Eliminación de la oncocercosis en Malawi: Mapeo de sitios de cría del vector Simulium mediante un enfoque integrado...

Large areas in Malawi have not been treated for onchocerciasis. In order to understand whether to provide treatment in these areas of unknown onchocerciasis endemicity, the Neglected Tropical Diseases Program conducted onchocerciasis elimination mapping (OEM). Identifying and mapping of breeding sites is a prerequisite for conducting OEM and the Malawi onchocerciasis program undertook this activity.

To expedite the river surveys, the team employed a community knowledge approach using questionnaires and discussions, alongside the standard method of using topographical maps, to plan and implement river prospections for Simulium vector breeding sites.

A total of 188 sites was prospected from 180 rivers, with 122 sites (67.8%) identified from community information and 58 (32.2%) from topographic maps. Out of 188 sites visited, 30 were positive for Simulium damnosum larvae/pupae and 91 were considered potential breeding sites and need to be visited in a different season for confirmation. A breeding site map for OEM areas in Malawi was developed. Prospection using the community knowledge approach lasted for 24 days (approximately eight rivers/day) compared to a previous prospection with the same team that used 12 days to prospect 25 rivers (approximately two rivers/day).

This demonstrates the potential of using the health system structure and community knowledge to plan and implement breeding site surveys, shortening the prospection time whilst effectively identifying fast-flowing rivers and breeding sites.