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.     

The Pediatric Investigators Collaborative Network on Infections in Canada study of predictors of hospitalization for respiratory syncytial virus infection for infants born at 33 through 35 completed weeks of gestation

BACKGROUND: Infants born at 33 through 35 completed weeks of gestation (33-35GA) are at risk for severe respiratory syncytial virus (RSV) infection, and palivizumab prophylaxis lowers hospitalizations for RSV infection by as much as 80%. The 33-35GA cohort comprises 3-5% of annual births; thus expert panels recommend limiting prophylaxis to situations in which frequency or health care impact of RSV infection is high. This study sought to identify independent risk factors for hospitalization for RSV infection. METHODS: This was a multicenter, prospective, observational cohort study of 33-35GA infants followed through their first RSV season (2001/2002 or 2002/2003). Baseline data were collected by interview with parents and review of medical records. Respiratory tract illnesses were identified by monthly phone calls, and medical records were reviewed for emergency room visits or hospitalizations. Risk factors were determined by stepwise logistic regression. RESULTS: Of 1,860 enrolled subjects, 1,832 (98.5%) were followed for at least 1 month, and 1,760 (94.6%) completed all follow-ups. Of 140 (7.6%) subjects hospitalized for respiratory tract illnesses, 66 infants had proven RSV infection. Independent predictors for hospitalization for RSV infection were: day-care attendance (odds ratio, 12.32; 95% confidence interval, 2.56, 59.34); November through January birth (odds ratio, 4.89; 95% confidence interval, 2.57, 9.29); preschool age sibling(s) (odds ratio, 2.76; 95% confidence interval, 1.51, 5.03); birth weight <10th percentile (odds ratio, 2.19; 95% confidence interval, 1.14, 4.22); male gender (odds ratio, 1.91; 95% confidence interval, 1.10, 3.31); > or = 2 smokers in the home (odds ratio, 1.87; 95% confidence interval, 1.07, 3.26); and households with >5 people, counting the subject (odds ratio, 1.79; 95% confidence interval, 1.02, 3.16). Family history of eczema (odds ratio, 0.42; 95% confidence interval, 0.18, 0.996) was protective. CONCLUSIONS: Specific host/environmental factors can be used to identify which 33-35GA infants are at greatest risk of hospitalization for RSV infection and likely to benefit from palivizumab prophylaxis.     

校正胎龄40周时早产儿潮气呼吸肺功能研究

目的初步探讨早产儿在校正胎龄40周时的潮气呼吸肺功能状况。方法选择我院2011年1～9月新生儿科收治的早产儿,机械通气组和非机械通气组各入选20例,于校正胎龄40周时分别测定潮气呼吸肺功能的各项指标,与同期产科分娩、胎龄39～40周健康对照组(分别入选剖宫产组30例和阴道分娩组20例)生后5～7天时的潮气呼吸肺功能相比较。结果机械通气组吸气时间(TI,s)、呼气时间(TE,s)较阴道分娩组和非机械通气组明显延长[TI:(0.68±0.17)比(0.52±0.06)、(0.53±0.11),TE:(0.72±0.15)比(0.59±0.13)、(0.57±0.09),P<0.05],呼吸频率(RR,次/min)明显降低[(44.4±7.7)比(56.2±10.8)、(56.1±9.5),P<0.05)];两个早产儿组达峰时间比(TPEF/TE,%)、达峰容积比(VPEF/VE,%)、达峰容积(VPEF,ml)、达峰时间(TPEF,s)均低于阴道分娩组[TPEF/TE:(21.8±5.8)、(25.4±11.2)比(35.4±8.8),VPEF/VE:(24.4±2.9)、(26.8±8.1)比(33.8±7.3),VPEF:(5.5±1.2)、(6.0±1.1)比(6.7±1.2),TPEF:(0.15±0.10)、(0.14±0.04)比(0.20±0.05),P<0.05];剖宫产组平均吸气流速(MIF,ml/s)、平均呼气流速(MEF,ml/s)较阴道分娩组明显减低[MIF:(35.7±5.1)比(40.1±4.0),MEF:(31.8±6.7)比(36.4±7.0)P<0.05];各组TPEF/TE与VPEF/VE呈高度正相关,r值分别为剖宫产组0.990,阴道分娩组0.992,机械通气组0.933,非机械通气组0.990,P均<0.05。结论在校正胎龄40周时,早产儿潮气呼吸肺功能接近正常同胎龄足月儿,气道发育比足月儿慢,出生早期行机械通气早产儿可能存在肺组织的代偿能力受限和呼吸中枢调节功能不协调。     

The risk of respiratory syncytial virus-related hospitalizations in preterm infants of 29 to 35 weeks' gestational age

Among 1158 preterm infants of 29-35 weeks' gestational age, respiratory syncytial virus (RSV) -related hospitalizations (RSV-H) occurred in 4.2% during the first year of life. Four independent factors influenced the risk for RSV-H: neurologic problems (odds ratio [OR], 3.6), male gender (OR, 2.8), presence of an older sibling (OR, 1.7) and discharge from October to December (OR, 1.7). The estimated risk of RSV-H varied between 1% (no risk factor present) and 30% (4 risk factors present).     

