Fig. 1

Study design for analysing the transmissibility of TB among students and non-students. The four subscripts are denoted as follows: TB transmission in student groups (₁₁ subscript), TB transmission of student-to-non-student groups (₁₂ subscript), TB transmission in non-student groups (₂₂ subscript), TB transmission of non-student-to-student groups (₂₁ subscript)