DAKAR – The Ebola epidemic in Democratic Republic of Congo is on track to surpass 4,000 cases this week and has been described as the fastest-spreading on record since it was officially declared in May.

It is already the world’s second-largest epidemic after West Africa’s 2014-16 outbreak in Guinea, Liberia and Sierra Leone, when the World Health Organization (WHO) recorded more than 28,000 cases and 11,000 deaths.

Delayed detection, overwhelmed surveillance, military conflict and a lack of vaccines and treatments for the species of the virus involved have allowed the disease to outrun containment efforts this time.