Rotavirus carriage, asymptomatic infection, and disease in the first two years of life. II. Serological response

Serological response to rotavirus and virus shedding were prospectively studied in 179 children (neonatal to 24-month-old) upon admission to a hospital during an 11-month period. Analysis of the evolution of IgG and IgM ELISA titers revealed 24 cases of rotaviral disease (serological response and diarrhea), 13 cases of asymptomatic infection (serological response and no diarrhea), 36 cases of virus carriage (absence of a serological response), three cases of past infection, and six possible cases of nosocomial infection. Rotaviral disease was encountered two out of three times and was characterized by diarrhea associated with fever and vomiting. Asymptomatic rotaviral infection and disease, observed from the neonatal period onwards, affected 2% of neonates, 20% of one- to six-month-old children, and 37% of 7-24-month-old children. In contrast, virus carriage occurred in 27%, 19%, and 14% of those children respectively. Altogether these results indicate that during the period 1-24 months of age, when asymptomatic rotaviral infection and disease were prevalent, approximately two of 10 children had rotaviral disease, one of 10 had asymptomatic infection, two of 10 were virus carriers, and five of 10 were not infected with rotavirus.     

Hospital-based surveillance for rotavirus diarrhea in children in Yangon, Myanmar

Diarrhea is a common childhood illness in Myanmar, and rotavirus is the single most important etiological agent of diarrhea. Surveillance for rotavirus diarrhea in children <5 years of age was conducted in a tertiary pediatric hospital in Yangon, Myanmar, from January 2002 through December 2003. Stool specimens obtained from children admitted to the hospital for acute diarrhea were tested for the presence of rotavirus by use of an enzyme-linked immunosorbent assay. Diarrhea was the cause of 5671 (18%) of all hospitalizations of children <5 years of age during the 2-year study period (n = 30,869). Rotavirus was identified in 923 (53%) of the 1736 stool specimens tested, and rotavirus infection was associated with approximately 10% of all hospitalizations of children. Rotavirus diarrhea most frequently occurred in children 6-17 months of age, and it was more commonly identified in boys (62% of children with rotavirus diarrhea were boys). The seasonal pattern of rotavirus disease mimicked that of diarrheal illness due to all causes, with the peak season for rotavirus disease occurring from November through February (i.e., during the cool, dry season). During the study period, 53 of the children who were hospitalized for diarrhea died. The present study confirms the importance of the etiological role that rotavirus plays in childhood diarrhea.     

The detection of enteropathogens in acute diarrhea in a family cohort population in rural Egypt

In 8 villages of rural northeastern Egypt, a 2-year study of the etiologic agents associated with episodes of diarrhea was carried out. Stool specimens (3,243) from 3,513 episodes of diarrhea were processed for enteropathogens. The most commonly identified agents in the group with diarrhea were Giardia lamblia (44%), heat stable enterotoxin (ST)-producing enterotoxigenic Escherichia coli (ETEC) (15%), heat labile toxin (LT)-producing ETEC (12%), enteropathogenic E. coli (EPEC) (4%), rotavirus (3%), Shigella (2%) and Salmonella (1%). Isolation rates were increased in cases compared to controls for all agents except G. lamblia and EPEC strains. Rotavirus, Salmonella and ST-producing ETEC were more frequently isolated during cooler months and Shigella and LT-ETEC occurred more commonly in warmer months. Campylobacter, EPEC, Giardia and E. histolytica did not show a discernable seasonal pattern. Rotavirus was primarily associated with diarrhea in infants only. Forty-four percent of children experienced at least 1 bout of rotavirus diarrhea by the age of 3 years. Vomiting was reported in 65% of cases of rotavirus infection. Dehydration was reported in greater than 40% of those with rotavirus-, Salmonella-, Campylobacter-, LT-ETEC- and EPEC-associated illness and in those without an identifiable agent. While rotavirus was implicated in 3% of cases overall, when vomiting or vomiting plus dehydration occurred, rotavirus was identified with a rate of 10% and 12%, respectively. Dysentery was common only in Shigella cases, occurring in 24%. A decrease in occurrence of rotavirus, Campylobacter and possibly EPEC illness was seen in the infants less than 6 months of age who were breast-fed when compared to those who were not.     

Enteropathogens and other factors associated with severe disease in children with acute watery diarrhea in Lima, Peru

To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children <5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (out-patients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio [OR]=2.3, 95% confidence interval [95% CI]= 1.6-3.2); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics OR=6.8, 95% CI=3.6-12.8). The high prevalence of rotavirus and its association with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.     

