Nosocomial respiratory syncytial virus infection in Canadian pediatric hospitals: a Pediatric Investigators Collaborative Network on Infections in Canada Study

OBJECTIVE: To determine nosocomial transmission of respiratory syncytial virus (RSV) in Canadian pediatric hospitals, outcomes associated with nosocomial disease, and infection control practices. DESIGN: A prospective cohort study in the 1992 to 1994 winter respiratory seasons. SETTING: Nine Canadian pediatric university-affiliated hospitals. PARTICIPANTS: Hospitalized children with symptoms of lower respiratory tract infection (at least one of cough, wheezing, dyspnea, tachypnea, and apnea) and RSV antigen identified in a nasopharyngeal aspirate. RESULTS: Of 1516 children, 91 (6%) had nosocomial RSV (NRSV), defined as symptoms of lower respiratory tract infection and RSV antigen beginning >72 hours after admission. The nosocomial ratio (NRSV/[com-munity-acquired RSV {CARSV})] + NRSV) varied by site from 2.8% to 13%. The median length of stay attributable to RSV for community-acquired illness was 5 days, but 10 days for nosocomial illness. Four children with NRSV (4. 4%) died within 2 weeks of infection, compared with 6 (0.42%) with CARSV (relative risk = 10.4, 95% confidence interval: 3.0, 36.4). All sites isolated RSV-positive patients in single rooms or cohorted them. In a multivariate model, no particular isolation policy was associated with decreased nosocomial ratio, but gowning to enter the room was associated with increased risk of RSV transmission (incidence rate ratio 2.81; confidence interval: 1.65, 4.77). CONCLUSIONS: RSV transmission risk in Canadian pediatric hospitals is generally low. Although use of barrier methods varies, all sites cohort or isolate RSV-positive patients in single rooms. Children with risk factors for severe disease who acquire infection nosocomially have prolonged stays and excess mortality.     

Case-control study of the risk factors linked to respiratory syncytial virus infection requiring hospitalization in premature infants born at a gestational age of 33-35 weeks in Spain

BACKGROUND AND OBJECTIVE: The aim of this study was to identify those risk factors most likely to lead to the development of RSV-related respiratory Infection and subsequent hospital admission among premature infants born at 33-35 WGA (FLIP study) METHODS: This was a prospective case-control study. Cases (186) hospitalized for respiratory syncytial virus (RSV) illness were recruited from 50 participating Spanish hospitals during the 2002-2003 RSV season (October 2002-April 2003). Controls (371) were selected in June 2003 but born at same time as cases. RESULTS: Of these cases, 20.5% were admitted to the intensive care unit intensive care unit, and 7.6% required mechanical ventilation. None of the patients died. Conditional logistic regression analysis adjusted for medical center demonstrated that the risk of RSV-related respiratory infection requiring hospital admission in preterm infants 33-35 weeks of gestation (WGA) in Spain was most often associated with absolute chronologic age at start of RSV season < or =10 weeks [ie, born between July 15 and December 15; odds ratio (OR), 3.95; 95% confidence interval (CI), 2.65-5.90], breast-feeding for < or =2 months total (OR 3.26; 95% CI 1.96-5.42), presence of > or =1 school age siblings (OR 2.85; 95% CI 1.88-4.33), > or =4 residents and visitors at home (discounting school age siblings and the case/control him/herself) (OR 1.91; 95% CI 1.19-3.07) and a family history of wheezing (OR 1.90; 95% CI 1.19-3.01). CONCLUSIONS: In premature infants born 33-35 WGA, certain underlying risk factors significantly increase the risk of RSV-related respiratory infection and hospitalization. Premature infants 33-35 WGA with additional risk factors should be considered for RSV prophylaxis with palivizumab.     

Improved outcome of respiratory syncytial virus infection in a high-risk hospitalized population of Canadian children. Pediatric Investigators Collaborative Network on Infections in Canada.

