Burden of respiratory syncytial virus hospitalisation among infants born at 32-35 weeks' gestational age in the Northern Hemisphere: pooled analysis of seven studies.

To provide comprehensive information on the epidemiology and burden of respiratory syncytial virus hospitalisation (RSVH) in preterm infants, a pooled analysis was undertaken of seven multicentre, prospective, observational studies from across the Northern Hemisphere (2000-2014). Data from all 320-356 weeks' gestational age (wGA) infants without comorbidity were analysed. RSVH occurred in 534/14 504 (3.7%) infants; equating to a rate of 5.65 per 100 patient-seasons, with the rate in individual wGA groups dependent upon exposure time (P = 0.032). Most RSVHs (60.1%) occurred in December-January. Median age at RSVH was 88 days (interquartile range (IQR): 54-159). Respiratory support was required by 82.0% of infants: oxygen in 70.4% (median 4 (IQR: 2-6) days); non-invasive ventilation in 19.3% (median 3 (IQR: 2-5) days); and mechanical ventilation in 10.2% (median 5 (IQR: 3-7) days). Intensive care unit admission was required by 17.9% of infants (median 6 days (IQR: 2-8) days). Median overall hospital length of stay (LOS) was 5 (IQR: 3-8) days. Hospital resource use was similar across wGA groups except for overall LOS, which was shortest in those born 35 wGA (median 3 vs. 4-6 days for 32-34 wGA; P < 0.001). Strategies to reduce the burden of RSVH in otherwise healthy 32-35 wGA infants are indicated.

Cost-utility analysis of Palivizumab for Respiratory Syncytial Virus infection prophylaxis in preterm infants: update based on the clinical evidence in Spain.

BACKGROUND: This study aimed at estimating the efficiency of palivizumab in the prevention of Respiratory Syncytial Virus (RSV) infection and its sequelae in preterm infants (32day 1-35day 0weeks of gestational age -wGA-) in Spain. METHODS: A decision-tree model was developed to compare health benefits (Quality Adjusted Life Years-QALYs) and costs of palivizumab versus a non-prophylaxis strategy over 6 years. A hypothetical cohort of 1,000 preterm infants, 32day 1-35day 0 wGA (4.356 kg average weight) at the beginning of the prophylaxis (15 mg/kg of palivizumab; 3.88 average number of injections per RSV season) was analysed. The model considered the most recent evidence from Spanish observational and epidemiological studies on RSV infection: the FLIP II study provided hospital admission and Intensive Care Unit (ICU) admission rates; in-hospital mortality rate was drawn from an epidemiological study from 2004 to 2012; recurrent wheezing rates associated to RSV infection from SPRING study were adjusted by the evidence on the palivizumab effect from clinical trials. Quality of life baseline value, number of hospitalized infants and the presence of recurrent wheezing over time were granted to estimate QALYs. National Health Service and societal perspective (included also recurrent wheezing indirect cost) were analysed. Total costs (€, 2016) included pharmaceutical and administration costs, hospitalization costs and recurrent wheezing management annual costs. A discount rate of 3.0% was applied annually for both costs and health outcomes. RESULTS: Over 6 years, the base case analysis showed that palivizumab was associated to an increase of 0.0731 QALYs compared to non-prophylaxis. Total costs were estimated in €2,110.71 (palivizumab) and €671.68 (non-prophylaxis) from the National Health System (NHS) perspective, resulting in an incremental cost utility ratio (ICUR) of €19,697.69/QALYs gained (prophylaxis vs non-prophylaxis). Results derived from the risk-factors population subgroups analysed were in line with the total population results. From the societal perspective, the incremental cost associated to palivizumab decreased to an €1,253.14 (ICUR = €17,153.16€/QALYs gained for palivizumab vs non-prophylaxis). One-way and probabilistic sensitivity analyses confirmed the robustness of the model. CONCLUSIONS: The prophylaxis with palivizumab is efficient for preventing from RSV infections in preterm infants 32day 1-35day 0 wGA in Spain.

Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference.

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

[Update of recommendations on the use of palivizumab as prophylaxis in RSV infections]. / Actualización de las recomendaciones de la Sociedad Española de Neonatología para la utilización del palivizumab como profilaxis de las infecciones graves por el virus respiratorio sincitial.

The Standards Committee of the Spanish Neonatology Society (SENeo) considers that the new document from the American Academy of Pediatrics, including recommendations for palivizumab use to prevent serious infections produced by the Respiratory Syncytial Virus (RSV), provides no new scientific evidence which would justify the modification of the current recommendations of the SENeo. However, some adjustments to the criteria of the existing recommendations are proposed to reduce the cost of the drug by its correct and judicious management.

[Influence of in-home nursing care on the weight of the early discharged preterm newborn]. / Evolución del peso del prematuro con alta precoz y atención domiciliaria de enfermería.

INTRODUCTION: In-Home nursing care of the preterm newborn helps to bring the family situation to normal, promotes breastfeeding and development of the newborn, and enables the reorganization of health care resources. The purpose of this paper is to demonstrate that in-home nursing care of the preterm newborn leads to an increase in weight and a similar morbidity. PATIENTS AND METHODOLOGY: A total of 65 cases and 65 controls (matched by weight, age and sex) were studied, all of them preterm newborns born in hospital and weighing less than 2100 g at discharge. In-home nursing care was carried out by a pediatrician neonatologist, as well as two nurses specialized in neonatology who made several visits to the home. Weight gain was calculated as g/day and g/Kg/day, comparing the first week of the study with the week prior to the beginning of the study. RESULTS: The groups were comparable. Weight gain in the group with home nursing care was 38 g per day, significantly higher than the weight gain in the control group (31 g/day). The independent predictive variables of the increase in g/Kg/day during the study were in-home nursing care, male gender, breastfeeding less, and not having suffered from a peri-intraventricular hemorrhage. Neonatal morbidity was similar in both groups. CONCLUSIONS: In-home care was associated with a greater weight gain of the newborn at home than during their stay in the hospital, and can be considered safe because neonatal morbidity was not increased.

High risk for RSV bronchiolitis in late preterms and selected infants affected by rare disorders: a dilemma of specific prevention.

Respiratory syncytial virus (RSV) is the most frequent aetiologic agent that causes bronchiolitis and lower respiratory tract infection in infants. These infections may be severe and even life-threatening in selected high-risk populations. Traditional, well-established, high-risk populations are preterm infants with or without chronic lung disease and children with congenital heart disease. For these children, RSV prophylaxis using palivizumab, a monoclonal anti-RSV humanised antibody against the F-protein of RSV, has proven safe and efficacious in preventing RSV-related hospitalisation. Recently, a number of rare medical conditions have been associated with the risk of severe RSV infections. Evidence of safety and efficacy of RSV prophylaxis in these populations is lacking. Given the low incidence of these conditions, randomised trials are not feasible. A practical, opinion-based approach to this dilemma is offered in this paper. It is proposed that these rare disorders may qualify for RSV prophylaxis if the association between a specific condition and the risk of severe RSV infection is confirmed in at least 3 independent publications, of which at least 1 includes a prospective cohort study. To facilitate pharmaco-economic analyses, at least one of the three studies must also report on the absolute risk of severe RSV infection in the specified illness. The authors believe that qualification criteria will enable caregivers to target RSV prophylaxis more effectively in children with rare conditions and the proposed approach provides direction for future epidemiological studies on the risk of severe RSV infection in children with these uncommon, medical illnesses.

[Erythropoietin treatment for late anaemia after haemolytic disease of the newborn]. / Tratamiento con eritropoyetina para la anemia tardía tras enfermedad hemolítica del recién nacido.

