Guest blog by David M. Olson, MD, Medical Advisor, Médecins Sans Frontières/Doctors Without Borders (MSF), New York, NY, USA. This week I have been called back to Haiti because of the cholera epidemic that first hit in late October and which continues to have a devastating effect. At the time of writing this post, more than 1,100 people have died and over 18,000 hospitalizations due to cholera have been reported throughout the country.