of the cases, respectively. Rotavirus was found in 69 (16.1%) of 428 cases, a part of the 862 cases. Significant differences in age distribution were seen in diarrheal cases due to Campylobacter spp., G. lamblia, and rotavirus. No significant seasonal incidence of specific pathogens was found, but the number of diarrheal patients was significantly correlated to rainfall. Drinking water was contaminated with bacteria at concentrations ranging from 10(3) to 10(6) CFU/ml in 98% of the households and by coliform bacteria at concentrations of 10(2) to 10(5) CFU/ml in 72% of the households. These results suggest that the main routes of infection may be contaminated drinking water and fecal-oral transmission of enteric pathogens. Consequently, we propose that the enhancement of hygienic practice through health education is a feasible control measure of diarrhea in the study area.

[Cryptosporidiosis in children with acute diarrhea from Ciego de Avila province, Cuba]

An epidemiological and clinical study of criptosporidiosis in children from Ciego de Avila province was carried out from 1987 to 1994. During this period 14,895 children with acute diarrhea were studied. Cryptosporidium sp. oocysts were found in the feces of 1,256 (8.4%) of them. Isolated cases prevailed over outbreaks, being the incidence rate proportional in both urban and rural areas. Seventy nine point seven per cent of infected children were less one year old, predominating the age group 6-11 months old. No influence of seasons on the occurrence of the parasitose was observed. The most frequently detected symptoms and signs were diarrhea, vomits and loss of weight. The main epidemiological factors were: 81.0% of ill children drank water directly from the aqueduct, 12.8% lived in overcrowded conditions, 11.0% had animals and 10.7% attended nursery schools.

Cryptosporidium parvum in children with diarrhea in Zulia State, Venezuela

The prevalence and importance of Cryptosporidium parvum as a causal agent of acute diarrhea among pediatric patients from Zulia State, Venezuela was assessed. Single stool specimens were collected from 310 children 0-60 months of age with acute diarrheal disease who were admitted to three public hospitals and from 150 comparable control children without gastrointestinal symptoms who were seen as outpatients. Cryptosporidium parvum oocysts were identified in 35 (11.2%) of 310 children with diarrhea and the coccidium was the single detectable pathogen in only 12 (34.2%). Other potential pathogenic parasites were present in most of the patients shedding oocysts (23 of 35, 65%). In nondiarrheal control children, oocysts were identified in nine (6%) of 150. The data suggest that C. parvum is relatively highly endemic in children 0-60 months of age in Zulia State and that although C. parvum may be an important pathogen associated with diarrhea, it may be a cause of only a small proportion of diarrheal episodes.

Yield from stool testing of pediatric inpatients

OBJECTIVES

To quantify the yield from stool testing in pediatric inpatients and to identify criteria to test stool more deliberately without sacrificing diagnostic sensitivity.

DESIGN

A retrospective review was performed of all stool cultures, ova and parasite examinations, and Clostridium [correction of Clostridia] difficile toxin assays performed on pediatric inpatients, aged 3 days to 18 years, at Thomas Jefferson University Hospital, Philadelphia, Pa, for 1 year. Medical records were reviewed for positive cases, each with 2 controls matched for age and test type. For this study, the term admission refers to the interval between the times each patient was admitted to and discharged from the hospital. Some patients had multiple stool tests sent to the laboratory during a single admission; some patients had more than 1 admission during the study period. Statistical analysis was performed using X2 analysis and the Student 2-tailed t test with a commercially available statistical software package (Statworks, Cricket Software, Philadelphia).

RESULTS

Of 250 patient admissions to the hospital for which stool was cultured, 7 cultures (2.8%) were positive. Of 63 patient admissions having ova and parasite testing, 1 (2%) had a positive result. Clostridium [correction of Clostridia] difficile toxin assays were performed on 40 patient admissions to the hospital, and 7 (18%) had a positive result. Only 18 (3.0%) of 598 of all test results reviewed were positive. Costs of negative test results totaled $26,084. More patients (71%) with positive stool cultures than control patients (21%) had a temperature higher than or equal to 38 degrees C (X2, P < .05); however, relying on this sign missed 29% of the children with bacterial infection. A white blood cell band count of at least 0.10 was 100% sensitive and 79% specific in identifying patients with positive stool culture. There was no statistically significant relationship between stool culture results and age, total white blood cell count or white blood cell segmented neutrophil count, and no relationship between C. difficile toxin assay results and any of the above characteristics. Clostridium [correction of Clostridia] difficile was the most common pathogen identified (6 of 9) in patients developing gastrointestinal symptoms after admission; however, Salmonella enteritidis and Shigella sonnei were also significant causes (3 of 9).

