By Olivia Le Poidevin

GENEVA, July 15 (Reuters) - The Ebola epidemic in the Democratic Republic of Congo is spreading faster than efforts to ‌contain it, global medical charity Médecins Sans Frontières (MSF) warned on Wednesday, ‌calling for an urgent expansion of containment and care measures.

The number of confirmed Ebola cases ​had tripled in less than five weeks to 1,926, including 702 deaths, as of Sunday, official data showed, making it the third-largest and the fastest-growing Ebola outbreak on record, according to MSF.

The charity operates seven Ebola treatment centres and more than ‌15 isolation units in ⁠Congo.

The often fatal viral disease spreads through direct contact with bodily fluids from infected people or animals and causes symptoms ⁠that can include high fever, vomiting and internal and external bleeding. This particular epidemic is caused by the Bundibugyo strain of the virus.

"Every delay costs lives. We ​are still ​chasing the outbreak instead of staying ​ahead of it," said MSF's emergency ‌programme manager, Trish Newport, urging more coordinated international action to improve Ebola care.

MSF raised alarm at the geographic spread of the outbreak, while communities outside urban areas continue to face inadequate support with limited access to medical care and an overstretched surveillance system.

The World Health Organization said last week that ‌the outbreak remained in an expansion phase, driven ​partly by population movements and delays in ​treatment.

The U.S. administration is blocking ​American citizens in Congo from travelling to the United States ‌on commercial flights, according to a ​White House official.

MSF said ​surveillance, testing, and safe and dignified burials all needed more resources.

"In Mongbwalu, we are seeing the deadly human consequences of these gaps every ​day," said Ayokunnu Raji, ‌medical doctor and MSF medical programme manager, explaining that patients often ​arrive in critical condition with little chance of survival.

(Reporting by Olivia ​Le Poidevin, editing by Andrei Khalip)