INTRODUCTION: After several years of erythropoietin (EPO) use in the prophylaxis of anaemia of prematurity, it also began to be administered to treat post-haemolytic disease anaemia of the newborn in order to avoid blood transfusions. OBJECTIVE: To show the results obtained with EPO treatment in post-haemolytic disease anemia of the newborn. PATIENTS AND METHODS: Observational study in 13 newborns with late anaemia due to an hemolytic disease caused by Rh isoimmunization (9 cases), AB0 isoimmunization (2 cases), glucose-6-P-dehydrogenase deficiency (1 case) or idiopathic (1 case). The newborns began EPO treatment when they reached the haematocrit level for a blood transfusion. RESULTS: EPO treatment was started at 26±7 days of life (15-46), with a haematocrit value of 21.7±3% (18-27) and a reticulocyte count of 3.8±2.2%. Blood transfusion was not necessary in 11 newborns (haematocrit of 30.7±4.4% and reticulocytes of 5.9±1.4%), and only 2 newborns were admitted for a blood transfusion (haematocrit 18±4.4% and reticulocytes 0.6%). Significant increases in haemoglobin and reticulocyte figures were seen after EPO treatment. CONCLUSIONS: EPO administration proved useful to avoid blood transfusion in 84% of treated newborns. No adverse events were detected which could be attributed to this treatment,.

[Recommendations for the use of palivizumab in the prevention of respiratory syncytial virus infection in late preterm infants (32(1) to 35(0) weeks of gestation)]. / Recomendaciones de uso de palivizumab para la prevención de la infección por virus respiratorio sincitial en prematuros de 32(1) a 35(0) semanas de gestación.

Late preterm infants (32(1) to 35(0) weeks gestation) aged less than 6 months at start of RSV station or discharged during this time may benefit from RSV monoclonal antibodies (palivizumab) administration to decrease the rates of RSV hospitalization. The Spanish Society of Neonatology considers, based on FLIP2 results in Spain, that palivizumab prophylaxis is strongly recommended if the "2 major risk factors" are present (chronological age less than 10 weeks at start of RSV season or being born during its first 10 weeks; sibling of school age or attending day-care assistance). Palivizumab is also recommended when "1 major risk factor and the 2 minor risk factors" are present. Minor risk factors are: mother smoking during pregnancy and being a male.

[Quality of life of preterm infants and admissions due to respiratory infections]. / Calidad de vida en lactantes nacidos prematuros según ingresos por infección respiratoria.

INTRODUCTION: Study of the association between lower respiratory tract infection hospitalisations and health related quality of life (HRQoL) in preterm infants of 32-35 weeks of gestational age. METHODS: Survey study nested into a prospective follow-up cohort study of preterm infants (FLIP-2). During the last FLIP-2 visit, 216 preterm-parent pairs were interviewed. The structured questionnaire included measures of HRQoL (QUALIN modified scale for the infant, and SF-12 for the parent, and Visual scales for both), caregiver overload (Zarit modified scale and indirect measurements). RESULTS: From October 2006 to March 2007 (RSV season), there were 71 respiratory hospitalisations (33%). Triplets and infants living in homes with >5 inhabitants were most likely to be hospitalised. Parents of hospitalised children were most likely, to have more and longer times off work for child care (47% vs. 18%), to have higher overload, and to obtain lower values in the physical dimension of SF-12. Multiple regression model associated infant HRQoL with higher gestational age, having 0-3 year-old siblings, being recommended palivizumab and had received it, lower caregiver overload, higher caregiver mental HRQoL and no absence from work for child care. CONCLUSIONS: Although respiratory hospitalisations were not associated with infant HRQoL, caregivers' HRQoL and overload were. Preterm infant HRQoL is associated with their caregivers' HRQoL and overload, and with receiving RSV prophylaxis when their risk profile recommends it.

Attempt to normalize simulated exhaled nitric oxide according to ventilatory settings.

