"We help people worldwide where the need is greatest, delivering emergency medical aid to people affected by conflict, epidemics, disasters, or exclusion from health care." From their website, they try to help people in medical emergencies where there isn't access to adequate healthcare.
This article discusses emergency response in the historical incidents and described why emergency responders had difficulty rescuing victims and why there were so many fatalities. The article did not, however, discuss the details of the emergency response, it focused much more on how the situation happened and the political and social aftermath.
This question is a little difficult to answer due to the lack of bibliography; however, one can infer that the author conducted interviews or found interviews which were conducted by third parties as a portion of his research. The author also appears to have researched laws in France and the rest of the European Union.
UN - potentially caused the cholera outbreak, organized/managing response to the cholera outbreak without acknowledging responsibility for it
Pedro Medrano - UN coordinator for the response in Haiti
USAID - donor of approximately $1.5 billion since earthquake, uses international contractors to rebuild Haiti
Health Ministry - part of the Haitian govt. that manages country health and vaccinations
Ban Ki-moon - won't acknowledge possible UN role in creating cholera outbreak, UN Secretary-General
Haitian Government - currently undergoing disruption due to a change in terms of its Senators and disagreements between parties