Caused by the bacillus Corynebacterium diphtheriae, it can be fatal if not treated promptly.
Diphtheria spreads in droplets of moisture from the mouth, nose, or throat of an infected person.
It may also be spread by handkerchiefs, towels, eating utensils, or any other object used by an infected person or sprayed by his coughing or sneezing. It may also be transmitted by a healthy person who is nevertheless a carrier of the disease or by someone who is convalescing from diphtheria. The incubation period of the disease is generally between 2 and 5 days, sometimes longer. An infected person may continue to have the bacilli in his throat from 2 to 4 weeks after he has recovered from its effects. The first symptoms of diphtheria usually include sore throat, fever, headache, and nausea.