It was February 25, 2012, and I was tracing cholera's path around Haiti, trying to understand how a disease so treatable could kill so many people. A cholera outbreak could never happen in Miami, all the experts said, but I didn't understand how a bacterium could discriminate against who it would infect and kill, and why it was picking Haiti of all places to do this.

Silver bursts of sunlight caught my eye at irregular intervals as we wound around the bends of the Artibonite River on our way from Saint-Marc to Mirebalais. At 320 km long, the Artibonite is the longest river in Haiti. It provides the 1.2 million residents of Haiti's capital city, Port-au-Prince, with hydroelectric power, making it the most powerful river in Haiti. And ever since the Nepalese faction of the United Nation's military operation infected the river with cholera by improperly disposing of their infected waste, it has been the deadliest river in Haiti.

Whenever Americans hear that UN peacekeepers brought cholera to Haiti for the first time, they're skeptical. But we know that's where it came from because the Vibrio cholerae bacteria responsible for the outbreak has a genetic fingerprint, just like we all have fingerprints that distinguish us as individuals, and that particular strain came from Nepal. That's where the troops were from who were stationed at the UN base directly upstream from the location of the first documented cholera case in Mirebalais.

Since the first case of cholera was documented in October of 2010, the disease has killed over 8,000 people and infected 649,000 others — over 5% of the population. When I was in Haiti in the spring of 2011, there had already been 4,672 cholera deaths. Health organizations were circulating information about the disease in hopes that simple awareness would curb it. Cartoon figures on concrete fences smiled patronizingly at pedestrians walking along rubble-littered streets, explaining how to properly wash one's hands. There were rumors of advice whispered amongst the bourgeois: “Don't eat the salad at such-and-such place, someone got sick because they washed the lettuce with contaminated water.” “Stay away from seafood, because, you know.”

In Port-au-Prince, there is no public water system — no infrastructure of pipes connecting residences to a main supply. But there is access to treated water, if you can afford it. Drinking water comes in jugs like the kind you've probably seen in offices attached to a conical paper cup dispenser. You drink it, rinse dishes with it, and use it to brush your teeth. Sometimes when you're walking or driving around outside, you hear the high-pitched mechanical tunes that in developed countries signals an ice cream truck is near. In Haiti, it means the water truck is near. Little kids and adults alike chase after the truck, pay a few cents and receive a clear plastic baggie of water they carefully break open with their teeth or poke straws into to hydrate.

There's a different kind of water for bathing. It's treated with bacteria-killing chemicals in a much cruder way. Some people have reservoirs underground to store it, and pumps to circulate it through pipes and out of faucets — if there happens to be electricity. Electricity from the main grid comes and goes in an unpredictable fashion. Forget about heated water. Without electricity, the pumps can't circulate the water, which means bucket showers. You never, ever want to drink this water. The eyeballed methods of chlorination are unreliable. Too little and the reservoir is subject to microorganisms, too much and the chlorine leaves your skin with an itchy burn after your freezing bucket shower.

Many of the victims of cholera, I later learned, were too poor to afford these luxuries.

The car pressed on around the river, tracing the spread of disease from the first documented case, to the site of the first massive outbreak. Along the way, we passed several banners reprimanding the UN for bringing cholera to Haiti.

With me was Paul Clammer, the British documentarian who wrote all the major guidebooks to Haiti in the past decade. Our driver, Edzer, was a former member of the Haitian police force who had retired to go back to school to be a social worker. To earn money, he translated for journalists and helped them get around in Haiti. His laid back smile made him seem like a big teddy bear, but when a street vendor popped out of nowhere next to the car startling us all, his reflexes in hitting the lock button told me he was a teddy bear who could kill someone in two seconds if he had a reason.

We were driving along the path that Jon Lascher, the Haiti Program Manager for Partners In Health, had directed us to take to meet him at the new teaching hospital in Mirebalais. He had just taken us on a tour of the hospital in Saint-Marc that had once been filled far past capacity with cholera victims, their bodies all violently expelling fluid in attempt to rid themselves of the toxin-releasing bacteria that rapidly replicates in the low acid environment of the small intestine. The Vibrio cholerae bacterium doesn't kill people directly — its goal is merely to exit the body and spread to new hosts. When people die from cholera, they actually die from dehydration.

