By Astrid R.N. Haas
On Oct. 16, 1979, Ali Maow Maalin, a health worker from Somalia, officially became the last person with smallpox. To some public health professionals this represents the greatest triumph of the 20th century. However, to date smallpox still remains the first and only human disease that we have ever eradicated.
It is not for lack of trying that we have not managed to eliminate other diseases. In fact, there have been six official eradication initiatives to date, such as yellow fever, malaria and polio. However, eradication of a disease is a very intensive process that lies at the nexus of health, politics, and economics. More specifically, the conditions for a successful initiative have been defined as biological and technical feasibility, broad societal and political support, and consensus on positive costs and benefits.
Based on these conditions, many consider Dracunculiasis (Guinea worm) to be the next candidate disease for eradication. This parasitic infection is transmitted to humans via drinking water from sources contaminated with Guinea worm larvae. Since the Guinea worm eradication effort started in 1986, the number of infections has fallen by 99.99 percent, from 3.5 million to 22 cases in four countries in 2015.
Biological and Technical Feasibility
Unlike with smallpox, there is no vaccination for Guinea worm. Instead, elimination and ultimately eradication can be achieved through a concerted effort to provide filters for drinking water, to educate on prevention of Guinea worm transmission, to monitor water sources to prevent contamination, and to treat contaminated water sources with the larvicide Abate. If this process is successful, in addition to becoming the second disease to ever be eradicated, Guinea worm will also be the first disease to be eradicated without vaccination.
Broad Political and Societal Support
Although the epidemiology is right for eradication of Guinea worm, as it was with smallpox, evidenced by the fact that we have an effective strategy for treatment and prevention, the ultimate success of the initiative will ultimately come down to societal and, more importantly, political factors, as this effort is heavily reliant upon being able to physically access endemic areas.
One of the four countries where Guinea worm is still endemic is South Sudan, and the success of the eradication effort has always been and is still highly contingent on this area of the world. South Sudan is a country that has experienced many decades of war. Sudan, before it split into two countries, was originally left out of the Guinea Worm Eradication Program (GWEP) due to the civil war during the early 1990s. However, the Carter Center soon realized that Sudan was key to the eradication effort and that establishing a successful program would require peace. In an attempt to broker this peace in 1995, former U.S. President Jimmy Carter approached the leaders of the two main warring factions: John Garang, the leader of Southern Sudan at the time, and Sudanese President Omar al-Bashir. They both eventually consented to a cease-fire, now known as the “Guinea Worm Cease-fire,” which commenced in March 1995 and lasted for six months. In this time 64,000 cases of Guinea worm were documented and over 200,000 cloth filters were successfully distributed, jump-starting elimination efforts in Sudan. It will be imperative that relative stability continues during the final efforts to eradicate Guinea worm, through the implementation of the peace process.
Consensus on the Positive Costs and Benefits
Estimates have shown that smallpox eradication has saved the world approximately $1.35 billion annually. This encompasses savings from the overall control programs, including large-scale vaccination campaigns, losses due to diminished economic productivity, and the cost of care, among others. With a total cost of about $100 million, the eradication program has clearly paid off.
The calculations are not as straightforward for Guinea worm. This is primarily due to the fact that this is a disease that results in severe morbidity rather than mortality. However, it is also a disease that affects the poorest societies in our world, as evidenced by the fact that the last four countries to still have reported cases are South Sudan, Chad, Mali, and Ethiopia. Many of the benefits of eradication will also come through concurrent efforts, such as the provision of better drinking water and the establishment of stronger community health based systems, through the cadre of local volunteers who have been trained to educate people on Guinea worm eradication and to distribute filters and larvicide. These volunteers have been further trained to disseminate other health messaging and products as well. Furthermore, eradication will mean future generations in these countries will not suffer the risk of infection. This can potentially result in savings on health care provision, increases in productivity, and improved school attendance by children.
A recent statement by South Sudan Minister of Health Riek Gai Kok noted that his country is on its way to eliminating Guinea worm by the end of 2016. The numbers do look promising: In 2013 South Sudan had 113 reported cases and now there are only five isolated cases. Due to the fact that Guinea worm has an incubation period of 14 months, it may take a bit longer to confirm total elimination in South Sudan. However, now more than ever, it seems that the epidemiology, politics, and economics seem to be aligning for the second eradication of our time.
Astrid R.N. Haas is an economist working in Uganda and South Sudan. She blogs on her site www.50shadesofmzungu.com.
[Photo courtesy of Kendra Helmer]