BACKGROUND: Simulated exhaled nitric oxide (eNO) depends on ventilatory settings used in different experimental conditions. OBJECTIVES: To normalize the simulated minute exhaled nitric oxide according to different ventilatory settings. WORKING HYPOTHESIS: Different ventilatory settings influence the concentrations of exhaled nitric oxide and these results can be normalized. METHODOLOGY AND STUDY DESIGN: We used a rubber lung model (50 ml) with an orifice through which a 3 mm endotracheal tube was introduced. The NO, which simulated that of endogenous production, was delivered through the base of the lung using a unidirectional rotameter and obtaining a concentration of around 25 ppb. The sample of gas was recorded through a 6 F arterial catheter introduced into the endotracheal tube to its tip. The ventilator used was a Babylog 8000. Air delivered was compressed and filtered and had an NO content of under 0.3 ppb. The NO level assessed was the plateau value given by the software of the Sievers NOA apparatus. Each experiment involved sampling during 1 min, three times. Normalization was done using a multiple cubic regression formula. RESULTS: An increase in respiratory frequency or in peak of inspiratory pressure were accompanied by a decrease in eNO (ppb). Minute volume was adjusted for the percentage of leakage given by the ventilator. Normalization was obtained analyzing 518 respirations with different ventilatory settings. The coefficient of variation fell from 15.5% to 0.27%. Validation of the normalization formula was performed in other three groups (320, 372, and 372 respirations) with different simulated NO concentrations (25, 16, and 50 ppb), resulting in reduction of the coefficient of variation from 42.7% to 9.3%, from 42.3% to 10.6% and from 45.2% to 9.6%, respectively. CONCLUSIONS: Normalization of simulated minute eNO according to ventilatory settings is possible using the equipment and experimental set-up reported. Extrapolation to patients is not possible without constraints.

Clinical relevance of prevention of respiratory syncytial virus lower respiratory tract infection in preterm infants born between 33 and 35 weeks gestational age.

Premature infants are vulnerable to severe respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) resulting in hospitalisation and the potential for longer-term respiratory morbidity. Whilst the severity and consequence of RSV LRTI are generally accepted and recognised in infants born

Probable early-onset group B streptococcal neonatal sepsis: a serious clinical condition related to intrauterine infection.

BACKGROUND: The estimated incidence of true early-onset group B streptococcal (GBS) neonatal infection is based on positive GBS blood or cerebrospinal fluid (CSF) culture results, but the real burden of disease is underestimated owing to the high incidence of culture-negative sepsis possibly because of antibiotic administration to the mother. OBJECTIVE: To examine the rate of probable early-onset GBS neonatal sepsis and to assess its impact on total GBS neonatal disease. DESIGN: A multicentre longitudinal prospective surveillance of 107,021 deliveries. RESULTS: The rates of culture-proven and probable early-onset GBS sepsis were 0.39 and 0.47 per 1000 live births, respectively. Of great concern was the finding of three deaths related to the infection in the group with probable early-onset GBS sepsis. CONCLUSIONS: The use of chemoprophylaxis in GBS-colonised pregnant women, especially when it is incomplete, may not be sufficient to prevent clinical neonatal infection, but may inhibit the growth of GBS in blood and CSF cultures. In assessing the effectiveness of GBS prophylaxis, it is advisable to consider the incidence of culture-positive and probable culture-negative GBS neonatal infection.

Efficacy of three treatment schedules in severe meconium aspiration syndrome.

