Hal Hudson from New Scientist wrote a great article on how OpenStreetMap helps Médicins Sans Frontières (MSF) fight Ebola in Guinea:
WHEN doctors working for Médecins Sans Frontières (MSF) arrived in the West African nation of Guinea last month to combat an outbreak of the deadly Ebola haemorrhagic fever, they found themselves working in an information vacuum.
MSF enlisted the help of the Humanitarian OpenStreetMap team (HOT) and within a few days, a huge number of mappers flocked to OpenStreetMap, putting the affected areas on the map. Where existing Bing imagery was not sufficient, Astrium and DigitalGlobe provided fresh takes.
Even if this crisis is not in all the medias, the contribution from the OSM contributors is fantastic. In 8.5 days, 302 contributors, 1.2 million objects, 114,000 buildings, 5,000 places and 6,100 landuse polygons.
The New Scientist article explains how OpenStreetMap helps fight the virus:
Mathieu Soupart, who leads technical support for MSF operations, says his organisation started using the maps right away to pinpoint where infected people were coming from and work out how the virus, which had killed 95 people in Guinea when New Scientist went to press, is spreading. "Having very detailed maps with most of the buildings is very important, especially when working door to door, house by house," he says. The maps also let MSF chase down rumours of infection in surrounding hamlets, allowing them to find their way through unfamiliar terrain.
Since the response to the Haiti earthquake we are now seeing time and again how OpenStreetMap is facilitating incredibly mapping of badly needed geo data, helping first line emergency responders do their work.
You can't do this with any other map but OpenStreetMap.
This type of massive mapping effort is only possible because of OpenStreetMap allowing direct editing of data to anyone and the availability of OpenStreetMap as raw and open data. The former allows anyone to get involved in helping respond to a crisis, the latter gives full power to responding parties over how exactly maps should look like or access to raw data for analysis. No other map offers this level of openness at a global scale.