The panic began to set in after Tropical Storm Isaac’s rains had subsided and the sun finally began to shine on this storm-damaged beachfront hamlet. Frantz Pierre-Louis, looking at the trail of fallen trees and flooded farms confronting him, had something much more pressing on his mind.

“We have to prevent a cholera outbreak,” Pierre-Louis, sitting in his pick-up truck, said, his voice filled with urgency.

Just when Haiti thought it had cholera under control, Tropical Storm Isaac came along. The storm left at least 24 dead in Haiti, and reignited fears that the floods and rains could accelerate a peak in cholera deaths and infections. Even worse, the deadly diarrheal disease could spread to the sprawling tent cities in Haiti’s capital where 390,000 victims of the January 2010 earthquake still live and where — until now — it has remained at bay.

“Today with the situation in the camps, it is clear they are most at risk,” said Yolette Etienne, Oxfam’s program director, alluding to the lack of potable water in camps.

Last week, U.N. Secretary General Ban Ki-moon told the U.N. Security Council that living conditions in many of the 575 camps have deteriorated to the point where Haitians remain “extremely vulnerable” to cholera, and the government’s Health Ministry is unable to effectively address a crisis on its own.

“The resurgence of the cholera outbreak is particularly worrying since non-governmental organizations, which responded at the beginning of the epidemic, are phasing out due to lack of funding,” Ban said.

“We can assume there is going to be an increase in patients,” said Oliver Schulz, Doctors Without Borders/Médecins Sans Frontières (MSF) country manager, from inside a cholera treatment center in the Port-au-Prince suburb of Delmas, where post-Isaac patients had begun trickling in. “The storm increases the risk.”

This is especially true in flooded communities, where the drinking water is at risk of becoming contaminated by wastewater from latrines. Along Route 9 near the Cité Soleil slum in the capital, for example, a nearby river flooded about 1,200 homes, turning front rooms and yards into chocolate-colored lakes.

Diana Victor’s family house was among those that were flooded, the young woman said, sitting on a cot at an MSF cholera treatment center. Weak and her voice barely audible, Victor, 21, said she has no idea how she contracted cholera.

“I didn’t drink any water, I only walked in it,” she said, the day after she showed up at the treatment center on the back of a motorcycle taxi covered in vomit and clear-colored diarrhea. “I didn’t feel well at all, I couldn’t stand, couldn’t eat.”

Schulz said while cholera is easily preventable, it is also easy to get, especially when heavy rains and floods limit access to clean water.

“You might have a nice distribution of soap for instance, but if you don’t have clean water to wash your hands, the soap is useless,” he said.

The annual Atlantic hurricane season, which runs from June 1 to Nov. 30, has become a dreadful reminder of not just how environmentally fragile Haiti is, but how susceptible Haitians are to contracting cholera, the deadly waterborne epidemic that arrived in Haiti two years ago next month.

Nepalese U.N. troops have been accused of bringing cholera to Haiti after the Artibonite River, located near the troops’ latrines, became contaminated with the cholera bacteria. On Wednesday, more than a dozen human rights groups are expected to issue a letter renewing calls for the U.N. to make clean water and sanitation available in Haiti to help curtail the cholera crises.