by Aline Hesse
The eradication of smallpox is considered one of the greatest achievements in the field of public health. Despite initial skepticism following a failed attempt to eradicate malaria and little funding, the global effort to eradicate smallpox was finally achieved in 1975.
Though all diseases are potentially eradicable, there are a few important components that help to dramatically increase the likelihood of success. A disease is a good candidate for elimination if the following are true: humans are the only reservoirs of infection, low-cost diagnostic tools are available, and both treatment and prevention methods are inexpensive and effective. Smallpox, confined to humans with its distinctive skin manifestation and low-cost vaccine, perfectly satisfied these three conditions.
The elimination of smallpox was a success considering not only its prevalence across the globe and legacy dating back 3500 years, but also its high mortality rate, estimated at 25-30% according to a lecture in October hosted by the USC Institute for Global Health. At the event, titled The Eradication of Smallpox and the Discovery of Pandora’s Box, Dr. D.A. Henderson, the epidemiologist who headed the smallpox eradication effort, explained just how important this global accomplishment truly was.
“This was one of the most serious pestilential diseases in history. Those who recovered from smallpox were scarred for life, and many a number were blind. In India, this was the leading cause of blindness even into the 20th century,” said Henderson.
Now having successfully eradicated one disease, those in the public health field are seeking to end Guinea Worm and polio.
Guinea Worm, a debilitating parasitic disease contracted by drinking contaminated water, seems particularly promising. The parasitic worm is visible under the skin’s surface, allowing for easy diagnosis; the treatment is free, simply involving removal of the worm by winding it around a stick; and humans are the only known reservoirs of infection. Additionally, the main preventative measure is to filter water through cloth to eliminate the worm’s insect vector, an easy and cost-free solution.
Despite these facts, there are definite barriers that must be overcome. Due to the frequent need for disease eradication to be a global effort, there are several obstacles that can arise. Among these are economic, political and geographic complications.
For example, in the case of Guinea Worm, initial efforts at eradication in Sudan were responsive. However, when the country entered a civil war, healthcare workers were denied access due to the violence. It was only 22 years later that the war ended and eradication efforts could be resumed.
Although obstacles such as war can significantly affect global health efforts to eliminate disease, the eradication of smallpox demonstrates that these barriers can be overcome and success achieved. With low-cost diagnostic tools, treatments, and preventative measures, in addition to human-only reservoirs of infection, a disease has great potential for eradication. It simply takes a determined set of individuals with the proper funding and global cooperation to create world-wide changes in health.