Estimation of Basic Reproductive Number of Flu-like Syndrome in a Primary School in Iran

Introduction: iran, similar to other countries, had faced h1n1flu outbreak in 2009. in order to assess its transmission dynamic,we estimated its force of infection (b) and basic reproductivenumber (r0).methods: within a middle size primary school in iran, we activelyfollowed students and detected flu?like syndrome among studentsand their families in the first three months of academic year;october through december 2009. we estimated the probabilityof disease transmission within families (b) fitting random effectspoisson regression model. moreover, r0 within the school wascomputed based on the number of detected cases.results: in 452 students, 204 influenza?like syndromes weredetected. the estimated b within families was 0.10; increasing oneinfectious member within each family was associated with 30%increase in this number. the estimated r0 for the first month was1.21 (95% c.i.: 0.99, 1.47); corresponding numbers for the firsttwo and first three months were 1.28 (95% c.i.: 1.05, 1.54) and1.32 (95% c.i.: 1.11, 1.59), respectively.conclusion: it seems that the dynamic transmission of h1n1virus was more or less comparable with that in other seasonalspecies. our findings showed that the virus mainly circulatedamong students within schools. in addition, it seems that thetransmission rate within families was relatively high.