CROSS INFECTION IN PNEUMOCOCCIC PNEUMONIA

Pneumonia presents another instance in which medical science is attempting to prevent disease before its pathogenesis is clearly understood. The cause of lobar pneumonia was discovered many years ago. Not only have recent bacteriologic and immunologic studies of the pneumococcus and its products made possible a much better understanding of the pathologic picture but, in the field of therapeutics, results have been so promising that already attention is being focused on the prevention rather than the treatment of the disease. Yet, despite these advances in our knowledge, no accurate information exists as to how the disease is contracted. Hence prevention for the present must be largely empirical.

As with many other diseases of the respiratory tract, the high incidence of morbidity during the colder months of the year has long been noted. Obviously this exciting cause does not suggest any angle of attack. For many years lobar pneumonia was considered