SciDev.Net

A patient being treated for HIV, a common EID

Flickr/Mocha Club

Emerging infectious diseases (EIDs) are on the increase, but their monitoring and surveillance is poorly allocated, with little in areas where outbreaks are likely to occur, say researchers.

The team, led by Kate Jones, senior research fellow at the UK-based Institute of Zoology, publish their findings in Nature today (21 February).

EIDs include newly evolved pathogens such as drug resistant bacteria and pathogens that have recently entered human populations from wild or domestic animals — HIV or SARS for example.

The researchers analysed 335 EID 'events' — the occurrence of a pathogen in humans for the first time — between 1960 and 2004 to identify and map socioeconomic, environmental and ecological factors associated with EIDs.

They found that the occurrence of EIDs is increasing, and that population density and antibiotic drug use, for example, are linked to the emergence of drug-resistant pathogens, while outbreaks caused by wildlife pathogens are usually correlated with regions high in both human populations and biodiversity.

With this they created a predictive model of 'hotspots' where diseases are likely to emerge, and found that while traditional areas — such as the northeast United States and western Europe — are still at risk, many developing countries appear on the list.

East Asia, the Indian subcontinent, the Niger delta, the Great Lakes region of Africa and parts of Latin America are particularly vulnerable to the emergence of diseases from wild animals, said Mark Levy of the Earth Institute at Columbia University and one of the paper's authors, in a press teleconference. Similar areas are also at risk from vector-borne pathogens.

The model is a useful tool for deciding where to allocate resources, said Peter Daszak, executive director of the US-based Consortium of Conservation Medicine and an author of the paper, at the teleconference.

"Now we can move on from waiting for these diseases to emerge and being surprised when they do, to actually dealing with them ahead of the game."

The authors recommend reallocation of surveillance resources to tropical Africa, Latin America and Asia — at present richer countries in Europe, North America, Australia and parts of Asia receive greater efforts.

"The benefits would not just be felt locally: in an era of increasing globalisation, emerging infectious diseases are everybody's problem," Mark Woolhouse, chair of Infectious Disease Epidemiology at the University of Edinburgh, writes in an accompanying Nature News and Views article.

Link to full paper in Nature

Reference: Nature 451, 990 (2008)