Fecal rotaviruses, adenoviruses, coronavirus-like particles, and small round viruses in a cohort of rural Costa Rican children

Excretion patterns of fecal viruses were studied in a cohort of 51 rural Costa Rican children. The presence of rotavirus, adenovirus, coronavirus-like particles, and small round viruses was investigated by electron microscopy (EM) in 2,516 extracts of weekly fecal specimens. Rotavirus was in addition studied with ELISA. The incidence of diarrhea was 0.7 episodes per child-year. Rotavirus was the most common virus (0.53 infection/child-year), followed by adenovirus (0.46 infection/child-year), and coronavirus-like particles (0.24 infection/child-year). However, the pathogenicity of rotavirus and adenovirus was low: only 3 of 24 rotavirus infections and 2 of 21 adenovirus infections were associated with diarrheal illness (12.5% and 9.5%, respectively). Small round viruses were detected in 23 specimens, but could not be assigned to a particular group of viruses. Children who excreted coronavirus-like particles and small round viruses were asymptomatic. Typical Norwalk-like viruses, astrovirus or calicivirus were not encountered. Rural conditions, good hygiene and prolonged breast feeding may explain the reduced exposure and pathogenicity of viral enteropathogens in rural Costa Rica.     

Diarrhea associated with rotavirus in rural Guatemala: a longitudinal study of 24 infants and young children.

A population of 24 infants and young children followed prospectively during the first 3 years of life was studied for the occurrence of rotavirus infection by using enzyme-linked immunosorbent assay to detect virus in stools. Infection with rotavirus was associated with 26 (14.2%) of 183 selected diarrheal episodes. Twenty of the 24 infants and young children had diarrhea associated with rotavirus on at least one occasion and six had two such episodes. Rotavirus infection was documented in over 50% of the dehydrating episodes studied, thus further indicating the importance of rotavirus in this population.     

Gastroenteritis in children: a two-year review in Manitoba. I. Etiology.

During two years, 1,217 children hospitalized with gastroenteritis at the Children's Centre in Winnipeg, Manitoba, Canada were studied. Bacterial pathogens were present in 25% of these children: enteropathogenic Escherichia coli in 120, Shigella in 139, Salmonella in 24, and multiple pathogens in 18. Rotavirus was detected in 54 (11%) of 472 patients examined. Rotavirus and enteropathogenic E. coli were the most common pathogens in infants, and Shigella was the most common in older children. Bacterial diarrhea occurred more commonly in summer, whereas rotavirus infection occurred more commonly in winter. Among 276 children screened, enterotoxigenic E. coli was found in three, and Aeromonas shigelloides that produced a similar toxin in two others. Enteroinvasive E. coli was not detected in 70 children. Organisms producing toxins "cytotoxic" to HeLa cells were isolated from three of 90 children. Screening for enterotoxigenic or enteroinvasive organisms was not productive of a significant number of pathogens, and, although screening for rotavirus did improve the number of etiologic diagnoses, the etiology of the majority of cases of diarrhea remained unknown.     

Burden of Norovirus and Rotavirus in Children after Rotavirus Vaccine Introduction,Cochabamba, Bolivia

The effectiveness of rotavirus vaccine in the field may set the stage for a changing landscape of diarrheal illness affecting children worldwide. Norovirus and rotavirus are the two major viral enteropathogens of childhood. This study describes the prevalence of norovirus and rotavirus 2 years after widespread rotavirus vaccination in Cochabamba, Bolivia. Stool samples from hospitalized children with acute gastroenteritis (AGE) and outpatients aged 5–24 months without AGE were recruited from an urban hospital serving Bolivia''s third largest city. Both viruses were genotyped, and norovirus GII.4 was further sequenced. Norovirus was found much more frequently than rotavirus. Norovirus was detected in 69/201 (34.3%) of specimens from children with AGE and 13/71 (18.3%) of those without diarrhea. Rotavirus was detected in 38/201 (18.9%) of diarrheal specimens and 3/71 (4.2%) of non-diarrheal specimens. Norovirus GII was identified in 97.8% of norovirus-positive samples; GII.4 was the most common genotype (71.4% of typed specimens). Rotavirus G3P[8] was the most prevalent rotavirus genotype (44.0% of typed specimens) and G2P[4] was second most prevalent (16.0% of typed specimens). This community is likely part of a trend toward norovirus predominance over rotavirus in children after widespread vaccination against rotavirus.     