This is the ironic tragedy of the disease. Nobody should ever die from cholera because the solution is so simple: rehydrate. The miracle treatment that patients get when they go to the hospital for treatment for a cholera infection, is something called “Ringer Lactate”. It is essentially salt water. A standard package costs about $1.50. But for most people in Haiti, this luxury is simply unavailable.

As we drove, Jon texted me that there would be some scenic views of the Artibonite river as we got closer to Mirebalais, and asked where we were. I texted back that we had passed a town called Verettes 15 minutes ago. There were no stores or other landmarks along the way, just houses here and there — floorless concrete walls painted in cheery pastels with various plant life thatched over top to protect against the harsh sun and relentless downpours of the rainy seasons.

The rainy seasons, peaking in May and October, are when the cholera cases spike. Just when the epidemiologists grow hopeful that all the efforts of the public health workers have finally managed to quell the outbreak, turbulent storms rip across the country, mixing infected water sources with clean ones and enabling cholera's transport far and wide, all over again.

I was staring out the window, looking at that treacherous river and thinking about all this and how horrible it would be to die that way, when I started noticing people walking along the side of the road, carrying massive loads of things atop their heads as Haitians do. I wondered how long it would take them to get where they were going, since we'd been driving a long time through a whole lot of nowhere. I noticed some of them were carrying big jugs of water, and I felt so bad for them because water is so heavy and they had to carry it so far since there were no stores for at least 15 miles.

“Edzer, where do you think they're getting that water from?” I asked.

“I don't know,” he said after thinking about it for a minute. “I hope not the river.”

“No, they know that river is contaminated,” I said. “We have to find out.”

Edzer pulled the car over and we all got out and started walking in the direction the people were moving. We caught up with a young woman and Edzer introduced himself and asked her where everyone carrying water was coming from. “La Source,” said the woman, who said her name was Michou Felix. We didn't understand. She pointed down into the brush beyond the road. We asked if she could show us, and she shrugged and agreed. We walked down the street for a few minutes until she pointed out a break in the brush. She led the way along the path, down far away from the road into a shady grotto. It started to get muddy, and we passed an opportunistic wild pig basking near a puddle. Nearby, a chicken pecked the ground.

“La Source,” Michou announced with a wave of her hand. Paul and Edzer and I all looked at each other with different forms of surprise. In front of us was a twisted bunch of exposed tree roots out of which a natural spring was trickling fresh water into a puddle far more shallow than your average kiddie pool. A man was standing on a root off to the side, patiently holding a plastic container below the trickle to fill it up while his three kids played off to the side. He had another plastic container with blue liquid in it.

“Is this their drinking water?” I asked Edzer to have him translate. It was, indeed, the sole source of drinking water for the surrounding community, where people mostly worked farming sweet potatoes, bananas and peas. Michou estimated this measly spring supplied the water needs of 5,000 people. She said some people treat it with "detergent," the blue liquid the man was holding containing anyone's guess about what cocktail of chemicals it contained.

“Aren't they worried about cholera?” I asked. Edzer took a deep breath and translated. Michou shrugged the most helpless shrug anyone has ever shrugged in the history of the world, and responded in Kreyol. Edzer turned to me and said, “This is what we got to drink. It's the life we have.”

“But, what are they going to do when the rainy season comes? What if the river contamination seeps into their spring?” I asked. He didn't turn back to her, but instead leaned in closer to me. “They live under the fate of God,” he said. “If you kept asking them about it, they would say, they live under the fate of God.”

We thanked Michou and gave her some money, then headed back to the car. It finally all made sense. That was real Haiti. That was how most people outside the city lived, with their most important resource transformed into a roulette wheel of excruciating death and disease. When cholera struck communities like that, seeping into their drinking water reservoirs then crawling from family to family as people tried in vain to treat their sick, there were no simple rehydration mechanisms. The public health task at hand, to make clean water and sanitation systems accessible by communities like Michou's, would take decades, if it could ever be completed at all.

As we walked back to the car along the road, I was blinded by the irony of the situation where on one side of the road was a massive river, overflowing with the most precious commodity on the island, but to drink from it likely meant death. Meanwhile, the all-but-hidden spring on the other side of the road was trickling groundwater at a rate that the average American wouldn't have the patience to fill a bathtub with, and was supporting a community of 5,000 people.

A cholera outbreak could never have spread in Miami, the experts all said. I now understood why.