Health authorities struggling to control the worst outbreak of Ebola on record said drastic action is needed to prevent more deaths.

More than 390 people have died in the outbreak in Guinea, Sierra Leone, and Liberia, the World Health Organization said in a statement Thursday. That toll is greater than the 280 people killed in 1976, when the virus was first identified near the Ebola River in what is now the Democratic Republic of Congo.

The WHO plans to meet with health ministers from 11 countries Wednesday and Thursday in Accra, Ghana, to agree on a plan to bring the outbreak under control. Health workers will have to tackle resistance from local people who are hiding infected family members, destroying medicines intended to help, and adhering to rituals that fuel the spread of the virus.

"This is no longer a country-specific outbreak but a sub- regional crisis that requires firm action by governments and partners," said Luis Sambo, the WHO's regional director for Africa. "WHO is gravely concerned of the ongoing cross-border transmission into neighboring countries as well as the potential for further international spread."

The outbreak is expected to last another three to four months, said Francis Kasolo, the WHO's director of disease prevention and control for Africa.

"What we are seeing is a lot of cross-border movement," Kasolo said in a telephone interview. "When somebody comes in contact with a sick person in Guinea and crosses into Sierra Leone, as long as they don't report having come into contact with an Ebola patient, there is a grave possibility that that person will transmit the disease."

At next week's meeting, the WHO will discuss forming a multi-country team that will share information daily on Ebola cases and people who have come into contact with those infected, Kasolo said. The Geneva-based organization has deployed more than 150 people to fight the epidemic, with surveillance, communication, infection control, logistics and data management.

Allowing infected patients to leave the hospital and employing unsafe burial practices also aid the spread.

Effective communication of safe measures to local communities is a challenge that will be discussed in Accra, said WHO spokesman Daniel Epstein.