Epidemiology of rotaviral infection in adults

Although classic rotaviral gastroenteritis occurs in children between the ages of six and 24 months, infection with rotavirus is common in all age groups, including adults. Virtually all adults have been infected, as is demonstrated by the presence of serum antibodies, but previous infection does not protect against new infection with the same or a different serotype. Rotaviral infection of adults is seen in five settings: secondary contacts from pediatric cases, with variable attack rates in adults; waterborne outbreaks, which are often characterized by higher attack rates in adults than in children; travelers' diarrhea; epidemic spread in isolated or closed populations, often in the absence of contact with children; and endemic infections, which may account for 5%-10% of sporadic cases of diarrhea in adults. Frequent asymptomatic infections with rotavirus occur, and they may be important in the epidemiology of the disease. Although rotaviral infections in adults tend to be milder than those in children, death due to rotaviral infection in adults have been reported.     

Sentinel hospital surveillance for rotavirus diarrhea in the People's Republic of China, August 2001-July 2003

China has the second largest birth cohort in the world and the second highest number of deaths due to rotavirus infection. It is also the only country with a licensed rotavirus vaccine. Chinese policy makers now need credible estimates of the burden of rotavirus disease, to decide about vaccine use. From August 2001 through July 2003, prospective hospital-based surveillance for rotavirus diarrhea among children <5 years of age was conducted in 6 sentinel hospitals. Rotavirus isolates were characterized to determine the G and P genotypes circulating during the study. Of 3149 children who were admitted to the hospitals for diarrhea and for whom screening for rotavirus was performed, 1590 (50%) had positive results of an antigen detection assay. Of all episodes of rotavirus diarrhea, 95% occurred during the first 2 years of life. The most common rotavirus strain was P[8]G3 (49% of episodes), and all the common strains were detected, including G9 strains (4% of episodes). Ongoing efforts are under way to more precisely define the burden of rotavirus diarrhea in urban and rural populations, to assess the proportion of episodes that may be due to unusual or emerging strains, and to estimate the economic burden of rotavirus disease.     

Treatment of rotaviral gastroenteritis with Qiwei Baizhu powder

AIM To observe the effects of Qiwei Baizhu Powder(QWBZP)on rotaviral gastroenteritis in children and inanimal models.METHODS Enrolled patients were divided into twogroups,and one group was treated with oral rehydrationsolution(ORS)and the other treated with oral liquid ofQWBZP.Neonate mice were orally infected with 50μLrotavirus suspension(4×10~8 PFU/mL)and treated withORS or oral liquid of QWBZP,respectively.RESULTS Eighty-three cases of rotaviral gastroenteritistreated with QWBZP revealed a better efficacy than thattreated with ORS(X~2=10.87,P<0.05).The contents ofsodium and glucose as well as number of patients withpositive human rotavirus antigen in stool in QWBZP groupwere all less than that in ORS group.In animal models,QWBZP was found effective in treating rotavirusgastroenteritis in neonate NIH mice,as compared withcontrol groups.In QWBZP group,the mortality of infectedmice was decreased by 73.3%,the body weight ofinfected mice was increased,the contents of sodium andglucose as well as number of mice with positive rotavirusantigen in feces were significantly reduced,and thepathological changes such as damage of small intestinalmucosa and villi were also obviously alleviated.CONCLUSION QWBZP has effects on improving theabsorptive function of small intestine,shortening theduration of diarrhea and rotavirus shedding from stool andalleviating the pathological changes of small intestineinduced by rotavirus.     

Sentinel hospital surveillance for rotavirus diarrhea in Taiwan, 2001-2003

We examined the epidemiological profile of rotavirus infection among children hospitalized for diarrhea in Taiwan, to assess the burden of this disease. From 1 April 2001 through 31 March 2003, children <5 years old with gastroenteritis admitted to 4 sentinel hospitals were enrolled in a surveillance study and had stool specimens tested for the presence of rotavirus, enteric adenovirus, and the bacterial pathogens for which routine screening is performed. For 52% of patients, a recognized enteric pathogen was identified, including rotavirus (43% of patients), bacteria (11%), enteric adenovirus (2.5%), and a mixture of pathogens (3.9%). Rotavirus was detected year-round, but great month-to-month variability made it difficult to identify a distinct seasonal pattern. Rotavirus disease was most common among children 7-23 months old, but the rate of rotavirus detection varied little between the youngest and oldest age groups. The novel strain P[8]G9 was detected most commonly (37% of strains), followed by strains P[8]G1 (31%), P[4]G2 (10%), P[8]G3 (9.3%), and P[8]G4 (3.7%). Rotavirus infection is the most important cause of diarrhea among hospitalized children in Taiwan, and a rotavirus vaccination program for young children might significantly reduce this problem.     

