What is Wrong?

ytd my whole family fall sick..
dad came hm frm work lookin weak..
said he've been diarrhoa-ing & vomitting whole day..
while my mum suddenly say she feel feverish in the aftn..
even my sis came hm frm work sayin she felt feverish too.. =\

oddly enough, im not affected?
nor my sis's bf is affected as well..

2dae, my mum jux told me she vomitted in e morn..
diarrhoa when she woke up jux now.. ;s
my sis oso look pale & keep feelin cold..

i really wonder what they ate???