A probable case of food
poisoning was defined as a previously well individual who
suddenly developed any two of the following symptoms after
eating dinner on 28 May 2011: diarrhoea (three or more loose
stools in 24 h or less), fever, abdominal pain, nausea or vomiting.
An epidemiological case sheet was developed for collecting
the information on demographic particulars of
individuals, date and time of onset of illness and time of
reporting, food items eaten, presenting symptoms, and history
of consumption of water or food outside the mess.