The Cubans have sent doctors abroad since the 1960s as a form of “medical diplomacy” that brings badly needed doctors to remote areas of poor countries, mainly in Africa, as well as to allied countries like Venezuela, while sowing international solidarity, said Katrin Hansing, a Baruch College professor who is writing a book on Cuban overseas aid.

“It gives them a lot of political capital in the developing world, to keep up that heroic image of Cuba against the United States, that despite the embargo they still champion help to less-developed countries,” she said.

It has also been an important source of foreign currency for Cuba, with earnings from the export of medical services, including 37,000 health workers overseas, estimated at more than $2 billion. Ms. Hansing said that these days the Cubans typically ask host countries to pay a sliding scale that averages $2,500 per doctor, per month. But Haiti, she said, is one of a few countries that are not charged.

Image The mission in Mirebalais has had no cholera deaths in 2011. Credit... The New York Times

There is no doubt that the Cuban mission has been vital here. It was among the largest international aid contingents to respond after the January 2010 earthquake that tumbled Haiti into crisis. And since the cholera outbreak, the mission has treated more than 76,000 cases of the disease, with just 272 fatalities — a much lower ratio, at 0.36 percent, than the average across Haiti as a whole, in which 1.4 percent of cases ended in death, according to the Health Ministry.

“We work a lot on the education of the population,” said Dr. Lorenzo Somarriba, the chief of the Cuban medical mission. “We send people to the homes of the victims and educate them on the disease and provide them with tabs to clean the water. This is absolutely vital.” Such purification tablets have been critical in a country where treated water is rare.

Indeed, here in Mirebalais the team has not seen a fatal cholera case since December, he said.

It is a success the Cubans eagerly promote, with Fidel Castro issuing several “reflections,” personal commentaries that appear in state-run media and Web sites, chronicling the group’s endeavors and achievements.