AbstractIndigenous children in the Northern Territory (NT) of Australia and children in Papua New Guinea (PNG) share an extraordinarily high burden of ear and respiratory disease. In the NT, 90% have otitis media (OM), with 15% of young children experiencing chronic suppurative otitis media (CSOM). In PNG, high colonisation rates with OM pathogens, such as pneumococcus, predispose children to respiratory infections, yet there are few studies on OM burden and aetiology. With introduction of infant pneumococcal conjugate vaccine (PCV) programs in PNG in 2014, it will be important to monitor the change in the incidence and antibiotic susceptibility patterns of pneumococcus in OM and respiratory disease.
For this thesis, secondary analysis was carried out on two randomised controlled trials: (i) Analysis of nasopharyngeal bacterial carriage and antimicrobial susceptibility patterns from a 7-valent pneumococcal conjugate vaccine (PCV7) trial comparing early PCV schedules in PNG infants; (ii) Microbial outcomes from a trial comparing topical Ciprofloxacin to Sofradex® for the treatment of CSOM in Indigenous children. The aim of this thesis is to advance our understanding of the OM pathogens of significance in these high-risk populations to inform future OM studies in PNG. The principle findings are as follows;
1. There was a limited impact of neonatal or accelerated infant PCV7 schedules on vaccine serotypes in carriage and OM in PNG infants. This is likely due to the early onset of dense carriage of a broad range of pneumococcal serotypes, primarily non-PCV7 serotypes.
2. PCV7 had no impact on carriage of non-susceptible pneumococcus in PNG children. 45% of pneumococcus-positive swabs exhibited non-susceptibility to one or more antibiotics.
3. Haemophilus influenzae in ear discharge is associated with worse treatment outcome for CSOM when using topical Sofradex or ciprofloxacin. Interventions targeting H. influenzae should be trialled to combat CSOM in high-risk populations.
|Date of Award||Feb 2019|
|Supervisor||Heidi Smith-Vaughan (Supervisor), Michael Binks (Supervisor) & Amanda Leach (Supervisor)|