The role of Clostridium difficile and viruses as causes of nosocomial diarrhea in children.

OBJECTIVE: We report surveillance of nosocomial diarrhea in children at our institution during the past decade and note different epidemiology of diarrhea due to viruses and Clostridium difficile. DESIGN: A prospective cohort study. SETTING: A university-affiliated pediatric hospital with 180 beds serving an urban area and providing referral care for the Maritime Provinces of Canada. PARTICIPANTS: Children younger than 18 years. METHODS: Surveillance was conducted from 1991 to 1999 using personal contact with personnel and review of microbiology and medical records. Nosocomial diarrhea was defined as loose stools occurring more than 48 hours after admission, with at least two loose stools in 12 hours and no likely non-infectious cause. RESULTS: Nosocomial diarrhea was the third most common nosocomial infection (217 of 1,466; 15%), after bloodstream and respiratory infections, with from 0.5 to 1 episode per 1,000 patient-days. Of 217 nosocomial diarrhea episodes, 122 (56%) had identified pathogens: C. difficile (39 of 122; 32%), rotavirus (38 of 122; 31%), adenovirus (36 of 122; 30%), and other viral (9 of 122; 7%). The median age was 1.3 years (range, 11 days to 17.9 years), 0.80 year for children with viral diarrhea, 3.9 years for children with C. difficile, and 1.5 years for children with diarrhea without a causative organism identified (P< .0001). Most children with nosocomial diarrhea were incontinent (diapered) at the time of their first episode (138 of 185; 75%), but preexisting incontinence was more common in those with viral diarrhea (93%) compared with those with no organism identified (71%) or those with C. difficile-associated diarrhea (CDAD) (49%) (P <.0001). CONCLUSIONS: C. difficile is the single most common cause of nosocomial diarrhea in our tertiary-care center, although all viral pathogens account for 69% of cases. Diapered status appears to be a risk factor for CDAD in children, and CDAD occurs more often in older children than viral nosocomial diarrhea. Further characterization of risk factors for, and morbidity associated with, nosocomial CDAD in children is warranted.     

Salmonella and Shigella gastroenteritis at a public teaching hospital in Nairobi, Kenya.

OBJECTIVE: To measure the proportion of nosocomial diarrhea cases associated with Salmonella and Shigella species. DESIGN: Prospective 6-month survey. SETTING: Tertiary care center in a developing country. PATIENTS: Pediatric and adult patients admitted with the previous 24 hours and all consenting adult or pediatric medical patients with nosocomial diarrhea. OUTCOME MEASURES: Prevalence of Salmonella and Shigella species isolated from rectal swabs at admission and among subjects with nosocomial diarrhea. RESULTS: Salmonella species and Shigella species were isolated from 3.0% and 2.5%, respectively, of 667 patients screened on admission. All admission Salmonella isolates were identified in children under 13 years of age; Shigella prevalence was similar for children and adults. Children with Salmonella at admission were significantly older and more likely to have diarrhea, fever, and some indicators of malnutrition than those from whom Salmonella was not isolated. Salmonella and Shigella were isolated from rectal cultures in 36 (10%) and 9 (2.5%) of 360 nosocomial gastroenteritis cases, respectively. Nosocomial cases occurred equally in adults and children. In adults, nosocomial Salmonella acquisition was associated with sharing a room with a diarrhea patient and previous institutionalization. In children, it was associated with recent antimicrobial therapy, crowding at home, and age between 6 months and 6 years. Nine (41%) of 22 nosocomial Salmonella cases in adults occurred in patients with human immunodeficiency virus-type 1 (HIV-1) infection, while none of 79 HIV-1-positive patients had Salmonella isolated at admission. CONCLUSIONS: Salmonella is a frequent cause of nosocomial gastroenteritis in this tertiary care institution in a developing country. Risk factors appear to differ for children and adults, and HIV-1-infected subjects may be at increased risk of acquisition. Control measures feasible for the limited resources available to such institutions require evaluation.     

