After smallpox eradication: yaws?

The WHO-coordinated Smallpox Eradication Program (SEP) has reduced the number of smallpox-endemic countries from 30 to 1, and now expects to complete the eradication of smallpox after a 10-year campaign. Campaigns to eradicate yaws were begun in the early 1950's with WHO and UNICEF support, and have greatly reduced the prevalence of that disease. Yaws has not yet been eradicated from any large geographic area, however, and is already resurgent in some countries. Some of the differences between the two diseases and available control measures are discussed. The thesis of this paper is that yaws programs have been deficient in failing to aggressively seek and contain yaws cases and contacts after mass treatment campaigns reduced yaws prevalence to low levels. It is further suggested that by using a modified SEP-type strategy to focus investigation and control efforts on infections yaws cases and their contacts, and by taking advantage of new methods to obtain more accurate diagnosis of yaws cases in the field, it should be possible to control yaws more effectively and efficiently, and perhaps to eradicate it. Outstanding barriers to yaws eradication are also discussed.