Diptheria, Tetanus, and Pertussis

Diphtheria. Diphtheria is caused by the bacterium Corynebacterium diphtheriae, which can occur as either a toxic or nontoxic strain. When only the skin is involved, it is known as cutaneous diphtheria, and is likely to be a nontoxic strain. If the toxic strain affects the mucus linings in the body, such as the throat, diphtheria becomes life threatening. In the first quarter of the twentieth century diphtheria infected 200,000 people every year and killed between 5 - 10% of them, mostly the very young and very old. Because of immunizations, only one case was reported in 2000.

Tetanus. Tetanus is a disease that causes severe muscular contractions and convulsions. It iscaused by a powerful toxin secreted by the bacterium Clostridium tetani. The bacterium is anaerobic, which means it lives without oxygen. People become infected by this dangerous bacterium through wounds in the skin. It is fatal in 15 - 40% of cases. Only 35 cases were reported in the US in 2000, mostly in adults. One case, however, occurred in a 12-year-old boy whose parents refused to vaccinate him.

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Pertussis. Pertussis (whooping cough) was a very common childhood illness throughout the first half of the century. The disease is very easily spread from one person to another, and it is most severe in babies. Although immunizations caused a decline in cases to only 1,700 in the US in 1980, the incidence has risen recently, with almost 30,000 cases reported between 1997 and 2000 (17 infants died of the disease in 2000). Many more cases are reported worldwide. Nearly half of pertussis cases now occur in people 10 years of age or older, perhaps due to waning immunity in adolescents and adults. Such cases may be greatly underreported. One study suggested that as many as 25% of adults who see a doctor for persistent cough may actually have pertussis, but it may go undiagnosed because symptoms are usually mild and adults are unlikely to have the classic whooping cough. This is of some concern, because such adults may unknowingly infect unvaccinated children. The younger the patient, the higher the risk for severe complications, including pneumonia, seizures, and even death. Children younger than 6 months are at particular risk because even with vaccination, protection is incomplete.

Vaccinations for Diphtheria, Tetanus, and Pertussis