बांद्रार बेराम नुजानाय समाव, सानैसो सुबुंखौ सोंथि खालामनो हागौ एबा दबथायनाय बिजिरनायजों नायसंनोबो हागौ।
In large outbreaks, a sample of population may be interviewed, or the investigations may be by case control studies.