Recurrent gastroenteritis among infants in Western Australia: a seven-year hospital-based cohort study

PURPOSE: To investigate factors that affect the frequency of recurrent gastroenteritis among infants in Western Australia (WA). METHODS: A 7-year retrospective cohort study was undertaken on all infants born in 1995 who were admitted for gastroenteritis during their first year of life (n=514). Linked hospitalization records of the cohort were retrieved to derive the number of readmissions, microbiologic diagnoses, patient demographics, and co-morbidities at the index episode. A negative binomial regression model adjusting for inter-hospital variations was used to determine the prognostic factors influencing recurrent gastroenteritis. RESULTS: Diarrhea with no specific etiology accounted for 54.7% of the cases presented at index admission and 55.8% of the total 676 admissions for the cohort. Of the 514 infants, 119 (23%) experienced repeated episodes of gastroenteritis. The lowest proportion of recurrences was 15.4% for patients initially admitted for bacterial or viral diarrhea. Over 85% of the recurrences from either bacterial and viral diarrhea or etiology unspecified were readmitted under the same category. Aboriginality and dehydration were significantly associated with the recurrence frequency, the adjusted incidence rate ratio being 2.86 (95% CI, 1.92-4.26) and 0.66 (95% CI, 0.49-0.88), respectively. Aboriginal infants contributed to 58% of those patients in the cohort who sustained repeated episodes of gastroenteritis. The proportion of patients with the recurrent disease was also significantly higher for Aboriginals (39%) than for non-Aboriginals (15%). The effect of dehydration was evident after accounting for within hospital correlations. CONCLUSIONS: Hospitalizations for recurrent gastroenteritis were more frequent among Aboriginal children than non-Aboriginal children in WA. Readmissions were also related to the presence of dehydration at the index episode. These findings have implications for preventive strategies to reduce the burden of gastroenteritis.     

天津市秋冬季腹泻患儿星状病毒调查

目的了解天津市秋冬季腹泻患儿的星状病毒感染情况及其分型特点。方法采用逆转录聚合酶链反应(RTPCR)技术,于2014年9月—2015年2月收集天津市儿童医院住院部1 127例疑似病毒性腹泻的婴幼儿粪便样品中的星状病毒核酸进行检测,并将部分阳性株的PCR产物进行测序,采用序列分析软件分析测序结果,推断其毒株型别,同时收集患儿的临床资料进行综合分析。结果 1 127份腹泻粪便样品中,星状病毒RT-PCR阳性99份,检出率为8.78%。感染星状病毒的患儿多为1岁以下,患儿年龄中位数为3.00月龄,且1月检出率最高。99例阳性星状病毒患儿中,有52例与其他病毒混合感染,混合感染率为4.61%,其中以诺如病毒合并星状病毒最常见。26份PCR阳性产物送往测序,经Genbank Blast及系统进化树分析,所有星状病毒均为人类星状病毒1型。结论星状病毒是天津市秋冬季婴幼儿病毒性腹泻的重要病原体,本次调查期间星状病毒以人类星状病毒1型毒株流行为主,此外存在一定比例的混合感染。     

中国七个地区1998-2005年急性腹泻住院患儿中星状病毒感染研究

目的 研究中国5岁以下腹泻住院患儿中星状病毒感染的流行病学特点，确定流行毒株血清型。方法 选择国内7个地区收集5岁以下腹泻住院患儿粪便标本，应用酶联免疫或PCR方法检测星状病毒，对星状病毒阳性标本应用RT-PCR方法分型并经测序确证。结果 1998—2005年在7个地区的调查点共收集1668份急性腹泻粪便标本，检测出星状病毒阳性标本91份，平均检出率为5．5％；病例全年均有发生，发病高峰主要集中在10月份到次年1月份；95％患儿年龄在2岁以下，其中以9～11月龄儿童发病最多，检出率为7．4％，12～17月龄、6～8月龄、0～6月龄儿童的检出率依次为6．1％、5．6％、5．6％。确定型别的49份标本中45份为HAstV-1型，1例为HAstV-3型，2例为HAstV-5型，1例为HAstV-8型。结论 星状病毒是中国婴幼儿病毒性腹泻的重要病原之一，流行毒株以1型为主，同时存在多个型别的散在流行。     

