PORT-AU-PRINCE, Haiti — Once health officials detected the first cases of cholera in Haiti’s capital on Saturday, the Haitian government, the United Nations and humanitarian agencies began a race to thwart a potential pandemic from spreading within the city’s many tent camps and across the nation.

More than 200 people have died since the first known case was detected one week ago outside the Haitian capital, while 2,646 people have so far been infected, according to U.N. figures.

The outbreak comes less than one year after a massive earthquake struck the country, killing about 300,000 people.

Despite some reports Monday that the outbreak may be "stabilizing," residents in Port-au-Prince are preparing for the worst. The mood is tense, as rumors swirl that airports will be closed and borders shut down.

“People aren’t in a panic just yet,” said one resident. “But conversations in the street are more and more about cholera instead of soccer or politics, as they usually are.”

To make matters worse, the U.N.’s Office for the Coordination of Humanitarian Affairs confirmed today that they are investigating the first suspected cases of cholera in Haiti’s North and South regions.

Until Saturday, the epidemic appeared to be limited to the Central and Artibonite regions, where the Haitian government has declared a state of emergency.

“There’s a lot of rumors about suspected cases … The situation is changing by the hour,” said Imogen Wall, head of communications for the U.N. humanitarian agency. “We are planning for the worst-case scenario — a nationwide outbreak.”

The five people found to be infected with cholera in Port-au-Prince Saturday had traveled from the country’s Artibonite and Central regions.

It is the first cholera epidemic here in at least a century, which means there is a relatively low level of immunity to the bacterium among Haiti’s population. Many of the infected, in fact, are arriving at hospitals too late, some dying within a few hours of showing symptoms.

“People’s immunity to this disease is nonexistent,” Wall said. “The medical profession here has no experience with cholera, and it moves incredibly fast. It’s not a good combination of factors.”

St. Nicolas hospital in the town of St. Marc has been overwhelmed by more than a thousand cholera patients since Thursday. The hospital has been quarantined and 20 doctors, nurses, and logistical specialists from Médecins Sans Frontières have arrived to help.

Staff at St. Nicolas have been working around the clock and are exhausted,said Yolaine Surana, coordinator for the government's Civil Protection Department. Other medical staff members were sent to the border of the Artibonite region on Thursday to try and grasp the spread of the disease in the region. Many are worried that the number of deaths is being underreported.

“We sent them to the top of the mountain, there is no road there,” said Surana, highlighting the difficulty of containing and treating an epidemic in the Haitian countryside which lacks even basic infrastructure. “We are crossing our fingers.”

In Port-au-Prince, five cholera treatment centers are being constructed in the event of a mass outbreak, and nongovernmental organizations are launching public information campaigns in the camps as well as distributing soap and chlorine.

Despite these efforts, there are no guarantees that the disease can be prevented from spreading into the crowded tent cities, where more than a million Haitian have been living in since a massive earthquake struck on Jan. 12, many without adequate sanitation or clean water.

“The level of sanitation in Haiti and in Port-au-Prince was not good even before [the quake],” said Melody Munz, environmental health coordinator with the International Rescue Committee. “The public messaging is absolutely critical. But people here are very frightened so they’re paying close attention.”

In recent weeks, human rights groups such as Refugees International have decried the condition of the camps, claiming that 70 percent of them are unmanaged because of a lack of coordination between the United Nations and other international humanitarian agencies.

Government officials now believe that the source of the outbreak is the Artibonite River, which runs across the middle of Haiti from the Dominican Republic into the Gulf of Gonave. Heavy rains in past weeks may have flooded the river with sewage, but it is not known why the bacterium has affected the country now after being nonexistent for so many decades.

“The awful thing about the outbreak is that it’s a total coincidence,” Wall said about the outbreak following so closely after the earthquake. “Cholera is not present across the Caribbean … But because of the earthquake response we have the supplies we need in country and the medical staff.”

Even as suspected cases appear to be spreading nationally, there is a faint sign of hope that the fatality rate in Artibonite may be dropping.

“The first couple of days was very high, about 9 percent,” said Munz. “Now it seems to be about 5 percent. The goal is to get it down to one and then have no new cases. It’s a question of time and our vigilance.”