Researchers: Deborah Lehmann, Anke Bergmann (Telethon Institute for Child Health Research), Paul van Buynder & Carolien Giele (Communicable Diseases Directorate, Western Australian Department of Health), David Smith & Jacinta Bowman (Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine), Amanda Leach & Kim Hare (Menzies School of Health Research, Darwin)
Funding: Department of Health WA
Project summary: The bacterium Streptococcus pneumoniae (pneumococcus) can cause middle ear infection and invasive pneumococcal disease (IPD) resulting in meningitis, pneumonia and blood poisoning. The Australian Aboriginal population has among the highest reported IPD rates worldwide. The existence of 90 different types (serotypes) of pneumococci increases the challenge of prevention, particularly vaccine development. A vaccine covering the 7 most common serotypes (Prevenar) and a booster with a vaccine covering 23 serotypes (Pneumovax) is offered to Aboriginal children. Pneumovax is also offered to Aboriginal adults. Following the introduction of Prevenar in 2001 incidence of IPD has fallen in children, though the serotypes causing disease are not entirely those not included in Prevenar. Further cause for concern is a marked increase of IPD in Aboriginal adults, also predominantly due to serotypes not included in the Prevenar vaccine. The likelihood of replacement diseases due to non-vaccine serotypes needs further investigation. Surveillance of IPD is hampered because antibiotics are often given before there is an opportunity for collecting blood cultures, particularly in remote parts of WA. However pneumococci are carried in the back of the nose of healthy individuals (up to 50% of Aboriginal children and more than 25% of Aboriginal adults). Carriers can transmit pneumococci to other members of the community. Surveillance of pneumococcal carriage can assist in predicting emerging serotypes causing IPD and susceptibility of pneumococci to antibiotics. Furthermore, carriage studies can assist in developing appropriate policies with regard to the next generation of pneumococcal vaccines, two of which are likely to be licensed in Australia soon.
Progress: Ongoing