The disease and its transmission
Dracunculiasis causes temporary disability, lasting from a few weeks to a few months, which may prevent patients from leaving their beds while the worm emerges. Disability usually occurs during the peak agricultural season when labour is in a great demand.
Distribution of the disease is determined largely by the availability of open stagnant water sources such as ponds and shallow or step wells and patients of dracunculiasis. Artificial ponds are the main source of transmission.
Transmission of the disease is seasonal and depends on climatic factors. In endemic areas of Africa, there are two broad patterns: in the Sahelian zone, transmission generally occurs during the rainy season (May to August); in the humid savannah and forest zones, transmission usually peaks during the dry season (September to January). However, there are local variations in these patterns.
Other risk factors include mobility and infection occurring during the previous year.
Dracunculiasis is a vulnerable disease because humans alone are responsible for maintaining its transmission cycle. Permanent interruption of transmission is feasible through the following approaches:
- implementing effective surveillance to detect all cases within 24 hours of the worm’s emergence, and containing all cases;
- ensuring access to safe drinking-water by providing new safe drinking water sources and converting unsafe sources into safe water sources;
- by constructing copings around well heads or installing boreholes with hand pumps, to prevent not only dracunculiasis but also diarrhoeal diseases;
- ensuring regular and systematic filtering of drinking-water collected from shallow unprotected wells and surface water sources such as ponds. Fine-mesh cloth or, preferably, a filter made from nylon mesh (0.15 mm) effectively filters Cyclops from water;
- treating unsafe water sources with temephos to kill the Cyclops;
- advocating healthy drinking-water behaviours in communities through health education and social mobilization.
Implementation of these measures by village communities will ensure the ultimate goal of dracunculiasis eradication.