Emerging Diseases – Ready and Waiting Aileen J Plant Curtin University of Technology 19 October, 2004 Emerging Diseases: the human health perspective

Today Emerging diseases – here to stay A tale of 3 diseases Why they arise What should we worry about?

Some of the diseases Tuberculosis Malaria Cholera Dengue Nipah virus West Nile virus Hendra virus Aust bat lyssav. SARS Antibiotic resistance (MRSA, VRE) The big ones! AIDS, vCJD (?) Influenza

Controlling disease Surveillance Response Control Prepare/Prevent next time

A new disease extensive spread before noticed good outbreak investigation multiple methods of spread quickly discovered how to prevent quickly discovered good tests no vaccine but OK treatment But AIDS is still a global disaster

AIDS > 40 million people with HIV > 20 million have died >40 mill kids with 1-2 parents dead differentially affects working aged people impact on GNP – 8-10% ignorance and denial

SARS - a potential pandemic No identified agent No diagnostic assays No defined risk factors No specific treatment or prevention No knowledge of virus origin Ill-defined infection control practices

SARS left in its wake…. 8,098 cases, 774 deaths Billions lost in airlines, tourism World wide economic down turn Devastated health care system

…. but within 5 months (Feb-July) Virus identified Diagnostic tests developed Infection control practices established International public health response Surveillance programs established 5 July: WHO removed the last region from the list of areas with recent local transmission

Avian influenza - humans 3 prerequisites for pandemic novel influenza sub-type must be transmitted to humans new virus must be able to replicate in humans and cause disease new virus must be efficiently transmitted human to human Since 1997, first 2 met 4 times – 1997 Hong Kong (H5N1), 2003 Hong Kong (H5N1), 2003 Netherlands (H7N7), 2004 Vietnam and Thailand (H5N1)

Avian influenza (H5N1) - summary Unprecedented scale of outbreak in birds (size and no of countries) Modelling – concerning ! First time humans infected directly without prior modification in mammalian host Some evidence of human to human – but not efficient

Surveillance for pandemic preparedness Public health interventions Antivirals - their use and availability Better vaccines – better access Avian influenza – global consultation

Keys to success Speed Leadership Govt engagement Intersectoral approaches Resource support Global engagement Public discussion Assistance given/accepted Technical skills SARSAIDS ? FLU

Some of the causes (1) Microbial adaptation & change Human demographics & behaviour Technology & industry (includes animal practice, food production) Economic development & land use International travel & commerce Breakdown of public health measures

Some of the causes (2) Human susceptibility to infection Climate and weather Changing ecosystems Poverty & social inequality War & famine Lack of political will Intent to harm Microbial threats to health, Institutes of Medicine, USA, 2003

Conclusions More emerging diseases to come Scientific approaches are essential Science necessary but not enough Challenge re integrating science and practice Dealing with diseases we have is best preparation for the diseases we await! Watch for influenza, antibiotic resistance, hospital-acquired infections, CJD ….. and something new!