One of the difficulties faced by teams responding to the current Ebola outbreak in West Africa is identifying individuals and communities residing in remote areas. Existing maps of these regions either do not exist or are inadequate or outdated. This means that basic data like location of houses, buildings, villages, and roads are not easily accessible, and case finding and contact tracing can be extremely difficult.

To help aid the outbreak response effort, volunteers from around the world are using an open-source online mapping platform called OpenStreetMap (OSM) to create detailed maps and map data of  Guinea, Sierra Leone, Liberia, and parts of Mali.

Commonly referred to as “Wikipedia for maps,” OSM is working toward the goal of making a map of the world that is freely available to anyone who wants to use it. The Humanitarian OpenStreetMap Team (HOT) is a U.S.-based non-profit organization that represents a subset of the OSM community. HOT’s mission is to use OSM data and tools to help prepare and respond to humanitarian disasters. Because OSM data is available for free download anywhere in the world, volunteer mappers generate data that are useful not only to CDC but also to other agencies involved in the Ebola response, such as Doctors Without Borders (MSF), International Red Cross (IRC), and World Health Organization.

Mappers frequently use satellite images to identify villages, houses, paths, and other details that were previously unmapped. The U.S. State Department’s Humanitarian Information Unit (HIU) is supporting HOT and OSM by creating the MapGive.org website, which provides easy-to-follow instructions on how to begin mapping very quickly. Personnel in CDC’s Division of Global Migration and Quarantine (DGMQ) are coordinating with HIU and HOT to support and promote volunteer mapping in affected West African areas where CDC teams are currently working.

Members of Emory’s Student Outbreak and Response Team (SORT) are some of these volunteer mappers. SORT is a graduate student organization that collaborates with CDC and provides hands-on training in outbreak response and emergency preparedness. Ryan Lash, a mapping scientist in DGMQ’s Travelers’ Health Branch, initially contacted SORT for help in August as the number of Ebola cases in West Africa continued to rise. He has since provided two workshops for SORT members, taught a small number of CDC staff, and trained students at the University of Georgia.

In the 8 months that HOT has been mapping countries with Ebola outbreaks, more than 2,500 volunteers have mapped more than 750,000 buildings and hundreds of kilometers of roads, resulting in detailed maps of affected West African communities. Not only do these maps help first responders and other organizations around the world, they also contribute to the national information infrastructure essential to the recovery and rebuilding of affected regions. The value of OSM was highlighted especially well during the 2010 Haiti earthquake, after which the U.S. State Department decided to promote volunteer mapping as a way for the general public to get involved in humanitarian emergencies.

Volunteer mapping in OSM for HOT can be done by anyone. All you need is a computer, an internet connection, and the time and willingness to learn. Find out more about how you can help here: Learn to Map