Comparison of the Canadian vs. the international risk scoring tool for respiratory syncytial virus prophylaxis in moderate-to-late preterm infants.

Aim: The study objective was to compare the Pediatric Investigators Collaborative Network on Infections in Canada risk scoring tool (CRST) that determines need for respiratory syncytial virus (RSV) prophylaxis in infants 33-35 weeks gestational age during the RSV season, with the newly developed international risk scoring tool (IRST). Methods: Children 33-35 weeks gestational age born during the 2018-2021 RSV seasons were prospectively identified following birth and scored with the validated CRST and IRST, that comprises seven and three variables respectively, into low- moderate- and high-risk groups that predict RSV-related hospitalization. Correlations between total scores on the two tools, and cut-off scores for the low-, moderate- and high-risk categories were conducted using the Spearman rank correlation. Results: Over a period of 3 RSV seasons, 556 infants were scored. Total risk scores on the CRST and the IRST were moderately correlated (rs = 0.64, p < 0.001). A significant relationship between the risk category rank on the CRST and the risk category rank on the IRST (rs = 0.53; p < 0.001) was found. The proportion of infants categorized as moderate risk for RSV hospitalization by the CRST and IRST were 19.6% (n = 109) and 28.1% (n = 156), respectively. Conclusion: The IRST may provide a time-efficient scoring alternative to the CRST with three vs. seven variables, and it selects a larger number of infants who are at moderate risk for RSV hospitalization for prophylaxis. A cost-utility analysis is necessary to justify country-specific use of the IRST, while in Canada a cost comparison is necessary between the IRST vs. the currently approved CRST prior to adoption.

Respiratory syncytial virus hospitalization and incurred morbidities the season after prophylaxis.

OBJECTIVES: The primary objective of this study was to determine the incidence and incurred morbidities of Respiratory syncytial virus (RSV)-related hospitalization (RSVH), the season following completion of prophylaxis. METHODS: A retrospective study was conducted of all infants enrolled in a prophylaxis clinic in one institution during the 2009 to 2014 RSV seasons. RSV infection was identified by Diseases codes and confirmed by RSV-positivity. Data were classified into five groups based on indications for prophylaxis. The incidence of RSVH was calculated. For each subgroup, differences in characteristics between children with and without RSVH were analyzed by independent t test or chi-square test. RESULTS: During five RSV seasons, 827 infants were enrolled. RSVH incidence the season following prophylaxis was 2.1% (n=17/827). Children with chronic lung disease (CLD) had the highest RSVH incidence (7.7%; n=4/52) followed by preterms 33 to 35 weeks gestation (2.5%; n=4/162), those with complex medical disorders (2.2%; n=3/135), those with congenital heart disease (1.5%; n=1/66) and preterms less than or equal to 32 weeks gestation (1.2%; n=5/412). There was no statistically significant association between indications for prophylaxis and RSVH (Fisher exact test, P=0.060). The odds of RSVH were 4.9 times greater (odds ratio [OR]=4.9; 95% CI: 1.53, 15.55; P=0.007) in CLD compared to those without CLD. The median length of RSVH stay was 4 days; 58.8% (n=10/17) required oxygen (median 1 day); 29.4% (n=5/17) required intensive care. CONCLUSIONS: Infants with CLD are at highest risk for RSVH in the season postprophylaxis and may merit palivizumab for more than two seasons dependent on disease severity. However, larger prospective studies are necessary to confirm the findings before embarking on a strategy of providing prophylaxis for a third RSV season.

Respiratory syncytial virus prophylaxis in children with cardiac disease: a retrospective single-centre study.

