5.1 The human cost of guinea worm disease
Dracunculiasis was once endemic in many parts of the world but, by the 1950s, the provision of piped water in towns and cities had eradicated it from North Africa, Egypt, Iraq, Brazil, the West Indies and Uzbekistan. At that time it was confined to rural areas of the Indian subcontinent, Yemen, Iran and parts of Sub-Saharan Africa, but over 50 million people still suffered its effects each year.
Until the 1980s, international health agencies attached a low priority to this ‘forgotten disease of forgotten people’, partly because it is rarely fatal and permanent disability is unusual; infected people generally recover within a few weeks of the worm’s emergence.
However, attitudes gradually changed as a number of research studies evaluated the human cost of a disease with a global burden estimated in 1986 to be affecting at least 3.3 million people. Although the case fatality rate is less than 0.1% (death is usually caused by a secondary tetanus infection) and permanent disability is rare, many microbes can infect the lesion caused where the worm emerges and they can penetrate deep into the tissues along the track of the worm (Figure 18).
Around half of all cases become infected, which greatly increases the disabling effects of the parasite, in terms of both pain in the affected limb, which can reduce mobility for several weeks, and the fever, nausea and debility associated with an acute inflammatory reaction against secondary bacterial infection. More serious complications occur in about 1% of cases and include worms emerging into joints and triggering severe arthritis, or emerging from the breast, genitals, tongue or eye.
How could guinea worm infection have a serious impact on life in rural communities in endemic countries?
An immobilising condition impacts heavily on rural economies where people earn their livelihoods from working on the land. They often walk long distances to reach their fields, herd livestock, collect firewood and drinking water, and – in the case of children – attend school.
The loss of agricultural productivity in affected communities can be seen in terms of ‘stunted’ growth among children whose diet was impoverished as a result of endemic infection. In Mali, the local name for dracunculiasis is ‘the disease of the empty granary’. The economic impact is particularly severe because the highest rates of infection occur in the rural working population (i.e. people aged 15–45).