In The Killer Hiding in the CDC Map, it's alleged the CDC knows what caused the Haiti cholera outbreak but is covering it up:
What caused Haiti’s cholera epidemic? The CDC museum knows but won’t say.
...
In fact, despite making the direct analogy between Snow’s map and the Haiti map, the CDC display does not indicate a source of the epidemic at all.
Why not? A spokeswoman for the CDC says in an email that the Haiti map was devised “to optimize response activities on the ground.” Mapping the origin of the epidemic, she says, “was not germane to the purpose.”
That’s one answer. Another is that the CDC knows as well as anyone else that the source—that unidentified spot beside the red triangle, the Broad Street pump of Haiti—was a U.N. peacekeeping base. This one:
...
Since the first days of the epidemic, the U.N. has tried to cover up what it did. Everyone from the soldiers on the base to Secretary-General Ban Ki-moon has been implicated. The Obama administration and the U.S. government did not want the U.N. to be held accountable, because doing so might persuade other people elsewhere to hold U.S. peacekeeping missions accountable—and because the U.S. foots about a quarter of the U.N. peacekeeping budget.
The CDC, a U.S. government agency, discouraged journalists from asking about the epidemic’s origin, telling them that pinpointing the source, Dr. Snow–style, was “not productive,” “not central,” and would likely never happen. Its epidemiologists did provide a key detail early on, when they identified the strain in Haiti as having a recent South Asian origin—meaning it could have come from Nepal and not from South America, Africa, or anywhere else cholera was circulating at the time. But after that, the CDC refused to take environmental samples from around the base or test the soldiers during the small window when doing either would have been worthwhile. All of this detailed in a damning new book by Ralph R. Frerichs called Deadly River: Cholera and Cover-Up in Post-Earthquake Haiti.
Is the CDC engaged in a coverup about the cause of the Haiti cholera outbreak?