Diphtheria is caused by the bacteria Corynebacterium diphtheriae and mainly affects the nose and throat. The bacteria spreads through airborne droplets and shared personal items. C. diphtheriae creates a toxin in the body that produces a thick, gray or black coating in the nose, throat or airway, which can also affect the heart and nervous system. Even with proper antibiotic treatment, diphtheria kills about 10 percent of the people who contract it. The first diphtheria vaccine was unveiled in 1913, and although vaccination has made a major dent in mortality rates, the disease still exists in developing countries and other areas where people are not regularly vaccinated. The World Health Organization (WHO) estimates that worldwide there are about 5,000 deaths from diphtheria annually, but the disease is quite rare in the United States, with fewer than five cases reported each year.