Respiratory syncytial virus infections in infants and children with congenital heart disease: update on the evidence of prevention with palivizumab

Improvement in Palivizumab Administration Prior to Discharge for Hospitalized Infants with Hemodynamically Significant Congenital Heart Disease: A Quality Improvement Initiative

In this quality improvement initiative, we aimed to increase provider adherence with palivizumab administration guidelines for hospitalized infants with hemodynamically significant congenital heart disease. We included 470 infants over four respiratory syncytial virus (RSV) seasons from 11/2017 to 03/2021 (baseline season: 11/2017-03/2018). Interventions included the following: education, including palivizumab in the sign-out template, identifying a pharmacy expert, and a text alert (seasons 1 and 2: 11/2018-03/2020) that was replaced by an electronic health record (EHR) best practice alert (BPA) in season 3 (11/2020-03/2021). The text alert and BPA prompted providers to add "Need for RSV immunoprophylaxis" to the EHR problem list. The outcome metric was the percentage of eligible patients administered palivizumab prior to discharge. The process metric was the percentage of eligible patients with "Need for RSV immunoprophylaxis" on the EHR problem list. The balancing metric was the percentage of palivizumab doses administered to ineligible patients. A statistical process control P-chart was used to analyze the outcome metric. The mean percentage of eligible patients who received palivizumab prior to hospital discharge increased significantly from 70.1% (82/117) to 90.0% (86/96) in season 1 and to 97.9% (140/143) in season 3. Palivizumab guideline adherence was as high or higher for those with "Need for RSV immunoprophylaxis" on the problem list than for those without it in most time periods. The percentage of inappropriate palivizumab doses decreased from 5.7% (n = 5) at baseline to 4.4% (n = 4) in season 1 and 0.0% (n = 0) in season 3. Through this initiative, we improved adherence with palivizumab administration guidelines for eligible infants prior to hospital discharge.

ER stress protein PERK promotes inappropriate innate immune responses and pathogenesis during RSV infection

The activation of dendritic cells (DC) during respiratory viral infections is central to directing the immune response and the pathologic outcome. In these studies, the effect of RSV infection on development of ER stress responses and the impact on innate immunity was examined. The upregulation of ER stress was closely associated with the PERK pathway through the upregulation of CHOP in RSV infected DC. The inhibition of PERK corresponded with decreased EIF2a phosphorylation but had no significant effect on Nrf2 in DC, two primary pathways regulated by PERK. Subsequent studies identified that by blocking PERK activity in infected DC an altered ER stress response and innate cytokine profile was observed with the upregulation of IFNβ and IL-12, coincident to the down regulation of IL-1β. When mitochondria respiration was assessed in PERK deficient DC there were increased dysfunctional mitochondria after RSV infection that resulted in reduced oxygen consumption rates (OCR) and ATP production indicating altered cellular metabolism. Use of a CD11c targeted genetic deleted murine model, RSV infection was characterized by reduced inflammation and diminished mucus staining as well as reduced mucus-associated gene gob5 expression. The assessment of the cytokine responses showed decreased IL-13 and IL-17 along with diminished IL-1β in the lungs of PERK deficient infected mice. When PERK-deficient animals were assessed in parallel for lung leukocyte numbers, animals displayed significantly reduced myeloid and activated CD4 and CD8 T cell numbers. Thus, the PERK activation pathway may provide a rational target for altering the severe outcome of an RSV infection through modifying immune responses.

Impact of Viral PCR Positive Nasal Swabs (Non Covid-19) on Outcomes Following Cardiac Surgery

Viral bronchiolitis is a relative contraindication to elective pediatric cardiac surgery. Nasopharyngeal swab utilizing polymerase chain reaction (PCR) screening for viruses known to cause bronchiolitis are commonly available. The objective of this study was to evaluate clinical outcomes in patients with nasopharyngeal viral PCR positive findings at the time of cardiac surgery. Retrospective review from January 2013 to May 2019 for patients with virus detected by PCR on nasopharyngeal swabs at the time of cardiac surgery. Single ventricle and two ventricle patients were compared to control group of age and procedure matched patients viral negative at the time of surgery. Outcome measures included OR extubation, reintubation, hospital length of stay, and mortality. For two ventricle patients (n = 81; control group = 165), there was no statistical difference in any outcome variable (OR extubation 74% vs 72%; p = 0.9; reintubation 9% vs 11% vs; p = 0.7; hospital length of stay 5 days (1-46) vs 4 days (2-131); p = 0.4; mortality 2 vs 1; p = 0.3). For single ventricle patients, there was no statistical difference in any outcome variable (OR extubation 81% vs 76%; p = 0.6; reintubation 14% vs 21% vs; p = 0.5; hospital length of stay 9.5 days (3-116) vs 15 days (2-241); p = 0.1; mortality 0 vs 3; (p = 0.6)). PCR is a sensitive test that fails to predict which patients will proceed to have a clinically significant infection. Viral bronchiolitis remains a relative risk factor for cardiac surgery; presence of detectable virus via nasopharyngeal swab with limited clinical symptoms may not be a contraindication to cardiac surgery.