Prospective study of rotaviral infections in children hospitalized at the Clinic of Pediatric Infectious Diseases in Białystok in 2003

Rotavirus is the most common gastrointestinal pathogen in infants and young children. The aim of this study was to determine the role of rotavirus in acute diarrhea in children hospitalized in Pediatric Infectious Diseases Clinic in Bialystok. 658 children aged 0-7 years admitted to the ward: 466 children with gastroenteritis and another 192 without any diarrheic symptoms were tested for rotavirus infection by latex agglutination. Rotavirus was detected in 16.1% stool specimens collected from children with acute diarrhea. None of patients without diarrhea was positive for rotavirus on admission--2% of this patients acquired symptomatic rotavirus infection during hospitalization. This study delivers epidemiological data on rotavirus infection and shows the need of further study on etiology of viral gastroenteritis in children in our district.     

Nosocomial rotavirus infections in a pediatric unit: surveillance during four successive winters

The incidence of rotavirus and RSV outbreaks during winter seasons leads to overcrowding of pediatric units in the Paris area, and increases the risk of viral nosocomial infections in hospitalized young infants. OBJECTIVE: The aim of this study was to measure the incidence of rotavirus nosocomial infections in children less than 2 years of age during 4 consecutive winters. METHODS: All infants admitted in the pediatric unit during the winter were prospectively screened for rotavirus with a stools exam. All children with negative stools examination on admission but developing diarrhea after 2 days of hospitalization underwent a new screening test for rotavirus in stools. RESULTS: During the 4 consecutive winters, the global incidence of nosocomial rotavirus infection was 13.9% (12.7 to 15.9%). Asymptomatic carriage of rotavirus was detected in 3% of admitted infants. The risk of nosocomial rotavirus infection increases with young age and the length of hospital stay. CONCLUSION: The incidence of nosocomial rotavirus infections was high in this unit. It is related to overcrowding due to coincidence of diarrhea and bronchiolitis outbreaks in the Paris area and to the young age of hospitalized patients.     

163例住院腹泻患儿粪便标本星状病毒检测

目的 了解１６３例住院腹泻患儿的１７３份粪便标本中星状病毒感染情况。地应用酶联免疫吸附试验方法进行星状病毒抗原检测。结果 １６３例患儿星状病毒抗原阳性检出率为９．２％,感染主要在秋冬季。患儿多为１岁以内婴幼儿。结论该研究提示,星状病毒感染可能是北京地区秋冬季婴幼儿腹泻的重要病因之一。     

北京市儿童肠道门诊腹泻患者轮状病毒及人杯状病毒腹泻监测

目的:了解儿童腹泻患者轮状病毒及人杯状病毒腹泻流行病学特点。方法:2010年4月-2011年3月,收集228例儿童急性腹泻患者粪便标本,运用ELISA方法进行轮状病毒检测,RT-PCR方法进行人杯状病毒检测,采用Epi Info3.5.1进行统计分析。结果:228例便标本中轮状病毒、人杯状病毒检测阳性率分别为22.81%、32.89%;各月间两种病毒检出率的差异均有统计学意义(P<0.05);不同临床特征(呕吐、大便性状、便检白细胞)与轮状病毒检测阳性率的差异具有统计学意义(P<0.05),人杯状病毒检测阳性率与患者是否呕吐的差异具有统计学意义(P<0.05);轮状病毒、人杯状病毒阳性患者的误诊率分别为78.85%、77.33%。结论:儿童急性腹泻患者轮状病毒、人杯状病毒感染率较高,临床诊断存在较高的误诊率。     

