CBG Research Themes
The program of research is summarised under three main themes, each with three sub-themes containing specific projects. Over 20 individual research projects are planned, a number of which are already in progress.
THEME 1: Population threats from infectious diseases
Bioterrorism and emerging IDs (preparedness and control): The possibility of a new influenza pandemic and the SARS experience illustrate the need for substantial responses in terms of disease control. The CBG is collaborating on the development of mathematical models as an aid to determining the most effective control strategies (such as use of vaccines, antiviral drugs, isolation etc.) for such an event.
Nosocomial infections: The spread of multi-drug resistant organisms in hospitals pose a difficult management problem, involving prolonged, expensive treatment. Infection contributes to critical illness and intensive care admission in a high proportion of all hospital patients. Models of transmission of VRE, MRSA and MDR-TB will consider the effect of patient isolation, staff infection control procedures, cohorting and the impact of individual risk factors such as antibiotic exposure.
Control of drug resistance: Two projects consider the effective use of antivirals for HIV, and using modeling to inform computerised clinical decision support tools for antibiotic prescribing. This will allow for formulation of best-practice hospital infection control guidelines. The work on computerised antibiotic decision support tools is well advanced at VIDS.
THEME 2 . Control of existing infectious diseases
Optimal policy for mass vaccination: The public health impact of some existing population vaccination programs (e.g. pertussis) and new programs likely to be implemented in the future (Human papilloma virus (HPV), hepatitis A, varicella) require assessment. For example, a HPV vaccination program has the potential to prevent cancer of the cervix. Many policy questions about HPV vaccination remain unanswered.
Monitoring vaccination programs: It is important to monitor vaccination programs and refine models for estimation of population impact. For example, in the UK, the Netherlands and parts of the US there has been a resurgence of Hib disease 10 years after commencement of population vaccination. This is attributed to the change to a less effective vaccine, an accelerated schedule and reliance on a catch-up campaign. Hib models developed by TI McVernon in the UK will be adapted to the Australian setting, which is different in many key respects. Other projects will monitor the meningococcal C and measles vaccination programs.
Effect of behavioural changes: Thousands of new hepatitis C virus infections occur each year in Australia, despite widespread harm minimisation programs, including needle and syringe programs. Modeling studies will assess social and behavioural aspects of HIV and hepatitis C control, including the effects of antiretroviral treatment on different populations and changes in sexual behaviour on HIV transmission rates among homosexual men and impact of harm-minimisation programs on hepatitis C.
THEME 3. New methods to use data to improve transmission models
Research into data requirements: Existing methods for calibrating models from available data will be enhanced to accommodate the extra realism in models developed by Niels Becker, such as allowing the community to have a household structure. (Hall, 1996; Becker, 1996; Becker, 1995) Studies to obtain data for reliable parameter estimation will be undertaken. Data that are necessary but not available will be identified.
Social and behavioural data: New methods of analysing data for “who mixes with whom” information will be used to reduce arbitrariness in the assumptions. As an alternative approach to this estimation problem we will use the observation that similar contact matrices apply to diseases with similar modes of transmission. This basic research feeds into all the projects outlined above.
Surveillance and serological data: NCIRS conducted large national serosurveys in 1998 and 2002, which have enormous potential for modelling work. Hepatitis C, hepatitis B, herpes simplex and H. pylori serological testing is already funded, thereby increasing our access to reliable data. These studies will inform vaccination policy for new vaccines such as H. Pylori and herpes simplex.