Cross-border issues: an important component of onchocerciasis elimination programmes.

Endemic areas that involve national or local borders present an important challenge to the success of elimination of onchocerciasis; such cross-border endemic foci require special attention to ensure that programme activities are unified. It is vital that national programmes and the committees responsible for the oversight of progress towards elimination are aware and address such issues in their current planning and programmatic activities. Although international borders that intersect endemic zones present the biggest challenge, intracountry borders (such as between administrative districts or loiasis endemic and non-loiasis areas) can also pose problems. The recent change in the onchocerciasis programme from disease control to transmission interruption, given the historical lack of treatment in hypo-endemic areas, may have increased the already relatively high number of cross-national scenarios in Africa. It is vital that all national programmes address the issue of any cross-border endemic areas as a matter of urgency and include this important issue in their elimination plans.