Isolation of rotavirus from foals with diarrhoea.

A rotavirus, morphologically similar to other known rotaviruses, was demonstrated in the faeces of 5 foals with diarrhoea on two properties. Four of these 5 samples produced specific intracytoplasmic fluorescence in cell culture when reacted with calf rotavirus antiserum conjugate. Sixteen affected foals from both properties were depressed, did not suckle and became recumbent. Most had a watery diarrhoea which lasted for 3 days and resulted in some dehydration and loss of body condition. Sick foals were separated from their mothers following the onset of diarrhoea and given fluid therapy and antibiotics, but despite these measures 4 of 12 affected foals on one property died. Acute and convalescent sera were collected from 6 foals, and in each case a rise in the titres of complement fixing and neutralising antibodies was demonstrated. Faecal filtrates containing foal rotaviruses were fed to gnotobiotic piglets and the effects compared with those of other rotaviruses. Viral isolates from both properties produced an asymptomatic infection in piglets. This contrasts with the other rotaviruses isolated in Australia that have been shown to cause diarrhoea in gnotobiotic piglets.     

Detection of human rotavirus in hospitalized diarrheic children in central India

During the present study, group A human rotaviruses were detected among diarrheic children using polyacrylamide gel electrophoresis (PAGE) technique, with a typical RNA migration pattern of 4:2:3:2, suggestive of group A rotavirus. During the study, a total of 46 fecal samples collected from hospitalized children with acute diarrhea as well as children inhabiting nearby animal farms with history of presence of animal rotaviruses on the farms were processed for detection of human rotavirus. Out of 33 diarrheic children, 12 showed presence of rotavirus infection (36.36%), however, none of the children from animal farm areas showed presence of rotavirus. Female children were more susceptible to rotavirus infection (46.15%) than males (30%). Majority of the cases of rotavirus gastroenteritis belonged up to one year of the age, with an incidence of 40.91%. RNA profile of rotaviruses suggested circulation of 5 different electropherotypes in this geographical locale of the country, indicating existence of genomic diversity among human rotaviruses. Majority of the isolates were of long pattern (66.67%), whereas short pattern was detected only in one third of the viruses. This preliminary study emphasizes for further detailed studies on the molecular characterization of rotaviruses circulating in this part of country and their relationship with other human rotavirus strains and animal strains in the country.     

Acute diarrhoea in a community cohort of children who received an oral rotavirus vaccine in Northeast Brazil

Rotavirus is an important cause of childhood diarrhoea. A monovalent rotavirus vaccine (Rotarix?) was introduced into the Immunization Program of Brazil in 2006. In this study, we describe the incidence and burden of disease of rotavirus diarrhoea in two cohorts of children (vaccinated and unvaccinated). We followed two groups of 250 children under one year old, who were enrolled in December 2006 from a low-income residential area in Northeast Brazil. The children were monitored every two weeks for two years. Stool samples from children with diarrhoea were examined for the presence of rotavirus. Rotaviruses were genotyped using real time-polymerase chain reaction. The mean numbers of all-cause diarrhoea episodes/child (adjusted for age) in the first year were 0.87 and 0.84, in vaccinated and unvaccinated children, respectively. During the second year, the number of episodes/child decreased to 0.52 and 0.42. Only 16 (4.9%) of 330 stool samples were rotavirus-positive (10 vaccinated and 6 unvaccinated children) and only P[4]G2 rotaviruses were identified. All-cause diarrhoea episodes were more severe in unvaccinated children in the first year of age (p < 0.05), while vaccinated children had more severe episodes 18 months after vaccination. Rotavirus diarrhoea incidence was very low in both groups.     

