THE BACTERIAL FLORA OF THE NASOPHARYNX IN RELATION TO THE COMMON COLD

IT IS NOW the consensus that the primary cause of the infectious common cold is a filterable virus. This initial viral infection, however, is usually followed by secondary bacterial infections, of varying severity, which are generally regarded as being largely responsible for such complications of the disease as paranasal or accessory sinusitis, pharyngitis, laryngitis, tracheobronchitis, pneumonia and secondary infections of the lesions of pulmonary tuberculosis. Just how or why the primary viral infection predisposes to these important secondary bacterial infections is unknown, but it is commonly thought that the local resistance of the tissues is reduced by the virus. On the other hand, the concomitance of virus and different bacteria may be due to symbiotic infection, or it may be the result of an increase of the virulence of various streptococci, staphylococci, pneumococci and other micro-organisms commonly occurring in the upper respiratory tract or gaining access to it. Be that