More than 2,000 Ebola cases, including 754 deaths, have been recorded in the DR Congo, where the World Health Organization warns the outbreak may be two to four times larger than official figures suggest.The outbreak has spread to five provinces in the central African country, according to the latest figures released by Congolese health authorities Wednesday.There is currently no approved vaccine or treatment for the Bundibugyo strain behind this outbreak, but the first clinical trial of an ant