PURPOSE: To determine the outcomes in children at high risk for death or complications from respiratory disease who are hospitalized with respiratory syncytial virus (RSV) infection. DESIGN: Retrospective chart review. SETTING: Twelve pediatric tertiary care centers. PATIENTS: All hospitalized children with an RSV infection diagnosed by a positive antigen detection test result or viral isolation during the study period from 1988 to 1991, encompassing three winter seasons. Charts from patients in the following high-risk groups were reviewed in detail: (1) congenital heart disease, (2) chronic lung disease, (3) immunodeficiency, (4) age less than 6 weeks, (5) gestational age less than 36 weeks, and (6) hypoxia (defined as oxygen saturation less than 90% or arterial oxygen pressure less than 60 mm Hg). MEASUREMENTS: The age of all children, the date of RSV identification, and the use of oxygen supplementation, intensive care, and ventilatory support. In addition, the duration of these treatments and the duration of hospitalization were noted. Left-to-right shunting and pulmonary hypertension before RSV infection were determined in those children with congenital heart disease. The nature of the chronic lung disease was noted. Death within 2 weeks of RSV identification was recorded, and the use of ribavirin, bronchodilators, and corticosteroids was determined. RESULTS: Significant year-to-year variation in the frequency of RSV infection was confirmed, with a peak during the 1989-1990 winter noted by the majority of centers (p = 0.0001). Of the 1584 patients in the study, 260 had underlying cardiac disease, 200 had chronic lung disease, 35 had compromised immune function, 378 had been premature, 373 were less than 6 weeks of age, and 338 had hypoxia. Seventeen patients died within 2 weeks (mortality rate 1%); significantly more patients with underlying cardiac disease (3.4%) or lung disease (3.5%) died. Immunocompromised patients had the longest hospital stay (median 39 days), followed by those patients with underlying cardiac or pulmonary disease (11 days); patients less than 6 weeks of age (5 days) and those with hypoxia (6 days) had the shortest hospital stays. Patients with underlying cardiac and pulmonary disease also required oxygen supplementation for a significantly longer period. CONCLUSION: The year-to-year variation in frequency of RSV infection was confirmed in this study. Morbidity and mortality rates associated with RSV infection in a high-risk population in Canada were significantly lower than previously reported.     

FLIP-2 Study: risk factors linked to respiratory syncytial virus infection requiring hospitalization in premature infants born in Spain at a gestational age of 32 to 35 weeks

BACKGROUND: Ex-premature infants are more predisposed to complicated primary respiratory syncytial virus (RSV) infection. The aim of the present study was to validate the risk factors found in a previous epidemiologic case-control study regarding hospitalization as a result of RSV infection in premature infants born at 32-35 weeks of gestational age (WGA) in Spain. METHODS: A prospective 2-cohort study was conducted during the 2005-2006 (October 2005 to April 2006) and 2006-2007 (October 2006 to April 2007) RSV seasons, respectively. Cases were premature infants hospitalized for RSV infection whereas controls were premature infants of the same age who did not require any hospitalization for respiratory causes. RESULTS: During the study period 5441 children from 37 Spanish hospitals were included in the risk factor analysis. Two hundred two (3.7%) were cases and the rest controls. Of the cases, 17.8% were admitted to the intensive care unit and 7.4% required mechanical ventilation. None of the patients died. Logistic regression analysis demonstrated that the risk of RSV-related respiratory infection requiring hospital admission in preterm infants (32-35 WGA) was associated with the following factors: absolute chronologic age of < or = 10 weeks at the onset of RSV season [odds ratio (OR): 2.99; 95% confidence interval (CI): 2.23-4.01]; presence of school-age siblings or day care attendance (OR: 2.04; 95% CI: 1.53-2.74); and smoking during pregnancy (OR: 1.61; 95% CI: 1.16-2.25). CONCLUSIONS: In premature infants (32-35 WGA), only 3 independent risk factors were found to significantly increase the risk of RSV-related respiratory infection and hospitalization.     

Variable morbidity of respiratory syncytial virus infection in patients with underlying lung disease: a review of the PICNIC RSV database. Pediatric Investigators Collaborative Network on Infections in Canada.

OBJECTIVE: We wished to compare outcomes of respiratory syncytial virus (RSV) infection in children with bronchopulmonary dysplasia (BPD) with those with other pulmonary disorders: cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, and tracheoesophageal fistula. METHODS: Children with RSV infection hospitalized at seven Canadian pediatric tertiary care hospitals in 1993 through 1994 and 9 hospitals in 1994 through 1995 were enrolled and prospectively followed. This study is a secondary analysis of data from this prospective cohort. RESULTS: Of the 1516 patients enrolled the outcomes of 159 with preexisting lung disorders before RSV lower respiratory tract infection constitute this report. There were no significant differences among the 7 groups (BPD, cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, tracheoesophageal fistula, other) for the morbidity measures: duration of hospitalization, intensive care unit (ICU) admission, duration of ICU stay, mechanical ventilation and duration of mechanical ventilation. Patients using home oxygen were more likely to be admitted to the ICU than those who had never or previously used home oxygen (current 57.1%, past 23.8%, never 33.3%, P = 0.03). CONCLUSIONS: Children with other underlying diseases have morbidity similar to those with BPD. Prophylactic interventions against RSV should also be studied in these groups.     

The Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) study of neonatal group B streptococcal infections in Canada

OBJECTIVES:

To determine the presentation and medical outcomes of neonatal group B streptococcus (GBS) disease in Canada, and describe maternal and obstetrical risk factors.

DESIGN:

Retrospective review of health records and laboratory databases using standardized data collection forms.

SETTING:

All neonates diagnosed with GBS infections in 1992 at 13 Canadian paediatric centres.

RESULTS:

A total of 105 infants meeting the criteria for neonatal GBS disease were identified. The majority of cases (78 or 74.3%) had early-onset disease (EOD); 78.9% (60 of 76) of these cases presented within 24 h of delivery. Rates of EOD (less than seven days) varied from 0.44/1000 live births to 2.1/1000 live births, with an overall rate of 1.2/1000 live births. Pneumonia was the most common clinical illness (43.8%), followed by bacteremia without focus (23.8%) and meningitis (16.2%). At least one maternal risk factor for neonatal GBS disease was noted in 46 of 78 (59%) infants with EOD. A median of one dose (range one to 23 doses) of intrapartum antibiotics was given in 18 of 75 (24%) of the pregnancies. Overall, the mean gestational age at birth was 36.2±4.7 weeks, with 38 of 96 (39.6%) infants having a gestational age at birth younger than 37 weeks (31 of 73 [42.5%] EOD cases were born with a gestational age younger than 37 weeks). The median birth weight was 3099 g (range 610 g to 4830 g). Thirty of 94 (31.9%) infants had a birth weight less than 2500 g. Seventeen (16.2%) infants died.

CONCLUSIONS:

In 1992, neonatal GBS disease was a significant cause of morbidity and mortality in Canadian infants. More than half of the cases identified in this study could have been potentially preventable by the use of intrapartum antibiotics for women with known risk factors. There is a need for prospective studies to better define risk factors and preventative measures for neonatal GBS infections in Canada.     

Duration of hospitalization in previously well infants with respiratory syncytial virus infection

To describe the typical hospital course of infection in previously well infants hospitalized with respiratory syncytial virus (RSV) infection, we reviewed the charts of 196 patients with laboratory-proved respiratory syncytial virus infection in the 1987-1988 respiratory disease season. Eighty-seven of the children had been previously well. Their mean duration of hospitalization was 3.4 days. Previously well infants younger than 6 weeks of age experienced significantly longer hospitalizations and more days of supplemental oxygen and were more likely to require intensive care than were older children. Children older than 12 weeks of age were hospitalized for a mean of 2.5 days and did not require intensive care. Oxygen saturation was measured in the emergency room for 67 of the previously well infants; in 42 oxygen saturation was at least 90% whereas in 25 saturation was less than 90% or infants were receiving supplemental oxygen at the time of measurement. Decreased initial oxygen saturation was associated with a prolonged hospitalization (5.3 vs. 3.2 days, P less than 0.01) and with more days of supplemental oxygen (4.4 vs. 1.5 days, P less than 0.01). We conclude that among previously well infants admitted to the hospital with respiratory syncytial virus infection, infants younger than 6 weeks of age are at increased risk for a prolonged and more severe hospital course than are older children.     

Respiratory syncytial virus and premature infants born at 32 weeks' gestation or earlier: hospitalization and economic implications of prophylaxis

OBJECTIVES: To assess the risk of hospitalization associated with respiratory syncytial virus (RSV) and to estimate the economic impact of RSV prophylaxis with either RSV immune globulin (RSV-Ig) or RSV monoclonal antibody (palivizumab) on a cohort of preterm infants born at 32 weeks' gestation or earlier. DESIGN: Historical cohort study. SETTING: A 12-county neonatal network served by the regional center in Rochester, NY. PARTICIPANTS: One thousand twenty-nine infants born at 32 weeks' gestation or earlier followed up until 1 year of corrected age. MAIN OUTCOME MEASURES: Rate of hospitalization with an RSV-associated illness; cost per hospitalization prevented resulting from either form of RSV prophylaxis. RESULTS: The probability of hospitalization with an RSV-associated illness for infants born at 32 weeks' gestation or earlier was estimated at 11.2%. The incidence of RSV hospitalization increased with decreasing gestational age (13.9% vs 4.4% for infants born at < or =26 weeks' gestation vs those born at 30-32 weeks' gestation). Infants requiring respiratory support at 36 weeks of postconceptual age (PCA) or older had a higher hospitalization rate (16.8% vs 6.2%), longer hospital stays, and higher hospital charges than infants requiring respiratory support at less than 36 weeks of PCA. For infants requiring respiratory support at less than 36 weeks of PCA, the incidence of RSV hospitalization still increased with decreasing gestational age (10.2% vs 4.3% for infants < or =26 weeks' gestation vs those 30-32 weeks' gestation). Analysis indicated that both forms of RSV prophylaxis would increase the net cost of care for all groups. Palivizumab was more cost-effective than RSV-Ig for preventing RSV hospitalization among infants who required respiratory support at less than 36 weeks of PCA, especially those born at 26 weeks' gestation or earlier. Overall, RSV-Ig was more cost-effective than palivizumab for infants requiring respiratory support at 36 weeks of PCA or older. CONCLUSIONS: This analysis suggests that available forms of RSV prophylaxis would increase the net cost of care not only for the entire cohort but for each of the subgroups studied. However, the RSV hospitalization rate and the cost-effectiveness of prophylaxis varied markedly by subgroup.     

