As WHO sounds alarm over Ebola in DRC, what can be learned from previous outbreaks?

Students in the DRC wash their hands as a preventive measure. The WHO declared the outbreak a public health emergency of international concern within 48 hours. Photograph: Marie Jeanne Munyerenkana/EPA

To be around the centre of an Ebola outbreak is to become used to the smell of chlorine. At hospitals and government buildings, surfaces are sprayed with it and hands washed in a 0.05% solution that can kill the virus in 60 seconds.

Infrared handheld thermometers take temperatures at airports and border crossings. Any indication of a fever prevents passage. Contact-tracing teams crisscross the countryside.