In a recent report1 the occurrence of influenzal meningitis in brothers was described, and the suggestion was made that this disease is potentially contagious, though the condition has not generally been so regarded. The literature had contained only one previous report of influenzal meningitis occurring in siblings.2 It has now become established that type B Haemophilus influenzae is the causative organism in practically all cases of influenzal meningitis.3 More recently this organism has been found to be responsible also for serious forms of infection outside the central nervous system,4 namely, obstructive laryngotracheobronchitis and pneumonia associated with empyema in infants. The multiple occurrence of the latter infections in families in addition to meningitis may point to the potential contagiousness of type B H. influenzae infections in general, as indicated, for example, by the 2 instances of acute influenzal laryngitis in the same family mentioned by Sinclair.4c