CONCLUSIONS

There is low yield from stool testing of pediatric inpatients: C. difficile toxin assay has the highest yield. Clostridium [correction of Clostridia] difficile testing is most valuable for children with nosocomial gastrointestinal symptoms although other bacterial pathogens do cause nosocomial symptoms in children. More selective stool testing could help us be more efficient with our patient care resources.

[Enteropathogenic agents isolated in persistent diarrhoea]

Out of 45558 patients admited in our hospital, from January 1990 to December 1993, the clinical records of 4445 children with diarrhoea (4289 with acute diarrihoea and 156 with persistent diarrhoea) were reviewed. Those with positive bacteriological or parasitological results were taken as sample. Salmonella was the bacteria most frequently isolated in both groups of patients. ECEP and ECEH had a similar distribution while Shigella showed a higher frequency in cases of persistent diarrhoea, for a third pace of incidence. From the parasitological point of view, Cryptosporidium and Giardia had the same behavior.

Cryptosporidium sp. in children suffering from acute diarrhea at Uberlândia City, State of Minas Gerais, Brazil

This study's objective was to search for Cryptosporidium sp. in diarrheic feces from children aged zero to 12 years and cared for at medical units within Universidade Federal de Uberlândia or at a private practice in Uberlândia, State of Minas Gerais, Brazil, from September 1992 to August 1993. Three fecal samples preserved in 10% formalin, were collected from 94 children. Oocyst concentration was performed through Ritchie's (modified) method and staining of fecal smears for each sample (total of 1128 slides) was done by the "Safranin/Methylene Blue" and the "Kinyoun (modified)" techniques. The Hoffmann, Pons & Janer method was also employed to look for other enteroparasites. From 94 children, 4.26% excreted fecal Cryptosporidium oocysts. The infection seemed to vary according to age: 5.08% of patients aged zero to two years old; 33.33% of those aging eight to ten years (P > 0.05). Cryptosporidium appeared in November, December and March, during the rainy season. 20.21% of the children harbored at least one enteroparasite different from Cryptosporidium, mainly Giardia intestinalis (12.77%). From Cryptosporidium infected patients, two had only this kind, another harbored Giardia intestinalis; the last one hosted Strongyloides stercoralis.

[Infectious diarrhea in young children and infants]

Acute diarrhoea is one of the major causes of outpatient paediatric consultation, especially during infancy. An infectious cause should be suspected on the acute onset of diarrhoea associated with fever. The specific pathogen is seldom investigated and individualized. Rotavirus has been recognized as the most important enteric pathogen, particularly in infants during winter months. It may be responsible for nosocomial infections in hospital and outbreaks in day-care centers. Bacteria may cause a diarrhoea by elaboration of enterotoxins, by invasiveness, or both. Use of antibiotic is usually not necessary even in bacterial infections because they are self-limited. Choice of the antibiotic is complicated by the rapid emergence of resistant pathogenic strains. The first step is rapid assessment of the hydratation status of the patient. Fluid and electrolytes replacement is the mainstay in the treatment of infectious diarrhoea of any cause.

Cryptosporidiosis in children seen at the children's clinic of Yekatit 12 Hospital, Addis Ababa

The stools of 214 children under five years of age with diarrhoea were examined for Cryptosporidium oocysts using the Modified Ziehl Nelson Technique. Twelve (5.6%) of the children had Cryptosporidium oocysts in their faeces. All of these were above 6 months of age and were either partially or fully weaned. There were 15 exclusively breast fed children of whom 11 were less than 6 months of age. None of these cases had the evidence of Cryptosporidial infection. The present study indicates the importance of Cryptosporidium as a possible etiologic agent in patients with diarrhoeal diseases. However, a comprehensive investigation is needed in order to rule out other enteropathogens.