Anticipated costs of hospitalization for respiratory syncytial virus infection in young children at risk

BACKGROUND: Reliable estimates of hospitalization costs for severe respiratory syncytial virus (RSV) infection are necessary to perform economic analyses of preventive strategies of severe RSV disease. We aimed to develop a model that predicts anticipated mean RSV hospitalization costs of groups of young children at risk for hospitalization, but not yet hospitalized, based on readily available child characteristics. METHODS: We determined real direct medical costs of RSV hospitalization from a societal perspective, using a bottom-up strategy, in 3458 infants and young children hospitalized for severe RSV disease during the RSV seasons 1996-1997 to 1999-2000 in the Southwest of the Netherlands. We used a linear regression model to predict anticipated mean RSV hospitalization costs of groups of children at risk, based on 4 child characteristics [age, gestational age, birth weight and bronchopulmonary dysplasia (BPD)], expressed in EC Euros as of the year 2000. FINDINGS: The mean RSV hospitalization costs of all patients were 3110 Euros. RSV hospitalization costs were higher for patients with lower gestational age (5555 Euros; gestational age, 相似文献   

Frequency of and risk factors for necrotizing enterocolitis in infants born before 33 weeks of gestation

AIM: To investigate the frequency of and risk factors for necrotizing enterocolitis (NEC) among infants of <33 wk of gestation. METHODS: Prospective follow-up of 140 inpatients. RESULTS: 26 (18.6%) subjects developed NEC stage I-III and 12 (8.6%) severe NEC (stage II-III). Breast milk fortifier and duration of morphine infusion emerged as the statistically significant factors associated with NEC stage I-III, but only the latter had a significant association with severe NEC. CONCLUSION: Future studies are needed to be established whether morphine is a causative factor in NEC.     

Hospitalization rates for respiratory syncytial virus infection in premature infants born during two consecutive seasons.

OBJECTIVE: To collect data on hospitalization rates for respiratory syncytial virus (RSV) illness during the season of 1999 to 2000 in nonprophylaxed premature infants < or = 32 weeks gestational age (GA) in Spain and compare this with previously published data collected in the season of 1998 to 1999. METHODS: Children born at < or = 32 weeks GA between April 1, 1999, and April 31, 2000, and discharged from the hospital before April 31, 2000, were included. Neonatal and demographic data were obtained at the initial visit. Study subjects were followed at monthly intervals throughout the respiratory season. RSV status and morbidity data were collected on patients rehospitalized for respiratory illness. RESULTS: The 999 evaluable patients in the 2000 season were comparable to the 1999 sample, except for higher rates of family allergy history and number of multiple deliveries and a lower rate of neonatal morbidity. The hospitalization rate for RSV illness was 13.4% in the 1999 season and 13.1% in the 2000 season; 10 (8%) were RSV reinfections in the 2000 season. Significant independent prognostic variables for high risk of RSV hospital admission included: lower gestational age; chronologic age < 3 months at onset of the RSV season; living with school age siblings; and exposure to tobacco smoke. CONCLUSIONS: Hospitalization rates for RSV disease in nonprophylaxed preterm infants < or = 32 weeks GA were high in Spain and comparable during two consecutive RSV seasons (13%). Readmission for a second RSV infection was also common.     

