Here you go:
Quote:
| “Diphtheria seems, however, not to be a highly contagious disease in modern Western society. Since the epidemic started in Russia (in 1990), over 3 million trips have been made from Finland to St. Petersburg and its surroundings. Among the visitors, only 10 cases of diphtheria have occurred. Three of them have had severe infection, all were middle-aged men with sexual contacts with local people. None of the 10 patients transmitted the infection further in.” |
[“Resurgent Diphtheria - Are We Safe?” British Medical Bulletin.]
Quote:
| “The low incidence of imported cases of diphtheria in Finland despite the frequent travel of residents to an endemic area suggests that aerosol or droplets of respiratory tract secretions as well as food and poorly washed dishes are inefficient in transmitting diphtheria. Even using only usual barrier precautions in the treatment of patients, the risk of nosocomial spread is low.” |
[“Studies on the Epidemiology and Clinical Characteristics of Diphtheria during the Russian Epidemic of the 1990s.” Acta Universitatis Tamperensis.]
Quote:
| “However, immunization with diphtheria toxoid is protective only against the phage-mediated toxin, and not against infection by the C. diphtheriae organism. Thus immunized persons have less severe disease when infected, but may remain important as asymptomatic carriers in the transmission of disease. Outbreaks in communities with up to 94 percent immunization levels have been reported. Therefore, some authors have challenged whether herd immunity is applicable to diphtheria.” |
[“Immunity to Diphtheria and Tetanus in Inner-city Women of Childbearing Age.” American Journal of Public Health.]
Only 60.5% of a serological sample of nearly 20,000 Americans over 6 years had protective levels of diphtheria antibody in the 1980s. This means nearly 110 million are supposedly susceptible to diphtheria every year, yet there are only between 0-5 cases per year.
[“Serologic Immunity to Diphtheria and Tetanus in the United States.” Annals of Internal Medicine.]