World Health Organization (WHO) director general Chan told reporters on Friday that the Ebola virus was spreading in West Africa more quickly than health authorities could respond - particularly in the three worst-hit countries of Guinea, Liberia and Sierra Leone.

"The Ebola outbreak that is ravaging parts of West Africa is the largest and most complex and most severe in the almost four-decade history of this disease," Chan told reporters at the UN health body's Geneva headquarters on Friday. "As of September 12, we are at 4,784 cases and more than 2,400 deaths."

Cuba sends staff to Sierra Leone

Margaret Chan said that more international medical staff and equipment were urgently required to combat the disease's spread, lauding a pledge from Cuba to send 165 medical staff to Sierra Leone.

"If we are going to go to war with Ebola, we need the resources to fight," Chan said. "Cuba is world famous for its ability to train outstanding doctors and nurses and for its generosity in helping fellow countries on the route to progress."

Doctors, nurses, epidemiologists, infection control and intensive care specialists are among the personnel being dispatched by the government in Havana. Cuba's minister for public health, Roberto Morales Ojeda, also attended Friday's press conference.

Many Ebola patients have been medical staff, working close to patients with a disease that spreads via contact with bodily fluids. Some foreign doctors and missionary workers, several of them from the US, have contracted the disease.

Chan said that the most useful assistance the international community could offer was trained specialist personnel: "We still need about 500 to 600 doctors coming from abroad and at least 1,000 or more healthcare workers."

Equipment shortfalls

Chan, who is a Chinese doctor and in her second term after taking up the WHO post in 2006, said the affected countries were running low on "almost everything" in terms of equipment - from personal protective equipment to basic medical supplies and body bags. Safe disposal of the dead has been highlighted as a crucial means to slow the outbreak.

"Today there is not one single bed available for the treatment of an Ebola patient in the entire country of Liberia," she said.

As well as hard-hit Liberia, Sierra Leone and Guinea, patients have tested positive for Ebola in Nigeria and Senegal, while the Democratic Republic of Congo reported seemingly isolated cases involving a different strain of the virus.

Chan also cautioned on Friday that the WHO's estimated numbers on patients and victims were always likely to lag behind the situation on the ground, and could be considered "an underestimate." Ebola's incubation period - the time between infection and symptoms materializing - can last anywhere from two to 21 days, according to the WHO.

msh/sb (AFP, Reuters)