婴幼儿呼吸道合胞病毒感染特点及支气管肺炎细胞免疫等指标的变化

目的　了解近年来苏州地区婴幼儿呼吸道合胞病毒 (RSV)的感染特点及支气管肺炎 (支肺 )细胞免疫等指标改变情况。方法　应用直接免疫荧光法 (DFA)对 2 6 72份下呼吸道感染婴幼儿鼻咽分泌物行RSV抗原检测 ;用间接免疫荧光法 (IFA)对 2 0例RSV支肺婴幼儿血液进行细胞免疫指标测定 ;用酶联免疫法(ELISA)测其血清IFN r、IL 4及IgE。设同龄健康对照组。结果　婴幼儿RSV感染率以冬春季最高(49.13% ) ,夏秋季最低 (4.6 0 % ) (χ2 =4 11.2 2　P <0 .0 0 1) ;1岁以内组 (不包括新生儿 )婴幼儿RSV感染率高于 1～ 2岁组 (χ2 =12 .34　P <0 .0 0 5 ) ,1～ 2岁组高于 2～ 3岁组 (χ2 =8.0 8　P <0 .0 0 5 ) ;男性婴幼儿RSV感染率高于女性 (χ2 =6 .6 7　P <0 .0 0 5 ) ;RSV支肺婴幼儿存在较低的CD3+ (% )、CD4 + (% )、CD8+ (% )水平 (5 3.17± 5 .4 8、34.4 8± 3.6 7、2 2 .5 4± 2 .93,P均 <0 .0 0 1)及较高HLA DR+ (% )水平 (2 3.70± 3.97,P <0 .0 0 5 ) ;血清IFN r(kU/L)、IL 4 (kU/L)水平则分别低于、高于健康组 (0 .38± 0 .2 0　P <0 .0 0 5 ;5 2 .18± 2 9.99,P <0 .0 5 ) ,而血清IgE(kU/L)差异无显著性 (P >0 .0 5 )。结论　婴幼儿RSV感染具有明显地区性和季节周期性 ;年龄越小其RSV感染率越高 ;RSV支肺     

Rates of hospitalization for respiratory syncytial virus infection among children in medicaid

OBJECTIVE: To determine rates of hospitalization associated with respiratory syncytial virus (RSV) infection among children with and without specific medical conditions. STUDY DESIGN: Retrospective cohort study of all children <3 years old enrolled in the Tennessee Medicaid program from July 1989 through June 1993 (248,652 child-years). RESULTS: During the first year of life, the estimated number of RSV hospitalizations per 1000 children was 388 for those with bronchopulmonary dysplasia, 92 for those with congenital heart disease, 70 for children born at < or = 28 weeks' gestation, 66 for those born at 29 to <33 weeks, 57 for those born at 33 to <36 weeks, and 30 for children born at term with no underlying medical condition. In the second year of life, children with bronchopulmonary dysplasia had an estimated 73 RSV hospitalizations per 1000 children, whereas those with congenital heart disease had 18 and those with prematurity 16 per 1000. Overall, 53% of RSV hospitalizations occurred in healthy children born at term. CONCLUSIONS: Children with bronchopulmonary dysplasia have high rates of RSV hospitalization until 24 months of age. In contrast, after the first year of life, children with congenital heart disease or prematurity have rates no higher than that of children at low risk who are <12 months old.     

The multicenter Italian birth cohort study on incidence and determinants of lower respiratory tract infection hospitalization in infants at 33 weeks GA or more: preliminary results

BackgroundRespiratory syncytial virus (RSV) causes respiratory infections during the first year of life. Very premature infants have more severe diseases and also ‘late preterm infants’ may be more susceptible to the infection.Aim of the studyTo evaluate in an Italian cohort the incidence and risk factors of severe hospitalized lower respiratory tract infection (LRTI) induced or not by RSV during the first year of life.MethodsA cohort of 33^+ 0d–34^+ 6d wGA newborns paired with two sex- and age-matched 35^+ 0d–37^+ 6d wGA and ≥ 38^+ 0d wGA newborns were enrolled. Hospitalization for LRTI induced or not by RSV during the first year of life was assessed through phone interview at the end of the RSV season (November–March) and at the completion of the first year of life. The parents were asked to report hospitalization for any reason.Results1064 neonates were enrolled (November 2009–October 2010), 697 had at least one phone follow-up by September 2010. Babies of 33^+ 0d–34^+ 6d wGA were more frequently conceived through assisted fertilization technologies, born from cesarean delivery had more frequently acute perinatal risk factors and were more frequently twins. After a mean 6 month-follow-up, we registered 29 hospitalizations for LRTI induced or not by RSV. Hospitalizations were slightly and non-significantly more frequent in 33^+ 0d–37^+ 6d wGA infants. The risk of hospitalization was significantly 60% reduced in breastfed babies and four folds significantly increased during the RSV season.ConclusionThe very preliminary data of this ongoing study suggest that in ‘late-preterm’ infants some individual/environmental characteristics of the infants play a relevant role in determining the risk of severe RSV infection.