Viral agents of gastroenteritis. Public health importance and outbreak management

Each year, infectious gastroenteritis causes greater than 210,000 children in the United States to be hospitalized and 4-10 million children to die worldwide. Since the mid-1970s, knowledge has increased dramatically concerning the viral agents that are responsible for much of this public health burden. Rotavirus, the most common cause of diarrhea among children, infects virtually every child in the United States by the age of 4 years and causes potentially lethal dehydration in 0.75% of children less than 2 years of age. Other recently identified pathogens include the enteric adenoviruses, calicivirus, astrovirus, and the Norwalk family of agents. Conclusive diagnosis of these viruses requires electron microscopic examination of stool specimens, a laboratory technique that is available only at a few large centers, including CDC. Stool samples from an outbreak that are submitted to CDC for detection of viral pathology should be collected in bulk from 10 ill persons during their first 48 hours of illness, while feces are still liquid, and should be stored at 4 C (not frozen). Acute- and convalescent-phase serum samples should be collected from the same persons, plus from an equal number of controls, during the first week of illness and 3 weeks thereafter. Control measures for outbreaks of viral gastroenteritis should focus on the removal of an ongoing common source of infection (e.g., an ill food handler or the contamination of a water supply) and on the interruption of person-to-person transmission that can perpetuate an outbreak in a population after the common source has been removed. Because improvements in environmental hygiene may not be accompanied by reductions of endemic diarrhea caused by viruses, immunization may play an important role in future control; vaccine trials for rotavirus are in progress. In anticipation of vaccine development and use, CDC recently began national surveillance for the viral agents of gastroenteritis. Health-care facilities involved in the detection of rotavirus or the other viral agents of diarrhea can participate.     

Nosocomial gastroenteritis in paediatric patients

Between November 1982 and April 1985, 2228 children under the age of 5 years with acute gastroenteritis were admitted to the paediatric isolation ward of Queen Mary Hospital, Department of Paediatrics, University of Hong Kong. In 56.2% the causative agent was identified as rotavirus, Salmonella, Campylobacter, Shigella, Escherichia coli or a combination of these pathogens. Our isolation procedures included cohort nursing of all diarrhoeal patients in two separate rooms (each accommodating 6 patients), barrier gowns and stringent handwashing with chlorhexidine. A total of 163 cases (13.4% of all positive cases) were identified as nosocomial infections. Rotavirus was the responsible agent for nosocomial infection in 128 cases (20% of all rotavirus infection). There were 35 patients with bacterial nosocomial infection, (7% of all the bacterial positive cases). Nosocomial rotavirus gastroenteritis was 3.4 times more frequent than nosocomial gastroenteritis due to bacterial pathogens. We conclude that modification of our present isolation procedures is necessary in order to reduce rotavirus nosocomial infection.     

诺瓦克样病毒医院感染调查

目的分析某医院诺瓦克样病毒医院感染流行特征。方法采用现场流行病学调查方法,用荧光PCR法从患者粪便标本中检出诺瓦克样病毒核酸。结果2006年12月23日-2007年1月10日,某医院报告18例老年患者群体性腹泻,病例对照分析显示年龄、南区病房、有基础病变者差异有统计学意义。结论诺瓦克样病毒医院感染可在老年住院患者中暴发,及时采取消毒为主的综合控制措施可避免疫情扩散。     

Sensor, a population-based cohort study on gastroenteritis in the Netherlands: incidence and etiology

