DR Congo’s fast-spreading Ebola outbreak has exceeded 3,500 cases, overtaking the country’s deadliest epidemic and becoming the world’s second-largest ever. The Bundibugyo strain has no approved vaccine or treatment.

As the death toll rises to almost 1,500, and with a vaccine against the Bundibugyo strain potentially still months away, health workers face a battle to slow the outbreak

The Democratic Republic of Congo's rapidly spreading Ebola outbreak has become the world's second-largest on record, government data showed...