The Differences in Viral Etiologies between Children with and without Severe Disability Admitted to the Pediatric Intensive Care Unit with Acute Respiratory Illness

Objectives The objectives of this study were to evaluate the differences in the viral etiologies and variability in the clinical course between children with and without severe disability (SD) admitted to the pediatric intensive care unit (PICU) with acute respiratory illness (ARI).

Methods The medical records of patients admitted to our PICU between June 2017 and July 2019 were retrospectively reviewed for viral etiology and clinical course.

Results Forty-eight of 136 patients included in the study had SD. The rates of requiring positive pressure ventilation (43.5% vs. 20.5%) or inotropic support (39.9% vs. 15.9%), and the median length of stay (11 [10] vs. 5 [8]) were significantly higher in children with SD (p < 0.01, each). Influenza infection was significantly higher in children with SD (20.8% vs. 2.3%; p < 0.01) whereas respiratory syncytial virus (RSV) infection was more common in children without SD (47.7% vs. 4.2%; p < 0.01). There was no statistically significant difference in terms of other viruses between study groups.

Conclusion In this present study, influenza was an important pathogen for children with SD, while RSV was the main cause of ARI-associated PICU admission in children without SD. By focusing on increasing the rate of immunization against influenza in children with SD and their caregivers the burden of influenza-associated PICU admissions could be decreased.

Perception of general pediatricians in Riyadh towards vaccination of patients with congenital heart diseases

Background:

Congenital heart defected (CHD) children are often predisposed to numerous conditions ranging from arrythmias, infections, to heart failure. Proper implementation of vaccination plan and multidisciplinary acts are mandatory for maintaining such cases to reduce the mortality and morbidity. Furthermore, CHD are also at risk of vaccine adverse reaction and several blooddisseminated pathogens infections, and at risk of death if such events where to occur. Perception and Interpretation of the knowledge and experience of general pediatricians towards vaccination of patients with congenital heart diseases is a crucial element to understand, and to improve healthcare practice in Riyadh, Saudi Arabia.

Aims:

To clarify, our aim is to investigate views of different pediatricians in vaccination plans, to perceive junior and senior pediatricians, and to identify extra vaccines given to children with a congenital heart defect.

Settings and Design:

This study is a cross-sectional study that includes the distribution of 246 questionnaires through personal interview focusing on pediatric cardiologists and general pediatricians with varying years of practice and degrees. Study was conducted by six medical interns: Mohammed O. Alfakhri, Meshal F. Alhajji, Abdulrahman M. Alyani, Yahya Z. Murad, Abdulrahman E. Alghannam, Alwaleed H. Algahtani, in six different teritiary hospitals, King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), King Faisal Specialist Hospital (KFSH), King Salman Hospital, and Alyamamah Hospital, in Riyadh, Saudi Arabia.

Methods and Material:

Data was collected through a convenient sampling technique and was analyzed using SPSS (version 20) and rearranged to observe the most frequent information obtained from the questionnaire.

Statistical Analysis Used:

Categorical study was described in frequencies and bar charts. Chi-Square test of significance was used after the data entry to assess the significance of the values obtained.

Results and Conclusions:

There was no significant difference between the six hospitals. In the following study, 81.7% of the participants believe that patients with congenital heart diseases are combined immunodeficient, and 84.6% agreed on giving special\extra vaccine with no preference over live and\or killed vaccine. On top of that, participants believe that the extra vaccines given to congenital heart disease patients with combined immunodeficiency are meningococcal and pneumococcal vaccines, and the special vaccine given to them are respiratory syncytial virus (RSV) and influenza vaccine. To conclude, congenitally heart defected children are widespread worldwide. Children suffering from the disease are having a serious problem that affects their lives from its earliest. For that, our research mainly focuses on improving their lives by trying to reduce the effect of several other preventable diseases using vaccines as and when they need. Several other studies believed in giving extra/special vaccines that vary depending on the location of the study. However, in Riyadh, we found that most pediatricians agree on giving extra vaccines as meningococcal and pneumococcal, and RSV and influenza as special vaccines to children with congenital heart defects.

Viral Respiratory Infection, a Risk in Pediatric Cardiac Surgery: A Propensity-Matched Analysis

OBJECTIVES

1) To describe the postoperative course and outcomes of cardiac surgery in children with perioperative viral respiratory infection, 2) to evaluate optimal surgical timing for preoperative viral respiratory infection patients, and 3) to define risk stratification.