A prospective population-based cohort study with a nested case-control study was conducted to estimate the incidence of gastroenteritis and the associated pathogens in the general Dutch population. Follow-up of two consecutive cohorts was performed by weekly reporting cards from December 1998 to December 1999. Cases and controls in the case-control study supplied a questionnaire and stool samples. The standardized gastroenteritis incidence was 283 per 1,000 person-years. The incidence rose with increasing level of education and was higher for persons with a history of diarrhea and for young children. Bacterial pathogens accounted for 5% of cases, bacterial toxins for 9%, parasites for 6%, and viral pathogens for 21%, with Norwalk-like virus (NLV) as the leading pathogen in 11% of cases. The gastroenteritis incidence was higher than that reported for England, but lower than for the United States. In community cases, viral pathogens are the leading cause of gastroenteritis, with NLV being the number one cause of illness in all age groups but one. In many countries, preventive measures are implemented to decrease bacterial infections. However, additional prevention of viral infections, especially NLV, might significantly decrease the number of gastroenteritis cases in the community.     

Outbreak of rotavirus gastroenteritis with high mortality, Nicaragua, 2005.

OBJECTIVES: We investigated a nationwide outbreak of severe rotavirus gastroenteritis in Nicaragua in children under 5 years old, leading to many consultations, hospitalizations, and deaths. We questioned whether a vaccine might have prevented these illnesses and deaths, sought to identify risk factors for death, and developed a clinical profile of children hospitalized with diarrhea. METHODS: We conducted a case-control study to determine whether children who died had access to routine immunizations, a proxy predicting access to a rotavirus vaccine. We identified risk factors for death among children who died in the outbreak compared with surviving age-matched controls with diarrhea. We collected stools, clinical data, and immunization data on children hospitalized for diarrhea to test for rotavirus, develop the profile, and forecast future access to a rotavirus vaccine. RESULTS: The outbreak from February to April 2005 caused 47 470 consultations and 52 deaths. Approximately 80% of cases and controls and 60% of children hospitalized with diarrhea had access to routine immunizations and would likely have had access to a rotavirus vaccine. With a vaccine efficacy of 85%, up to 51% of severe rotavirus cases and up to 68% of deaths could have been prevented if a rotavirus vaccine were available as part of routine childhood immunizations. Study of 35 case-control pairs indicated that severe illnesses, malnutrition, and care by traditional healers were risk factors for death. Rotavirus was found in 42% of samples from hospitalized children and was associated with severe disease and dehydration. CONCLUSIONS: The impact of the seasonal outbreaks of rotavirus disease could be diminished with a rotavirus vaccine, improvements in oral rehydration programs, and training of traditional healers in the proper management of children with acute diarrhea.     

Rotavirus vaccines and the prevention of hospital-acquired diarrhea in children

Rotavirus, the major cause of severe acute dehydrating gastroenteritis in children less than 5 years of age, is responsible for an estimated 20-50% of all hospitalizations for diarrhea and approximately 440,000 deaths annually, primarily in the developing world. Rotavirus vaccines are considered the most promising means for disease prevention. While the prime rationale for developing rotavirus vaccines has been the enormous burden of rotavirus infection leading to severe and fatal disease, a secondary benefit may be the prevention of nosocomial rotavirus diarrhea. We have reviewed the burden of intra-hospital-acquired rotavirus infections from several countries and found that in the United States alone, as many as 25% of rotavirus hospitalizations or approximately 16,000-18,000 hospitalizations each year might be due to rotavirus infections acquired within hospitals. To countries with low rotavirus-associated mortality, prevention of these infections and the resulting economic savings therefore represent an important secondary goal. Several rotavirus vaccines are in development, and two candidates are currently being tested in large-scale safety and efficacy trials. Development of safe and effective rotavirus vaccines will protect children worldwide against the severe consequences of rotavirus infections including prolonged hospitalizations for nosocomially acquired infections.     

