Hepatitis E in Hetian city. Analysis of 562 cases]

Between August and September 1987, 562 patients were hospitalized with acute non-A, non-B hepatitis. The male to female ratio was 1.4:1, and 75% of the patients was of 15-40 years of age. Jaundice developed in 87%. The overall case-fatality rate was 1.4%, but it was highest among pregnant women (5.2%) and newborn infants (24.2%). In general, the disease was self-limited with no evidence of chronic infection. Liver biopsies obtained during the acute illness showed portal inflammation and cytoplasmic cholestasis. Of 31 specimens of stool examined with a prototype ELISA for HEV antigen, 8 were found to be 'positive' and confirmed with immune electron microscopy (IEM). IEM examination of 'patients' stool revealed 27-32 nm viruslike particles. Inoculation of rhesus monkeys with patients stool containing virus-like particles produced acute hepatitis and the acute phase serum reacted with these particles in IEM, while preinoculation serum specimens were non-reactive.     

Small round viruses isolated from acute infectious nonbacterial gastroenteritis in Fukuoka

The existence of virus in fecal specimens was investigated by electron microscopy in five outbreaks of nonbacterial acute gastroenteritis. Small round viruses (SRV) were found in all outbreaks. The negatively stained particles were about 30-35 nm in diameter and with ragged edges. Morphological characteristics resembled each other. Immune electron microscopical examination revealed large aggregates of SRV particles and antibody in convalescent sera from patients of all outbreaks. Furthermore, the second outbreak caused by oysters contaminated with SRV seemed to be associated with the Hawaii agent.     

Persistent diarrhea signals a critical period of increased diarrhea burdens and nutritional shortfalls: a prospective cohort study among children in northeastern Brazil

Persistent diarrhea (PD; duration >/=14 days) is a growing part of the global burden of diarrheal diseases. A 45-month prospective cohort study (with illness, nutritional, and microbiologic surveillance) was conducted in a shantytown in northeastern Brazil, to elucidate the epidemiology, nutritional impact, and causes of PD in early childhood (0-3 years of age). A nested case-control design was used to examine children's diarrhea burden and nutritional status before and after a first PD illness. PD illnesses accounted for 8% of episodes and 34% of days of diarrhea. First PD illnesses were preceded by a doubling of acute diarrhea burdens, were followed by further 2.6-3.5-fold increased diarrhea burdens for 18 months, and were associated with acute weight shortfalls. Exclusively breast-fed children had 8-fold lower diarrhea rates than did weaned children. PD-associated etiologic agents included Cryptosporidium, Giardia, enteric adenoviruses, and enterotoxigenic Escherichia coli. PD signals growth shortfalls and increased diarrhea burdens; children with PD merit extended support, and the illness warrants further study to elucidate its prevention, treatment, and impact.     

Enteropathogens associated with acute and persistent diarrhea in Bangladeshi children less than 5 years of age.

A longitudinal study of diarrhea was carried out from May 1988 to April 1989 by household surveillance of 705 children less than 5 years old in rural Bangladesh. Stool samples were examined for enteric pathogens at the beginning of each diarrheal episode. For persistent episodes, stool examination was repeated on days 15-17 of the illness. For each case of persistent diarrhea, stool samples from age-matched acute diarrheal and healthy controls were examined. Compared with healthy controls, cases of diarrhea were associated with Shigella species (P = .07) and rotavirus (P less than .05). Diffusely adherent Escherichia coli (P less than .05) and cryptosporidia (P = .07) were the only enteropathogens associated with persistent diarrhea in comparison with acute diarrhea. No more than 15% of children had the same class of pathogen identified from stool on both days 1-3 and days 15-17, indicating that persistent infection was uncommon. However, a different enteropathogen was frequently found on days 15-17, suggesting that sequential infection may be a cause of persistent diarrhea.     

