This week the community of tropical disease experts working in South Sudan is holding its collective breath over recent news of ethnic attacks, a potential for civil war, and the prospect that a public health tragedy could soon emerge in the region.
A landlocked country about the size of Texas but with a population density equivalent to Utah or Nevada, South Sudan is a sparsely settled, highly rural, and profoundly poor tropical developing nation. Such conditions of extreme poverty and hot climate create the perfect storm for tropical diseases to flourish. Indeed, almost all of the 17 major neglected tropical diseases currently recognized by the World Health Organization are found in South Sudan. Information from Britain's Department for International Development (DFID) and other published documents indicate that South Sudan hosts some of the world's highest concentrations of these diseases. More than two-thirds of the nation's population is either affected by blinding trachoma or at risk of infection, more than 40 percent of the population suffers from schistosomiasis in some areas, and lymphatic filariasis, a highly disfiguring condition, is hyperendemic in more than four states in South Sudan.
A key feature about the extraordinarily high rates of the neglected tropical diseases in South Sudan is the fact that they are chronic and disabling conditions, which actually cause poverty because of their ability to prevent people from going to work or reduce child development. They also have a particularly devastating effect on girls and women because of their ability to cause disfigurement and stigma. Today, the neglected tropical diseases may represent the most potent force trapping the people of South Sudan in a perpetual cycle of poverty.
Beginning in 2008 and following the cessation of Sudan's last civil war, the United States Government through its Agency for International Development (USAID) began supporting a neglected tropical disease control and elimination program in South Sudan, which has since been led by the British DFID. The major approach is the implementation of a "rapid impact" package of donated drugs that can be used in programs of mass drug administration costing as little as fifty cents per person annually to administer, together with improvements in sanitation, water, and morbidity management. Such mass drug administration approaches represent some of the most cost-effective public health programs and mechanisms to lift people out of extreme poverty. We are also working to develop new vaccines for some of these diseases.
Now with the threat of civil war there is a terrible risk that neglected tropical disease programs could halt, thereby reversing our previous gains. Of particular concern is the legacy of the previous Sudanese civil war that created a path of death and destruction from two other neglected tropical diseases transmitted by insects, namely kala-azar and sleeping sickness.
Kala-azar (also known as visceral leishmaniasis) and sleeping sickness (human African trypanosomiasis) are highly lethal infections transmitted sandflies and tsetses, respectively. During the Sudan conflict of the 1980s and 90s more than 100,000 people are believed to have died from these neglected tropical diseases. The major factors promoting the emergence of kala-azar and sleeping sickness included breakdowns in public health infrastructure together with widespread exposure to insect bites as a result of living outdoors linked to forced human migrations among people fleeing conflict zones or those living in refugee camps. Mortality rates during the kala-azar outbreak were so high that it drew comparisons with Europe's 14th century bubonic plague.
Based on a past and horrific legacy, the renewed hostilities in South Sudan could portend a public health crisis from neglected tropical diseases. Reports from organizations such as MSF indicate they are now actively working in South Sudan and providing direct medical care, but we have deep and grave concerns on a potential neglected tropical disease public health tragedy to follow.
Peter Hotez, M.D., Ph.D., is president of the Sabin Vaccine Institute and the founding dean of the National School of Tropical Medicine at Baylor College of Medicine, where he is also Professor of Pediatrics and Texas Children's Hospital Endowed Chair of Tropical Pediatrics. Prof. Hotez is also the Fellow on Disease and Poverty at the James A. Baker Institute for Public Policy at Rice University. He is the author of Forgotten People, Forgotten Diseases (ASM Press).