Mapping of yaws endemicity in Ghana; Lessons to strengthen the planning and implementation of yaws eradication.

Yaws caused by Treponema pallidum subsp pertenue is a disease of poverty and affects communities where basic socio-economic amenities are lacking. With results showing that single dose azithromycin is effective in the treatment of yaws, the World Health Organisation introduced the Morges strategy with the intent to eradicate yaws by 2020. Ghana is one of the countries with the most yaws cases globally, and the National Yaws Eradication Program in Ghana intends to conduct Mass Drug Administration (MDA) of endemic communities in line with the Total Community Treatment plan of the Morges strategy. It is therefore important to map out endemic communities to ensure that MDA is both effective and financially efficient. Children with suspected yaws lesions were actively selected from the recruitment sites (schools and communities). A full medical history, study site information including GPS coordinates, demographic data including communities of residence and clinical assessment were taken. Each of the clinically diagnosed children were screened using the DPP Syphilis Screen & Confirm Assay (DPP). Samples for PCR were collected by swabbing ulcerative lesions of participants and tested for Treponema pallidum subsp pertenue and Haemophilus ducreyi DNA. In all, 625 children with a median age of 10 years were recruited into the study. While 401(64.2%) were DPP positive, only 141 of them had Treponema pallidum subsp pertenue DNA (TPE_DNA) accounting for 22.6% of those who were clinically diagnosed. Based on the DPP results, yaws was endemic in all the 4 study sites with participants from 88 communities in 13 districts in 4 regions in Ghana. There was no statistically significant difference between the various districts in terms of DPP results (x2=0.9364, p= 0.817) and 154 (24.6%) of those clinically diagnosed as yaws were positive for Haemophilus ducreyi DNA. Our study shows that communities endemic for yaws are also endemic for Haemophilus ducreyi i. Most yaws endemic communities were found at the border of other districts and regions. It is recommended that MDA should not only target endemic communities, but it should also target entire endemic districts as well as neighbouring districts in order to be effective.