What is the evidence for giving chemoprophylaxis to children or students attending the same preschool, school or college as a case of meningococcal disease?

A systematic review on effectiveness of administering chemoprophylaxis to contacts of invasive meningococcal disease (IMD) in school setting. We found that there is no reliable studies that would document the risk of secondary cases among schoolchildren attending the same school or the same class as children with confirmed IMD. However, we found some indirect evidence of increased risk of secondary cases in preschool groups, playing together. We therefore recommended chemoprophylaxis only to preschool children, attending the same group as confirmed IMD cases.