Protective effect of WC3 vaccine against rotavirus diarrhea in infants during a predominantly serotype 1 rotavirus season

We used a double-blind, placebo-controlled trial to study the efficacy of WC3 rotavirus vaccine administered to 104 infants (ages, three to 12 months) before the rotavirus season. Forty-nine infants received vaccine; 55 received placebo. Rotavirus disease during this season was predominantly caused by a serotype 1 strain. In placebo recipients there were 14 cases of rotavirus diarrhea (attack rate, 25%); 11 were moderate to severe (attack rate, 20%). Vaccinees experienced only three cases of rotavirus disease (attack rate, 6.1%), all mild. When all cases (whether associated with rotavirus or not) of clinically significant diarrhea (CSD) were evaluated, WC3 vaccine provided statistically significant (P less than .01) protection against the total number of episodes of CSD and reduced the number of days of CSD-associated diarrhea, vomiting, fever, or illness. Seventy-one percent of the WC3-vaccinated infants had serum antibody responses to the vaccine. The 14 placebo recipients who experienced natural disease predominantly had antibody responses to serotype 1. Sera taken after the rotavirus season revealed a nearly identical rate (40%) of natural rotavirus infection in the vaccinated and placebo groups.     

A comprehensive survey of pediatric diarrhea at a private hospital in Metro Manila.

The epidemiology of diarrhea among Filipino pediatric patients, representing a cross-section of socioeconomic strata, was investigated over a one year period. Rotavirus was detected in 33.9% of the diarrhea stools examined and was the leading cause of diarrhea in the study population. Although proportionately more rotavirus was found during the cold season, most children became infected with rotavirus during the rainy season, when diarrheal disease was at its peak in Metropolitan Manila. Enteric adenovirus types 40 or 41 were associated with only 5.4% of the diarrhea cases. Overall, one or more etiologic agents of diarrhea were detected in 67.2% of the stools examined. Many of these positive stools (21.6%) contained multiple diarrheogenic agents. Bacterial enteric pathogens were isolated from 32.3% of the cases. Nearly 70% of these patients with bacterial gastroenteritis became ill during the rainy season. Etiology specific and general risk factors associated with diarrheal illness in the study population are discussed.     

Treatment of rotaviral gastroenteritis with Oiwei Baizhu powder

AIM To observe the effects of Qiwei Baizhu Powder ( QWBZP) on rotaviral gastroenteritis in children and in animal models.``METHODS Enrolled patients were divided into two groups, and one group was treated with oral rehydration solution(ORS) and the other treated with oral liquid of QWBZP. Neonate mice were orally infected with 50 μLrotavirus suspension (4 × l0s PFU/mL) and treated with ORS or oral liquid of QWBZP, respectively.``RESULTS Eighty-three cases of rotaviral gastroenteritis treated with QWBZP revealed a better efficacy than that treated with ORS (x2 - 10.8T, P<0.05). The contents of sodium and glucose as well as number of patients with positive human rotavirus antigen in stool in QWBZP group were all less than that in ORS group. In animal models,QWBZP was found effective in treating rotavirus gastroenteritis in neonate NIH mice, as compared with control groups. In QWBZP group, the mortality of infected mice was decreased by 73.3%, the body weight of infected mice was increased, the contents of sodium and glucose as well as number of mice with positive rotavirus antigen in feces were significantly reduced, and the pathological changes such as damage of small intestinal mucosa and villi were also obviously alleviated.``CONCLUSION QWBZP has effects on improving the absorptive function of small intestine, shortening the duration of diarrhea and rotavirus shedding from stool and alleviating the pathological changes of small intestine induced by rotavirus.``     

Epidemiological profile of rotavirus infection in the Republic of Korea: results from prospective surveillance in the Jeongeub District, 1 July 2002 through 30 June 2004

