U.S. specialists in infections diseases, top left, and Cuban specialists, right, attend a meeting at the Pedro Kouri Tropical Medicine Institute (IPK) in Havana, Cuba, Wednesday, Oct. 19, 2016. The Obama administration sent some of the United States' top infectious disease specialists to Cuba to open a new phase in medical cooperation after more than a half-century of isolation .(AP Photo/Ramon Espinosa)

HAVANA - The Obama administration sent some of the United States' top infectious disease specialists to Cuba on Wednesday to open a new phase in medical co-operation after more than a half-century of isolation.

Two dozen U.S. and Cuban experts on tropical diseases opened three days of meetings about each country's research into insect-borne diseases such as dengue, chikungunya and Zika. U.S. Health and Human Services Secretary Sylvia Burwell was to fly to Cuba Thursday to attend.

The visit is part of President Barack Obama's push to build irreversible momentum behind his detente with Cuba in the final months of his administration. The administration has issued six sets of regulations loosening the 55-year-old U.S. trade embargo on Cuba, but the executive actions could be reversed by a future administration.

Democratic candidate Hillary Clinton, who leads in polls three weeks before the presidential election, has promised to continue normalization. Republican Donald Trump has pledged to roll back Obama's policy.

Obama visited in March. U.S. Trade Representative Michael Froman visited this month, as did Dr. Jill Biden, the vice-president's wife. More visits are planned in coming months.

"Representatives of the U.S. government are beginning to flock to Cuba," said Dr. Hugh Auchincloss, deputy director of the U.S. National Institute of Allergy and Infectious Diseases. "There's every reason in the world for us to be working together."

The meetings are meant to lay the foundation for permanent co-operation between public health officials and researchers in the U.S. and Cuba. The U.S. embargo has prevented virtually all interaction between the United States and Cuba, which has made medical research and health care one of the nation's highest priorities since Fidel Castro took power in 1959.

Cuba has reported remarkable success in containing the Zika virus, limiting its spread to only three cases caught on the island, according to Cuban officials, even as countries in the region such as Puerto Rico and Venezuela have been hit by thousands of cases of the disease.

U.S. and Cuban medical officials said Wednesday that another area of immediate interest was the dengue virus, which can have less severe effects than Zika but has been a longstanding problem throughout Latin America. Cuba and the U.S. are working on vaccines, and Cuban scientists said a combination of the U.S. and Cuban vaccines had shown promising results in initial animal testing.

____

Michael Weissenstein on Twitter: https://twitter.com/mweissenstein

News from © The Associated Press, 2016