Adults need tetanus shots, too - includes related articles on tetanus immunizations for children and adults

FDA Consumer, July-August, 1996 by Evelyn Zamula

Kathleen Bedford had her 15 minutes of fame in a hospital lecture room full of medical students when she was 65. Because there are only about two cases of tetanus a year in the eastern part of England where she lives, the hospital held a special session for the students. For most of them, it was their first--and maybe their last--opportunity to observe someone with the infection. With her injured leg suspended in a protective frame, Bedford was the center of attention. She would have preferred celebrity in some other way.

Bedford pierced the calf of her leg with a pitchfork crusted with dirt in a freak gardening accident. She was rushed to the emergency room. Her leg was bandaged from ankle to thigh, but she received no further treatment.

When she returned to the emergency room 24 hours later, feeling quite ill, the leg was highly inflamed. After the surgeon on duty took one horrified look at her leg, he rushed her to the operating room and cut her calf open deeply across the puncture site to expose the wound to air. During the next six weeks, the wound had to remain open; hence the frame. Bedford recalls she was treated with "all kinds of pills and shots" and escaped any secondary infection, such as pneumonia.

She experienced only one tetanus symptom--transitory stiffness. But the disease could have been avoided had she been properly immunized. Like many other older adults, Bedford had neglected to keep up her immunity to tetanus with periodic booster doses of tetanus vaccine.

`Lockjaw' Symptoms

Tetanus is an acute, often fatal disease that occurs worldwide. It affects the central nervous system, producing both the stiffness or muscular rigidity that Bedford experienced and convulsive muscle spasm. Tetanus can be localized, with muscle contractions in the part of the body where the infection began, or it can be generalized, affecting the whole body. About 80 percent of reported tetanus cases are generalized. The incubation period ranges from 2 to 50 days, but symptoms usually occur 5 to 10 days after infection. The shorter the incubation period, the greater the chance of death.

The most frequent symptom is a stiff jaw, caused by spasm of the muscle that closes the mouth-accounting for the disease's familiar name "lockjaw." Muscle stiffness all over the body may follow. An infected person may also have other symptoms: difficulty swallowing, restlessness and irritability, stiff neck, arms or legs, fever, headache, and sore throat. 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.

Hyperactivity of the autonomic (involuntary) nervous system may raise blood pressure dangerously or cause heart arrhythmias (irregular beats). 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.

Bacterial Cause

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. Clostridia bacteria are what scientists call "obligate anaerobic"--that is, they thrive only in the absence of oxygen. They also form spores, reproductive cells with thick walls that enable them to withstand unfavorable environmental conditions. Spores are tough to kill and highly resistant to heat and the usual antiseptics that treat wounds.

Tetanus bacteria may enter the body through a puncture wound or scratch. In the presence of dead tissue, tetanus spores reproduce and manufacture a poison (exotoxin) that travels through the body and causes tetanus symptoms. Though tetanus bacteria are found everywhere in the environment--in soil, street dust, and in animal intestines and feces--natural immunity to the disease is rare. This is why immunization is so important.

Vaccination with tetanus toxoid (tetanus vaccine) causes the body to respond to an inactivated form of the tetanus toxin by developing antibodies to tetanus. Tetanus toxoid is virtually 100 percent effective in preventing tetanus. It is prepared by growing tetanus bacteria (Clostridium tetani) in a special medium, and then detoxifying the resulting tetanus toxin with formaldehyde. The Food and Drug Administration reviews the manufacturer's testing records for each lot of vaccine to ensure that the product is safe and effective for its intended use. FDA also sometimes tests random lots to ensure that the manufacturer's testing records are accurate.