Hotspots for emerging zoonoses, infectious diseases that spread from animals to humans. The risk is highest in areas shaded in red

New Delhi, Feb. 25: The first worldwide analysis of emerging infections has shaded a belt across northern and eastern India among the areas where new diseases are most likely to occur.

The study has helped scientists establish for the first time through rigorous statistics that new and emerging infectious diseases aren’t random events but occur in patterns.

An international research team analysed 335 outbreaks of new infections over the past six decades and found that more than 60 per cent were zoonotic diseases, caused by microorganisms jumping from animals, mostly those in the wild, into humans.

These include HIV from chimpanzees, the deadly Ebola virus from fruit bats, the West Nile virus from common sparrows and avian influenza (H5N1 virus) from wild ducks.

“We found infectious diseases strongly linked to human population density, changes in population, rainfall, and wildlife bio-diversity,” said Kate Jones, a team member and research fellow at the Zoological Society of London. “These links allow us to predict where future outbreaks are most likely to occur,” Jones told The Telegraph.

The results, published last week in the journal Nature, show relatively large territories of India and China and pockets in tropical Africa and Latin America as likely sites of outbreaks.

The findings have shown that half of the new and emerging infections have been due to bacteria, including drug-resistant strains, while about 25 per cent are caused by viruses. This dispels assumptions that viruses account for more new outbreaks than bacteria.

The study has indicated that disease surveillance resources are misallocated, with the best efforts limited to rich countries. “Our map of hotspots shows that the next new zoonotic disease is likely to originate in developing countries in the tropics,” said Peter Daszak, a team member who is executive director of the Wildlife Trust in the US.

“We know there are a number of infections in India that do not get completely investigated — the microorganism remains unidentified,” Daszak said over the phone.

Indian biologists have long argued for a strong surveillance network to probe infectious diseases.

“We’ve been crying hoarse... but we still investigate only a fraction of infections in India,” said Shahid Jameel, head of the virology division at Delhi’s International Centre for Genetic Engineering and Biotechnology.

Jameel said understanding the ecology of an infection was important and was part of preparedness.

Humans coming into close contact with animals, including those in the wild, have been a major factor in the emergence of infectious diseases, Jones said. “Conserving areas rich in bio-diversity may be a way to prevent new diseases,” she added.

Apart from humans coming into close contact with wild animals, changes in land use and farming practices, abuse of antibiotics and breakdown of public health measures were among the triggers for the 335 infections analysed in the study.

Despite surveillance, most attempts to explain the seemingly random patterns of emergence and spread had been largely unsuccessful.