It was October 2010 when reports first emerged of a mysterious disease spreading through Haiti. In a hospital in Saint Marc, about an hour north of the country's capital Port-au-Prince, 400 cases of adults with watery diarrhoea had been reported in a single day. On a regular day, there might be four people show up at the hospital with these symptoms.
For the doctors at the hospital, diarrhoea and vomiting pointed to one disease — cholera.
Olivia Willis tells the story of how cholera came to Haiti in the first of a series about disease outbreaks