Infectious diseases spreading fast

Published: Monday 31 March 2008

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an international research team has provided the first scientific evidence that deadly emerging diseases have risen steeply across the world, and has mapped the outbreaks' main sources. Emerging diseases are those caused by newly identified pathogens, or old ones moving to new regions.

Researchers analyzed 335 episodes of emerging diseases from 1940 to 2004; then converted the results into maps correlated with human population density, population changes, latitude, rainfall and wildlife biodiversity.

The study found new disease hot spots are areas in sub-Saharan Africa, India and China; outbreaks occured on a smaller scale in Europe, and North and South America. It also says that conservation of biodiversity may be an important means of preventing new diseases.Following are the main findings of the study published in the February 21 issue of Nature

Down to Earth Disease emergences have quadrupled over the past 50 years; some 60 per cent of the diseases travelled from animals to humans (called zoonoses) and majority of those came from wild creatures; expansion of humans into shrinking pockets of biodiversity and resulting contacts with wildlife are the reasons

Down to Earth Humans have evolved no resistance to zoonoses, so the diseases can be lethal

Down to Earth About 20 per cent of known emergences are multidrug-resistant strains of previously known pathogens

Down to Earth More diseases emerged in the 1980s--likely due to the hiv/aids pandemic, which led to other new diseases

Down to Earth In the 1990s, insect-transmitted diseases saw a peak, possibly in reaction to rapid climate changes.

Down to Earth Richer nations are nursing outbreaks including multidrug-resistant pathogen strains through overuse of antibiotics, centralized food processing and other technologies

Down to Earth sars in Chinese bats cost up to us $100 billion

Down to Earth Outbreaks of exotic African Ebola virus have been small, but deadly.

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