II.

Course in Humans

At the end of the incubation period the site of the now-healed wound becomes irritated and painful, and the local tissues may become numb. Depression and anxiety are common. This initial stage lasts for about two days. In the next stage, the period of excitation, the patient becomes irritable and hypersensitive; the general attitude is one of terror, intensified by the onset of difficult breathing and swallowing and a feeling of strangulation, caused by spasmodic contractions of the diaphragm and larynx. The patient is extremely thirsty but experiences spasms of the larynx when water is presented or even mentioned, whence the original name of the disease, hydrophobia (Greek hydor, “water”; phobos, “fear”). Vomiting, pallor, and fever of about 39° C (102° F) are common during this stage. A thick secretion of mucus collects in the mouth and throat, and the individual expectorates frequently or attempts to cough. This stage lasts three to five days and usually terminates in death from a convulsive seizure or from cardiac or respiratory failure.