Current approaches to the laboratory diagnosis of diphtheria

Despite the success of mass immunization in many countries, diphtheria cont inues to play a major role as a potentially lethal resurgent infectious dis ease. Early, accurate diagnosis is imperative since delay in specific thera py may result in death. The microbiologic diagnosis of the disease, the ide ntification of contacts and carriers, and the appropriate clinical manageme nt of these patients are therefore crucial. The epidemiology of diseases ca used by Corynebacterium diphtheriae has changed dramatically over the decad es, a situation that is highlighted by the resurgence of infections in the European region. These factors have strengthened the need for laboratories to screen for C. diphtheriae. Many modified and new methodologies are now u sed widely within laboratories for diphtheria diagnosis. Recent development s have focused upon methods for detection of the lethal and potent exotoxin produced by the causative organism, C. diphtheriae; this detection is the definitive test for the microbiologic diagnosis of diphtheria.