Case-Control Study of Diarrheal Disease Etiology in a Remote Rural Area in Western Thailand

The objective was to assess the association of enteric pathogens in diarrheal disease in a remote rural area in Thailand. Stool specimens were collected from 236 children aged 3 months to 5 years with acute diarrhea (cases) and from 236 asymptomatic controls. Standard microbiologic methods, and enzyme immunoassay for viral pathogens, Giardia, and Cryptosporidium, were used to identify enteric pathogens with susceptibility testing by disk diffusion. Campylobacter, Plesiomonas, Salmonella, and enterotoxigenic Escherichia coli were commonly isolated from cases and controls (22% versus 25%, 10% versus 11%, 6% versus 9%, and 10% versus 6%, respectively). Only Shigella, rotavirus, and adenovirus were identified significantly more frequently in cases than controls (9% versus 0%, 18% versus 3%, and 16% versus 2%, respectively), whereas Giardia lamblia was detected less often in cases than controls. Most pre-school children were infested with enteric pathogens; laboratory-based studies are important to understand the epidemiology of enteric pathogens in remote areas among marginal populations.     

Micronutrients and infection: interactions and implications with enteric and other infections and future priorities

Symposium presentations have focused on the elegant molecular science and the biologic mechanisms by which micronutrients play critical roles in cellular and humoral immune responses, cellular signaling and function, and even in the evolution of microbial virulence. The concluding session examined the practical issues of how best to evaluate the nutritionally at-risk host, especially in the areas of greatest need-an analytical model of nutrient-immune interactions, implications of nutritional modulation of the immune response for disease, and the implications for international research and child health. This overview illustrated how malnutrition may be a major consequence of early childhood diarrhea and enteric infections, as enteric infections may critically impair intestinal absorptive function with potential long-term consequences for growth and development. The potentially huge, largely undefined DALY (disability-adjusted life years) impact of early childhood diarrheal illnesses demonstrates the importance of quantifying the long-term functional impact of largely preventable nutritional and infectious diseases, especially in children in developing areas.     

Prevalence of intestinal microsporidiosis in human immunodeficiency virus-infected patients with diarrhea in major United States cities

To determine the prevalence of intestinal microsporidiosis in HIV-infected patients, we performed a prospective study of HIV-infected patients with diarrheal illnesses in three US hospitals and examined an observational database of HIV-infected patients in 10 US cities. Among 737 specimens from the three hospitals, results were positive for 11 (prevalence 1.5%); seven (64%) acquired HIV through male-to-male sexual contact, two (18%) through male-to-male sexual contact and injection drug use, and one (9%) through heterosexual contact; one (9%) had an undetermined mode of transmission. Median CD4 count within six months of diagnosis of microsporidiosis was 33 cells/microL (range 3 to 319 cells/microL). For the national observational database (n = 24,098), the overall prevalence of microsporidiosis was 0.16%. Prevalence of microsporidiosis among HIV-infected patients with diarrheal disease is low, and microsporidiosis is most often diagnosed in patients with very low CD4+ cell counts. Testing for microsporidia appears to be indicated, especially for patients with very low CD4+ cell counts.     

Acute diarrheal disease in children: epidemiology, prevention, and treatment

Diarrhea is one of the most common causes of morbidity and mortality in children worldwide. The causes of acute diarrhea in children vary with the location, time of year, and population studied. There is increasing recognition of a widening array of enteric pathogens associated with diarrheal diseases. Adequate fluid and electrolyte replacement and maintenance are key to managing diarrheal illnesses. Thorough clinical and epidemiologic evaluation is needed to define the severity and type of illness, exposures, and whether the patient in is immunocompromised to direct the performance of selective diagnosis cultures, toxin testing, parasite studies, and the administration of antimicrobial therapy.     

在淮南地区奶牛牛奶中发现类人乙肝病毒

近年来,我们用人的乙型肝炎标志物试剂检查了48头奶牛的牛奶,并选择4份标本作免疫电镜。结果矿务局23号、8629号奶牛的牛奶HBsAg(+);7826号和6-8238号奶牛的牛奶HBsAg(-)。免疫电镜在矿务局23号和8629号标本中查到了病毒颗粒。其中大球形颗粒直径35～45nm;小球形颗粒直径18～20nm,类似于HBV的Dane和HBsAg颗粒;较小型颗粒直径10～15nm,其本质有待于进一步研究。     

Epidemiologic and clinical features of endemic Campylobacter jejuni infection in Bangladesh

Epidemiologic and clinical features of infection with Campylobacter jejuni in Bangladesh were examined in (1) diarrheal patients infected with C jejuni, (2) healthy control subjects, and (3) village children who were cultured monthly and at each diarrheal episode during a 10-month period. C jejuni was isolated from 437 (14%) of 3,038 outpatients with diarrhea. These patients had no distinct clinical presentation and were more likely to have a mixed infection than were patients infected with other pathogens (59% vs 42%, P less than 0.01). Age-specific infection rates were greatest in infants and did not differ significantly from those in control subjects. C jejuni was isolated less frequently from village children with diarrhea than from those cultured routinely (5% vs 9%, P less than 0.05). Forty percent of 47 patients with C jejuni vs 23% of 48 control subjects (P less than 0.01) had an elevated convalescent-phase antibody titer as determined by complement fixation test. In Bangladesh, enteric infection with C jejuni is common but often asymptomatic, although pathogenicity is suggested by serologic response in some patients.     

