Why health officials do not have a good handle on the current Ebola outbreak

To get slightly ahead of the virus, health officials need to quickly identify people at risk of infection, a practice known as contact tracing. That's a challenge in the Democratic Republic of Congo.

To get slightly ahead of the virus, health officials need to quickly identify people at risk of infection, a practice known as contact tracing. That's a challenge in the Democratic Republic of Congo.

(Image credit: Michel Lunanga)