Emerging Diseases – Ready and Waiting Aileen J Plant

Curtin University of Technology

19 October, 2004

Emerging Diseases: Emerging Diseases:

the human healthe human healtth perspectiveh 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• 2010 - >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

SARS AIDS

?

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!