Neurodevelopmental outcome of premature infants born at less than 33 weeks of gestational age and not cerebral palsy at the age of 5 years]

AIM: To appreciate the impact of prematurity, fetal hypotrophy and familial environment on the neurodevelopmental performances of very premature infants without cerebral palsy at the age of five years. POPULATION AND METHODS: We followed a regional cohort of 171 very premature infants (< or = 32 weeks of gestation) until they were five years of age. Cognitive functions were tested with the WPPSI test and the development quotient was assessed by the ability to draw a "bonhomme". Twenty-two premature infants suffered from cerebral palsy diagnosed before the age of two years. Another infant had a moderate diplegia at the five-year examination. We had no information for 16 prematures (9.3% of survivors). Twenty-eight premature infants were considered as having no severe disability on phone or mailed contact, and another child had a severe isolated mental retardation. We examined 104/148 infants, and 96/148 survivors without cerebral palsy passed the tests. The cognitive functions of these premature infants are compared to the performances of a control group made up of 108 children born at term > or = 37 weeks, matched for birthplace and single or twin characteristics of the pregnancy. RESULTS: The values of the different quotients are significantly decreased in the preterm group. The global IQ and the performance IQ are 0.8 SD, verbal IQ is 0.5 SD and the development quotient is 0.4 SD below the values observed in the control group. A performance IQ less than -2 SD for the mean of the control group is observed three times more than in the controls (13.5% vs 3.7%, P < 0.01). Multiple linear regression shows that prematurity explains, independent of hypotrophy and socioeconomic environment, 8% of the variation of the performance IQ (P < 0.01), 2% of the variation of the verbal IQ and 2% of the development quotient (P < 0.05). CONCLUSION: The five-year neurologic outcome of the children born prematurely in this regional study is similar to the results observed in regional studies conducted in Europe: 13.4% of the survivors have cerebral palsy, and the cognitive functions of the children with no cerebral palsy are significantly lower than the term control group. Other risk factors such as hypotrophy, which modulates the developmental quotient, and the socioeconomic status, which modulates the verbal IQ, are underlined.     

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.     

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.     

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   

The rate of candidaemia in preterm infants born at a gestational age of 23-28 weeks is inversely correlated to gestational age

AIM: To assess the rate of candidaemia and the associated case fatality rate in relation to gestational age, and the variation in the rate of candidaemia over time in the neonatal period. METHODS: Retrospective review of medical records of infants with a positive blood culture for fungi while in the neonatal unit, Uppsala University Children's Hospital or at autopsy following death in the unit from 1994 to 2001 (n = 30). RESULTS: The number of cases per year was found to vary between zero and eight. The annual rate of infection did not change significantly during the study period. The preterm infants with candidaemia (n = 29) were born at a gestational age ranging from 23-28 wk. The rate of candidaemia in this group was inversely related to gestational age and varied from 2 to 24%. Five infants (17%) died from Candida infection. Of these five, four were born at a gestational age of 23 wk. CONCLUSION: candidaemia in newborns occurs predominately in infants born at a gestational age < or =28 wk, where the rate of infection is inversely correlated to gestational age in infants born at a gestational age of 23-28 wk. The highest case fatality rate is observed in infants born at a gestational age of 23 wk.     

Rehospitalization for respiratory syncytial virus infection in infants with extremely low gestational age or birthweight in Denmark

AIM: To determine the risk of rehospitalization for respiratory syncytial virus (RSV) infection during the first 2 y of life in extremely preterm infants. METHODS: Records on all rehospitalizations during the first 2 living years of all infants born with gestational age <28 wk or birthweight <1,000g during 1994 and 1995 in Denmark were retrospectively reviewed. RESULTS: Among 240 eligible infants, 43 (18%) had been rehospitalized 48 times owing to RSV. In infants (n = 210) without CLD the risk of rehospitalization for RSV was 16%, whereas in infants with CLD (n = 30) it was 30% (p = 0.065). Eighteen infants (38%) required respiratory support (supplemental oxygen only 3, continuous positive airway pressure 14, mechanical ventilation 1). Apart from CLD the only factor that could be associated with increased risk of hospitalization for RSV was discharge during autumn (p = 0.05). No infant died from RSV infection. CONCLUSION: The high rate of rehospitalization for RSV in extremely preterm infants in Denmark, especially in infants with CLD, should lead to considerations concerning more widespread use of prophylaxis against RSV in these infants.     

Short-term outcome predictors in infants born at 23-24 gestational weeks.

AIM: Outcome is uncertain in infants born at 23-24 gestational weeks. The aim of the present study was to identify possible early predictors of outcome in these infants. MATERIALS AND METHODS: Data from the Swedish medical birth register (MBR) for live-born infants with gestational ages (GAs) 23 and 24 weeks, born during the time-period 2000-2002, were analysed in relation to short-term outcomes, that is survival and survival without severe brain damage (intraventricular haemorrhage [IVH] grades 3 and 4 and/or periventricular leukomalacia [PVL]). RESULTS: In 57 infants born at 23 gestational weeks, survival was associated with birthweight (BW) (p = 0.018) and 5-min Apgar score (p = 0.020) on univariate analyses. In 99 infants born at 24 weeks of gestation, survival without severe brain damage correlated with BW (p = 0.039), birth type (singleton/multiple) (p = 0.017) and Apgar score at 1, 5 and 10 min (p = 0.028, 0.014 and 0.030, respectively). The best model for predicting survival without severe brain damage in infants born at 24 gestational weeks was based on 5-min Apgar score and birth type. The small number of live-born infants at 23 weeks of gestation did not allow for multiple logistic regression analyses. CONCLUSION: The 5-min Apgar score is associated with short-term outcome in live-born infants at 23-24 gestational weeks. The association is stronger for infants born at 24 weeks of gestation.     

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.