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North Adelaide, Australia

Clarke M.,University of Adelaide | McIntyre P.B.,National Center for Immunisation Research and Surveillance of Vaccine Preventable Diseases | McIntyre P.B.,University of Sydney | Blyth C.C.,University of Western Australia | And 15 more authors.
Journal of Infection

Objectives: Changes in circulating Bordetella pertussis genotypes, including a novel pertussis toxin promoter ptxP3 allele and absence of pertactin (Prn) antigen, have been reported from several countries but limited data on relative severity are available. We compared markers of disease severity in children with B. pertussis infection due to strains of differing genotype. Methods: Culture confirmed cases presenting to tertiary paediatric hospitals in three Australian states between 2008 and 2012 were classified as severe if they required a hospital stay greater than seven days, were admitted to intensive care, or if death occurred. Associations between age, vaccination, genotype and severity were assessed. Results: Of 199 pertussis cases, 81 (41%) were <3 months, including 32/39 (82%) of severe cases. The proportion of isolates from these cases that were Prn deficient increased markedly between 2008 and 2012. Of B. pertussis isolates, the proportion considered severe was similar for Prn positive (27/128, 21%) and Prn deficient (12/71, 17%) cases but only 1/22 (4.5%) of non ptxP3 cases were severe versus 38/177 (21.4%) ptxP3 positive. Adjusting for ptxP type, vaccination status and age, disease severity was not significantly associated with Prn status (RRA: 0.95, [0.57-1.56]; p = 0.83). Conclusions: In children, we found no relationship between Prn status and markers of severe pertussis. An increased proportion of severe disease in isolates with the ptxP3 allele was observed. © 2015 The British Infection Association. Source

Marshall H.,Discipline of Paediatrics | Marshall H.,University of Adelaide | Tooher R.,Discipline of Paediatrics | Collins J.,Discipline of Paediatrics | And 4 more authors.
American Journal of Infection Control

This study compared community response prior to and during the H1N1 2009 influenza pandemic using a cross-sectional phone survey of rural and metropolitan South Australia, conducted in 2007 and 2009. Awareness of pandemic influenza was significantly higher and anxiety lower in 2009 than in 2007. Reported seasonal influenza vaccine uptake increased from 51.7% in 2007 to 61.4% in 2009, but there was more interest in receiving pandemic vaccine in 2007 (87.5%) than in 2009 (57%). © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved. Source

Clarke M.F.,Discipline of Paediatrics | Davidson G.P.,University of Adelaide | Gold M.S.,Discipline of Paediatrics | Marshall H.S.,Discipline of Paediatrics

Rotavirus vaccine for infants was introduced into the National Immunisation Program in Australia in July 2007. To determine the impact of rotavirus vaccination on gastroenteritis hospitalisations amongst children less than six years of age in South Australia, we conducted a retrospective analysis of hospital admissions over two time periods: 1 May 2005-30 April 2007 (prior to rotavirus vaccination introduction) and 1 May 2008-30 April 2010 (post rotavirus vaccination introduction). The introduction of rotavirus vaccination has been associated with a marked reduction in hospital admissions for serious rotavirus gastroenteritis (RVGE) and all-cause gastroenteritis (ACGE). Following the introduction of rotavirus vaccination in South Australia, there was an 83% reduction in RVGE coded admissions (955 vs 165) and a 48% reduction in ACGE coded admissions (4153 vs 2142) for children aged less than six years. Children less than two years demonstrated the greatest reduction (90%) in RVGE admissions and ACGE admissions (57%). Age-specific RVGE hospitalisation rates decreased from 933/100,000 prior to rotavirus vaccine introduction to 88/100,000 for children less than two years of age. In addition, for gastroenteritis hospitalisations for children aged five years at time of admission (unvaccinated cohort) there was a reduction in the number of RVGE cases (24 vs 4), a reduction in age-specific RVGE hospitalisation rates (65/100,000 vs 11/100,000) and a significant reduction in the proportion of overall gastroenteritis cases which were rotavirus positive (11.5% vs 3.5%), suggesting a positive impact on both unvaccinated and vaccinated children less than six years of age in South Australia. © 2011 Elsevier Ltd. All rights reserved. Source

Quinn P.,Discipline of Paediatrics | Quinn P.,University of Adelaide | Gold M.,Discipline of Paediatrics | Gold M.,University of Adelaide | And 9 more authors.

Objectives: The aim of this study was to compare the immunogenicity and reactogenicity of a lower dose diphtheria, tetanus and pertussis vaccine (dTpa) with the recommended vaccine (DTPa) given as a fifth dose to 4-6-year old children who previously experienced an extensive injection site reaction (ISR). Material and methods: Children aged 4-6 years who had experienced an extensive ISR following a 4th dose of DTPa were recruited and randomly assigned to receive either the recommended DTPa or the lower dose dTpa vaccine. Parents recorded local reactions and systemic events for 15 days following vaccination. Immunogenicity was assessed pre and post vaccination by ELISA for diphtheria (D), tetanus (T), pertussis toxin (PT), filamentous haemagglutinin (FHA), and pertactin (PRN). Results: A total of 53 participants were vaccinated. There was a 72% recurrence rate of ISR, with a trend (p= 0.055) towards fewer ISR in the dTpa (61.5%) compared with the DTPa group (85.2%). There was no difference in reports of pain or irritability between groups. All participants had seroprotective levels of antibody to D and T and seroresponse to each of the 3 pertussis antigens following vaccination with higher GMCs in DTPa vs dTpa group. There was no increase in antibody avidity observed post vaccination, regardless of vaccine given. Conclusion: Recurrence of ISR with the 5th dose of diphtheria, tetanus and pertussis vaccination in children who have previously experienced an extensive ISR is high. Vaccination with a dTpa vaccine may reduce the risk of fifth dose ISR. © 2011 Elsevier Ltd. Source

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