AIM: To compare three different schedules in severe meconium aspiration syndrome (MAS) treatment: standard, bronchoalveolar lavage (BAL) with diluted surfactant, and diluted surfactant BAL plus a single early dexamethasone dose. METHODS: Twenty-four full-term newborns with severe MAS (needing mechanical ventilation and with oxygenation index > or = 15) were divided into three groups: group I (historical control group; n = 6) treated with standard therapy; group II (n = 7) treated in the first hours of life with one BAL using diluted surfactant (beractant 5 mg/mL) in a volume of 15 mL/kg in four aliquots; and group III (n = 11) treated with one diluted surfactant BAL and a previous single dose of intravenous dexamethasone (0.5 mg/kg). RESULTS: At 12 h, groups II and III showed a significant improvement in oxygenation index (OI) compared with group I (14.7% and 27.0% vs -19.6% respectively; p = 0.012). Group III also showed a significantly lower OI than group I at 24 h (63.6% vs -27.9%) and at 48 h (87.1% vs 49.6%). Group III, in comparison to group I, showed a lower FiO2 requirement at 12 h (0.66 vs 1), at 24 h (0.4 vs 0.87) and at 48 h (0.35 vs 0.67), and a decrease in the number of days of inhaled nitric oxide administration, mechanical ventilation, oxygen therapy and hospitalisation period. All patients from groups II and III survived and none developed pneumothorax or respiratory infections. CONCLUSION: Diluted surfactant BAL in the first hours of life combined with an intravenous single dose of dexamethasone may be an effective treatment for severe MAS.

Plasma nitrite/nitrate and endothelin-1 concentrations in neonatal sepsis.

AIM: To determine the changes in plasma nitrite/nitrate (NOx) and endothelin-1 (ET-1) concentrations during neonatal sepsis. METHODS: In a prospective study, 60 consecutive newborns meeting the criteria for sepsis and without receiving exogenous nitric oxide (25 haemoculture-positive [HC+] and 35 haemoculture-negative [HC-]) were compared with 68 healthy newborns (46 full-term and 22 preterm). NOx and ET-1 concentrations were measured in each newborn within 48 h of diagnosis of sepsis and then every third day up to three determinations. SNAP-II and SNAPPE-II severity scores were performed at the moment of highest clinical severity. RESULTS: At the beginning of the sepsis period, controls and septicaemic newborns had similar NOx and ET-1 levels, with the exception of infants with severe HC+ sepsis. Throughout the sepsis period, NOx increased in moderate HC+ sepsis and decreased in HC--sepsis, reaching a significant difference at the end of the study period (59.9 +/- 72.7 vs 33.9 15.3 micromol/L; p = 0.036). Meanwhile, ET-1 in newborns with severe HC+ sepsis remained higher than that in the moderate HC+ sepsis group and HC--group, reaching significant differences in all the periods. The highest ET-1 value was positively correlated with SNAP-II and SNAPPE-II scores. CONCLUSION: NOx concentrations increased throughout the neonatal HC+ sepsis period, reaching significant differences after 7-9 d. The highest ET-1 levels in neonatal HC+ sepsis emerged before the NOx peak, at 3-5 d, and later decreased. Only newborns with severe HC+ sepsis presented a significant increase in ET-1 concentrations from the beginning of the septicaemic process.

[Neonatal convulsions and subarachnoid hemorrhage after in utero exposure to paroxetine]. / Convulsiones y hemorragia subaracnoidea tras exposición a paroxetina in utero.

INTRODUCTION: Selective serotonin reuptake inhibitors (SSRIs) are often used as antidepressants in pregnant women. SSRIs do not appear to increase the teratogenic risk when used in their recommended doses. However, not enough information is available at this time about the risk of toxicity and complications in newborns, after mother treatment with SSRI during the third trimester of pregnancy. We are limited to the existing reports that describe newborns with symptoms due to hyperserotoninemia or withdrawal. CASE REPORT: One newborn whose mother had been treated with paroxetine 20 mg/day during pregnancy, presented convulsions and subarachnoid haemorrhage in the first six hours of life. The newborn did not present symptoms of hypoxic ischaemic encephalopathy, withdrawal syndrome, infection, metabolic alterations, cerebral malformations or coagulopaties. DISCUSSION: The most probable etiology is that the paroxetine could decrease the seizure threshold, taking place the first seizure during delivery. The difficult fetal extraction would have provoked the subarachnoid haemorrhage in a patient with an impaired haemostatic function due to a depletion of platelet serotonin and may also contribute the increased vascular fragility due to paroxetine and reported in adults or in animals. CONCLUSION: Neonatal convulsions and subarachnoid haemorrhage may occur after paroxetine treatment in the third trimester of pregnancy. An accurate follow up of these newborns in the firsts days of life is strongly recommended.

