5.4.1 Protection of water sources
The features listed in Box 4 underlie the strategies that have succeeded in eradicating guinea worms from most countries and greatly reducing their incidence in the few remaining endemic areas. The eradication campaign illustrates several features of the public health approach to the control of infectious diseases, particularly in remote regions with high levels of poverty and low literacy rates. It has relied primarily on three simple, low-technology strategies, operated within the affected communities by local people: the protection of drinking-water sources from reinfection; the routine filtering of water at the point of use; and the case containment of infected people.
Protection of drinking water sources from reinfection
Drinking water sources can be protected from reinfection by persuading people with emerging worms not to enter the water until the lesion has healed. In some countries, ‘pond caretakers’ (usually elderly men) are paid a small fee to guard local ponds and step wells during the season of worm emergence.
Routine filtering of water at the point of use
A second important control measure is the routine filtering of water at the point of use, just before drinking it, to remove the infected cyclops. This initiative has been supported by the donation of hundreds of thousands of square metres of fine mesh nylon cloth.
- Squares of cloth are placed over the neck of containers when water is poured for drinking; it is long lasting and easily washed, which has helped greatly in popularising the use of these simple filters.
- Short pieces of small diameter plastic pipe with one end covered in fine cloth are also supplied as drinking straws. A string attached at the open end enables the straw to be hung around the neck, so workers can take it with them to the fields to use when they drink from shallow pools during the day.
Case containment has also been practised in the later stages of a campaign (it is too labour intensive to be used on a large scale). It involves the controlled release of worm larvae by plunging the affected limb into a bucket of cold water, followed by simple palliative treatment (e.g. painkillers, antibiotic ointment), and bandaging of the worm-emergence site. The infected person agrees not to remove the bandage or enter sources of drinking water, and the procedure is repeated every few days until the worm has completely emerged.