Waning Vaccine Immunity and Vaccination Responses in Children Treated for Acute Lymphoblastic Leukemia: A Canadian Immunization Research Network Study.

BACKGROUND: There is no uniform guideline for postchemotherapy vaccination of children with acute lymphoblastic leukemia (ALL). We evaluated waning immunity to 14 pneumococcal serotypes, pertussis toxin (PT), tetanus toxoid (TT) and varicella, and immunogenicity of postchemotherapy diphtheria, tetanus, pertussis, hepatitis B, polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) and pneumococcal vaccination among previously vaccinated children treated for ALL. METHODS: This was a multicenter trial of children with ALL enrolled 4-12 months postchemotherapy completion. Exclusion criteria included: infant ALL, relapsed ALL, and stem cell transplant recipients. Immunocompetent children were recruited as controls. Postchemotherapy participants received DTaP-IPV-Hib and 13-valent pneumococcal conjugate vaccine (PCV13) concurrently, followed by 23-valent pneumococcal polysaccharide vaccine (PPV23) 2 months later. Serology was measured at baseline, 2 and 12 months postvaccination. Adverse events were captured via surveys. RESULTS: At enrollment, postchemotherapy participants (n = 74) were less likely than controls (n = 78) to be age-appropriately immunized with DTaP (41% vs 89%, P < .001) and PCV (59% vs 79%, P = .008). Geometric mean concentrations (GMCs) to TT, PT, PCV serotypes, and varicella were lower in postchemotherapy participants than controls after adjusting for previous vaccine doses (P < .001). Two months postvaccination, GMCs to TT, PT, and PCV serotypes increased from baseline (P < .001 for all antigens) and remained elevated at 12 months postvaccination. Antibody levels to PPV23 serotypes also increased postvaccination (P < .001). No serious adverse events were reported. CONCLUSIONS: Children treated for ALL had lower antibody levels than controls against pneumococcal serotypes, tetanus, pertussis, and varicella despite previous vaccination. Postchemotherapy vaccination with DTaP-IPV-Hib, PCV13, and PPV23 was immunogenic and well tolerated. Children with ALL would benefit from systematic revaccination postchemotherapy. CLINICAL TRIALS REGISTRATION: NCT02447718.

Expert consensus on palivizumab use for respiratory syncytial virus in developed countries.

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalisation in early childhood and palivizumab is the only licensed intervention for prevention. Palivizumab guidelines should reflect the latest evidence, in addition to cost-effectiveness and healthcare budgetary considerations. RSV experts from Europe, Canada and Israel undertook a systematic review of the evidence over the last 5 years and developed recommendations regarding prophylaxis in industrialised countries. Almost 400 publications were reviewed. This group recommended palivizumab for: preterm infants (<29 and ≤31 weeks gestational age [wGA] and ≤9 and ≤6 months of age, respectively; high-risk 32-35wGA), former preterm children ≤24 months with chronic lung disease/bronchopulmonary dysplasia, children ≤24 months with significant congenital heart disease; and other high-risk populations, such as children ≤24 months with Down syndrome, pulmonary/neuromuscular disorders, immunocompromised, and cystic fibrosis. Up to 5 monthly doses should be administered over the RSV season. It is our impression that the adoption of these guidelines would help reduce the burden of RSV.

Asymmetric eye size in an infant.

Toxoplasmosis is an uncommon congenital infection in Canada, but one with potentially severe clinical manifestations, including fetal death. Neurologic and ocular manifestations are frequent in untreated disease; however, small eye size (microphthalmia) is a rare finding. This finding may be a marker of severe ocular disease. As universal screening does not occur in Canada, clinicians' early recognition is imperative, particularly given the lack of risk factors in many patients and the benefit that treatment may have even in initially asymptomatic disease. Here, we report a case of congenital toxoplasmosis and review the diagnostics and treatment of the infection.

La toxoplasmose est une infection congénitale rare au Canada, mais au potentiel de manifestations cliniques graves, y compris la mort fœtale. Les manifestations neurologiques et oculaires sont fréquentes lorsque la maladie n'est pas traitée, et dans de rares cas, on remarque des globes oculaires de petite dimension (microphtalmie). Cette observation peut être un marqueur de maladie oculaire grave. Il n'y a pas de dépistage universel au Canada, mais il est impératif que les cliniciens reconnaissent rapidement la maladie, notamment en raison de l'absence de facteurs de risque chez de nombreux patients et des avantages potentiels des traitements lorsque la maladie est d'abord asymptomatique. Les auteurs déclarent un cas de toxoplasmose congénitale et analysent les diagnostics et le traitement de l'infection.

Possible Neonatal Herpes Simplex Virus (HSV) Acquired Postpartum from Maternal Oral HSV Reactivation after Neuraxial Morphine.

In this report, we describe a case of a neonatal oral herpes simplex virus (HSV) infection possibly acquired from a mother who had oral HSV reactivation in association with neuraxial morphine. Neuraxial morphine is commonly administered for postpartum analgesia after cesarean delivery. While there is evidence that neuraxial morphine increases the risks of oral HSV reactivation in parturients, there has been no report of neonatal HSV infection directly acquired from a mother who had HSV recurrence from neuraxial morphine.

Discordant diagnosis of malaria in a family of child refugees from Sierra Leone.

The clinical presentation and diagnosis of malaria involving a family with seven children who arrived in Canada as refugees is reported. Discrepancies in front-line testing using microscopy and rapid diagnostic tests compared with confirmatory testing using real-time polymerase chain reaction in this cluster of symptomatic and asymptomatic patients were identified.

Les auteurs exposent la présentation clinique et le diagnostic de paludisme dans une famille de sept enfants arrivée au Canada à titre de réfugiés. Ils ont constaté des variations entre les examens de première ligne à l'aide du microscope et de tests diagnostiques rapides et les tests de confirmation faisant appel à la réaction en chaîne de la polymérase au sein de ce groupe de patients symptomatiques et asymptomatiques.

Paediatric Investigators Collaborative Network on Infections in Canada (PICNIC) study of aseptic meningitis.

BACKGROUND: The seasonality, clinical and radiographic features and outcome of aseptic meningitis have been described for regional outbreaks but data from a wider geographic area is necessary to delineate the epidemiology of this condition. METHODS: A retrospective chart review was completed of children presenting with aseptic meningitis to eight Canadian pediatric hospitals over a two-year period. RESULTS: There were 233 cases of proven enteroviral (EV) meningitis, 495 cases of clinical aseptic meningitis and 74 cases of possible aseptic meningitis with most cases occurring July to October. Headache, vomiting, meningismus and photophobia were more common in children > or = 5 years of age, while rash, diarrhea and cough were more common in children < 5 years of age. Pleocytosis was absent in 22.3% of children < 30 days of age with proven EV meningitis. Enterovirus was isolated in cerebrospinal fluid (CSF) from 154 of 389 patients (39.6%) who had viral culture performed, and a nucleic acid amplification test for enterovirus was positive in CSF from 81 of 149 patients (54.3%). Imaging of the head by computerized tomography or magnetic resonance imaging was completed in 96 cases (19.7%) and 24 had abnormal findings that were possibly related to meningitis while none had changes that were definitely related to meningitis. There was minimal morbidity and there were no deaths. CONCLUSION: The clinical presentation of aseptic meningitis varies with the age of the child. Absence of CSF pleocytosis is common in infants < 30 days of age. Enterovirus is the predominant isolate, but no etiologic agent is identified in the majority of cases of aseptic meningitis in Canadian children.