The world will face a new deadly threat on the scale of Aids, Sars and Ebola within a decade, the world's leading authority on health said yesterday, as it warned that diseases were spreading more quickly than at any time in history.New diseases are emerging at an unprecedented rate, of one a year, and are becoming more difficult to treat, says the World Health Organisation's annual report. It paints a bleak picture of future health threats, with science struggling to keep up as diseases increasingly become drug resistant.
The authors point to passenger flights, now numbering more than 2bn a year, as being a chillingly efficient mechanism for spreading diseases rapidly across continents. New diseases that pose a sudden threat in one part of the world are only "a few hours away" from becoming a threat somewhere else, the WHO says.
"Profound changes have occurred in the way humanity inhabits the planet," said Margaret Chan, the director general of the WHO. "The disease situation is anything but stable. Population growth, incursion into previously uninhabited areas, rapid urbanisation, intensive farming practices, environmental degradation, and the misuse of anti-microbials, have disrupted the equilibrium of the microbial world. The rate of emergence of new diseases, at one year, was "historically unprecedented".
The report, A Safer Future, identifies 40 diseases unknown a generation ago, and reveals that during the past five years the WHO has verified more than 1,100 epidemic events worldwide. It says:
· Cholera, yellow fever and epidemic meningococcal diseases made a comeback in the last quarter of the 20th century.
· Severe acute respiratory syndrome and avian influenza in humans still have the potential to wreak havoc globally.
· Viral diseases such as Ebola, Marburg haemorrhagic fever and Nipah virus, pose threats to global public health security.
· The use of smallpox in bioterrorism is a particularly worrying threat. Authorities around the world should work together to combat the kind of bioterrorism that occurred with the letters warning of anthrax after September 11 2001.
· A flu pandemic would affect more than 1.5 billion people, or 25% of the world's population. Even if the disease were mild in itself the economic and social disruption would be "enormous".
The WHO report adds: "It would be extremely naive and complacent to assume that there will not be another disease like Aids, another Ebola, or another Sars, sooner or later."
To prepare for these events will take unprecedented global and political collaboration, it advises. "No single country, however capable, wealthy or technologically advanced, can alone prevent, detect and respond to all public health threats." The organisation is calling for renewed international efforts to share information.
The UK's Department of Health said it strongly supported "the approach of managing these risks through cooperation".
Worries about the effects of international travel were underscored in June when an American national, Andrew Speaker, 31, who had a contagious and deadly strain of tuberculosis, took an international flight. US authorities tracked every passenger who had shared one of two transatlantic flights with Mr Speaker, who had fallen ill with the drug-resistant XDR form of TB while on honeymoon in Europe. He went back home via Montreal to avoid the US authorities, who had ordered him into quarantine, and would not have allowed him to fly, he believed.
In South Africa, the courts have considered forcibly detaining people who have the same form of TB to prevent its spread, amid fears that many more than those officially diagnosed are suffering and have not informed the authorities. The XDR strain of TB is a highly infectious disease spread by airborne droplets and kills 98% of those infected within about two weeks. Experts believe it emerged after inappropriate and overuse of antibiotics to treat TB.