(Adds final declaration)
By Daniel Trotta
HAVANA, Oct 20 (Reuters) - The world must confront Ebola in West Africa to prevent what could become one of the worst pandemics in human history, Cuban President Raul Castro said on Monday.
"I am convinced that if this threat is not stopped in West Africa with an immediate international response ... it could become one of the gravest pandemics in human history," Castro told a summit of the leftist ALBA bloc of Latin American and Caribbean countries in Havana.
Cuba is sending 461 doctors and nurses to West Africa, the largest medical contingent of any single country to fight the worst Ebola outbreak on record.
The virus has killed more than 4,500 people since March, mostly in Sierra Leone, Guinea and Liberia. Among the dead are 239 healthcare workers, the World Health Organization said.
Castro reiterated Cuba's willingness to set aside 55 years of hostility with the United States to stand together against Ebola. Washington is sending up to 4,000 military engineers, medical personnel and other troops to West Africa.
"Cuba is willing to work side-by-side with all countries, including the United States," said Castro, who took over as president from his older brother Fidel Castro in 2008.
The United States has welcomed Cuba's aid, with U.S. Secretary of State John Kerry highlighting the size of Cuba's contribution in relation to its population of 11 million.
With 83,000 doctors, Cuba says it has 7.2 physicians per 1,000 people, one of the highest rates in the world, although many are sent overseas in exchange for cash or goods such as Venezuelan oil.
Although there have been no Ebola cases reported in Latin America or the Caribbean, it has reached the United States and Spain.
Labeling the world's response to date "insufficient," the ALBA countries promised to reinforce detection and prevention, and share training and education for public health workers.
They said at the end of their meeting that they might send more doctors and nurses to West Africa, though none made a specific commitment.
They also praised Cuba for its record of medical diplomacy. Havana has dispatched medical brigades to disaster sites around the world since the 1959 revolution that brought Fidel Castro to power.
The ALBA summit came together quickly after a Liberian man, the first person diagnosed with Ebola in the United States, died from the virus in Dallas on Oct. 8.
The presidents of Cuba, Venezuela, Bolivia, Nicaragua and Haiti attended along with the prime ministers of Saint Lucia and Saint Vincent and the Grenadines.
ALBA members Ecuador, Dominica, and Antigua and Barbuda sent senior officials, as did the United Nations, the World Health Organization and the Pan American Health Organization.
Reporting by Daniel Trotta; Editing by Tom Brown and Kieran Murray