DESIGN

Retrospective study of children undergoing cardiac surgery. Children were tested using a multiplex polymerase chain reaction (respiratory virus polymerase chain reaction) panel capturing seven respiratory viruses. Respiratory virus polymerase chain reaction testing was routinely performed in patients under 2 years old. Those with negative results yet highly suspected of viral respiratory infection after surgeries would be tested again.

SETTING

A pediatric cardiac surgical ICU of pediatric cardiac surgery department at Fuwai Hospital.

PATIENTS

Children admitted between January 1, 2014, and December 31, 2016, to perform respiratory virus polymerase chain reaction testing and cardiac surgery were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 2,831 patients had respiratory virus polymerase chain reaction testing, and viruses were detected in 91 patients (3.2%), including 35 preoperative and 56 postoperative. Of the 35 preoperative viral respiratory infection patients, there were 29 viral respiratory infection-resolved (patients for whom surgery was postponed until resolution of viral respiratory infection symptoms and negative respiratory virus polymerase chain reaction) and six viral respiratory infection-unresolved (who underwent cardiac surgery before resolution of symptoms and clearance of carriage) patients. Furthermore, there were seven deaths, including one in the preoperative viral respiratory infection-unresolved group and six in the postoperative viral respiratory infection group. A propensity score matching was performed to correct the selection bias and identify the comparable patient groups. Compared to their matched nonviral respiratory infection patients, viral respiratory infection-resolved patients had similar duration of mechanical ventilation and length of stay, while viral respiratory infection-unresolved patients had longer durations of postoperative mechanical ventilation (p = 0.033), PICU (p = 0.028) and hospital length of stay (p = 0.010), and postoperative viral respiratory infection patients had significantly greater duration of postoperative recovery (p < 0.001) and higher mortality (p < 0.001). Earlier diagnosis of postoperative viral respiratory infection was associated with longer mechanical ventilation duration (r = 0.422; p < 0.001). Palliative cardiac surgery was the only variable significantly associated with mortality in multivariate analysis (odds ratio, 12.0; 95% CI, 1.6-87.5; p = 0.014).

CONCLUSIONS

The preoperative-unresolved and postoperative viral respiratory infection were associated with prolonged postoperative recovery, increased severity, and mortality in children with cardiac surgeries. Our results suggested the optimal surgical timing may be after the resolution of viral respiratory infection symptoms and carriage unless the perceived benefits of early surgery outweigh the risk of death, prolonged ventilation, and PICU length of stay. Palliative surgeries were associated with increasing mortality.

Testing for Common Respiratory Viruses in Children Admitted to Pediatric Intensive Care: Epidemiology and Outcomes

OBJECTIVES

Viral infections are common in children, but there is a lack of data on severe viral infections in critically ill children. We investigated testing for viral infections in children requiring PICU admission and describe the epidemiology and outcomes.

DESIGN

Multicenter retrospective study. Results of viral testing for nine respiratory viruses using polymerase chain reaction were collected.

PARTICIPANTS

Children less than 16 years old nonelectively admitted to PICU over a 6-year period.

SETTING

Two tertiary PICUs in Queensland, Australia.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Primary outcome was PICU length of stay. Secondary outcomes included need for and duration of intubation and mortality in PICU. Univariate and multivariate regression analyses were performed, adjusting for age, indigenous status, comorbidities, and severity of illness.

RESULTS

Of 6,426 nonelective admissions, 2,956 (46%) were polymerase chain reaction tested for a virus of which 1,353 (46%) were virus positive. Respiratory syncytial virus was the most common pathogen identified (n = 518, 33%), followed by rhinovirus/enterovirus and adenovirus. Across all patients who underwent polymerase chain reaction testing, identification of a respiratory virus was not significantly associated with longer overall length of stay (multivariate odds ratio, 1.08; 95% CI, 0.99-1.17; p = 0.068) or longer intubation (p = 0.181), whereas the adjusted odds for intubation and mortality were significantly lower (p < 0.01). Subgroup analyses restricted to patients with acute respiratory infections (n = 1,241), bronchiolitis (n = 761), pneumonia (n = 311), confirmed bacterial infection (n = 345), and malignancy (n = 95) showed that patients positive for a virus on testing had significantly longer PICU length of stay (multivariate p < 0.05). In children with pneumonia, identification of a respiratory virus was associated with significantly increased duration of ventilation (p = 0.003). No association between positive test results for multiple viruses and outcomes was observed.

CONCLUSION

Viral infections are common in critically ill children. Viral infections were associated with lower intubation and mortality rates compared with all children testing negative for viral infections. In several subgroups studied, identification of viral pathogens was associated with longer PICU length of stay while mortality was comparable. Prospective studies are required to determine the benefit of routine testing for respiratory viruses at the time of PICU admission.