Acute viral gastroenteritis

Two virus-like particles have been found to be associated with acute viral gastroenteritis. One, a 270-nm parvovirus-like particle (the Norwalk agent), was visualized and recognized by immune electron microscopy in an infectious stool filtrate derived from a community outbreak of nonbacterial gastroenteritis. It appears to be one of the etiologic agents of a usually self-limited form of gastroenteritis which commonly occurs in community outbreaks. The other, a 70-nm reovirus-like particle, has been observed by electron microscopy in specimens from infants and children with severe diarrhea in many parts of the world. The reovirus-like particle may emerge as a major etiologic agent of diarrhea of infants and young children.     

Caregiver knowledge, attitudes, and practices regarding childhood diarrhea and dehydration in Kingston, Jamaica.

OBJECTIVE: To study the knowledge, attitudes, and practices of caregivers in Kingston, Jamaica, regarding childhood diarrhea and dehydration in order to determine if limited caregiver knowledge about the prevention and treatment of diarrhea and dehydration puts children at increased risk of presenting at the hospital for these concerns. METHODS: The study was an observational case-control study conducted between February 1997 and May 1997 at Bustamante Hospital for Children in Kingston. Convenience sampling was used and data were collected by face-to-face interviews with two groups of caregivers of children under 5 years of age. One group (n = 117) presented with children with acute gastroenteritis, and the other group (n = 98) presented with acute concerns unrelated to gastroenteritis. While 197 of the 215 caregivers interviewed were the mother of a child, there were also 9 guardians, 5 fathers, and 4 grandmothers in the sample. RESULTS: The mean caregiver age, level of education, and socioeconomic status were similar for the two groups. The caregivers in the gastroenteritis group were more likely to present with younger children and to have less convenient access to running water or a refrigerator. Children of caregivers who had never heard of oral rehydration therapy were at increased risk of presenting with gastroenteritis and dehydration (odds ratio [OR], 4.6; 95% confidence interval [CI], 1.8-11.7), as were children of caregivers with low knowledge scores about the prevention and treatment of diarrhea and dehydration (OR, 3.7; 95% CI, 1.6-8.8). Another independent risk factor was a caregiver's poor sense of self-reliance in managing a child's diarrhea (OR, 2.3; 95% CI, 1.1-4.9). CONCLUSIONS: These findings highlight a need to enhance educational efforts that will empower caregivers to protect their children from diarrhea-associated morbidity and mortality.     

Astrovirus MLB2 viremia in febrile child

Astroviruses cause diarrhea, but it is not known whether they circulate in human plasma. Astrovirus MLB2 was recently discovered in diarrhea samples from children. We detected MLB2 in the plasma of a febrile child, which suggests that MLB2 has broader tropism than expected and disease potential beyond the gastrointestinal tract.     

2009-2010年湖南省哨点医院婴幼儿病毒性腹泻病原学研究

目的了解湖南省哨点医院2009-2010年常见腹泻病毒的病原学特征,为病毒性腹泻的综合防治提供科学依据。方法收集湖南省哨点医院2009-2010年5岁以下住院腹泻患儿的粪便标本,采用Dako公司酶免疫试剂盒检测轮状病毒,采用逆转录-聚合酶联反应(RT-PCR)进行分型鉴定;采用聚合酶链反应(PCR)检测腺病毒;逆转录-聚合酶链反应(RT-PCR)法检测星状病毒和杯状病毒,对部分PCR阳性标本进行测序加以验证。结果检测2009-2010年湖南省哨点医院婴幼儿腹泻标本759份,其中轮状病毒占22.79%(173/759)、杯状病毒占9.22%(70/759)、腺病毒占4.61%(35/759)、星状病毒占0.79%(6/759)、混合感染占2.50%(19/759)。173份轮状病毒G血清型与P基因型以G1、G3、P[4]型为优势株。四种病毒主要是感染2岁以下婴幼儿,且有明显的季节特征。测序结果证实12份阳性标本的PCR产物均为其所对应的病毒。结论轮状病毒是2009-2010年湖南省婴幼儿病毒性腹泻的最主要病原,杯状病毒、腺病毒和星状病毒也是本省婴幼儿病毒性腹泻的重要病原。