Epidemiologic and clinical characteristics of acute diarrhea with emphasis on Entamoeba histolytica infections in preschool children in an urban slum of Dhaka, Bangladesh

The epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 Bangladeshi children (147 boys and 142 girls) 2-5 years old. The use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of Entamoeba histolytica to total diarrheal illness in this community setting. The average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average observation period of 2.8 years/child. Seventy-five percent of the diarrheal episodes were < or = 2 days in duration. Persistent diarrhea was relatively uncommon (0.2% of the children) and chronic diarrhea was observed in only one episode. Compared with malnourished and/or stunted children, better-nourished children experienced significantly fewer diarrheal episodes. The diarrheal incidence rate for children with blood group A was significantly less that that of the children with blood groups O and AB. The most frequent bacterial enteropathogens isolated from diarrheal stool specimens were enterotoxigenic Escherichia coli (9%) and Aeromonas species (9%), followed by Plesimonas shigelloides (4%) and Shigella flexneri (3.8%). Rotavirus was the most common viral agent isolated from diarrheal stool samples (5%). Giardia lamblia, Cryptosporidium parvum, and E. histolytica were identified in 11%, 8.4%, and 8%, respectively, of the diarrheal stool specimens. Dysentery was observed in 7.7% of all diarrheal episodes. The most common pathogens isolated from dysenteric stool were S. flexneri (11.6%), Aeromonas sp. (10%), E. histolytica (8.7%), Campylobacter jejunii (5.8%), P. shigelloides (4.3%), and A. caviae (4.3%). The overall incidence rate of E. histolytica-associated diarrhea was 0.08/child-year. Visible blood and hemoccult test-detected blood loss was found in 7% and 25%, respectively, of cases of E. histolytica-associated diarrhea. Children who had recovered from a diarrheal episode with E. histolytica, but not E. dispar, had half the chance of developing subsequent E. histolytica-associated diarrhea, consistent with the development of species-specific acquired immunity. In conclusion, the use of modern diagnostic tests demonstrated that E. histolytica contributed to overall morbidity from diarrheal illness. Understanding the etiology, frequency, and consequences of acute diarrhea in children from a developing country should aid in the design of interventions to improve child health.     

INFECTIOUS DIARRHEA IN CHILDREN UNDERGOING BONE-MARROW TRANSPLANTATION

Fecal flora of 12 children undergoing bone-marrow transplantation was monitored prospectively using comprehensive microbiological techniques. Diarrhea developed at least once in ten of the 12 children (83%), and a total of 24 episodes were recorded. Recognised gut pathogens were isolated from 11/21 (52%) diarrheal episodes where fecal specimens were obtained. Enteric pathogens identified included viral pathogens in 19% (rotaviruses, 'enteric' adenoviruses), parasites in 19% (cryptosporidium, Giardia lamblia) and cytotoxic C. difficile (14%). Excretion of clostridial species (including cytotoxin negative C. difficile, C. innocuum ) occurred in 90% of diarrheal episodes when no enteric pathogen was identified. These results suggest that infection is often responsible for diarrhea associated with bone-marrow transplantation. Prophylaxis against enteric infection might reduce the morbidity and mortality associated with severe diarrhea in bone-marrow transplanted children. (Aust NZ J Med 1989; 19: 31–36.)     

