… Though experts at the World Health Organization, medical NGOs, and the U.S. Centers for Disease Control and Prevention (CDC) had been emphasizing that a major epidemic would be unlikely after the quake, they pushed out vaccinations to be sure. I’d dutifully chased down every lead, increasingly joining the experts in their skepticism. But something about this — the number of people, the specificity of the symptoms, and the pinpointing of a locale — was different. This sounded real. We pulled out our phones, Evens dialing the health ministry to try to confirm the report. …

The cameras were back on Haiti. Brian Williams set the tone on NBC: “It’s what all of us worried about when we arrived in Haiti just hours after the quake … beyond the death toll, the inevitable spread of disease. Now it’s happening in Haiti, an outbreak of cholera in that nation struggling every day, still, just to survive.”

But the narrative didn’t make sense. If cholera was the inevitable result of the earthquake, centered 15 miles southwest of the capital, why had the first concentration of cases appeared in the countryside, some 45 miles to the north? And why had it taken nine months to appear? …