Clinical features of infantile diarrhea associated with single or multiple enteric pathogens

Clinical features of infantile diarrhea were studied among 603 infants from birth to 12 months of age to determine the predominant clinical feature(s) seen in infantile diarrhea associated with a specific enteric pathogen. Among the major clinical features, fever was most often seen in diarrhea due to Yersinia spp. (61.5%) followed by that in rotavirus (26.1%). Vomiting was mostly associated with Vibrio cholerae infection (90.9%) and shigellosis (64.6%). Dehydration was predominant in Vibrio cholerae (90.9%) and Salmonella (84.9%) infections. Bloody diarrhea was mostly due to Shigella infection (74.3%). As regards diarrhea with multiple pathogens, vomiting and dehydration were most frequent with Campylobacter+Enteropathogenic Escherichia coli (EPEC) (88.9% and 77.8%, respectively), while fever was more common with rotavirus+Shigella+Escherichia coli and rotavirus+Giardia. Infection with invasive organisms lead to vomiting, 4-10 stools per day and dehydration significantly more often as compared to infections with non-invasive organisms. Similarly more stools of patients infected with invasive organisms showed presence of blood and more than 5 leukocytes/HPF as compared to those infected with non-invasive organisms.

Community survey of diarrhoea in children under 5 years in Kinshasa, Zaire

This community based survey was undertaken to assess the prevalence, characteristics and risk factors of diarrhoea in children < 5 years of age in an urban zone, at Kinshasa, Zaire. 155 community cases selected by cluster sampling, 155 age-matched controls, and 18 children with diarrhoea seen at a health centre (HC) were examined. The diarrhoea prevalence rate was 6.5%. The highest risk of persistent diarrhoea was in children of 2 to 3 years, non breast-fed, with more than one enteric agent in their stools and living in households without electricity. The rates of detection of Strongyloides stercoralis, Entamoeba histolytica and Salmonella, and heavy infections of Trichuris trichiura and Trichomonas hominis were significantly higher in cases (p < 0.05). The rate of detection of Cryptosporidium was rather high, specially in HC cases (22.2%). It was also found in both diarrhoeal (14.8%) and non-diarrhoeal specimens (12.9%). There was a lack of association between the presence of faecal white blood cells and enteric bacteria, and also between the presence of faecal red blood cells and E. histolytica, which might be due to the frequent practice of rectal injections and suppositories. A mother's perception of fever and stool aspect was fairly in agreement (respectively 70% and 53%) with that of the investigators. The high rate of dehydrated children (50.9%) may be due to the dehydration definition applied at the HC. The survey's results were used to improve the local case management flow chart and to adjust educational activities directed at mothers.

A study of infective aetiology of chronic diarrhoea in children in Amritsar

Examination of 150 stool samples from children of less than 3 years of age of chronic diarrhoea showed the presence of various enteropathogens in 58.7% cases. Cryptosporidium in pure form, Entamoeba histolytica and Giardia lamblia were detected in 1.3%, 2% and in 4% cases respectively. In 1.3% children Candida albicans was isolated. The predominant bacterial isolate was enteropathogenic Escherichia coli (21.4%). Salmonella typhimurium, shigella and campylobacter were isolated in 8.6%, 4% and 0.7% children respectively.