Palivizumab compliance in congenital heart disease patients: factors related to compliance and altered lower respiratory tract infection viruses after palivizumab prophylaxis

BACKGROUND

Lower respiratory tract infections caused by respiratory syncytial virus can be severe during infancy, which requires admission to the hospital. These infections may be more severe especially in patients with congenital heart disease. Passive immunisation with palivizumab, a monoclonal antibody, is recommended in high-risk infants. We tried to determine the compliance rates, factors affecting compliance, and also other microorganisms responsible for lower respiratory tract infections after palivizumab prophylaxis in these patients.

METHODS

We evaluated patients' compliance to prophylaxis with palivizumab in two consecutive respiratory syncytial virus seasons from pharmacy records. We also investigated factors affecting compliance and the frequency of hospitalisations for lower respiratory tract infections. We investigated the causative microorganisms detected in hospitalised patients.

RESULTS

In this study, 86.7% of the desired number of injections was achieved in 176 patients in two seasons. Out of these, 117 patients (66.4%) received all the doses they were prescribed. Although not statistically significant, compliance to prophylaxis was higher in male patients, cyanotic patients, those who started under 1 year old, and who lived in the city centre. Human metapneumovirus, parainfluenza type 3, and bocavirus were detected in the hospitalised patients.

CONCLUSION

Patients with congenital heart disease can survive the period of infancy with less problem by making palivizumab prophylaxis more effective, and awareness about non- respiratory syncytial virus factors may be a guide for the development of new treatments.

CHD and respiratory syncytial virus: global expert exchange recommendations

BACKGROUND

Palivizumab is the standard immunoprophylaxis against serious disease due to respiratory syncytial virus infection. Current evidence-based prophylaxis guidelines may not address certain children with CHD within specific high-risk groups or clinical/management settings.

METHODS

An international steering committee of clinicians with expertise in paediatric heart disease identified key questions concerning palivizumab administration; in collaboration with an additional international expert faculty, evidence-based recommendations were formulated using a quasi-Delphi consensus methodology.

RESULTS

Palivizumab prophylaxis was recommended for children with the following conditions: <2 years with unoperated haemodynamically significant CHD, who are cyanotic, who have pulmonary hypertension, or symptomatic airway abnormalities; <1 year with cardiomyopathies requiring treatment; in the 1st year of life with surgically operated CHD with haemodynamically significant residual problems or aged 1-2 years up to 6 months postoperatively; and on heart transplant waiting lists or in their 1st year after heart transplant. Unanimous consensus was not reached for use of immunoprophylaxis in children with asymptomatic CHD and other co-morbid factors such as arrhythmias, Down syndrome, or immunodeficiency, or during a nosocomial outbreak. Challenges to effective immunoprophylaxis included the following: multidisciplinary variations in identifying candidates with CHD and prophylaxis compliance; limited awareness of severe disease risks/burden; and limited knowledge of respiratory syncytial virus seasonal patterns in subtropical/tropical regions.

CONCLUSION

Evidence-based immunoprophylaxis recommendations were formulated for subgroups of children with CHD, but more data are needed to guide use in tropical/subtropical countries and in children with certain co-morbidities.

Comparing First- and Second-year Palivizumab Prophylaxis in Patients With Hemodynamically Significant Congenital Heart Disease in the CARESS Database (2005-2015)

BACKGROUND

Respiratory syncytial virus hospitalization (RSVH) rates in children <2 years of age with hemodynamically significant congenital heart disease (HSCHD) are 2- to 4-fold higher compared with healthy term infants. Pediatric recommendations differ as to whether palivizumab is beneficial beyond 1 year of age. The objective of this study was to determine whether differences exist in respiratory-related illness hospitalization (RIH) and RSVH in HSCHD infants receiving palivizumab during the first year versus second year of life in the Canadian Registry of Palivizumab.

METHODS

The Canadian Registry of Palivizumab is a prospective database of infants who received ≥1 dose of palivizumab in 32 hospitals from 2005 to 2015. Demographic data were collected at enrollment and RIH events recorded monthly. Infants <24 months of age with HSCHD were recruited.

RESULTS

Of 1909 HSCHD infants, 1380 (72.3%) in the first year (mean age, 4.2 months) and 529 (27.7%) in the second year of life (mean age, 17.8 months) received prophylaxis. Baseline demographics for day-care attendance, multiple births, enrollment age and weight differed between the groups (all P < 0.05). Additionally, second year infants had a more complicated neonatal course, with significantly longer length of stay (51.2 vs. 24.9 days) compared with those in the first year. The RIH and RSVH rates in the first year were 11.2% and 2.3% and in the second year were 10.6% and 1.7%. Cox regression analysis showed similar hazard for RIH [hazard ratio, 1.9; 95% confidence interval: 0.7-4.6; P = 0.18] and RSVH [hazard ratio, 2.0; 95% confidence interval: 0.2-16.5; P = 0.52].

