Eradicating smallpox was one of the greatest human accomplishments of the 20th century, but researchers say such initiatives are not a good a use of money.
New Zealand bio-geographer Michael Gavin says reducing the prevalence of diseases in regions most affected by them is a far more effective and efficient strategy than trying to eradicate them altogether, which is extremely difficult and costs billions of dollars.
New research shows the number of disease-causing pathogens in a region can be predicted just by knowing its climate, the diversity of birds and mammals found there, and whether it has a large human population and ineffective disease control efforts.
The Victoria University academic found climate played a role in determining how many different kinds of diseases there were, but not how many people would suffer from them.
Because disease was not restricted by political boundaries and local epidemics could rapidly transform into global pandemics, reducing prevalence in one part of the world also benefited people everywhere, according to Dr Gavin, who has studied geographic patterns of human infectious disease.
He worked with an international team of biologists and social scientists, including three biologists - Jonathan Davies, Robert Dunn and Nyeema Harris - of North Carolina State University.
High cost of vaccines
Their research has been published online by the Proceedings of the Royal Society: B, a leading peer-reviewed biology journal.
Recent flu outbreaks demonstrated how quickly diseases can spread to different parts of the world and the high cost of providing vaccines for millions of people.
By targeting just the populations most at-risk, it might be possible to prevent global outbreaks and save money at the same time.
The research showed that efforts should be concentrated in countries with large populations, such as India and Pakistan, and areas where there is almost no spending on healthcare, such as Madagascar and much of eastern Africa.
In addition to the health benefits, the researchers pointed out that disease affected human behaviour, the politics and political stability of countries, human fertility, global economies and more generally the course and dynamics of human history.
The ramifications of moving away from total eradication could be huge, as the degree to which epidemic disease affects people in the future will depend on the choices made now in the global allocation of healthcare dollars.