Protection against rotavirus diarrhoea in mice by trypsin inhibitor

To investigate the role of soyabean trypsin inhibitor (TI) during rotavirus (RV) diarrhoea, changes in enzyme activities of six relevant mucosal enzymes (lactase, sucrase, maltase, trehalase, glucoamylase and alkaline phosphatase) were assayed following inoculation of suckling mice with EB rotavirus (serotype 3) along with the TI and compared with the age-matched healthy control mice. The animals were divided into three groups i.e. group 1 (controls), group 2 (RV inoculated) and group 3 (RV + TI inoculated and sacrificed under light anaesthesia on 0, 1, 3, 5, 7 and 10 day post inoculation (dpi). Then intestines were excised and divided into two parts (jejunum and ileum). They were separately homogenized in 0.9% cold normal saline and activities of mucosal enzyme were measured. Alkaline phosphatase and disaccharidases were found to be decreased significantly in RV inoculated animals in both the anatomical portions of small intestine of mice. These enzyme levels were restored with the administration of TI i.e. in group 3 and became comparable to the controls in both intestinal portions. These studies suggest that activity of intestinal enzymes which are important in digestive absorptive functions of small intestine were restored with the addition of TI whengiven to infant mice showing its protective efficacy during rotavirus infection.     

Risk factors for death in complicated diarrhoea of children.

A total of 1330 children with complicated diarrhoea who were admitted to the general ward of the International Centre for Diarrhoeal Diseases Research, Bangladesh Health Complex, during 1979 were examined. The risk of death by complication of diarrhoea, aetiology, age, and nutritional state was analysed by a logit regression model. Serum sodium concentration and coma were found to be significant predictors of death, death being related directly to coma and inversely to serum sodium concentration. An earlier study had shown that the incidence of hyponatraemia was directly related to the degree of malnutrition, but the results of logit regression analysis did not show the nutritional state to be a predictor of death. Owing to lack of data, however, serum albumin concentration could not be taken as a variable in the logit regression analysis. To determine the relation of serum albumin concentration to hyponatraemia and the cause of death in hyponatraemia further prospective studies would be necessary.     

Intestinal microflora in young children with rotavirus infection]

A total of 270 children with rotavirus diarrhea were examined. The quantitative and qualitative composition of their intestinal microflora was studied. Most frequently microorganisms of the genus Enterobacter and most seldom, Serratia were isolated. A decrease in the amount of bifidobacteria, normal Escherichia coli and an increase in the amount of lactose-negative Escherichia were noted. In cases of pronounced dysbiosis in young children the clinical course of rotavirus infection is aggravated and the period of rotavirus excretion is prolonged.     

Polypeptide specificity of antiviral serum antibodies in children naturally infected with human rotavirus.

Reassortants between serotype 3 SA11 and serotype 6 NCDV rotaviruses were used to determine the relative amounts of serum-neutralizing antibody to VP4 and VP7 of serotype 3 SA11 rotavirus in children after natural rotavirus exposure. Sera from Ecuadorian children of a population-based study and sera from children of a hospital-based study in Germany (excluding diarrhea patients) demonstrated high titers of VP7-specific but only low titers of VP4-specific antibodies. In contrast, paired sera from German children hospitalized with a symptomatic primary rotavirus gastroenteritis demonstrated a titer increase to VP4 more frequently than to VP7 protein by neutralization test and immunoblotting. For these rotavirus patients, we provided, previously, direct evidence for the development of cross-neutralizing antibodies.     

Randomised controlled trial comparing oral and intravenous rehydration therapy in children with diarrhoea.

OBJECTIVE--To determine the effectiveness of oral rehydration in children with moderate dehydration caused by gastroenteritis, and to compare the complications of oral and intravenous treatment. DESIGN--Randomised controlled trial. SETTING--Emergency department and infectious diseases ward in a large urban teaching hospital. PATIENTS--111 children aged 3-36 months who had been previously healthy, had had diarrhoea for seven days or less, had clinical signs of dehydration, and were not in shock. Six children were withdrawn because the diagnosis was incorrect (four in oral group, two in intravenous group) and one (oral group) was withdrawn at her parents'' request. INTERVENTIONS--Oral rehydration fluid was given by mouth or nasogastric tube, or both to 52 children. The remaining 52 received intravenous rehydration fluids but were allowed to drink. MAIN OUTCOME MEASURES--Success or failure of rehydration. Number of times child vomited or passed stool after starting treatment. Time taken to rehydrate. RESULTS--Oral treatment failed in two children (failure rate 3.8%, upper 95% confidence limit 11.6%) and intravenous treatment in none. Vomiting was more common in the oral group (p less than 0.01): 26 of 50 children (52%) in the oral group and 11 of 50 (22%) in the intravenous group vomited during rehydration. There was no significant difference between the two treatment groups in the number of stools passed during rehydration (p = 0.09). None of the children had serious complications of treatment. CONCLUSION--Rehydration by mouth or nasogastric tube is a safe and effective treatment for moderately dehydrated children with gastroenteritis.     

