Five children given trovafloxacin died, as did six of those given ceftriaxone. The lead investigator, Abdulhamid Isa Dutse, later provided a letter of approval for human trials that was found to be falsified. The Nigerian government called the trial "an illegal trial of an unregistered drug". It has been alleged that participants and their families were not told that they were part of a trial, and that "Médecins Sans Frontières" was offering the standard treatment in another part of the same building. Pfizer acknowledged reducing the dose of the standard treatment, but said this was done to minimize injection-site pain and that the mortality rates in both the trovafloxin and ceftriaxone arms of its trial were lower than among those treated with chloramphenicol by "Médecins Sans Frontières".