CONCLUSIONS

Infants in the first and second year of life had a similar RSVH hazard. These findings suggest that infants in the second year with HSCHD, who remain unstable, are equally at risk for RSVH and merit prophylaxis.

Impact of Viral Respiratory Pathogens on Outcomes After Pediatric Cardiac Surgery

OBJECTIVES

Viral respiratory infection is commonly considered a relative contraindication to elective cardiac surgery. We aimed to determine the frequency and outcomes of symptomatic viral respiratory infection in pediatric cardiac surgical patients.

DESIGN

Retrospective cohort study of children undergoing cardiac surgery. Symptomatic children were tested using a multiplex Polymerase Chain Reaction (respiratory virus polymerase chain reaction) panel capturing nine respiratory viruses. Tests performed between 72 prior to and 48 hours after PICU admission were included. Mortality, length of stay in PICU, and intubation duration were investigated as outcomes.

SETTING

Tertiary PICU providing state-wide pediatric cardiac services.

PATIENTS

Children less than 18 years admitted January 1, 2008 to November 29, 2014 for cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Respiratory virus polymerase chain reaction was positive in 73 (4.2%) of 1,737 pediatric cardiac surgical admissions, including 13 children with multiple viruses detected. Commonly detected viruses included rhino/enterovirus (48%), adenovirus (32%), parainfluenza virus 3 (10%), and respiratory syncytial virus (3%). Pediatric Index of Mortality 2, Aristotle scores, and cardiopulmonary bypass times were similar between virus positive and negative/untested cohorts. Respiratory virus polymerase chain reaction positive patients had a median 2.0 days greater PICU length of stay (p < 0.001) and longer intubation duration (p < 0.001). Multivariate analysis adjusting for age, Aristotle score, cardiopulmonary bypass duration, and need for preoperative PICU admission confirmed that virus positive patients had significantly greater intubation duration and PICU length of stay (p < 0.001). Virus positive patients were more likely to require PICU admission greater than 4 days (odds ratio, 3.5; 95% CI, 1.9-6.2) and more likely to require intubation greater than 48 hours (odds ratio, 2.5; 95% CI, 1.4-4.7). There was no difference in mortality. No association was found between coinfection and outcomes.

CONCLUSIONS

Pediatric cardiac surgical patients with a respiratory virus detected at PICU admission had prolonged postoperative recovery with increased length of stay and duration of intubation. Our results suggest that postponing cardiac surgery in children with symptomatic viral respiratory infection is appropriate, unless the benefits of early surgery outweigh the risk of prolonged ventilation and PICU stay.

The impact of congenital heart diseases on the quality of life of patients and their families in Saudi Arabia. Biological, psychological, and social dimensions

Objectives:

To assess the impact of congenital heart diseases (CHDs) on bio-psychosocial aspects of the quality of life (QOL) of patients and their families.

Methods:

A cross-sectional study was carried out between May 2014 and August 2015, including children aged <16 years, and followed-up at King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia for CHD. A broad questionnaire was administered to investigate biological, psychological, and social dimensions of afflicted children, their parents, and siblings. Outcomes were computed as impact scores (0-100%) for each dimension and family member.

Results:

A total of 180 children (104 [57.8%] males; mean age ± standard deviation [SD] = 5.65 ± 4.8 years) were included. There were 25% children complaining of recurrent respiratory infections, 35% of frequent hospitalizations, 38.9% had milestone delay, and 12 (6.7%) only had a social security registration. Mothers declared difficulty coping with their children’s disease in 20% of cases and 22.2% reported being depressed. Mean ± SD impact scores in afflicted children were: 26.1 ± 26.2 (biological), 28.7 ± 28.8 (psychological), and (20.2 ± 25.7) social dimensions. Mothers’ impact scores were higher than fathers’. Complex CHDs had an additional impact, and children from families with less knowledge on CHD had relatively greater impact scores.

Conclusion:

Congenital heart diseases impact all aspects of QOL of patients and their families, and are associated with high comorbidity. Social and psychological support and education for patients and their parents are crucial factors for improving QOL.

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Infants with Congenital Heart Disease

Introduction

The REGAL (RSV Evidence—a Geographical Archive of the Literature) series provide a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This fourth publication covers the risk and burden of RSV infection in infants with congenital heart disease (CHD).

Methods

A systematic review was undertaken for articles published between January 1, 1995 and December 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov. Studies reporting data for hospital visits/admissions for RSV infection among children with CHD as well as studies reporting RSV-associated morbidity, mortality, and healthcare costs were included. The focus was on children not receiving RSV prophylaxis. Study quality and strength of evidence (SOE) were graded using recognized criteria.