Breastfeeding and immunity to intestinal infections

The purpose of this study was to compare immune response in breast and non breastfed children presenting with diarrhoea at Paediatric Observation Ward, Kenyatta National Hospital (KNH-POW) and Maternal and Child Health Clinic, Pumwani Maternity Hospital (PMH-MCH). Blood and stool samples were collected from the first four consecutive children aged 5 years and below per day, presenting with or without diarrhoea from January to December, 1992. The stools were tested for total IgA by single radial immunodiffusion (SRID) and specific IgA by enzyme linked immunosorbent assay (ELISA). Peripheral blood CD4 and CD8 enumeration was done by flow cytometry. Stools were cultured for bacteria on selective media while ova and cysts of parasites were identified by wet preparation microscopy. A total of 457 children were enrolled into the study, 69.6% of whom presented with diarrhoea. Breastfed children tended to have a shorter duration of diarrhoea than either mixed fed or bottle fed (8.3 vs 9.8 vs 11.2 days, p = 0.2). In general, E. coli were more commonly isolated from breastfed than mixed fed or bottle fed (56.7% vs 43.9% vs 28.9%, p = 0.004) while intestinal parasites were mostly in bottle fed than mixed or breastfed children (28.8% vs 8.2 vs 0.8, p < 0.004). However, when children with diarrhoea were considered, E. coli was more frequently isolated from bottle fed children who presented with diarrhoea than without (26.7% vs 7.7%, p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

[The first report in Cuba of human intestinal infection by Cyclospora cayetanensis, Ortega, 1993]

The human intestinal infection by Cyclospora cayetanensis, is reported for the first time in Cuba, Ortega, 1993. This coccidian parasite was being identified since several years in humans presenting with diarrhea, as a blue-green Alga, a similar body to cyanobacteria, or similar to a great coccidia. However, it was identified for the first time a genus of Cyclospora, in 1993, and the taxonomic description of the human species as C. cayetanensis is very recent. This paper reports on a child presenting with an acute diarrheal picture in which no other causative agent was found, and describes the morphological characteristics of this rounded organism which measures between 7.7 and 10 micras of diameter and results positive to Ziehl-Neelsen staining. This is a warning for all physicians and biomedical staff in charge of making the laboratory diagnosis of acute diarrheal diseases.

Cryptosporidiosis in Myanmar infants with acute diarrhea

Cryptosporidiosis has been found in Myanmar for the first time in infants presenting with a mild transient form of acute diarrhea. A total of 203 fecal samples collected from those infants were examined by Kinyoun's acid fast modified method. 3.4% of infants between 2 and 11 months of age were found passing cryptosporidium oocysts. All cases presented with features consistent with findings reported by other authors from developing countries. Cryptosporidium was the sole microorganism isolated. Hence, cryptosporidiosis may be responsible for acute diarrhea in these Myanmar infants.

Cryptosporidium parvum in children with diarrhea in Mexico

Using an anti-oocyst wall monoclonal antibody-based immunofluorescence assay, the presence of Cryptosporidium parvum was evaluated in children with diarrhea from rural areas (selected from a door-to-door community survey) and from urban areas (patients attending hospitals) in the State of Puebla, Mexico. Prevalences of 9.4% in a rural population (n = 85) and 29.6% in a hospital-based urban population (n = 81). There was no consistent correlation between water source and other environmental data and the presence of C. parvum in stools. It is concluded that C. parvum may be an important pathogen associated with diarrhea in this Mexican state.

Seroprevalence of cryptosporidial antibodies during infancy, childhood, and adolescence

Cryptosporidium parvum causes mild to moderately severe diarrhea in immunocompetent individuals. Cryptosporidial antibodies in the sera of 803 children seen at Children's Hospital of Oklahoma were measured by means of an ELISA. Thirteen percent of children younger than 5 years of age were seropositive for antibodies to C. parvum. The seropositivity rate for children who attended day-care facilities was higher than that for those who did not. In addition, children in this age group with a history of recent diarrhea were seropositive at a higher rate than were children without diarrhea. Thirty-eight percent of children (5-13 years of age) and 58% of adolescents (14-21 years of age) were seropositive for antibodies to C. parvum. Blacks and Native Americans in these age groups had higher seropositivity rates than did White non-Hispanics. There were no differences in seropositivity rates between sexes or between residents of the largest urban counties in Oklahoma and residents of the more rural counties. Exposure to C. parvum during childhood is common in Oklahoma. Socioeconomic factors may play a role in early exposure to this protozoal pathogen.

