Table 2. Characteristics of 23 children in whom clinically significant respiratory syncytial virus respiratory tract infection developed while receiving palivizumab immunoprophylaxis, Canada, 2006–2010*.
| Location and patient ID | Age, mo/ sex† | GA at birth, wk + d | Underlying comorbidities | No. doses PZB‡ | Delay, d§ | Clinical diagnoses | H | Multiplex PCR/DNA results | Mutation |
|---|---|---|---|---|---|---|---|---|---|
| Québec City, Québec (2006–2010) | |||||||||
| C0607-1023 | 9/F | 32 + 4 | Prematurity, LBW | 3 | 21 | Bronchiolitis | No | RSV-A; enterovirus type A | K272Q |
| H0607-064 | 24/M | 38 + 3 | Congenital myopathy | 3 | 15 | Pneumonia; bronchospasm | Yes | RSV-B | NF |
| H0607-132 | 12/M | 38 + 5 | Pulmonary artery stenosis | 5 | 7 | Bronchiolitis | Yes | RSV-A | NF |
| H0708-199 | 4/M | 30 + 4 | Prematurity, VLBW | 4 | 14 | Bronchiolitis | Yes | RSV-B | NF |
| H0809-037 | 11/F | 27 + 5 | Prematurity, ELBW | 3 | 14 | Bronchiolitis | Yes | RSV-A | NF |
| C0809-1055 | 6/F | 29 + 0 | Prematurity, ELBW, triplet | 4 | 27 | Bronchiolitis | No | RSV-A | N276S |
| C0809-1056 | 6/M | 29 + 0 | Prematurity, ELBW, triplet | 4 | 27 | Bronchiolitis | No | RSV-A | N276S |
| C0809-1057 | 6/M | 29 + 0 | Prematurity, VLBW, triplet | 4 | 27 | Bronchiolitis | No | RSV-A | N276S |
| H0910-004 | 4/F | 39 + 5 | Choanal hypoplasia | 1 | 16 | Apnea; upper RTI | Yes | RSV-A | N276S |
| H0910-140 | 6/M | 25 + 5 | Prematurity, ELBW | 4 | 29 | Bronchiolitis | Yes | RSV-B | NF |
| H0910-144 | 13/F | 26 + 5 | Prematurity, VLBW | 4 | 7 | Pneumonia | Yes | RSV-A | K272M, N276S |
| H0910-150 | 9/M | 28 + 3 | Prematurity, VLBW | 4 | 12 | Upper RTI; acute otitis media | Yes | RSV-A; adenovirus type C | N276S |
| Montréal, Québec (2009–2010) | |||||||||
| MCH0910-001 | 15/M | 40 + 4 | Total anomalous pulmonary venous return | 3 | 26 | Pneumonia | Yes | RSV¶ | N276S |
| MCH0910-002 | 6/F | 39 + 0 | Pulmonary valve stenosis, right aortic arch | 2 | 7 | Bronchiolitis | Yes | RSV¶ | N276S |
| MCH0910-003 | 5/M | 39 + 6 | Cystic fibrosis | 3 | 24 | Bronchiolitis | No | RSV¶ | N276S |
| MCH0910-004 | 7/M | 36 + 2 | Prematurity, BPD hypotonia | 4 | 6 | Bronchiolitis | Yes | RSV¶ | N276S |
| MCH0910-005 | 15/M | 40 + 4 | Neuromuscular disorder, recurrent aspirations | 4 | 13 | Upper RTI; acute otitis media | No | RSV¶ | N276S |
| MCH0910-006 | 2/M | 34 + 6 | Prematurity, LBW | 1 | 14 | Bronchiolitis | Yes | RSV¶ | N276S |
| MCH0910-007 | 19/F | 25 + 0 | Prematurity, ELBW, BPD | 3 | 19 | Bronchiolitis, bronchospasm | Yes | RSV¶ | N276S |
| MCH0910-008 | 2/F | 38 + 1 | Neuromuscular disorder, ventricular septal defect | 2 | 12 | Bronchiolitis | Yes | RSV¶ | N276S |
| Hamilton, Ontario (2009–2010) | |||||||||
| MAC0910-001 | 1/F | 34 + 5 | Prematurity, LBW | 2 | 3 | Bronchiolitis | Yes | RSV¶ | N276S |
| MAC0910-002 | 6/F | 34 + 3 | Prematurity, LBW, twin | 1 | 25 | Bronchiolitis | Yes | RSV¶ | N276S |
| MAC0910-003 | 6/F | 34 + 3 | Prematurity, VLBW, IUGR, twin | 1 | 27 | Bronchiolitis | Yes | RSV¶ | N276S |
*Patient identification (ID) nomenclature: hospitalized (H) or clinic (C) prospective study participant, Montréal Children’s Hospital (MCH) or McMaster Children’s Hospital (MAC) patient. GA, gestational age; PZB, palivizumab; multiplex PCR/DNA, hybridization assay; mutation, mutation in respiratory syncytial virus fusion protein PZB binding site (residues 262–276); RSV, respiratory syncytial virus; LBW, low birthweight (1,500–2,500 g); NF, no mutation found in PZB binding site; VLBW, very low birthweight (1,000–1,499 g); ELBW, extremely low birthweight (<1,000 g); RTI, respiratory tract infection; BPD, bronchopulmonary dysplasia; IUGR, intrauterine growth restriction. †Median patient age 6.0 mo (range 1–24 mo). ‡Mean ± SD no. palivizumab doses received that winter: 3.0 ± 1.2 doses. §Median interval between last palivizumab dose and symptom onset: 15.0 d (range 3–27 d). ¶Retrospectively identified participants from Montréal Children’s Hospital or McMaster Children’s Hospital were RSV-positive by direct immunofluorescence assay (Chemicon International, Temecula, CA, USA) and were not tested by the multiplex PCR/DNA hybridization assay (14).