Results

A total of 1325 studies were identified of which 38 were included. CHD, in particular hemodynamically significant CHD, is an independent predictor for RSV hospitalization (RSVH) (high SOE). RSVH rates were generally high in young children (<4 years) with CHD (various classifications), varying between 14 and 357/1000 (high SOE). Children (<6 years) with RSV infection spent 4.4–14 days in hospital, with up to 53% requiring intensive care (high SOE). Infants (<2 years) with CHD had a more severe course of RSVH than those without CHD (high SOE). Case fatality rates of up to 3% were associated with RSV infection in children with CHD (high SOE). RSV infection in the perioperative period of corrective surgery and nosocomial RSV infection in intensive care units also represent important causes of morbidity (moderate SOE).

Conclusion

CHD poses a significant risk for RSVH and subsequent morbidity and mortality. RSV infection often complicates corrective heart surgery. To reduce the burden and improve outcomes, further research and specific studies are needed to determine the longer-term effects of severe RSV infection in young children with CHD.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-016-0142-x) contains supplementary material, which is available to authorized users.

Retrospective Multicenter Study of Respiratory Syncytial Virus Prophylaxis in Korean Children with Congenital Heart Diseases

BACKGROUND AND OBJECTIVES

We conducted a review of current data on respiratory syncytial virus (RSV) prophylaxis with palivizumab, in Korean children with congenital heart diseases (CHD). In 2009, the Korean guideline for RSV prophylaxis had established up to five shots monthly per RSV season, only for children <1 year of age with hemodynamic significance CHD (HS-CHD).

SUBJECTS AND METHODS

During the RSV seasons in 2009-2015, we performed a retrospective review of data for 466 infants with CHD, examined at six centers in Korea.

RESULTS

Infants received an average of 3.7±1.9 (range, 1-10) injections during the RSV season. Fifty-seven HS-CHD patients (12.2%) were hospitalized with breakthrough RSV bronchiolitis, with a recurrence in three patients, one year after the initial check-up. Among patients with simple CHD, only five (1.1%) patients received one additional dose postoperatively, as per the limitations set by the Korean guideline. Among the 30 deaths (6.4%), five (1.1%) were attributed to RSV infection; three to simple CHD, one to Tetralogy of Fallot, and one to hypertrophic cardiomyopathy (HCM). Of the three HCM patients that exceeded guidelines for RSV prophylaxis, two (66.6%) were hospitalized, and one died of RSV infection (33.3%).

CONCLUSION

In accordance to the Korean guideline, minimal injections of palivizumab were administered to patients having HS-CHD <one year of age during the RSV season; the risk of RSV infection remains significant among children with simple CHD, cardiomyopathy, and children above the age of one year with HS-CHD.

Timing of Haemophilus influenzae type b vaccination after cardiac surgery

BACKGROUND

The best time for vaccination in infants with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery is unclear, but it is important to prevent Haemophilus influenzae type b (Hib) infection in infants with CHD after CPB surgery. To identify the best time for Hib vaccination in infants with CHD after CPB surgery, we investigated the immunological status, and the efficacy and safety of Hib vaccination after CPB surgery.

METHODS

Sixteen subjects who underwent surgical correction of ventricular septal defect with CPB were investigated. Immunological status and cytokines were analyzed before surgery, 2 months after surgery, and before Hib booster vaccination. Hib-specific IgG was also measured to evaluate the effectiveness of vaccination.

RESULTS

Immunological status before and 2 months after surgery (e.g. whole blood cells and lymphocyte subset profile) was within the normal range and no subjects had hypercytokinemia. Additionally, all subjects who received Hib vaccination at 2-3 months after CPB surgery had effective serum Hib-specific IgG level for protection against Hib infection without any side-effects.

CONCLUSIONS

CPB surgery does not influence acquired immunity and Hib vaccination may be immunologically safe to perform at 2 months after CPB surgery. Hib vaccination at 2-3 months after CPB surgery was effective in achieving immunization for infants with simple left-right shunt-type CHD.

Respiratory syncytial virus-associated hospitalizations over three consecutive seasons in children with congenital heart disease

The purpose of this investigation was to analyze the burden of respiratory syncytial virus (RSV)-related hospitalizations in infants and children with congenital heart disease (CHD) over three consecutive RSV seasons. Retrospectively, all children with hemodynamically significant (HS-CHD) and not significant (HNS-CHD) CHD born between 2004 and 2008 at a tertiary care university hospital and identified by ICD-10 diagnoses were included. Data on RSV-related hospitalizations over the first three years of life covering at least three RSV seasons (November-April) were analyzed. The overall incidence of RSV-related hospitalization was 9.6 % (58/602), without a statistically significant difference between HS-CHD and HNS-CHD (7.3 % vs. 10.4 %; p = 0.258). Recommendation of palivizumab prophylaxis did not influence the RSV hospitalization rates between groups. Patients with HS-CHD and early surgery were significantly less often hospitalized due to RSV compared to those with delayed surgery (1.3 % vs. 14.3 %; p = 0.003). The median duration of hospitalization was 8.5 days (HS-CHD: 14 vs.

