SURVEY OF INFLUENZA IMMUNISATION UPTAKE IN ‘HIGH RISK’ CHILDREN

Abstract

24 January 2006 Dear Editor, In Australia, influenza vaccine is recommended for children aged >6 months considered at risk of severe influenza, with (i) chronic cardiac disease; (ii) chronic suppurative lung disease, e.g. cystic fibrosis (CF); (iii) chronic illness; (iv) immune deficiency; and (v) residents of long-term care facilities.1 Two doses of influenza vaccine are recommended for first-time recipients < 10 years old.1 Influenza vaccine uptake rates in Australia for high risk children are unknown. In 2004/2005, we performed a cross-sectional, retrospective survey of 74 high-risk children aged between 6 months to 18 years for whom influenza vaccine is recommended.1 Numbers according to category were as follows: (i) cardiac, n = 14; (ii) cystic fibrosis, n = 20; (iii) chronic illness, n = 20; and (iv) immunodeficiency, including cancer, n = 20. The method of recruitment varied with each group and was tailored to the individual departments. Patients were randomly selected while waiting in the outpatients department for a consultation (chronic medical illness including diabetes, haemoglobinopathy, chronic liver disease, metabolic disease) or on the inpatient ward (cardiac); or were randomly selected from a patient list (oncology, cystic fibrosis) and telephoned at home. The first 20 telephoned who were at home were included in the survey. The recruitment rate of eligible patients was high, with only one parent refusing to participate. Telephone recruitment proved a faster, more effective method of recruitment. Additional information regarding cardiac disease and Schwachman score (for CF) was obtained from medical records. Overall, 31 (42%) of the 74 study children had received influenza vaccine in 2004: 11/20 (55%) immuno-compromised children; 10/20 (50%) children with cystic fibrosis; 5/14 (35%) children with chronic cardiac disease and 5/20 (25%) children with chronic illness were immunised against influenza. These differences were not statistically significant by χ-square analysis. Five of seven children given influenza vaccine for the first time in 2004 were <10 years old, and should have received two doses, but all were given only one dose. Only two families reported adverse events, one fever and one mild upper respiratory symptoms. The reasons that 43 children did not receive the vaccine in 2004 are shown in the Table 1. Of those 31 who did receive the vaccine, 17 (55%) were advised to do so by a treating specialist, 16 of them by subspecialist paediatricians and one by a general paediatrician. Eight were advised to have the vaccination by their GPs, four by a family member, one by ‘other’ and one by no-one. Disease severity did not influence uptake. There was no significant difference in vaccination uptake between children with and without haemodynamically significant cardiac disease, and no difference in the mean Shwachman scores of the vaccinated and unvaccinated children with cystic fibrosis (vaccinated, mean = 79; unvaccinated, mean = 80). Influenza vaccination uptake in high-risk children at this Australian tertiary institution is poor. No child <10 years old who received vaccine for the first time received the recommended two doses. Rates of vaccination have not been studied in children in Australia previously, but are consistent with the uptake rates in high-risk Australian adults.2 We are making every effort to educate our staff and parents about the benefits of influenza immunisation and the dangers of influenza.