Diarrhoeal disease in children in Gaza

A 1-year prospective study in Gaza of diarrhoeal disease in children aged < 5 years demonstrated that Salmonella spp. (18.5% of cases), Cryptosporidium (14.6%), Campylobacter spp. (8.3%) and rotavirus (6.8%) were the major pathogens. However, when compared with non-diarrhoeic controls, only Cryptosporidium and rotavirus were significantly associated with diarrhoea. Cryptosporidiosis was found only in children aged < 2 years and significantly more children with cryptosporidiosis were malnourished. This malnutrition may have been due to the infection, since children with cryptosporidiosis tended to have had diarrhoea for relatively long periods prior to admission. It was not possible to distinguish between the different enteropathogens on clinical grounds. However, more children with rotavirus infection vomited and cryptosporidial diarrhoea lasted significantly longer (14.9 days) than rotavirus diarrhoea (5.9 days). Overcrowding was linked with an increased risk of cryptosporidiosis and breast feeding was associated with some protection. Twenty-one of the 29 children who died during the study died with diarrhoea and Cryptosporidium was detected in eight (38%) of these 21 children.

Effect of dietary nucleotide supplementation on diarrhoeal disease in infants

The effects of a nucleotide-supplemented formula on diarrhoeal disease was studied in 141 infants (group 1) who belonged to the low socioeconomic stratum; 148 controls (group 2) received the same formula but unsupplemented. Group 1 experienced less episodes of diarrhoea (109 versus 140), including less first episodes (74 versus 102; chi-square = 8.19, p < 0.004; odds ratio 2.01) and for a lesser number of days (807 versus 996 days); 45.0% and 31.1% of infants in groups 1 and 2, respectively, never developed episodes of diarrhoea. There were no differences in the clinical characteristics of the episodes or in the enteropathogens isolated from symptomatic or asymptomatic infants. The mechanisms through which nucleotides decrease the incidence of diarrhoeal disease in infants remain unclear.

[Epidemiologic study of infectious diarrhea in infants]

The authors considered the epidemiological and microbiological aspects of the infectious diarrhea caused by bacteria, protozoan and viruses observed at the Infantile Hospital, Alessandria, and at the Malpighi Diagnostic Center, Chivasso, Turin, over a period of 14 months. Furthermore, a greater interest has been given to the role of Clostridium difficile diarrhea, since hospitalized patients are often predisposed to the development of this disease due to the antimicrobial prophylaxis or therapy.

High prevalence of Cryptosporidium in young children with prolonged diarrhea

A prospective study was done to identify Cryptosporidium in the stools of young children, aged 2 months to 3 years, admitted to hospital. Of a total of 387 stool samples from 387 individuals, 131 stool specimens forming the control group were from children with non-diarrheal, respiratory tract infections, 200 and 56 stool samples were from children with acute diarrhea and prolonged diarrhea, respectively. No Cryptosporidium was discovered in the control group. Only 1 sample positive for Cryptosporidium was found in the group with acute diarrhea, whereas 4 samples of Cryptosporidium were found in the group with prolonged diarrhea. The prevalence of Cryptosporidium in the group with prolonged diarrhea was significantly higher than the other two groups (p < 0.05). In those children with prolonged diarrhea, Cryptosporidium should always be included in the differential diagnosis.

[Prevalence of enteropathogens in children with liquid diarrhea]

Between january 1 and october 31, 1991 148 samples of feces corresponding to the same number of children with acute diarrhea, aged 0-2 years, admitted to Hospital O'Horan of the Secretariat of Health in the city of Merida, Yucatan, Mexico, were studied. Stools from 105 (70.9%) patients were described as watery diarrhea; from these samples at least one enteric pathogen was detected in 49 (46.6%): a single pathogen was isolated in 37 (35.2%), and mixed infections were observed in 12 (11.4%). We isolated enterotoxigenic Escherichia coli in 18 (17.1%) samples; a predominance of strains producing only ST (11.4%) was observed. Rotavirus was detected in 14.3%, Shigella spp in 8.6%, Salmonella spp in 5.7%, Giardia lamblia in 4.8%, Campylobacter jejuni in 3.8%, enteroinvasive E. coli in 2.8%, Entamoeba histolytica in 2.8% and adenovirus in 1.9%. From watery samples, 80 (76.2%) were negative for fecal blood, and these were most frequently associated with enterotoxigenic E. coli (17.5%) and rotavirus (12.5%). E. coli LT+ and rotavirus association was observed in two patients, and E. coli ST+ and adenovirus association was observed in another one.

