The outbreak was expected to continue spreading, but aid groups and the government said a drop in the death rate and the number of new cases suggested it could progress more gradually than feared.
"The situation is beginning to stabilize. Since yesterday we have registered only six new deaths," Health Ministry Director Gabriel Timothee said at a news conference.
Officials said no cases have originated in the capital, Port-au-Prince, where authorities fear abysmal hygiene, poor sanitation and widespread poverty could rapidly spread the disease through the sprawling tent slums erected after the Jan. 12 earthquake.
Five patients were diagnosed with cholera here over the weekend, but officials said they got sick outside the capital.
As part of the effort to slow the spread of the disease, Timothee said the government has asked for garbage to be removed around the camps of homeless.
If efforts to keep cholera out of the camps fail, "The worst case would be that we have hundreds of thousands of people getting sick at the same time," said Claude Surena, president of the Haiti Medical Association. Cholera can cause vomiting and diarrhea so severe it can kill from dehydration in hours.
Robyn Fieser, a spokeswoman for Catholic Relief Services, said she was confident that aid groups and the Haitian government will be prepared to respond to an outbreak should it occur in the camps. But she stressed that the challenge of preventing its spread is "immense."
"There are proven methods to contain and treat cholera, so we know what we're dealing with. The biggest challenge is logistics, that is, moving massive amounts of medicine, supplies and people into place to treat them and prevent the disease from spreading," Fieser said from the neighboring Dominican Republic.
CBS News medical correspondent Dr. Jon LaPook reports that the first case was confirmed last Sunday evening in Cap Haitien, on the country's northern coast.
Doctors Without Borders issued a statement saying that some Port-au-Prince residents were suffering from watery diarrhea and were being treated at facilities in the capital city. Cholera infection among the patients had not been confirmed, however, and aid workers stressed that diarrhea has not been uncommon in Port-au-Prince since the earthquake.
"Medical teams have treated many people with watery diarrhea over the last several months," Doctors Without Borders said.
Aid workers in the impoverished nation say the risk is magnified by the extreme poverty faced by people displaced by the quake, which killed as many as 300,000 people and destroyed much of the capital city. Haitians living in the camps risk disease by failing to wash their hands, or scooping up standing water and then proceeding to wash fruits and vegetables.
Timothee said the outbreak has killed 259 people and sickened 3,342.
"We are expecting a gradual spreading of cholera in the country, and the way it will do that is still unpredictable," said Michel Thieren, an official with the Pan-American Health Organization in Haiti.
Aid workers are coaching thousands of impoverished families how best to avoid cholera. Various aid groups are providing soap and water purification tablets and educating people in Port-au-Prince's camps about the importance of washing their hands.
Aid groups also began training more staff about cholera and where to direct people with symptoms. The disease had not been seen in Haiti for decades, and many people don't know about it.
Members of one grassroots Haitian organization traveled around Port-au-Prince's camps booming warnings about cholera from speakers in the bed of a pickup truck.
"Many people have become sick," announced Etant Dupain, in front of the Champs de Mars camp by Haiti's broken national palace. "If you have a family member that has diarrhea, bring them to the hospital immediately. Have them use separate latrines."
In a promising development, aid group Partners in Health said hospital management was improving in the city at the center of the initial outbreak, St. Marc, which is about a 60-mile (95-kilometer) drive northwest of Haiti. Just 300 patients were hospitalized on Saturday, a number that has decreased by the end of each day.
A cholera treatment center in St. Marc is expected to be functional within the week, and efforts were ongoing to make clean water available in rural communities, especially those where rivers were the only source of water.
Some health experts were hopeful that they will be able to control the outbreak of cholera in impoverished Haiti.
"In a way, it couldn't have happened at a better moment than now because everyone is on the field lots of (non-governmental organizations), lots of money. We haven't had any hurricanes so far this fall but people are here, and people are prepared," said Marc Paquette, Haiti director for the Canadian branch of Medecins du Monde.