Yaws eradication: guidance for serological surveys to assess interruption of transmision

Overview

This document summarizes guidance developed for national programmes on conducting serosurveys to assess whether interruption of yaws transmission has been achieved, with the objective of confirming yaws seroprevalence below 1% at each of three serosurveys over a period of 3–10 years after reporting the last case of active yaws in a region. It proposes active testing of children aged 1–5 years through population-based surveys and includes recommendations on survey design, sample size determination, sampling of primary sampling units (PSUs) within an evaluation unit (EU), sampling of households within PSUs, integration with existing public health surveys and follow-up protocols for positive results. Geospatial analysis and sustained surveillance are emphasized for accurate assessment of transmission interruption. Key terms used in this document are defined in the Glossary.

The guidance was drafted by the Informal World Health Organization (WHO) Working Group on Yaws Survey Protocol Development convened by WHO’s Global Neglected Tropical Diseases Programme. The Working Group was composed of independent experts from multiple disciplines. The guidance in the document is derived from their expert opinion and perceptions of current best practice at the time of the document’s development. Recommended sample sizes and other parameters are best estimates and should be interpreted with caution and flexibility