Enterotoxigenic Bacteroides fragilis-associated diarrhea in children 0-2 years of age in rural Bangladesh

The burden of enterotoxigenic Bacteroides fragilis (ETBF)-related diarrhea was determined in a birth cohort of 252 children in rural Bangladesh. Isolation rates of ETBF in stool and risk factors for acquisition of ETBF and disease were established. Of 382 B. fragilis-positive specimens, 14.4% of the strains found in them produced enterotoxin, as determined by a tissue-culture assay. The overall isolation rate of ETBF was 2.3% (40/1750) from diarrheal specimens and 0.3% (15/5679) from nondiarrheal specimens collected throughout the 2 years of the study (P < .001). ETBF was isolated from 20.3% (40/197) of the B. fragilis-positive diarrheal specimens and from 8.1% (15/185) of the B. fragilis-positive nondiarrheal specimens (P < .001) and was significantly associated with acute diarrheal disease in children > or = 1 year of age (P = .0001). The diarrheal illness was mild in nature. In conditional multivariate analyses that examined environmental and host risk factors, the presence of livestock in the household area was linked to the acquisition of ETBF (chickens, P < .05; cows, P = .06). ETBF was found to be a small but significant contributor to diarrheal disease in this rural community. Improved management of livestock may be useful for the prevention of ETBF infection.     

Endemic Cryptosporidium and Giardia lamblia infections in a Thai orphanage

We conducted a point prevalence survey for enteric protozoa in 205 institutionalized orphans 1-61 months of age in Bangkok, Thailand. Cryptosporidium was identified in 17 children (8%), Giardia lamblia in 42 (20%), and 3 children (1%) had both parasites. At the time of diagnosis, diarrheal symptoms were present in a minority of subjects: 36% of children with Cryptosporidium alone, 10% with G. lamblia alone, and in 20% of those with neither parasite. Although chronic nutritional status (height/age) was similar in all groups, acute nutritional status (weight/height) was lower only in children with Cryptosporidium (Z score = -1.39 +/- 0.13) compared with children with G. lamblia (mean Z score +/- SEM = -0.56 +/- 0.26) or neither parasite (Z score = -0.78 +/- 0.13; P = 0.05). Detectable levels of Cryptosporidium-specific IgG antibodies by ELISA were identified in 15 of 16 Thai children with Cryptosporidium and in 17 of 19 Thai children without Cryptosporidium (mean OD +/- SEM = 1.27 +/- 0.18 vs. 1.06 +/- 0.13, respectively), but in only 1 of 18 sera from toddlers in day-care centers in Denver, CO (OD = 0.128 +/- 0.03). Although neither infection with Cryptosporidium nor G. lamblia was consistently associated with acute diarrheal symptoms, Cryptosporidium was more often associated with depressed acute nutritional status than G. lamblia. The high prevalence of specific antibodies to Cryptosporidium in Thai orphans suggests an association between high rates of exposure with asymptomatic excretion of the parasites.     

Cryptosporidium in 100 Australian children.

Over a consecutive 36 month period, 100 patients out of 6,980 (1.4%) from whom stool samples were examined had oocysts of Cryptosporidium detected on fecal microscopy. Three patients were receiving cytotoxic chemotherapy and adequate clinical information was available from 84 of the remainder. Fifty per cent of patients were aged 1 to 2 years, 29% were less than 12 months and the rest were more than 2 years of age. More than one-quarter of the patients were Australian Aborigines. Isolations of cryptosporidia were most prevalent in late summer, autumn and early winter. Most patients (89%) had diarrhea, more than 75% had vomiting and 44% were dehydrated, mostly to a mild degree. Other symptoms included fever (11%) and abdominal pain (11%). Ten percent of patients were apparently symptomless. Cryptosporidium sp. is the second most commonly identified intestinal parasite, after Giardia intestinalis, in fecal specimens examined in our children's hospital. The high rate of isolation in Aboriginal children emphasized the importance of enteric pathogens in this group and the role of inadequate hygiene in relation to diarrheal disease in young Aborigines.     

Enteric infections and diarrhea in human immunodeficiency virus-infected persons: prospective community-based cohort study. Swiss HIV Cohort Study.

