Health Programs

Definition of Case Containment:  Guinea Worm Disease

A case of Guinea worm disease is contained if all of the following conditions are met:

1. The patient is detected before or within 24 hours of worm emergence; and



2. The patient has not entered any water source since the worm emerged; and



3. The village volunteer has properly managed the case, by cleaning and bandaging until the worm is fully removed, and by giving health education to discourage the patient from contaminating any water source (if two or more emerging worms are present, the case is not contained until the last worm is pulled out); and



4. The containment process, including verification that it is a case of Guinea worm disease, is validated by a supervisor within 7 days of the emergence of the worm.

What Is An Endemic Village?

The question of exactly when is a village "endemic" has acquired increasing urgency as programs wind down to fewer and fewer cases of dracunculiasis and seek to focus their resources with greater efficiency. In short, an endemic village is one in which indigenous transmission of dracunculiasis is occurring, or has occurred in the past year. If, for example, a case of dracunculiasis is imported into a village and is reported there, that village is endemic only if the imported case has contaminated water and transmitted the disease to others. It is obviously necessary to investigate each apparently imported case carefully, and especially to ascertain whether cases of dracunculiasis in villages with only one or a few case(s) are the result of effective control measures having reduced the incidence of infection in the village that previously had more cases, or are imported from other areas into a non-endemic village.

Both situations require vigilance, but only the endemic village requires implementation of control measures, unless the imported case has contaminated a local source of drinking water. Hence, not all villages that report one or more cases of dracunculiasis in a given year are necessarily "endemic", meaning that they contain foci of local transmission. In this context it is important to keep villages for at least three years on the operational list of the GWEP, but these should be clearly identified as villages under surveillance and not as endemic villages. National and local governments and external partners need to assist with the development and/or strengthening of the capacity for surveillance of dracunculiasis in formerly endemic areas. Elsewhere in this issue, it is apparent that an increasing proportion of villages that report one or more cases in a country in fact report only one case in a given year. Such villages are villages with one case of dracunculiasis. They may or may not be endemic villages.