HNS-CHD

7 days; p = 0.003). Thirteen patients (22.4 %) were admitted to the intensive care unit (ICU), for a median of 10 days. The median age at admission was 2 months, with a significant difference between HS-CHD and HNS-CHD (6 vs. 2 months; p = 0.001). The majority (97 %) of RSV-related hospitalizations occurred before 12 months of age. Patients with HS-CHD had a significantly more severe course of RSV disease and were older at the time of hospitalization. Early surgery seemed to significantly reduce the risk of RSV hospitalization during the first RSV season.

Revised recommendations concerning palivizumab prophylaxis for respiratory syncytial virus (RSV)

Respiratory Syncytial Virus infections are one of the leading causes of severe respiratory diseases that require hospitalization and, in some cases, intensive care. Once resolved, there may be respiratory sequelae of varying severity. The lack of effective treatments for bronchiolitis and the lack of vaccines for RSV accentuate the role of prevention in decreasing the impact of this disease. Prevention of bronchiolitis strongly relies on the adoption of environment and the hygienic behavior measures; an additional prophylactic effect may be offered, in selected cases, by Palivizumab, a humanized monoclonal antibody produced by recombinant DNA technology, able to prevent RSV infection by blocking viral replication.After many years the Italian Society of Neonatology, on the basis of the most recent scientific knowledge, has decided to revise recommendations for the use of palivizumab in the prevention of RSV infection.

Risk of respiratory syncytial virus infection in preterm infants: reviewing the need for prevention

Premature infants are at substantial risk for a spectrum of morbidities that are gestational age dependent. Respiratory syncytial virus (RSV) infection is most common in the first two years of life with the highest burden in children aged <6 months. Preterm infants ≤35 weeks' gestation are handicapped by incomplete immunological and pulmonary maturation and immature premorbid lung function with the added risk of bronchopulmonary dysplasia. Superimposed RSV infection incites marked neutrophilic airway inflammation and innate immunological responses that further compromise normal airway modeling. This review addresses the epidemiology and burden of RSV disease, focusing on the preterm population. Risk factors that determine RSV-disease severity and hospitalization and the impact on healthcare resource utilization and potential long-term respiratory sequelae are discussed. The importance of disease prevention and the evidence-based rationale for prophylaxis with palivizumab is explored, while awaiting the development of a universal vaccine.

Efficacy of palivizumab prophylaxis among infants with congenital heart disease: A case control study

BACKGROUND

Palivizumab prophylaxis for RSV has been consistently reported to reduce the risk of hospital admissions related to RSV infection in children with symptomatic cardiac disease. This study was designed to investigate the efficacy of palivizumab prophylaxis among infants with congenital heart disease (CHD) in Turkey.

METHODS

A total of 91 infants with CHD who received palivizumab prophylaxis and 96 infants with CHD without prophylaxis (0-12 months:52; 12-24 months:44) were included in this single-center retrospective case control study. Data on patient characteristics, household environment, and LRTIs were evaluated.

RESULTS

In patients without prophylaxis, the rate of overall lower respiratory tract infections (LRTIs) (P < 0.001), complicated LRTIs (P = 0.006), LRTI-related hospitalization (P < 0.001) and ICU admission (P = 0.008) were significantly higher than control patients. Weight <10th percentile (odds ratio (OR) 5.78, 95% confidence interval (CI):1.37; 24.4, P < 0.001) and concomitant chromosome abnormality (OR 4.01, 95% CI:1.01;16.45, P < 0.001) in patients with prophylaxis, while presence of a sibling <11 years of age (OR 3.38, 95% CI: 1.21; 9.46, P < 0.001) and congestive heart failure (OR 8.63, 95% CI: 2.81; 26.6, P < 0.001) in the control group were the significant correlates of LRTI-related hospitalization.

CONCLUSION

Our findings revealed significantly lower rate of overall and complicated LRTIs, LRTI-related hospitalization and ICU admissions in infants with CHD via palivizumab prophylaxis.

The impact of human rhinovirus infection in pediatric patients undergoing heart surgery

Human rhinovirus (HRV), the most common cause of upper respiratory infection in children, can present as bronchiolitis, pneumonia, or asthma exacerbations. The impact of HRV in infants and toddlers with congenital heart disease is poorly defined. A case-control study was performed to compare the clinical course for 19 young children with respiratory symptoms who tested positive for rhinovirus after heart surgery with that of 56 matched control subjects. The control subjects were matched by surgical repair, age, weight, and time of the year. Patients with known HRVs before surgery and control subjects with respiratory symptoms or positive test results for viruses were excluded from the study. Human rhinovirus infection was associated with more than a tenfold increase in the odds of noninvasive ventilation after extubation (odds ratio [OR] 11.45; 95 % confidence interval [CI] 3.97-38.67), a 12-fold increase in the probability of extubation failure (OR 12.84; 95 % CI 2.93-56.29), and increased use of pulmonary medications including bronchodilator and nitric oxide (p < 0.001). As a result, the hospital length of stay (HLOS) was two times longer than for the control subjects (p < 0.001), and the cardiac intensive care unit (CICU) length of stay (CICU LOS) was three times longer (p < 0.0001). The intubation time was significantly longer (p < 0.001), and the CICU respiratory charges were significantly greater (p = 0.001) for the infected patients. Human rhinovirus increases resource use and prolongs postoperative recovery after pediatric heart surgery. Surgery timing should be delayed for patients with rhinovirus if possible.