BACKGROUND: Persons infected with human immunodeficiency virus (HIV) are at increased risk for diarrhea and enteric infections. We studied (1) the epidemiology of enteric pathogens associated with diarrhea, (2) the diagnostic yield of stool examination and endoscopic evaluation, (3) risks to develop diarrhea, and (4) the impact of diarrhea on patients' survival. METHODS: A total of 1933 participants in the Swiss HIV Cohort Study were prospectively followed up for a median of 25.5 months. A total of 560 diarrheal episodes were evaluated by standardized stool examination. Endoscopic evaluation was performed in 25% of patients with chronic diarrhea. RESULTS: The incidence of diarrhea was 14.2 per 100 person-years (95% confidence interval, 13.0-15.4). Among patients with CD4 cell counts below 0.05 x 10(9)/L, the probability to develop diarrhea within 1, 2, and 3 years was 48.5%, 74.3%, and 95.6%, respectively. The risk to develop diarrhea was increased among patients with severe immunodeficiency, homosexual men, and patients taking antiretroviral therapy. Pneumocystis carinii chemoprophylaxis did not reduce the risk of diarrhea. Diarrhea was an independent negative predictor of survival. Enteric pathogens were detected in 16.5% of 212 acute diarrheal episodes and in 46% of 348 chronic diarrheal episodes. The sensitivity of histological and stool examination was similar except for the diagnosis of intestinal cytomegalovirus infection and leishmaniasis, which required invasive evaluation. CONCLUSIONS: Intestinal infections were diagnosed in less than 50% of chronic diarrheal episodes. The prevalence of enteric pathogens tended to decrease during the observation period, possibly because of improved antiretroviral therapy. Endoscopic evaluation did not improve the diagnostic yield compared with stool examination except for the diagnosis of cytomegalovirus enteritis and leishmaniasis.     

Coronavirus-like particles and other agents in the faeces of children in Efate, Vanuatu

Between June 1979 and July 1980, faecal specimens were collected from 100 children in Efate, Vanuatu, and examined for the presence of virus-like particles by direct negative staining electron microscopy. Of the children, 40 were hospital patients 22 of whom had gastroenteritis and 18 had other illnesses. The remaining 60 children were apparently healthy controls. Coronavirus-like particles were the most common agents encountered and were detected in approximately 20% of all three groups of children. Particles with the morphological features of calicivirus, astrovirus, adenovirus and parvovirus were also detected.     

Diarrheal morbidity and mortality in children in the Central African Republic

Diarrheal morbidity and mortality in children less than 5 years old were studied in Bangui, Central African Republic, by a cluster survey. We found a high prevalence of diarrheal disease with an estimated annual incidence of 7 episodes of diarrhea per child per year. The estimated annual mortality rate for children less than 5 years old was 28.6 per 1,000 and 85.8 per 1,000 for infants; 51.6% of deaths were reported to be associated with diarrhea. During the survey, stool specimens were collected from 133 children with current diarrhea and 117 control children to study the etiologic agents of diarrheal disease in the community. An enteric pathogen was identified in 58% of diarrheal children's stools and 48% of stools of well children. A statistically significant association between diarrhea and rotavirus was found, with it being isolated from 8 of 33 (24%) of stools of infants with diarrhea compared to 0 of 25 (0%) of control infants. Isolation rates for Campylobacter jejuni, Entamoeba histolytica, pathogenic Escherichia coli, and other bacterial enteropathogens did not differ significantly between children with diarrhea and control children.     

Work-up for infectious diarrhea after allogeneic hematopoietic stem cell transplantation: single specimen testing results in cost savings without compromising diagnostic yield

BACKGROUND: Diarrhea is a common complication of allogeneic bone marrow transplantation. Microbiologic stool studies are frequently ordered to rule out infectious etiology. The utility of examining multiple stool specimens per diarrheal episode has not been examined. METHODS:. We performed a retrospective review of 169 adult and pediatric patients who underwent hematopoietic stem cell transplantation at Memorial Sloan-Kettering Cancer Center from January 1, 2000 though December 31, 2001, who had at least 1 microbiologic stool study. We report on the incidence of enteric pathogens in our population and diagnostic yield of stool studies. A diarrheal episode was defined as a 14-day period from the date of the first stool study. Cost savings analysis was based on projected savings from implementation of proposed guidelines to the study population. RESULTS: A total of 1649 stool tests were performed (mean 10.6 tests per patient). An infectious cause of diarrhea was found in 45 (28.8%) patients. Diagnostic yield was 6.2% for Clostridum difficile toxin assay, 12.9% for viral cultures, and 1.3% for rotavirus enzyme immunoassay. Bacterial cultures for enteric pathogens, examination for parasites, and rotavirus antigen assay combined had 0.5% positive yield. CONCLUSIONS: Testing of multiple specimens per diarrheal episode did not increase diagnostic yield. The estimated cost savings by implementing single testing for each type of stool study per diarrheal episode was $49,764 annually (in 2001 US dollars). Judicious use of stool tests to evaluate diarrhea results in significant cost savings without compromising diagnostic yield.