Prepared by Chatu Yapa, Masters in Applied Epidemiology trainee, Health Protection NSW
The eradication of disease is the ultimate goal of public health. In 1977, Somalia reported the last case of naturally occurring smallpox, effectively marking global eradication of this disease. Since then, the World Health Assembly – the policy-making body of the World Health Organization – declared the goals of eradicating dracunculiasis (guinea worm disease) in 1986 and poliomyelitis in 1988.
Both diseases are very close to eradication and currently poliomyelitis cases are only recorded in 3 countries – Nigeria, Pakistan and Afghanistan (figure 1). However, after more than 20 years of interventions, this target is yet to be achieved, eluding to the complex interaction between biological, social, political and economic factors underpinning disease control.
*circulating vaccine derived polio virus
Figure 1: Map showing countries with ongoing cases of poliomyelitis up to 9th June 2015 Source: Global polio eradication initiative, accessed 22nd June 2015, available from: http://www.polioeradication.org/Dataandmonitoring.aspx
Text alternative: Between 1 January and 9 June 2015 Nigeria, Pakistan and Afghanistan recorded poliomyelitis cases. These are the only three countries where polionyelitis disease is endemic.
There are certain biological features of an organism and technical factors of dealing with them that make a disease more or less likely to be eradicated.
The three essential criteria for eradicability of an infectious disease are:
- availability of an effective intervention for interrupting transmission of the agent
- practical diagnostic tools with sufficient sensitivity and specificity to detect infection
- the necessity for humans to be implicated in the life-cycle of the agent without any other vertebrate reservoir and without amplification in the environment.
- The terms elimination and eradication are often confused when it comes to infectious diseases. What is the difference between disease elimination and eradication?
- What are some other diseases that have been considered for global eradication?
- In addition to the biological and disease-specific criteria relevant to eradication, what are some examples of the economic, social and political considerations that should be considered?