Respiratory Syncytial Virus Infection in High-risk Infants - an Update on Palivizumab Prophylaxis

Morbidity due to respiratory syncytial virus (RSV) disease is still high in infants and children worldwide during the first two to five years of life. Certain categories of high-risk infants with increased morbidity and mortality attributed to RSV disease have been identified and are included in national recommendations for prophylaxis with the monoclonal RSV antibody palivizumab. Most guidelines recommend palivizumab for preterm infants born less than or equal to 32 weeks gestational age with or without bronchopulmonary dysplasia, those born between 33 and 35 weeks gestational age with additional risk factors, and infants and children with hemodynamically significant congenital heart disease. Over the last years several rare diseases have been identified demonstrating high morbidity associated with RSV disease, thus, extension of guidelines for the prophylaxis with palivizumab for these patients with rare diseases including children with malignancy, congenital and acquired immune deficiency, Down syndrome, neuromuscular impairment, cystic fibrosis, congenital diaphragmatic hernia and other severe respiratory disease is increasingly discussed. Efficacy of palivizumab prophylaxis is documented by meta-analysis, and different economic analyses demonstrate cost-effectiveness of palivizumab for the most common indications during the first RSV season.

Detection of respiratory syncytial virus fusion protein variants between 2009 and 2012 in China

Respiratory syncytial virus (RSV) causes respiratory tract infection, particularly acute lower respiratory tract infection (ALRTI), in early childhood. The RSV fusion protein (F protein) is an important surface protein, and it is the target of both cytotoxic T lymphocytes (CTL) and neutralizing antibodies; thus, it may be useful as a candidate for vaccine research. This study investigated the genetic diversity of the RSV F protein. To this end, a total of 1800 nasopharyngeal aspirates from hospitalized children with ALRTI were collected for virus isolation between June 2009 and March 2012. There were 333 RSV-positive cases (277 cases of RSV A, 55 of RSV B, and 1 with both RSV A and RSV B), accounting for 18.5 % of the total cases. Next, 130 clinical strains (107 of RSV A, 23 of RSV B) were selected for F gene sequencing. Phylogenetic analysis revealed that the F gene sequence is highly conserved, with significant amino acid changes at residues 16, 25, 45, 102, 122, 124, 209, and 447. Mutations in human histocompatibility leukocyte antigen (HLA)-restricted CTL epitopes were also observed. Variations in RSV A F protein at the palivizumab binding site 276 (N→S) increased between 2009 and 2012 and became predominant. Western blot analysis and microneutralization data showed a substitution at residue 276 (N→S) in RSV A that did not cause resistance to palivizumab. In conclusion, the RSV F gene is geographically and temporally conserved, but limited genetic variations were still observed. These data could be helpful for the development of vaccines against RSV infection.

Prevention and prophylaxis of respiratory syncytial virus in pediatric cardiology: a UK perspective

ABSTRACT: 

Respiratory syncytial virus (RSV) is a common infection, causing bronchiolitis in over 70% of infants each year and almost all children by the age of 2. It is the leading cause of acute lower respiratory tract infections and admissions to hospital worldwide. Previously healthy infants may have a prolonged cough or wheezing following RSV infection but up to 20% of those with congenital cardiac disease will be hospitalized and have significant morbidity and mortality. For this reason, it is generally recommended that many such infants should receive prophylaxis against RSV infection with palivizumab. This paper reviews the current state of knowledge about RSV affecting children with congenital heart disease from the perspective of those living in the UK and the current protection offered to such children. We also discuss the plans for the future of protection against RSV.

The use of humanized monoclonal antibodies for the prevention of respiratory syncytial virus infection

Monoclonal antibodies are widely used both in infants and in adults for several indications. Humanized monoclonal antibodies (palivizumab) have been used for many years for the prevention of respiratory syncytial virus infection in pediatric populations (preterm infants, infants with chronic lung disease or congenital heart disease) at high risk of severe and potentially lethal course of the infection. This drug was reported to be safe, well tolerated and effective to decrease the hospitalization rate and mortality in these groups of infants by several clinical trials. In the present paper we report the development and the current use of monoclonal antibodies for prophylaxis against respiratory syncytial virus.