Ebola virus spreads, kills at least 4 in Sierra Leone

The World Health Organization says at least four people have died from an Ebola virus outbreak in Sierra Leone, in West Africa. The BBC reports one of the victims was a health care worker.

The cases were reported in a region of the country that borders Guinea, a "disease hotspot" where more than 250 cases of Ebola, and at least 174 deaths, have been reported in the last six months.

WHO says it is sending six international experts to help coordinate the response to the outbreak in Sierra Leone and distribute medical supplies.

Ebola was suspected in two previous deaths in Sierra Leone in March, involving people who had traveled from Guinea.

Ebola causes internal bleeding and organ failure and is fatal in up to 90 percent of cases. It spreads through direct contact with infected people or through contact with wild animals such as bats or monkeys which can harbor the virus.

There is no cure or vaccine, so containing the outbreak has focused on supportive care for those infected with the virus and isolating them to limit its spread.

The recent outbreak in Guinea likely began last December and may have been smoldering for some time before that unrecognized, health officials say. They believe it involves a new strain of the virus, not one associated with past outbreaks in the Democratic Republic of Congo, where Ebola was first identified in 1976.