A study of the importance of the enterotoxigenic E. coli in children with acute diarrhoea in Recife, Brazil

Even today acute diarrhoea is a major cause of morbidity and mortality in young children. It is a serious public health problem in less-developed countries, primarily in households whose income is low. As such, it is one of the main causes of death, affecting the undernourished in particular. The potential enteropathogenic agents are distributed universally. However, there is a major difference in the prevalence, according to the areas and the characteristics of the population groups which were studied. In Brazil, since the 1970s, our attention has been drawn to the importance of the classic enteropathogenic strains of E. coli (EPEC) in the aetiology of diarrhoeal diseases, primarily those present in weaned infants in inner city neighbourhoods. On the other hand, Guerrant and co-workers, and Queiroz and co-workers found significant percentages of isolated colonies of enterotoxigenic coli (ETEC) in the stool material of children with symptoms of acute diarrhoea. In rural areas of less-developed countries the incidence of episodes of ETEC provoking diarrhoea is estimated to be between five and ten per person/year. Due to the social and medical gravity of acute diarrhoea, and to the lack of studies dealing with the aetiopathogenic role of the strains of ETEC in our area, we decided to analyse the frequency of isolation of ETEC in children with and without diarrhoea who were attending the out-patient department of the Instituto Materno Infantil de Pernambuco/IMIP.

Approach to the pediatric patient with diarrhea

Numerous viral, bacterial, and parasitic pathogens are known to cause diarrheal illnesses with increased frequency in children. Oral rehydration can be used to treat and prevent dehydration, the major sequela of diarrhea in children. The impact of diarrhea on nutrition may also be reduced through the rapid restoration of a normal, age-appropriate diet. Most diarrheal illnesses are acute and self-limited; however, increased knowledge of persistent diarrheal syndromes in children may lead to prompt recognition and diagnosis in children with diarrhea lasting more than 2 weeks.

[Chronic diarrhea due to Cryptosporidium: the efficacy of spiramycin treatment]

Cryptosporidium has received increasing attention as a pathogen in normal as well as immunocompromised persons. We report a case of cryptosporidiosis occurred in a 18-months-old-girl who was treated with spiramycin for 8 days with complete resolution of diarrhea within the first days of therapy; follow-up stool examination was negative for the protozoan. The incidence of diarrhea due to Cryptosporidium seems to be higher than it was reported before: so fecal samples, when negative for other etiological agents, should be examined for Cryptosporidium oocysts. Spiramycin seems to be an effective and well-tolerated drug: treatment is recommended in children with prolonged and/or severe diarrhea when Cryptosporidium seems to be the etiological cause of the disease.

[Frequency of intestinal and bacterial parasites producing diarrhea in children in a regional hospital]

The diarrhoea diseases are priority health problems in all countries of the Third World. The number of the cases of diarrhoea and other intestinal infections have very high morbi-mortality rate in mexican childhood. There are many factors that affect these pathologies, those related to social, economic and cultural aspects seem to be the most important. Although the intestinal viruses are frequent, the enteritis produced by bacteria are more severe and acute. There area also parasites that yield the chronic type disease. In this paper, the most frequent parasites and enteropathogenic bacteria infecting children below 15 years old, either hospitalized or being outpatients from the Hospital de Zona No. 29 del IMSS in México City, were studied. The data obtained were related to the socioeconomic level. A total of 415 stool samples were collected from newborn to 14 years old children over a period of nine months. The samples were classified according to the ages, schooling and number of persons who slept with the child in the same bedroom. The samples were examined by a centrifugal concentration technique and by cultivation. The group of children up to five years old were found to be the most infected by bacteria, while children from 10 to 14 years old were by parasites. Those children whose parents either have not finished the elementary school or can not read and write were the most parasitized (40%), these children were also found to be most infected, as the number of persons who slept in the same bedroom increased, the number of infections per children either by bacteria or parasites, also increased.(ABSTRACT TRUNCATED AT 250 WORDS)