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?

  • This sounds like a tough question to answer, especially as the CDC is a large organisation, and so what the CDC "know" isn't clear-cut. What sort of evidence do you think might convince you that there was a cover-up, and that there wasn't a cover-up? (I guess them openly publishing a statement that confirmed the claimed source would be evidence of no cover up!)
    – Oddthinking
    Commented Apr 19, 2016 at 4:04
  • @Oddthinking I'm not certain. I think the best answer would the citation of an expert epidemiologist addressing the claim and (if debunking) saying that the facts described are wrong, or that CDC's actions were consistent with Best Practice (or Government Incompetency) or (if agreeing) describing how its actions were not what should normally happen.
    – Golden Cuy
    Commented Apr 19, 2016 at 4:28
  • 5
    That first idea is an answer to the (more straightforward) question: Did the Haitian Cholera Epidemic spread from the U.N. Peacekeeping Base? Implicating the CDC in a cover-up is a much more difficult claim to address. [I'm not sure if identifying a source/Patient Zero is that simple - presumably it may have been in the water for years.]
    – Oddthinking
    Commented Apr 19, 2016 at 5:05

1 Answer 1


It's extremely puzzling to assert that the CDC is "covering up" the source of Cholera in Haiti given this paper, which contains the following passage:

Our epidemiologic study provides several additional arguments confirming an importation of cholera in Haiti. There was an exact correlation in time and places between the arrival of a Nepalese battalion from an area experiencing a cholera outbreak and the appearance of the first cases in Meille a few days after. The remoteness of Meille in central Haiti and the absence of report of other incomers make it unlikely that a cholera strain might have been brought there another way. DNA fingerprinting of V. cholerae isolates in Haiti (1) and genotyping (7,21) corroborate our findings because the fingerprinting and genotyping suggest an introduction from a distant source in a single event (22).

That was published in Emerging Infectious Diseases, a publication run by the CDC. If it's a coverup, it's an extremely poor job of it.

In the UN's official report on the outbreak, there's also the following passage:

The CDC group compared the entire genetic material (genome sequence) of 15 strains of Vibrio cholerae, including draft sequences of 3 Haitian strains (Peter Gerner-Smidt, CDC, personal communication). The analysis showed that the Haitian strains tightly clustered with recent isolates Page 25 of 32 from South Asia (India, Pakistan, Sri Lanka) and a recent isolate from Cameroon, which seems to have originated from the same ancestor as the Haiti strain but which has diverged away from it significantly. This CDC data showed that the Haitian strains were different to Vibrio cholerae from the United States Gulf coast and the 1991 cholera outbreak strains that were isolated in Peru. In addition, CDC concluded that all the Haiti strains were identical, which would indicate a common source.

Again, not only is there not a "coverup", but the CDC has actively contributed to the identification of the source.

Furthermore, as an epidemiologist, the CDC's actual explanation for the map makes sense - maps serve many purposes, and they're not all attempts to find a source, ala John Snow's map. The author of the article seems to assert that this is the only possible purpose a map would serve. A quick, easily digested snapshot of the state of the Cholera epidemic in Haiti is a perfectly legitimate use of a map, and the lack of a big, brightly labeled source doesn't really indicate much of anything. See this map from the WHO, which conspicuously doesn't have the source of the Ebola outbreak on it.

  • That paper and official report date from after many of the claims of cover-up that the article in the question refer to. They could be consistent with an initial cover-up that is not still ongoing.
    – Dan Getz
    Commented Apr 19, 2016 at 20:50
  • @DanGetz By that logic, as there's not a report the day the outbreak began saying the UN is responsible, there's always evidence of a transient cover-up. I think it strains credulity to say that there was an initial cover-up but for some reason the CDC still felt the need to sequence Cholera sequences to identify the source.
    – Fomite
    Commented Apr 19, 2016 at 20:52
  • I suspect the site's rules require a citation backing up the statement that maps are used for multiple purposes.
    – Golden Cuy
    Commented Apr 19, 2016 at 20:56
  • 1
    @Fomite to be honest, reading through the linked articles (and their linked articles), I'm having a hard time understanding what Katz means by "cover-up" to begin with. "The next day, less than two weeks after the outbreak was first confirmed, the CDC put out the results of an analysis it had undertaken", from another article of his that uses the word "cover-up".
    – Dan Getz
    Commented Apr 19, 2016 at 23:44
  • 3
    What I think is going on is the "cover-up" is the CDC waiting until the study is complete before saying anything. Commented Apr 20, 2016 at 0:29

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