[Blood ammonia and transaminases in full term infants suffering from perinatal asphyxia]. / Amoniaco y transaminasas en sangre en el recién nacido a término afectado de asfixia perinatal.

AIMS: To find hepatic markers of perinatal asphyxia. PATIENTS AND METHODS: Variations in blood ammonia during the first week of life and in transaminase in serum during the first 48 hours were analysed in four groups of newly born infants (NBI): Group I or control, in which 65 NBI were included, with suspected unconfirmed infection and no other pathologies; Group II, made up of 15 NBI with loss of foetal well being (LFW) with no posterior neurological clinical features; Group III, consisting of 27 NBI with LFW criteria and mild hypoxic ischemic encephalopathy (HIE); and Group IV, with 25 NBI with LFW criteria and mild HIE according to Amiel s criteria. RESULTS: The average blood ammonia values in full term infants remain steady during the first week of life (87.66 21.69 mg/dL), as occurs in infants with LFW but without HIE (89.08 24.69 mg/dL) and in those with mild HIE (89.08 20.75 mg/dL). In moderate HIE, the blood ammonia level rises until the third day (108.55 7.04 mg/dL) and then drops back to the initial values (p= 0.0045). When grouped by days, these values show significant differences (p= 0.04), with higher values in Group IV. The NBI with HIE presented higher levels of transaminases, especially of AST (GOT) (p= 0.000001), and this increase is proportional to its gravity. No relation was found between values of blood ammonia and transaminases. CONCLUSIONS: Both blood ammonia and transaminases can be considered to be perinatal asphyxia markers.

An update on respiratory syncytial virus epidemiology: a developed country perspective.

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and young children worldwide, and an important cause of morbidity, hospitalization, and mortality. The infections caused by RSV are seasonal, peaking predictably in the winter months in temperate climates, and in the hottest months and the rainy season in tropical climates. The involvement of the lower respiratory tract, manifest clinically as bronchiolitis or pneumonia, is the hallmark of severe RSV disease. Other indicators of severe disease include requirement for, and duration of, hospitalization, supplemental oxygen, management in an intensive care setting, and mechanical ventilation. Host-related risk factors for severe RSV disease include preterm birth, infection before 6 months of age, chronic lung disease, and congenital heart disease. Environmental risk factors for severe RSV infection include poverty, crowding, exposure to tobacco smoke, and malnutrition. Factors that increase frequency of the infection include young age, multiple gestation, family history of atopy, lack of parental education, household crowding, older school-age siblings, lack of breast feeding, day-care attendance, passive smoke exposure, and discharge from a neonatal intensive care unit between September and December. Recent studies in Europe, North America and Japan have evaluated the number of children affected as well as the medical resources necessary to care for these children. Continuing surveillance is the key to tracking the seasonality, risk factors, morbidity and mortality associated with RSV infection. Epidemiological studies are also the basis for development of appropriate local prevention strategies.

[Guidelines for respiratory syncytial virus prophylaxis. An update]. / Recomendaciones para la prevención de la infección por virus respiratorio sincitial: revisión.

Epidemiological studies performed by the IRIS study group in the last two respiratory syncytial virus (RSV) seasons found that the hospitalization rates for RSV in premature infants born before or in week 32 of gestation were 13.4 % and 13.1 %, respectively. Of these, 18 % and 25 % of the infants were admitted to the intensive care unit. Currently available information demonstrates the efficacy of RSV monoclonal antibodies (palivizumab) and the absence of major adverse effects. To date, there are no data that indicate the need to modify the guidelines for RSV prophylaxis in premature infants published in 2000.

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.