Polymicrobial infections in children with diarrhoea in a rural area of Jordan

Polymicrobial infections associated with diarrhoea are common in developing countries. Stool specimens were collected from 220 patient children and 100 controls. Potential pathogenic agents isolated from 143 (65%) children were identified by molecular and standard microbiological methods. Co-infections with two or more agents were detected in 50 (35%) cases. Escherichia coli, Shigella dysenteriae, Giardia and Entamoeba histolytica were found to be predominant. The etiologic agents could not be determined in 77 (35%) cases. The most significant risk factors were the age, the education level of the mother and the use of non-chlorinated water. The high infection rate of diarrhoeal diseases is a strong indication that these pathogens circulate easily through the population.     

Two or more enteropathogens are associated with diarrhoea in Mexican children

Background

The Apicomplexa are a diverse group of obligate protozoan parasites infesting a wide range of invertebrate and vertebrate hosts including humans. These parasites are notoriously difficult to control and many species continue to evolve resistance to commercial antibiotics. In this study, we sought to find an effective chemotherapeutic treatment against arthropod gregarines (Apicomplexa), and to identify candidate compounds for testing against other groups of protozoan parasites.

Methods

We tested eleven commercial antibiotics against a gregarine parasite of Romalea microptera grasshoppers. Infected insects were fed daily, lettuce containing known amounts of specific antibiotics. On Days 15 or 20, we measured the number of gregarines remaining in the digestive tract of each grasshopper.

Results

Treatment with metronidazole and griseofulvin in host insects significantly reduced gregarine counts, whereas, gregarine counts of insects fed, albendazole, ampicillin, chloramphenicol, fumagillin, quinine, streptomycin, sulfadimethoxine, thiabendazole or tetracycline, were not significantly different from the controls. However, albendazole produced a strong, but non-significant reduction in gregarine count, and streptomycin exhibited a non-significant antagonistic trend.

Conclusion

Our results confirm that gregarine infections are difficult to control and suggest the possibility that streptomycin might aggravate gregarine infection. In addition, the insect system described here, provides a simple, inexpensive, and effective method for screening antibiotics.     

Natural immunity to rotavirus infection in children

Annual deaths in infants and young children due to rotavirus (RV) infection are around 100,000 in India and about 600,000 globally. Development of a vaccine for this disease is a high priority. The protective mechanisms for RV diarrhea in human are not fully understood, but it is known that children develop natural immunity against RV. Early exposure to RV results in most severe episode of diarrhea and subsequent infections are milder or asymptomatic. Of the immune responses measured during natural infection, RV-specific antibodies have been well documented, whereas data on cellular immunity in humans are sparse. It is generally thought that two outer capsid proteins VP4 and VP7 play a critical role in protective immunity by stimulating production of neutralizing antibodies. While serotype- specific protection mediated by antibodies directed against the outer capsid proteins may be a mechanism of protection, such a correlate for protection has been difficult to demonstrate in humans during clinical trials. Increasing evidences suggest that viral proteins that lack a capacity of eliciting neutralizing antibody response also induce protective immunity. Limited efforts have focused on the role of non-structural proteins in protective immunity. This review describes current understanding of antibody responses in children with focus on responses specific to viral antigens with their possible role in protective immunity. We have also briefly reviewed the responses elicited to non-antibody effectors during RV infection in human subjects.     

Cryptosporidiosis in young children suffering from diarrhoea in Riyadh, Saudi Arabia.

A one-year study of patients (0-120 months of age) with diarrhoea at King Abdel-Aziz University Hospital (KAUH) in Riyadh, Saudi Arabia, detected two cases of cryptosporidiosis. Stool specimens from 174 children with diarrhoea and negative for other parasitic infection were examined using a safranin-methylene blue stain (S-MB). Two children (L.1%) were showing Cryptosporidium oocysts. None of 50 control children who did not have diarrhoea and was free of Giardia lamblia was Cryptosporidium positive.