Cholera patients are pictured receiving treatment at the Celia Sanchez Manduley hospital in Manzanillo, Cuba on July 11, 2012.

Story highlights

The cholera outbreak hit Granma Province the hardest

Doctors don't know how the disease was reintroduced to the island nation

10 days have passed since the last reported case of cholera, officials say

Havana, Cuba CNN  — 

Cuba’s government declared Tuesday that health workers had eradicated a cholera outbreak that infected 417 people and killed three, according to a statement from the country’s Health Ministry.

In early July, Cuba said the sometimes fatal water-borne illness had returned to the eastern part of the island. It was the first outbreak of the disease in Cuba in more than a century.

Cuban doctors battle to control cholera outbreak

Doctors were not certain how cholera was reintroduced to the island, but said that heavy rains that caused outhouses to flood into drinking wells were to blame for the disease’s rapid rate of transmission. Cholera, a bacterial infection of the small intestine, causes severe diarrhea and vomiting in infected people.

During a visit by CNN in July to hospitals at the epicenter of the outbreak, doctors said they initially struggled with the surge of people sickened by the disease.

“They started coming in a few at a time,” said Julio Cesar Fonseca Rivero, director of the Celia Sanchez Manduley Hospital, the largest in Granma Province. That province was the hardest hit by the outbreak. “The first day five came, and then eight. The most critical days were when there were 30 to 32 patients who arrived in a single day.”

The disease, according to the World Health Organization, still infects between 3 million and 5 million people each year, killing between 100,000 and 120,000.

Cuban health officials said they responded to the outbreak by bringing in clean drinking water, closing down food stands in affected areas and setting up checkpoints on roads to keep people ill with the disease from traveling.

Cuban leader Raul Castro mentioned the outbreak in a speech to the nation in late July, saying it had been brought under control.

According to the Health Ministry statement released Tuesday, 10 days have passed since the last reported case of cholera.