To facilitate future decisions regarding the usefulness of rotavirus vaccines in the Republic of Korea, active surveillance was conducted in a network of clinics, emergency departments, and hospitals serving Jeongeub District, Korea. Children with diarrhea underwent standard clinical evaluations, and stool specimens were collected to test for the presence of rotavirus. Parents were interviewed to collect demographic and family information. From 1 July 2002 through 30 June 2004, a total of 4106 children, representing 1 (50%) of every 2 children <5 years old in the study population, were evaluated for rotavirus diarrhea. Of the 2232 stool specimens obtained throughout the year, 460 (20.6%) were rotavirus positive; however, the monthly prevalence of rotavirus infection peaked at 49.5% in February 2004. Of the 460 rotavirus-positive stool specimens, 366 were obtained from children who visited outpatient clinics, and 94 were obtained from children who were hospitalized. By extrapolating the proportion of rotavirus-positive patients to all children with diarrhea in the surveillance system, we calculate that 882 children in Jeongeub District had rotavirus infection (which would predict that there would be 702 associated clinic visits and 180 hospitalizations). Genotyping of rotavirus strains showed that 39% of strains were type G9P[8], 24% were type G1P[8], 17% were type G3P[8], and 13% were type G2P[4]. The incidence of rotavirus diarrhea peaked at age 13-24 months, and 94% of cases occurred during the first 3 years of life. The annual incidence of all rotavirus disease-associated outcomes was 56.9 cases/1000 children <5 years old (95% confidence interval [CI], 51.9-62.2 cases/1000 children <5 years old). The incidence of rotavirus disease-associated hospitalizations was 11.6 cases/1000 children <5 years old (95% CI, 9.5-14.2 cases/1000 children <5 years old). In Korea, diarrhea is common during childhood, and the incidence of diarrhea due to rotavirus infection suggests that improved programs for the prevention and control of both rotavirus diarrhea and diarrhea due to other causes are needed.     

Rotavirus infection--clinical symptoms and influence of climate

Between January 1986 and December 1989, 957 fecal specimens were collected mainly from pediatric outpatients with acute gastroenteritis during the acute phase. Rotavirus (RV) and adenovirus (AV) antigens were found in 233 (24%) and 60 (6%) of these specimens, respectively. Seventy-five % of 76 RV antigen-positive specimens collected in 1989 were determined to be serotype 1. Although both RV and AV infections occurred slightly more often in boys than in girls, there were no significant differences. About 80% of the patients infected with RV or AV were at the age of below 2 years, and the youngest case was aged 2 months. The RV antigen was most frequently detected during the winter season in low temperature and low relative humidity. The detection rate of RV antigen had negative relation with mean temperature or mean relative humidity. Diarrhea in RV infection occurred 5.5 times/day on average, and the number of diarrhea per day was significantly higher in RV antigen-positive cases than in negative cases. The mean duration of diarrhea was 4.5 days. Diarrhea was significantly observed more in the watery or watery-whitish unformed ones than in other diarrhea. Vomiting occurred in 82% of the RV-infected cases, 4 times or less in a day. The duration of vomiting was as short as 1-2 days in about 90% of patients. Three symptoms (DFV symptoms), including diarrhea (D), fever (F) and vomiting (V), were more frequently observed in RV-infected cases than in the cases with non rotaviral infection.     

Diagnostic studies of nosocomial diarrhea in children: assessing their use and value

During a 17-month period (01/11/85-05/31/86) 225 cases of nosocomial diarrhea were identified in a children's hospital. Diarrhea was considered to be nosocomial if it began at least 72 hours after the patient's hospital admission or within 3 days after discharge. One or more routine diagnostic studies for identification of a pathogen were performed in 195 (87%) cases. The most commonly performed test was the bacterial stool culture. None of these samples yielded a bacterial pathogen. The only pathogens detected by routine laboratory studies were rotavirus (61/137 [45%] samples were positive for rotavirus by ELISA) and Clostridium difficile (9/54 [17%] positive for toxin). Of the patients whose tests were positive for rotavirus 56 were younger than 2 years of age, and all were identified in the winter and spring. When multiple stool samples were tested by the diagnostic laboratory, rotavirus was identified in an additional 14 patients whose initial stool samples were negative for rotavirus. All patients whose tests were positive for C. difficile toxin had received antibiotics within the previous 3 months. Ova/parasites were not detected in 53 of the tested stools. We also identified enteric adenovirus in six patients. Viruses were identified in 95 (42%) of the 225 cases of nosocomial gastroenteritis. Nosocomial diarrhea is common in a children's hospital. Rotavirus is the most commonly identified pathogen. Rotavirus testing is valuable in children with nosocomial diarrhea who are younger than 2 years of age, especially in the winter and spring. Multiple samples may be necessary to identify rotavirus. C. difficile toxin assay should be considered for patients who are receiving or who have received antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)