New scientific map shows Australia is not a hotspot for new diseases

Feb 21 2008

An international team of scientists has warned that tropical regions are likely to become a future hotspot for new diseases; but fortunately Australia is not one of them.

They say an early warning system needs to be established in vulnerable countries to spot outbreaks before they become unmanageable.

The scientists from the Zoological Society of London, the Wildlife Trust and Columbia University have analysed databases of outbreaks and found 335 cases of emerging diseases between 1940 and 2004.

Of these emerging diseases 60.3% were infections which also affected animals, and 71.8% were known to have triggered disease in humans after spreading from wildlife.

The researchers say diseases such as the Nipah virus in Malaysia, the SARS outbreak in China and others including the H5N1 strain of bird flu, Ebola and West Nile virus, which originally spread from animals, are an increasing threat to human health, and many infections have now become resistant to antibiotics.

Their investigation into emerging infections is the largest ever and shows that major outbreaks of disease have become more common around the globe in the past 4 decades.

They say the global pattern of diseases was closely linked to regions with high rainfall and biodiversity, alongside rapid growth in the human population.

While Europe and North America have experienced high numbers of outbreaks, these regions have invested heavily in detecting early signs of disease.

The scientists are concerned that other countries are less able to spot new diseases as they arise.

They have identified "hotspots" where new diseases are expected to come from.

According to their research more diseases emerged in the 1980s than any other decade, due to a large extent on the emergence of HIV, which put vast numbers of people at risk of contracting other diseases.

The vast majority of outbreaks were triggered by bacteria and viruses, with 20% caused by antibiotic-resistant microbes.

Dr. Kate Jones, of the Zoological Society, says areas of rich biodiversity harbour pools of pathogens, which are readily able to spread; when humans impact on these areas and develop them, they come into contact with wildlife through bushmeat, farming and the domestication of animals.

Dr. Jones says by increasing our human impact on these areas we are exposing ourselves to potential pathogens.

The scientists suggest that preserving wildlife-rich areas could help to protect people from new diseases, in the same way that conservation ensures cleaner water supplies and helps soak up carbon emissions.

They have produced a detailed map highlighting the world's hotspots for emerging infectious diseases and the main hotspots are located in low latitude regions, like South Asia and South-East Asia, which were not the financial focus of global funds to prevent the spread of EIDs.

Peter Daszak from the Wildlife Trust, says the world's public health resources are misallocated as most are focused on richer countries that can afford surveillance, when most of the hotspots are in developing countries.

Dr. John Gittleman from the University of Georgia describes the map as a "seminal moment in how we study emerging diseases".

The researchers say setting up "smart surveillance" measures in the hotspots identified on the map should be a priority and simple bio-security measures, such as screening people who come into contact with wild birds and mammals in the hotspot areas, could halt the next 'AIDS' or 'SARS' before it happens.

The map has three tones which indicate the level of risk and 99% of Australia is shown to be in the lowest range for risk.

The research is published in the journal Nature.