Muscle stiffness all over the body may follow. As the disease progresses, the victim may develop a fixed smile and raised eyebrows due to facial muscle spasms. Spasms of the diaphragm and the muscles between the ribs may interfere with breathing, often requiring mechanical ventilation. The abdominal or back muscles may become rigid. In severe cases, patients may become so sensitive to any kind of disturbance that they suffer painful spasms all over their bodies with profuse sweating if the bed is jarred or if they feel a draft or hear a noise.
Convulsions can be severe enough to break bones.
Although tetanus victims can usually think clearly when conscious, coma may follow repeated spasms. Aspiration pneumonia is a common late complication and is found in 50 to 70 percent of autopsied cases. The mortality rate is about 25 percent in the United States and 50 percent worldwide. The bacteria that cause tetanus belong to the Clostridium family, also responsible for some other serious diseases, such as botulism and the type of gangrene suffered in war wounds. They also form spores, reproductive cells with thick walls that enable them to withstand unfavorable environmental conditions.