OBJECTIVES: To examine the characteristics of congenital heart disease patients hospitalised with respiratory syncytial virus infection after prophylaxis and determine the associated comorbidities and the incidence of breakthrough respiratory syncytial virus infections. STUDY DESIGN: This is a retrospective, single-centre study that was conducted over a period of 7 years. Respiratory syncytial virus infection was identified by classification codes and confirmed by virological tests. Data on baseline demographics, cardiac anomalies, other underlying disease, criteria for hospitalisation, type of respiratory illness and management, complications, and palivizumab prophylaxis were analysed by standard descriptive methods and comparative statistics. RESULTS: A total of 30 patients were enrolled. The majority were ≤ 2 years (n = 24). The mean admission age was 15.1 months (standard deviation = 18.3). In all, 90% were acyanotic, 40% had haemodynamically significant disease, and 60% had ≥ 1 underlying medical illness. Patients were admitted with: respiratory distress (86.7%), hypoxaemia (66.7%), fever (60%), inability to maintain oral intake (36.7%), and apnoea (16.7%). More than 50% required mechanical ventilation and intensive care with a median stay of 11 days (range: 1-43); the length of hospital stay for all children was 10 days (range: 1-65). Complications included: concurrent bacterial sepsis (20%), electrolyte abnormalities (16.7%), and worsening pulmonary hypertension (13.3%). Of 10 infants ≤ 2 years with haemodynamically significant heart disease, four had received prophylaxis. There was one death, which was attributed to respiratory syncytial virus infection. CONCLUSIONS: Overall, 185 infants ≤ 2 years with haemodynamically significant cardiac disease received prophylaxis. In all, six qualifying infants missed immunisation and were hospitalised. Breakthrough respiratory syncytial virus infections occurred in 2.2%, demonstrating good efficacy of palivizumab in this population compared with the original, multi-centre, randomised trial.

Target fortification of breast milk with fat, protein, and carbohydrates for preterm infants.

OBJECTIVES: Fortification of breast milk is an accepted practice for feeding very low birth weight infants, however, fixed dosage enhancement does not address variations in native breast milk. This could lead to deficiencies in calories and macronutrients. We therefore established the infrastructure for target fortification in breast milk by measuring and adjusting fat, protein, and carbohydrate content daily. We analyzed nutrient intake, growth, and safety variables. STUDY DESIGN: Each 12-hour batch of breast milk was analyzed using near-infrared spectroscopy. Macronutrients were individually added to routine fortification to achieve final contents for fat (4.4 g), protein (3 g), and carbohydrates (8.8 g) (per 100 mL). Fully breast milk fed healthy very low birth weight infants (<32 weeks) were fed the fortified breast milk for at least 3 weeks. Matched pair analysis of 20 infants fed routinely fortified breast milk was performed using birth weight, gestational age, and postnatal age. RESULTS: All 650 pooled breast milk samples required at least 1 macronutrient adjusted. On average, 0.3 ± 0.4 g of fat, 0.7 ± 0.2 g of protein, and 1.2 ± 0.2 g of carbohydrate were added. Biochemistry was normal in the 10 target fortified infants (birth weight: 860 ± 309 g, 26.3 ± 1.6 weeks gestational age); weight gain was 19.9 ± 2.7 g/kg/d; and milk intake was 147 ± 5 mL/kg/d (131 ± 16 kcal/kg/d). Osmolality of fortified breast milk was 436 ± 13 mOsmol/kg. Matched pair analysis of infants indicated a higher milk intake (155 ± 5 mL/kg/d) but similar weight gain (19.7 ± 3.3 g/kg/d). No adverse event was observed. The linear relationship between milk intake and weight gain observed in study babies but not seen in matched controls may be related to the variable composition of breast milk. CONCLUSIONS: Daily target fortification can be safely implemented in clinical routine and may improve growth.

The impact of prophylaxis on paediatric intensive care unit admissions for RSV infection: a retrospective, single-centre study.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections and hospitalizations in children aged < 2 years. The aim of this retrospective, single-centre study was to examine the characteristics of patients admitted to a paediatric intensive care unit (PICU) with RSV infection following the implementation of a RSV prophylaxis programme. Electronic hospital medical records of all PICU admissions for RSV infection were searched from 2003 to 2009. Data on baseline demographics, underlying disease, criteria for hospitalization, respiratory diagnosis and management, complications and palivizumab prophylaxis were collected. A total of 181 patients were admitted with RSV infection, accounting for 5.7% of all admissions. Eighty-four percent were ≤ 2 years of age. Majority (70.2%) had no underlying medical illness, and 79.6% received antibiotics as part of their medical treatment. Comparison of children aged ≤ 2 years and those >2 years revealed that fewer of the younger cohort (20.4% versus 79.3%; p < 0.001) had an underlying medical condition. RSV infection occurred in 3.3% (n = 6) children who had received palivizumab prophylaxis, and there were two deaths. The results indicate that > 88% of all PICU admissions would not qualify for RSV prophylaxis under our established guidelines and 66% of the children aged ≤ 2 years were > 36 weeks gestation and are not currently targeted for prophylaxis. The number of high-risk infants admitted to PICU with RSV infection has likely plateaued, and further reductions in admission rates may only be realised with the use of universal, vaccine immunization programmes.