Nancy Leys Stepan

 

On her book Eradication: Ridding the World of Diseases Forever?

Cover Interview of November 16, 2011

The wide angle

I took up the topic of eradication in the aftermath of 9/11, when after the anthrax scare, the idea of bioterrorism entered political discourse.

Smallpox was suddenly being talked about because, since routine vaccination had been given up following smallpox’s eradication, the entire world was vulnerable to a potential smallpox bioterrorism attack.

I hasten to add that bioterrorism is not my subject. Disease eradication is.

But from smallpox I was led back to the entire history of the concept of absolute eradication. This in turn made me engage with some of the major issues on the global health agenda.

To take one big question: What role have public health interventions played in the improvements in life expectancy we see in the world over the last century or more?  Is an eradication campaign the kind of the public health intervention that has contributed greatly to improved life expectancy, or not?  Or is overall economic growth a more important determinant of health improvements? What about the role of routine, basic health services, such as maternal and child care?

The Malaria Eradication Programme (MEP), which I examine in Chapter 4 of the book, is particularly salient to these issues. Launched by WHO in 1955, it became the single largest eradication campaign of all. Based largely on DDT-spraying of the transmitting mosquitoes and their larvae, the MEP led to dramatic declines in malaria incidence in many places.

But malaria proved a much more complicated disease than originally thought. The top-down, one-plan-fits-all mode of eradication could not adapt to the very varied ecological and political situations in which the national eradication campaigns had to operate.

Eventually, in 1969, WHO gave up the goal, replacing it with the more modest one of “malaria control.” In many places this was a recipe for the collapse of anti-malaria efforts; malaria returned, often in epidemic form.

But in some countries, the low incidence achieved by the MEP was sustained for years, sometimes decades.

In this regard, India offers an intriguing contrast to Africa. India, with the single largest MEP, reduced its malaria morbidity and mortality dramatically in the post-independence decades (from an estimated 100 million cases and a million deaths a year in 1951 to less than 1,000 deaths a year fifty years later (in a population double the size). The figures have risen since then, but this was nevertheless a very considerable reduction.

Meanwhile, of the estimated 300-500 million malaria infections, and one million deaths, that occur each year today worldwide, 90% are found in Africa, the area of the world that had been essentially left out of the malaria eradication effort, and that today is the chief focus of international health aid.

Does the contrast suggest we need to re-consider the malaria eradication effort? Did malaria reduction contribute to the improved life expectancy that occurred in India in the same period, or were other factors, such as price controls on food, equally important? Is the Gates Foundation pinning too many hopes on high-tech solutions, neglecting the underlying socio-economic determinants of the disease?  This is the “wide angle” I take on disease eradication.